Patent Application
20230172715
The present application concerns aspects of a sheath for use with catheter-based technologies for repairing and/or replacing heart valves, as well as for delivering a prosthetic device, such as a prosthetic valve to a heart via the patient's vasculature.
Endovascular delivery catheter assemblies are used to implant prosthetic devices, such as a prosthetic valve, at locations inside the body that are not readily accessible by surgery or where access without invasive surgery is desirable. For example, aortic, mitral, tricuspid, and/or pulmonary prosthetic valves can be delivered to a treatment site using minimally invasive surgical techniques.
An introducer sheath can be used to safely introduce a delivery apparatus into a patient's vasculature (e.g., the femoral artery). An introducer sheath generally has an elongated sleeve that is inserted into the vasculature and a housing that contains one or more sealing valves that allow a delivery apparatus to be placed in fluid communication with the vasculature with minimal blood loss. A conventional introducer sheath typically requires a tubular loader to be inserted through the seals in the housing to provide an unobstructed path through the housing for a valve mounted on a balloon catheter. A conventional loader extends from the proximal end of the introducer sheath and therefore decreases the available working length of the delivery apparatus that can be inserted through the sheath and into the body.
Conventional methods of accessing a vessel, such as a femoral artery, prior to introducing the delivery system include dilating the vessel using multiple dilators or sheaths that progressively increase in diameter. This repeated insertion and vessel dilation can increase the amount of time the procedure takes, as well as the risk of damage to the vessel.
Radially expanding intravascular sheaths have been disclosed. Such sheaths tend to have complex mechanisms, such as ratcheting mechanisms that maintain the shaft or sheath in an expanded configuration once a device with a larger diameter than the sheath's original diameter is introduced.
However, delivery and/or removal of prosthetic devices and other materials to or from a patient still poses a significant risk to the patient. Furthermore, accessing the vessel remains a challenge due to the relatively large profile of the delivery system that can cause longitudinal and radial tearing of the vessel during insertion. The delivery system can additionally dislodge calcified plaque within the vessels, posing an additional risk of clots caused by the dislodged plaque.
Accordingly, there remains a need in the art for an improved introducer sheath for endovascular systems used for implanting valves and other prosthetic devices.
The disclosed herein, an expandable sheath can minimize trauma to the vessel by allowing for temporary expansion of a portion of the introducer sheath to accommodate a delivery system, followed by a return to the original diameter once the delivery system passes through. Some aspects can comprise a sheath with a smaller profile than that of prior art introducer sheaths. Furthermore, as described in certain aspects, the disclosed sheath can reduce the length of time a procedure takes, as well as reduce the risk of a longitudinal or radial vessel tear or plaque dislodgement because only one sheath is required, rather than several different sizes of sheaths. In still further aspects, the present expandable sheath can require only a single vessel insertion, as opposed to requiring multiple insertions for the dilation of the vessel.
In one aspect disclosed herein is a sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises an elongated tube forming an outer layer of the sheath that is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, having an inner surface and an outer surface, and wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
In one aspect, the first polymer can have a substantially same durometer along a total length of the elongated tube. Yet, in other aspects, a durometer of the first polymer at a proximal end of the elongated tube can be different from a durometer of the first polymer at a distal end of the elongated tube.
In one aspect, wherein the elongated tube comprises two or more polymer layers. In such an exemplary aspect, the elongated tube comprises at least a second polymer layer comprising a second compound composition comprising from greater than 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof. In certain exemplary aspects, the second compound composition can further comprise up to 20% of tackiness reducing additive based on a total weight of the second compound composition.
In still further aspects, the second polymer layer can comprise PEBAX®. While in other aspects, the second polymer layer can comprise polyurethane.
In some aspects, the sheath disclosed herein can exhibit at least a 20% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
In still further aspects, the disclosed sheath for introducing a prosthetic device comprises an inner layer and an outer layer. In one aspect, the sheath as disclosed herein further comprises an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; and a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; wherein the elongated tube is positioned such that at least a portion of the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
In still further aspects, the disclosed herein sheath has a proximal and a distal end and comprises: an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion, a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
Also disclosed herein is an aspect describing a sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion and wherein the outer surface of the inner liner is selectively etched; a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the outer layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the outer layer is positioned adjacent to at least a portion of the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
Also disclosed herein are aspects, where in an addition to the elongated tube as described in any of the preceding aspects, the sheath further comprises a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of a cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and wherein the elongated tube is positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner.
Also disclosed herein is a sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and an elongated tube forming an outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
Also disclosed herein is an expandable sheath comprising: an inner tubular layer comprising a longitudinal slit and partially defining an inner lumen; a first outer tubular layer enveloping the inner layer, the outer tubular layer comprising a longitudinally extending, folded flap that overlies a portion of an outer surface of the outer layer when the sheath is in an unexpanded state; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein an outwardly directed radial force from a prosthetic device moving through the inner lumen widens the longitudinal slit and unfolds the folded flap to allow expansion of the sheath.
Still further disclosed herein, is a sheath for delivering a medical device, the sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
Also disclosed herein is a sheath delivering a medical device comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; a coiled wire along a length of the sheath, the coil wire providing uniform bending of the sheath to prevent kinking; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition, wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
Also disclosed herein is a method of making a sheath having a proximal end and a distal end and comprising: a) extruding a tubular body to form an elongated tube comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; b) disposing the elongated tube on the sheath such that the elongated tube forms an outer layer of the sheath, and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the formed sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
Also disclosed herein is the method further comprising providing: a) a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; b) a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; and c) a coiled wire along a length of the sheath, the coil wire providing uniform bending of the sheath to prevent kinking; and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, and wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
Also further disclosed herein is the method further comprising: providing: a) a circumferentially continuous first elastic outer tubular layer defining an initial elastic lumen extending axially therethrough, the initial elastic lumen having an initial diameter; and b) an inner tubular layer extending through the initial elastic lumen of the first elastic outer tubular layer and comprising at least three circumferentially spaced, longitudinally extending thick wall segments and at least three circumferentially spaced, longitudinally extending thin wall segments, each thin wall segment extending between two adjacent thick wall segments to define an expanded lumen extending axially through the inner tubular layer, the expanded lumen having an expanded diameter larger than the initial diameter of the initial elastic lumen; c) wherein the inner tubular layer, in a compressed condition, forms at least three circumferentially spaced folds, each of the circumferentially spaced folds including a three-layer thickness in a radial direction comprised of portions of two adjacent thick wall segments and a thin wall segment sandwiched therebetween; wherein the inner tubular layer, in a locally expanded condition, has the thick wall segments and the thin wall segments unfolded and expanded apart; and wherein the inner tubular layer is configured to be urged by the first elastic outer tubular layer at least partially back to the compressed condition after passage of an implant through the expanded lumen; and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first elastic outer layer.
Also disclosed herein is a method comprising: providing: a) an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; b) a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, and wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
The foregoing and other features and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The present disclosure can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present articles, systems, and/or methods are disclosed and described, it is to be understood that this disclosure is not limited to the specific or exemplary aspects of articles, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
The following description of the disclosure is provided as an enabling teaching of the disclosure in its best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the disclosure described herein while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, those of ordinary skill in the pertinent art will recognize that many modifications and adaptations to the present disclosure are possible and may even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description is again provided as illustrative of the principles of the present disclosure and not in limitation thereof.
As used in this application and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Thus, for example, reference to a “polymer” includes aspects having two or more such polymers unless the context clearly indicates otherwise.
It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate aspects, can also be provided in combination in a single aspect. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single aspect, can also be provided separately or in any suitable combination.
As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance may or may not occur and that the description includes instances where said event or circumstance occurs and instances where it does not.
It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the specification and the claims, the term “comprising” can include the aspects “consisting of” and “consisting essentially of.” Additionally, the term “includes” means “comprises.”
For the terms “for example” and “such as,” and grammatical equivalences thereof, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise.
References in the specification and concluding claims to parts by weight of a particular element or component in a composition or article denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a composition or a selected portion of a composition containing 2 parts by weight of component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5 and are present in such ratio regardless of whether additional components are contained in the composition.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used. Further, ranges can be expressed herein as from “about” one particular value and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value.
Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint. Unless stated otherwise, the term “about” means within 5% (e.g., within 2% or 1%) of the particular value modified by the term “about.”
Throughout this disclosure, various aspects of the disclosure can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6 and any whole and partial increments therebetween. This applies regardless of the breadth of the range.
As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from a combination of the specified ingredients in the specified amounts.
A weight percent of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.
As used herein, the term “substantially” means that the subsequently described event or circumstance completely occurs or that the subsequently described event or circumstance generally, typically, or approximately occurs.
As used herein, the term “substantially,” when used in reference to a composition, refers to at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% by weight, based on the total weight of the composition, of a specified feature or component.
As used herein, the term “substantially,” in, for example, the context “substantially free” refers to a composition having less than about 1% by weight, e.g., less than about 0.5% by weight, less than about 0.1% by weight, less than about 0.05% by weight, or less than about 0.01% by weight of the stated material, based on the total weight of the composition.
As used herein, the terms “substantially identical reference composition” or “substantially identical reference article” refer to a reference composition or article comprising substantially identical components in the absence of an inventive component. In another exemplary aspect, the term “substantially,” in, for example, the context “substantially identical reference composition,” refers to a reference composition comprising substantially identical components and wherein an inventive component is substituted with a common in the art component.
Further, the terms “coupled” and “associated” generally mean electrically, electromagnetically, and/or physically (e.g., mechanically or chemically) coupled or linked and do not exclude the presence of intermediate elements between the coupled or associated items.
It will be understood that, although the terms “first,” “second,” etc., may be used herein to describe various elements, components, regions, layers and/or sections. These elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or a section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example aspects.
It is understood that the terms “layer” and “liner” can be used interchangeably. It is further understood that for the purposes of the current disclosure, the term “outer jacket” refers to the elongated tube having the disclosed herein composition and characteristics.
It is further understood that the phrases “insertion force” and “push force” can be used interchangeably.
Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein are interpreted accordingly.
As used herein, the term “atraumatic” is commonly known in the art and refers to a device or a procedure that minimizes tissue injury.
As used herein, the term or phrase “effective,” “effective amount,” or “conditions effective to” refers to such amount or condition that is capable of performing the function or property for which an effective amount or condition is expressed. As will be pointed out below, the exact amount or particular condition required will vary from one aspect to another, depending on recognized variables such as the materials employed and the processing conditions observed. Thus, it is not always possible to specify an exact “effective amount” or “condition effective to.” However, it should be understood that an appropriate, effective amount will be readily determined by one of ordinary skill in the art using only routine experimentation.
Although the operations of exemplary aspects of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that disclosed aspects can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may, in some cases, be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular aspect are not limited to that aspect and may be applied to any aspect disclosed.
While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only, and one of ordinary skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class. Unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that an order be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.
Moreover, for the sake of simplicity, the attached figures may not show the various ways (readily discernable, based on this disclosure, by one of ordinary skill in the art) in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses. Additionally, the description sometimes uses terms such as “produce” and “provide” to describe the disclosed method. These terms are high-level abstractions of the actual operations that can be performed. The actual operations that correspond to these terms can vary depending on the particular implementation and are, based on this disclosure, readily discernible by one of ordinary skill in the art.
The present disclosure may be understood more readily by reference to the following detailed description of various aspects of the disclosure and the examples included therein and to the Figures and their previous and following description.
The present disclosure may be understood more readily by reference to the following detailed description of various aspects of the disclosure and the examples included therein and to the Figures and their previous and following description.
Disclosed aspects of an expandable sheath can minimize trauma to the vessel by allowing for temporary expansion of a portion of the introducer sheath to accommodate the delivery system, followed by a return to the original diameter once the device passes through. In some aspects, the sheath can comprise a sheath with a smaller profile (e.g., a smaller diameter in the rest configuration) than that of prior art introducer sheaths. Furthermore, as disclosed in the present aspects, the sheath can reduce the length of time a procedure takes, as well as reduce the risk of a longitudinal or radial vessel tear or plaque dislodgement because only one sheath is required, rather than several different sizes of sheaths. In certain aspects, the present expandable sheath can avoid the need for multiple insertions for the dilation of the vessel. Such expandable sheaths can be useful for many types of minimally invasive surgery, such as any surgery requiring introduction of an apparatus into a subject's vessel. For example, the sheath can be used to introduce other types of delivery apparatus for placing various types of intraluminal devices (e.g., stents, prosthetic heart valves, stented grafts, etc.) into many types of vascular and non-vascular body lumens (e.g., veins, arteries, esophagus, ducts of the biliary tree, intestine, urethra, fallopian tube, other endocrine or exocrine ducts, etc.).
Also, disclosed herein aspects refer to the sheaths having a reduced insertion force as compared to any other available commercial sheaths. As one of ordinary skill in the art would readily appreciate, the reduction in the insertion force of the sheath and any medical device passing through results in reduced or substantially eliminated danger to the patients during the medical procedure. It is understood that the insertion force of the inventive sheaths, reference sheaths, and any other commercially available sheaths is measured using the same standardized technique for a proper comparison. In such aspects, a tensile tester, Instron 3366, has been used to measure a simulated insertion force that is required for a prosthetic valve to enter the described sheath. An additional constriction tube has been used to simulate vascular elasticity that contributes to push force. In certain exemplary aspects, the test is performed in a water bath in a temperature range from room temperature to a normal body temperature (for example and without limitation from about 20° C. to less than about 40° C.). The specimen can be kept in a straight configuration. The test can be performed with a tapered mandrel to simulate a valve entering the sheath.
The present disclosure relates to various configurations of the sheath. These exemplary aspects are directed to a sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises an elongated tube forming an outer layer of the sheath that is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, having an inner surface and an outer surface, and wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
It is understood, however, that also disclosed are aspects where the disclosed sheaths can comprise additional components. These exemplary aspects are disclosed herein, as shown below in detail.
In certain aspects, the elongated tube comprises a first polymer layer. In such exemplary aspects, the first polymer layer can comprise a first compound composition comprising from greater than 0 wt % to less than 100 wt %, including exemplary values of about 0.01 wt %, about 1wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, about 95 wt %, and about 99.9 wt % of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof.
In still further aspects, the first compound composition can comprise from greater than about 35 wt % to less than about 80 wt %, including exemplary values of about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, and about 75 wt % of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof.
In certain aspects, the polymer in the first compound composition comprises a polyether block amide. In such exemplary aspects, the polyether block amide can comprise PEBAX® from Arkema. In yet further aspects, the polymer can comprise polyurethane, for example, NEUSoft®. While in still further aspects, the polymer can compromise a combination of the polyether block amide, such as, for example, PEBAX® and polyurethane. It is further understood that if the mixture of the polymers is present, such a mixture can comprise each component in any amount relative to another component to provide the desired polymer falling within the disclosed above range.
In still further aspects, the first compound composition can comprise less than about 65 wt % of an inorganic filler based on a total weight of the first compound composition, including exemplary values of less than about 60 wt %, less than about 55 wt %, less than about 50 wt %, less than about 45 wt %, less than about 40 wt %, less than about 35 wt %, less than about 30 wt %, less than about 25 wt %, less than about 20 wt %, less than about 15 wt %, less than about 10 wt %, less than about 5 wt %, and less than about 1wt % of the inorganic filler.
In yet further aspects, the inorganic filler can be present in an amount of at least about 1wt %, at least about 2 wt %, at least about 5 wt %, at least about 10 wt %, at least about 15 wt %, at least about 20 wt %, at least about 25 wt %, at least about 30 wt %, at least about 35 wt %, at least about 40 wt %, at least about 45 wt %, at least about 50 wt %, or at least about 55 wt %.
In still further aspects, the inorganic filler can comprise any inorganic materials that can be used as a filler and are acceptable for the desired application. In certain exemplary and unlimiting aspects, the inorganic filler can comprise bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof. Again it is understood that the inorganic filler can comprise a combination of the various fillers. In such exemplary aspects, an amount of each filler in the combination can be in any range to provide a final combination that falls within the disclosed above range.
In still further aspects, the first compound composition can comprise up to about 20 wt % of a solid lubricant filler based on a total weight of the first compound composition, including exemplary values of about 0.01 wt %, about 0.1 wt %, about 0.5 wt %, about 1wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, about 10 wt %, about 11 wt %, about 12 wt %, about 13 wt %, about 14 wt %, about 15 wt %, about 16 wt %, about 17 wt %, about 18 wt %, about 19 wt %, and about 19.9 wt %. In yet further aspects, the solid lubricant filler can be present up to about 20 wt %, up to about 15 wt %, or up to about 10 wt % based on a total weight of the first compound composition.
In still further aspects, the solid lubricant filler can comprise any additive that is known to reduce friction and behave as a lubricant. In such exemplary and unlimiting aspects, the solid lubricant filler can comprise one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicones, talc, polytetrafluorethylene (PTFE), fluorinated ethylene propylene, and the like. In still further aspects, the solid lubricant comprises a PTFE filler. In yet further aspects, the PTFE filler is a powder.
In still further aspects, the first compound composition can further comprise at least one tackiness reducing compound. Any compounds known in the art as capable of reducing the tackiness of the polymer composition can be considered and used for the purpose of this disclosure. In yet further exemplary and unlimiting aspects, the at least one tackiness reducing compound comprises ProPell™ from Foster Corporation
In certain aspects, the at least one tackiness reducing compound is present in an amount from 0 wt % to about 20 wt %, including exemplary values of about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, about 10 wt %, about 11 wt %, about 12 wt %, about 13 wt %, about 14 wt %, about 15 wt %, about 16 wt %, about 17 wt %, about 18 wt %, and about 19 wt % based on a total weight of the first compound composition. In still further aspects, the at least one tackiness reducing compound is present in any amount having a value between any two foregoing values. For example and without limitation, the at least one tackiness reducing compound can be present in an amount from about 1wt % to about 5 wt %, or from about 5 wt % to about 10 wt % based on a total weight of the first compound composition.
In still further aspects and as disclosed herein, the first polymer has a substantially same durometer along a total length of the elongated tube. It is understood, however, the durometer of the first polymer of the elongated tube can also be varied along the length of the tube. For example, and without limitation, disclosed herein are aspects where a durometer of the first polymer at a proximal end of the elongated tube is different from a durometer of the first polymer at a distal end of the elongated tube.
In still further aspects, the first polymer in the first polymer layer has a Shore D from about 20 D to about 72 D, including exemplary values of about 25 D, about 30 D, about 35 D, about 40 D, about 45 D, about 50 D, about 55 D, about 60 D, about 65 D, and about 70 D. In still further aspects, the first polymer in the first polymer layer has a Shore D from about 20 D to about 35 D. In still further aspects, the first polymer in the first polymer layer has a Shore D of about 30 D. Yet, in still further aspects, the first polymer in the first polymer layer has a Shore D of about 25 D.
It is understood that the elongated tube, as disclosed herein, can comprise aspects where only one polymer layer is present. Yet, in other aspects, two or more polymer layers can be present in the elongated tube. In such exemplary aspects, the elongated tube comprises at least a second polymer layer comprising a second compound composition comprising from greater than 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof. Similar to the first compound composition, the second polymer can be present in any amount that falls within the disclosed range. For example, the second polymer can be present in the second compound composition from greater than 0 wt %, about 0.01 wt %, about 1wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, about 95 wt %, and about 99.9 wt % of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof. In yet further aspects, the second polymer can be present in the second compound composition from greater than about 95 wt % to less than about 99 wt %, including exemplary values of about 95.5 wt %, about 96 wt %, 96.5 wt %, about 97 wt %, about 97.5 wt %, about 98 wt %, and about 98.5 wt %.
In yet further aspects, the second compound composition can further comprise up to 20 wt % of a tackiness reducing additive, including exemplary values of about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, about 10 wt %, about 11 wt %, about 12 wt %, about 13 wt %, about 14 wt %, about 15 wt %, about 16 wt %, about 17 wt %, about 18 wt %, and about 19 wt % based on a total weight of the second compound composition. In still further aspects, the at least one tackiness reducing compound is present in any amount having a value between any two foregoing values. For example and without limitation, the at least one tackiness reducing compound can be present in an amount from about 1wt % to about 5 wt %, or from about 5 wt % to about 10 wt % based on a total weight of the second compound composition. In still further aspects and as disclosed herein, the second compound composition can be substantially free of a solid lubricant filler.
It is further understood that in certain aspects, the first polymer in the first compound composition can be the same as the second polymer in the second compound composition. Yet, in other aspects, the first polymer in the first compound composition is different from the second polymer in the second compound composition. In yet further aspects, the second polymer layer comprises PEBAX®. While in further aspects, the second polymer layer can comprise polyurethane, for example, NEUSoft® from PolyOne.
In still further aspects, the second polymer has a Shore D from about 20 D to about 35 D. Yet, in further aspects, the second polymer has a Shore D of about 25 D or about 35 D.
In still further aspects, the second compound composition can be substantially free of an inorganic filler. While in certain aspects, the inorganic filler can be present in the second compound composition in any amount from greater than 0 wt % to less than 100 wt %, including exemplary values of about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1wt %, about 5 wt %, about 10 wt %, about 20 wt %, about 30 wt %, about 40 wt %, about 50 wt %, about 60 wt %, about 70 wt %, about 80 wt %, about 90 wt %, and about 95 wt %. In the aspects where the inorganic filler is present in the second compound composition, a such inorganic filler can comprise any filler disclosed above.
In still further aspects, and as disclosed herein, the elongated tube has a predetermined thickness, and wherein at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100% of the predetermined thickness comprises the first and/or the second compound composition comprising the first and/or the second polymer having a Shore D equal to or lower than about 30 D.
In still further aspects, the predetermined thickness of the elongated tube can vary along a length of the sheath. While in other aspects, the predetermined thickness of the elongated tube is the same along a length of the sheath. Yet, in further aspects, the predetermined thickness of the elongated tube is greater at the proximal end. In still further aspects, the predetermined thickness of the elongated tube is up to 6 mils, for example, and without limitation from about 1 mil to about 6 mils, including exemplary values of about 1.5 mils, about 2 mils, about 2.5 mils, about 3 mils, about 3.5 mils, about 4 mils, about 4.5 mils, about 5 mils, about 5.5 mils, and about 5.9 mils.
In still further aspects, the first polymer layer and the second polymer layer can have the same thickness. While in other aspects, the first polymer layer and the second polymer layer have different thicknesses. For example, in some aspects, the first polymer layer has a thickness of about 1 mil to about 5 mils, including exemplary values of about 1.1 mils, about 1.2 mils, about 1.3 mils, about 1.4 mils, about 1.5 mils, about 1.6 mils, about 1.7 mils, about 1.8 mils, about 1.9 mils, about 2.0 mils, 2.1 mils, about 2.2 mils, about 2.3 mils, about 2.4 mils, about 2.5 mils, about 2.6 mils, about 2.7 mils, about 2.8 mils, about 2.9 mils, about 3.0 mils, about 3.1 mils, about 3.2 mils, about 3.3 mils, about 3.4 mils, about 3.5 mils, about 3.6 mils, about 3.7 mils, about 3.8 mils, about 3.9 mils, about 4.1 mils, about 4.2 mils, about 4.3 mils, about 4.4 mils, about 4.5 mils, about 4.6 mils, about 4.7 mils, about 4.8 mils, and about 4.9 mils. Yet still, in further aspects, the second polymer layer can have a thickness of about 2 mils to about 6 mils, including exemplary values of 2.1 mils, about 2.2 mils, about 2.3 mils, about 2.4 mils, about 2.5 mils, about 2.6 mils, about 2.7 mils, about 2.8 mils, about 2.9 mils, about 3.0 mils, 3.1 mils, about 3.2 mils, about 3.3 mils, about 3.4 mils, about 3.5 mils, about 3.6 mils, about 3.7 mils, about 3.8 mils, about 3.9 mils, about 4.0 mils, about 4.1 mils, about 4.2 mils, about 4.3 mils, about 4.4 mils, about 4.5 mils, about 4.6 mils, about 4.7 mils, about 4.8 mils, about 4.9 mils, about 5.1 mils, about 5.2 mils, about 5.3 mils, about 5.4 mils, about 5.5 mils, about 5.6 mils, about 5.7 mils, about 5.8 mils, and about 5.9 mils.
In still further aspects, the predetermined thickness of the elongated tube is greater at the proximal end. While in other aspects, the predetermined thickness of the elongated tube is smaller at the distal end as compared to the predetermined thickness of the elongated tube at the proximal end.
In still further aspects where two or more layers are present in the elongated tube, the first polymer layer can define the inner surface of the elongated tube, while the second polymer layer can define the outer surface of the elongated tube. However, there are also aspects where the first polymer layer defines the outer surface of the elongated tube, while the second polymer layer defines the inner surface of the elongated tube. It is also understood that other aspects are also enclosed, where one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.
In still further aspects, the elongated tube can be extruded. In the aspects where the first and the second polymer layers are present, such polymer layers can be co-extruded. In still further aspects, the first polymer layer can be substantially bonded to the second polymer layer. In such exemplary aspects, the first polymer layer substantially does not delaminate from the second polymer layer. It is understood that in some aspects, the bonding can be physical or chemical or any other type known in the art.
In still further aspects, any sheath that comprises the disclosed herein elongated tube can exhibit at least about 10% reduction, at least about 15% reduction, at least 20% reduction, at least about 25% reduction, at least about 30% reduction, at least about 35% reduction, at least about 40% reduction, at least about 45% reduction, or at least about 50% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
In still further aspects, any sheath that comprises the disclosed herein elongated tube can exhibit an insertion force of less than about 55 N, less than about 50 N, less than about 45 N, less than about 40 N, less than about 35 N, or less than about 35 N when a medical device is pushed through the sheath.
In still further aspects, the elongated tube can also exhibit a friction force of less than about 10 N, or less than about 9 N, or less than about 8 N, or less than about 7 N, or less than about 6 N, or even less than about 5 N, in the dry state against a substrate surface comprising one or more of polytetrafluoroethylene, fluorinated ethylene propylene, or high-density polyethylene having a diameter of about 0.300″.
In still further aspects, the elongated tube can exhibit a hoop force at 10 mm extension (about 85% strain) of less than about 10 N, or less than about 9 N., or less than about 8 N, or less than about 7 N, or less than about 6 N, or even less than about 5 N. In such exemplary aspects, the elongated tube can have a diameter of about 0.290″ (7.4 mm) and wall thickness, as disclosed herein. In aspects where the elongated tube has a diameter of about 0.290″ (7.4 mm) and a total wall thickness of about 0.0045″, with a sample length of about 0.25″ (6.4 mm), a hoop direction forces at 10 mm extension can be less than about 8 N. It is understood that in some exemplary and unlimiting aspects, a low force at 10 mm extension is desired for low sheath expansion force.
In still further aspects, the elongated tube can exhibit an elongation at break of ranging between about 650% and about 800%, including exemplary values of about 680%, about 700%, about 710%, about 750%, and about 780%. It is understood that in some exemplary and unlimiting aspects, a high elongation is preferable for expansion to a larger diameter before the elongated tube breaks.
In still further aspects, the elongated tube is substantially kink resistant.
In certain aspects, the elongated tube extends along a portion of the length of the sheath. In such exemplary aspects, the elongated tube can be positioned at the proximal end of the sheath, or in the middle of the sheath, or at the distal portion of the sheath. While in other aspects, the elongated tube extends along the whole length of the sheath. In such exemplary aspects, the elongated tube can be positioned at the proximal end of the sheath and extend to the distal end of the sheath.
In still further aspects, the sheath can further comprise an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; and a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; wherein the elongated tube is positioned such that at least a portion of the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
In still further aspects, the elongated tube disclosed herein can comprise at least two polymer layers. In still further aspects, the elongated tube disclosed herein can comprise at least one intermediate reinforcement layer disposed between the first polymer layer and the second polymer layer. In still further aspects, the at least one intermediate reinforcement layer is a polymer layer.
In some aspects, the at least one intermediate layer can extend along the whole circumference of the elongated tube. In yet further aspects where the first polymer layer forms the inner surface of the elongated tube and the second polymer layer forms the outer surface of the elongated tube, the intermediate layer is disposed between the outer surface of the first polymer and the inner surface of the second polymer layer. Yet in other aspects, and as disclosed above, if the second polymer layer forms the inner surface of the elongated tube and the first polymer layer forms the outer surface of the elongated tube, the intermediate layer is disposed between the outer surface of the second polymer layer and the inner surface of the first polymer layer. In still further aspects, the intermediate reinforcement layer can bond the first and second polymer layers and can also assist in bonding the elongated tubing as a whole to an inner member of the sheath.
In still further aspects, the at least one intermediate layer has a finite width that is smaller than the circumference of the elongated tube. In such aspects, the at least one intermediate layer can be inserted as a strip between the first and the second polymer layers. In some exemplary and unlimiting aspects, if the elongated tube has a distal outer diameter of about 0.200″, the strip can have a width between about 0.010″ to about 0.150″, including exemplary values of about 0.03″, about 0.035″, about 0.04″, about 0.045″, about 0.05″, about 0.055″, about 0.06″, about 0.065″, about 0.07″, about 0.075″, about 0.08″, about 0.085″, about 0.09″, about 0.095″, about 0.10″, about 0.105″, about 0.110″, about 0.115″, about 0.120″, about 0.125″, about 0.130″, about 0.135″, about 0.140″, and about 0.145″. It is understood that the widths shown above are exemplary, and if the distal outer diameter of the elongated sheath has a size different from 0.200″, the strip width can be adjusted in the same or a different ratio.
In still further aspects, the at least one intermediate layer has a finite width that is smaller than the circumference of the elongated tube. In such aspects, the at least one intermediate layer can be inserted as a strip between the first and the second polymer layers. In some exemplary and unlimiting aspects, if the elongated tube has a distal outer diameter of about 0.200″, the strip can have a width between about 5% to about 50% of the circumference of the elongated tube. In still further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the elongated tube. It is understood that the widths shown above are exemplary, and if the distal outer diameter of the elongated sheath has a size different from 0.200″, the strip width can be adjusted in the same or a different ratio.
In still further aspects, the elongated tube can comprise two or more intermediate layers. In such aspects, the two or more intermediate layers can be disposed, as individual strips, circumferentially between the first and the second polymer layers at a predetermined distance from each other. In aspects where the two or more intermediate layers are disposed between the first and the second polymer layers of the elongated tube, a total combined width of all the strips is about 5% to about 50% of the circumference of the elongated tube. In still further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the elongated tube.
In still further aspects, the at least one intermediate layer is configured to provide an axial reinforcement to the elongated tube and, as a result, to the sheath where the elongated tube can be used. In such exemplary aspects, the at least one intermediate layer can be disposed along the length of the elongated tube or along a portion of the length of the elongated tube.
In some aspects, the portion of the length of the elongated tube where the at least one intermediate layer is disposed is positioned at the distal end and/or proximal end of the elongated tube. In yet other aspects, the at least one intermediate layer can also be positioned anywhere along the length of the elongated tube.
It is further understood that in the aspects where the intermediate layer is present as one or more strips disposed circumferentially along the length of the sheath, the width of the strip can be the same along the length, or it can vary along the length. In aspects where the strips' width varies along the length of the elongated tube, such a strip can have any of the disclosed above width values.
In still further aspects, the first polymer layer used in this exemplary elongated tube can be any of the first polymer layers described above. In still further exemplary and unlimiting aspects, the first polymer layer forms the inner surface of the elongated tube and comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
Any of the disclosed above inorganic fillers, and solid lubricant fillers can be present in any amount as disclosed. For example, the inorganic filler can comprise bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof. In yet other aspects, the inorganic filler can be present in at least 10 wt %. In still further aspects, the inorganic filler can be present in an amount of less than about 50 wt % based on a total weight of the first compound composition.
In yet further aspects, the solid lubricant filler can comprise a PTFE filler.
The first compound can also comprise any of the disclosed above additives. For example, the compound can comprise at least one tackiness reducing compound in an amount from about 1wt % to about 20 wt %.
In still further exemplary aspects, the polymer present in the first compound can have Shore D from about 20 D to about 35 D, including exemplary values of about 22 D, about 25 D, about 27 D, about 30 D, and about 32 D.
In yet further aspects, a durometer of the first polymer in the first polymer layer at a proximal end of the elongated tube can be different from a durometer of the first polymer in the first polymer layer at a distal end of the elongated tube.
In still further aspects, the polymer in the first compound can comprise poly ether block amide, for example, PEBAX®. While in other aspects, the polymer in the first compound can comprise polyurethane. In still further aspects, the first compound can also comprise polyamide.
In still further aspects, the thickness of the first polymer layer can be from about 1 mil to about 5 mils, including exemplary values of about 1.1 mils, about 1.2 mils, about 1.3 mils, about 1.4 mils, about 1.5 mils, about 1.6 mils, about 1.7 mils, about 1.8 mils, about 1.9 mils, about 2.0 mils, 2.1 mils, about 2.2 mils, about 2.3 mils, about 2.4 mils, about 2.5 mils, about 2.6 mils, about 2.7 mils, about 2.8 mils, about 2.9 mils, about 3.0 mils, about 3.1 mils, about 3.2 mils, about 3.3 mils, about 3.4 mils, about 3.5 mils, about 3.6 mils, about 3.7 mils, about 3.8 mils, about 3.9 mils, about 4.1 mils, about 4.2 mils, about 4.3 mils, about 4.4 mils, about 4.5 mils, about 4.6 mils, about 4.7 mils, about 4.8 mils, and about 4.9 mils.
In still further aspects, the second polymer layer can comprise any of the disclosed above polymers. In some aspects, the second polymer layer can comprise a second compound composition comprising from greater than 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof. In still further aspects, the second polymer layer can comprise a polyamide. In yet some other aspects, the second compound can also comprise any of the fillers or additives disclosed above. While in some aspects, the second compound does not comprise the solid lubricant fillers disclosed herein. While in still further aspects, the second compound can comprise a tackiness reducing additive described in this disclosure. In some aspects, the second polymer can be a polyurethane. In still further aspects, the polyurethane is a thermoplastic polyurethane. While in still further aspects, the second polymer can be a blend comprising a polyurethane with a styrene block copolymer. In still further aspects, the blend can further comprise additional polymers and copolymers. For example, ether-based polymers can be present in the blend. In some exemplary and unlimiting aspects, the second polymer can be chosen from commercially available polymers sold under the trade name of Neusoft™. In still further aspects, the second polymer can have a Shore A durometer from about 20 A to about 75 A, including exemplary values of about 25 A, about 30 A, about 35 A, about 40 A, about 45 A, about 50 A, about 55 A, about 60 A, about 65 A, and about 70 A. In yet further aspects, the second polymer can have a Shore A durometer of less than 60 A. In some exemplary aspects, the second polymer can be Neusoft™ 597-50A.
In still further aspects, the thickness of the second polymer layer can be from about 1 mil to about 6 mils, including exemplary values of about 1.1 mils, about 1.2 mils, about 1.3 mils, about 1.4 mils, about 1.5 mils, about 1.6 mils, about 1.7 mils, about 1.8 mils, about 1.9 mils, about 2.0 mils, 2.1 mils, about 2.2 mils, about 2.3 mils, about 2.4 mils, about 2.5 mils, about 2.6 mils, about 2.7 mils, about 2.8 mils, about 2.9 mils, about 3.0 mils, about 3.1 mils, about 3.2 mils, about 3.3 mils, about 3.4 mils, about 3.5 mils, about 3.6 mils, about 3.7 mils, about 3.8 mils, about 3.9 mils, about 4.1 mils, about 4.2 mils, about 4.3 mils, about 4.4 mils, about 4.5 mils, about 4.6 mils, about 4.7 mils, about 4.8 mils, about 4.9 mils, about 5.1 mils, about 5.2 mils, about 5.3 mils, about 5.4 mils, about 5.5 mils, about 5.6 mils, about 5.7 mils, about 5.8 mils, and about 5.9 mils. In still further aspects, the thickness of the at least one intermediate reinforcement layer can be anywhere between about 1 mil to about 6 mils, including exemplary values of about 1.1 mils, about 1.2 mils, about 1.3 mils, about 1.4 mils, about 1.5 mils, about 1.6 mils, about 1.7 mils, about 1.8 mils, about 1.9 mils, about 2.0 mils, 2.1 mils, about 2.2 mils, about 2.3 mils, about 2.4 mils, about 2.5 mils, about 2.6 mils, about 2.7 mils, about 2.8 mils, about 2.9 mils, about 3.0 mils, about 3.1 mils, about 3.2 mils, about 3.3 mils, about 3.4 mils, about 3.5 mils, about 3.6 mils, about 3.7 mils, about 3.8 mils, about 3.9 mils, about 4.1 mils, about 4.2 mils, about 4.3 mils, about 4.4 mils, about 4.5 mils, about 4.6 mils, about 4.7 mils, about 4.8 mils, about 4.9 mils, about 5.1 mils, about 5.2 mils, about 5.3 mils, about 5.4 mils, about 5.5 mils, about 5.6 mils, about 5.7 mils, about 5.8 mils, and about 5.9 mils.
In still further aspects, the at least one intermediate layer can comprise any of the polymers disclosed herein. In some aspects, the at least one intermediate layer can comprise the first compound disclosed above. Yet, in other aspects, the at least one intermediate layer can comprise the second compound disclosed above. While in still further aspects, the at least one intermediate layer can comprise the first compound. Yet, in still further aspects, the at least one intermediate layer can comprise any polymers that are known in the art and suitable for the desired application. In some aspects, the at least one intermediate layer can comprise polyether block amide, polyurethane, or a combination thereof. While in still further aspects, the at least one intermediate layer is a polyether block amide, for example, PEBAX®. While in still further aspects, the intermediate layer is a polyurethane. In such exemplary aspects, the at least one intermediate layer does not comprise a solid lubricant filler, such as a PTFE. In yet other aspects, the at least one intermediate layer does not comprise an inorganic filler. In still further aspects, the at least one intermediate layer can comprise a polymer comprising PEBAX® or polyurethane having a Shore D (or Shore A) durometer between about 45 D (85A) to about 90 D, including exemplary values of about 50 D, about 55 D, about 60 D, about 65 D, about 70 D, about 72 D, about 75 D, about 80 D, and about 85 D.
In yet further aspects, the at least one intermediate reinforcement layer can comprise a polyolefin. In still further aspects, the at least one intermediate reinforcement layer can comprise a polyethylene, a polypropylene, a graft modified polyethylene or polypropylene. In yet further aspects, the at least one intermediate reinforcement layer can comprise the grafted low-density polyethylene (LDPE), grafted medium density polyethylene, grafted ultra-low-density polyethylene (ULDPE), grafted high density polyethylene (HDPE), grafted heterogeneously branched linear low-density polyethylene (LLDPE), grafted homogeneously branched linear ethylene polymers and substantially linear ethylene polymers, grafted polypropylene, or ethylene vinyl acetate (EVA), or any combination thereof. In such exemplary aspects, a maleic anhydride or an acrylic acid can be used to graft the disclosed above polymers. In still further aspects, the at least one intermediate reinforcement layer can comprise a maleic anhydride or an acrylic acid grafted low-density polyethylene. In yet further aspects, the at least one intermediate reinforcement layer can comprise a maleic anhydride or an acrylic acid grafted polypropylene. In still further aspects, the at least one intermediate reinforcement layer can comprise a maleic anhydride or an acrylic acid grafted ethylene vinyl acetate. In still further aspects, the at least one intermediate reinforcement layer can comprise a maleic anhydride grafted polyolefin sold under a trademark of OREVAC®.
In still further aspects, any of the disclosed above at least one intermediate reinforcement layer can thermally bond the elongated tube to the inner member of the sheath. In still further aspects, the intermediate reinforcement layer can be extruded to be positioned between the first polymer layer and the second polymer layer. In still further aspects, the at least one intermediate reinforcement layer can be fused with the first and second polymer layers by at least one of heat or compression.
In still further aspects, the elongated tube, as disclosed herein, comprising the at least one intermediate reinforcement layer can exhibit an expansion force of less than about 50 N, less than about 49N, less than about 48N, less than about 47N, less than about 46N, less than about 45N, less than about 44N, less than about 43N, less than about 42N, less than about 41N, or even less than about 40 N.
In still further aspects, the elongated tube as disclosed herein that comprises the at least one intermediate reinforcement layer can exhibit a burst pressure greater than about 8 psi, greater than about 8.5 psi, greater than about 9 psi, greater than about 9.5 psi, greater than about 10 psi, greater than about 10.5 psi, greater than about 11 psi, greater than about 11.5 psi, about 12 psi, greater than about 12.5 psi, greater than about 13 psi, greater than about 13.5 psi, greater than about 14 psi, greater than about 14.5 psi, or greater than about 15 psi.
The outer polymeric tubular layer 26 and the inner polymeric tubular liner 24 can comprise, for example, polytetrafluoroethylene (PTFE) (e.g., Teflon®), polyimide, PEEK, polyurethane, nylon, polyethylene, polyamide, polyether block amides (e.g., PEBAX®), polyether block ester copolymer, polyesters, fluoropolymers, polyvinyl chloride, thermoset silicone, latex, poly-isoprene rubbers, polyolefin, other medical grade polymers, or combinations thereof. In yet other aspects, the outer tubular layer can also comprise a high-density polyethylene (HDPE).
The intermediate tubular layer 28 can comprise a shape memory alloy such as Nitinol and/or stainless steel, cobalt chromium, spectra fiber, polyethylene fiber, aramid fiber, or combinations thereof.
The inner polymeric tubular liner 24 can advantageously be provided with a low coefficient of friction on its inner surface. For example, the inner polymeric tubular liner 24 can have a coefficient of friction of less than about 0.5, less than about 0.1, less than about 0.05, or even less than about 0.01. Some aspects of a sheath 22 can include an additional lubricious liner on the inner surface 32 of the inner polymeric tubular liner 24. Such a liner can facilitate the passage of a delivery apparatus through the lumen 30 of the sheath 22. Examples of suitable lubricious liners include materials that can reduce the coefficient of friction of the inner polymeric tubular liner 24, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for a lubricious liner also include other materials desirably having a coefficient of friction of less than about 0.5, less than about 0.1, less than about 0.05, or even less than about 0.01.
The inner diameter of the intermediate tubular layer 28 varies depending on the application and size of the delivery apparatus and prosthetic device. In some aspects, the inner diameter ranges from about 0.005 inches to about 0.400 inches, including exemplary values of about 0.01 inches, about 0.05 inches, about 0.100 inches, about 0.120 inches, about 0.150 inches, about 0.170 inches, about 0.200 inches, about 0.220 inches, about 0.250 inches, about 0.270 inches, about 0.300 inches, bout 0.320 inches, about 0.350 inches, and about 0.370 inches.
The thickness of the intermediate tubular layer 28 can be varied depending on the desired amount of radial expansion, as well as the strength required. For example, the thickness of the intermediate tubular layer 28 can be from about 0.002 inches to about 0.0025 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, 0.009 inches, about 0.010 inches, about 0.011 inches, about 0.012 inches, about 0.013 inches, about 0.014 inches, about 0.015 inches, about 0.016 inches, about 0.017 inches, about 0.018 inches, 0.019 inches, about 0.020 inches, about 0.021 inches, about 0.022 inches, about 0.023 inches, and about 0.024 inches.
The thicknesses of the inner polymeric tubular liner 24 and the outer polymeric tubular layer 26 can also be varied depending on the particular application of the sheath 22. In some aspects, the thickness of the inner polymeric tubular liner 24 ranges from about 0.0005 inches to about 0.010 inches, including exemplary values of about 0.0006 inches, about 0.0007 inches, about 0.0008 inches, about 0.0009 inches, about 0.001 inches, about 0.002 inches, 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, and about 0.009 inches. In one aspect, the thickness can be about 0.002 inches. Outer polymeric tubular layers 26 can have a thickness of from about 0.002 inches to about 0.015 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, 0.009 inches, about 0.010 inches, about 0.011 inches, about 0.012 inches, about 0.013 inches, and about 0.014 inches. In certain aspects, the outer polymeric tubular layer 26 can have a thickness of about 0.010 inches.
The hardness of each layer of the sheath 22 can also be varied depending on the particular application and desired properties of the sheath 22. In some aspects, the outer polymeric tubular layer 26 has a Shore D durometer of about 25 D to about 75 D.
Additionally, some aspects of a sheath 22 can include an exterior hydrophilic coating on the outer surface 34 of the outer polymeric tubular layer 26. Such a hydrophilic coating can facilitate the insertion of the sheath 22 into a patient's vessel. Examples of suitable hydrophilic coatings include the Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, Minn. DSM medical coatings (available from Koninklijke DSM N.V., Heerlen, the Netherlands), as well as other hydrophilic coatings, are also suitable for use with the sheath 22.
In some aspects, the outer surface 34 of the outer polymeric tubular layer 26 can be modified. For example, surface modifications such as plasma etching can be performed on the outer surface 34. Similarly, other surfaces, both outer and inner, can be surface modified according to certain aspects and desired applications. In some aspects, surface modification can improve adhesion between the layers in the areas of the modification.
In certain aspects, the outer surface of the first outer tubular layer can be at least partially etched. In yet still, further aspects, the outer surface of the inner liner can be selectively etched around the circumference, linearly along at least a portion of the length of the sheath, or a combination thereof.
The sheath 22 also can have at least one radiopaque filler or marker. The radiopaque filler or marker can be associated with the outer surface 34 of the outer polymeric tubular layer 26. Alternatively, the radiopaque filler or marker can be embedded or blended within the outer polymeric tubular layers 26. Similarly, the radiopaque filler or marker can be associated with a surface of the inner polymeric tubular liner 24 or the intermediate tubular layer 28 or embedded within either or both of those layers.
Suitable materials for use as a radiopaque filler or marker include, for example, barium sulfite, bismuth trioxide, titanium dioxide, bismuth subcarbonate, or combinations thereof. The radiopaque filler can be mixed with or embedded in the material used to form the outer polymeric tubular layer 26 and can comprise from about 5% to about 45% by weight, including exemplary values of about 10% by weight, about 15% by weight, about 20% by weight, about 30% by weight, about 35% by weight, and about 40% by weight of the outer polymeric tubular layer. More or less radiopaque material can be used in some aspects, depending on the particular application.
In some aspects, the inner polymeric tubular liner 24 can comprise a substantially uniform cylindrical tube. In alternative aspects, the inner polymeric tubular liner 24 can have at least one section of discontinuity along its longitudinal axis to facilitate radial expansion of the inner polymeric tubular liner 24. For example, the inner polymeric tubular liner 24 can be provided with one or more longitudinal notches and/or cuts 36 extending along at least a portion of the length of the sheath 22. Such notches or cuts 36 can facilitate radial expansion of the inner polymeric tubular liner 24, thus accommodating passage of a delivery apparatus or other device. Such notches and/or cuts 36 can be provided near the inner surface 32, near the outer surface 37, and/or substantially through the entire thickness of the inner polymeric tubular liner 24. In aspects with a plurality of notches and/or cuts 36, such notches and/or cuts 36 can be positioned such that they are substantially equally spaced from one another circumferentially around the inner polymeric tubular liner 24. Alternatively, notches and cuts 36 can be spaced randomly in relation to one another or any other desired pattern. Some or all of any provided notches and/or cuts 36 can extend longitudinally along substantially the entire length of the sheath 22. Alternatively, some or all of any provided notches and/or cuts 36 can extend longitudinally only along a portion of the length of the sheath 22.
As shown in
Additionally or alternatively, as shown in
Additionally, the sheath 22 can comprise a soft tip 42 at the distal end 40 of the sheath 22. Such a soft tip 42 can be provided with a lower hardness than the other portions of the sheath 22. In some aspects, the soft tip 42 can have a Shore hardness from about 25 D to about 40 D, including polymers having a Shore hardness of about 30 D or about 35 D.
As shown in
As shown in
The sheath 22 has an unexpanded inner diameter equal to the inner diameter of the inner polymeric tubular liner (not visible in
In some aspects of a sheath according to the present disclosure, and as shown in section in
For example, in some aspects of a self-expandable sheath, the intermediate tubular layer 28 can comprise Nitinol and/or other shape memory alloys, and the intermediate tubular layer 28 can be crimped or radially compressed to a reduced diameter within the outer polymeric tubular layer 26 and the outer polymeric covering 50. Once the self-expandable sheath is at least partially inserted into a patient's vessel, the outer polymeric covering 50 can be slid back, peeled away, or otherwise at least partially removed from the sheath. To facilitate removal of the outer polymeric covering 50, a portion of the outer polymeric covering 50 can remain outside the patient's vessel, and that portion can be pulled back or removed from the sheath to allow the sheath to expand. In some aspects, substantially, the entire outer polymeric covering (the elongated tube as disclosed herein) 50 can be inserted, along with the sheath, into a patient's vessel. In these aspects, an external mechanism attached to the outer polymeric covering 50 can be provided, such that the outer polymeric covering can be at least partially removed from the sheath once the sheath is inserted into a patient's vessel.
In some aspects, once no longer constrained by the outer polymeric covering 50, the radially compressed intermediate tubular layer 28 can self-expand, causing expansion of the sheath along the length of the intermediate tubular layer 28. In some aspects, portions of the sheath can radially collapse, at least partially returning to the original crimped state, as the sheath is being withdrawn from the vessel after completion of the surgical procedure. In some aspects, such collapse can be facilitated and/or encouraged by an additional device or layer that, in some aspects, can be mounted onto a portion of the sheath prior to the sheath's insertion into the vessel.
The outer polymeric covering 50, in some aspects, is not adhered to the other layers of the sheath 22. For example, the outer polymeric covering 50 may be slidable with respect to the underlaying sheath, such that it can be easily removed or retracted from its initial position on the sheath 22.
Suitable materials for the outer polymeric covering 50 are disclosed in detail above.
Turning now to the intermediate tubular layer 28, several different configurations are possible. The intermediate tubular layer 28 is generally a thin, hollow, substantially cylindrical tube comprising an arrangement, pattern, structure, or configuration of wires or struts, however, other geometries can also be used. In some aspects, the intermediate tubular layer 28 is a braid. The intermediate tubular layer 28 can extend along substantially the entire length of the sheath 22, or alternatively, can extend only along a portion of the length of sheath 22. Suitable wires can be round, ranging from about 0.0005 inches thick to about 0.10 inches thick, or flat, ranging from about 0.0005 inches×0.003 inches to about 0.003 inches×0.007 inches. However, other geometries and sizes are also suitable for certain aspects. If a braided wire is used, the braid density can be varied. Some aspects have a braid density of from about thirty picks per inch to about eighty picks per inch and can include up to thirty-two wires in various braid patterns.
One representative aspect of an intermediate tubular layer comprises a braided Nitinol composite, which is at least partially encapsulated by an inner polymeric tubular member and an outer polymeric tubular member disposed on the inner and outer surfaces of the intermediate tubular layer, respectively. Such encapsulation by polymeric layers can be accomplished by, for example, fusing the polymeric layers to the intermediate tubular layer or dip coating the intermediate tubular layer. In some aspects, an inner polymeric tubular member, an intermediate tubular layer, and an outer polymeric tubular layer can be arranged on a mandrel, and the layers can then be thermally fused or melted into one another by placing the assembly in an oven or otherwise heating it. The mandrel can then be removed from the resulting sheath. In other aspects, dip coating can be used to apply an inner polymeric tubular member to the surface of a mandrel. The intermediate tubular layer can then be applied, and the inner polymeric tubular member is allowed to cure. The assembly can then be dip coated again, such as to apply a thin coating of, for example, polyurethane, which will become the outer polymeric tubular member of the sheath. The sheath can then be removed from the mandrel.
Additionally, the intermediate tubular layer 28 can be, for example, braided or laser cut to form a pattern or structure, such that the intermediate tubular layer 28 is amenable to radial expansion.
The structures shown in
Alternative aspects of a sheath for introducing a prosthetic device are also described. For example,
For example,
One particular aspect of a sheath 66 comprises a sheath having a notch or cut in the outer polymeric layer 70 or the inner polymeric layer (liner) 68 that extends longitudinally along approximately 75% of the length of the sheath 66. If such a notch or cut extends only partially through the associated layer, it can have a relatively low tear force, such as a tear force of about 0.5 lbs., so that the notch splits open relatively easily during use.
The inner polymeric liner 68 and the outer polymeric layer 70 can optionally be adhered together or otherwise physically associated with one another. The amount of adhesion between the inner polymeric liner 68 and the outer polymeric layer 70 can be variable over the surfaces of the layers. For example, little to no adhesion can be present at areas around or near any notches and/or cuts present in the layers so as not to hinder radial expansion of the sheath 66. Adhesion between the layers can be created by, for example, thermal bonding and/or coatings. Aspects of a sheath 66 can be formed from an extruded tube, which can serve as the inner polymeric layer (liner) 68. The inner polymeric layer (liner) 68 can be surface-treated, such as by plasma etching, chemical etching, or other suitable methods of surface treatment. By treating the surface of the inner polymeric liner 68, the outer surface of the inner polymeric liner 68 can have areas with altered surface angles that can provide better adhesion between the inner polymeric liner 68 and the outer polymeric layer 70. The treated inner polymeric liner can be dip coated in, for example, a polyurethane solution to form the outer polymeric layer 70. In some configurations, the polyurethane may not adhere well to untreated surface areas of the inner polymeric liner 68. Thus, by surface treating only surface areas of the inner polymeric liner 68 that are spaced away from the areas of expansion (e.g., the portion of the inner polymeric liner 68 near notches 74 and/or cuts 76), the outer polymeric layer 70 can be adhered to some areas of the inner polymeric liner 68, while other areas of the inner polymeric liner 68 remain free to slide relative to the outer polymeric layer 70, thus allowing for expansion of the diameter of the sheath 66. Thus, areas around or near any notches 74 and/or cuts 76 can experience little to no adhesion between the layers, while other areas of the inner and outer polymeric layers 68, 70 can be adhesively secured or otherwise physically associated with each other.
As with previously disclosed aspects, the aspects illustrated in
In some aspects, the outer diameter of the sheath 66 gradually decreases from the proximal end of the sheath 66 to the distal end of the sheath 66. For example, in one aspect, the outer diameter can gradually decrease from about 26 Fr at the proximal end to about 18 Fr at the distal end. The diameter of the sheath 66 can transition gradually across substantially the entire length of the sheath 66. In other aspects, the transition or reduction of the diameter of the sheath 66 can occur only along a portion of the length of the sheath 66. For example, the transition can occur along a length from the proximal end to the distal end, where the length can range from about 0.5 inches to about the entire length of the sheath 66.
Suitable materials for the inner polymeric liner 68 can have high elastic strength and include materials discussed in connection with other aspects, especially Teflon (PTFE), polyethylene (e.g., high density polyethylene), fluoropolymers, or combinations thereof. In some aspects, the inner polymeric liner 68 preferably has a low coefficient of friction, such as a coefficient of friction of from about 0.01 to about 0.5, including exemplary values of about 0.05, about 0.1, about 0.15, about 0.2, about 0.25, about 0.3, about 0.35, about 0.4, and about 0.45. In yet some other aspects of a sheath, 66 can comprise an inner polymeric liner 68 having a coefficient of friction of about 0.1 or less, or 0.05 or less.
Likewise, suitable materials for the outer polymeric layer 70 include materials discussed in connection with other aspects and other thermoplastic elastomers and/or highly elastic materials.
The Shore hardness of the outer polymeric layer 70 can be varied for different applications and aspects. Some aspects include an outer polymeric layer with a Shore hardness of from about 25 A to about 80 A, including exemplary values of about 30 A, about 35 A, about 40 A, about 45 A, about 50 A, about 55 A, about 60 A, about 65 A, about 70 A, and about 80 A. Yet, in other aspects, an outer polymeric layer can have a Shore hardness of from about 20 D to about 40 D, including exemplary values of about 25 D, about 30 D, and about 35 D. One aspect comprises a readily available polyurethane with a Shore hardness of 72 A. Another particular aspect comprises a polyethylene inner polymeric layer dipped in polyurethane or silicone to create the outer polymeric layer.
The sheath 66 can also include a radiopaque filler or marker, as described above. In some aspects, a distinct radiopaque marker or band can be applied to some portion of the sheath 66. For example, a radiopaque marker can be coupled to the inner polymeric liner 68, the outer polymeric layer 70, and/or can be positioned in between the inner and outer polymeric layers 68, 70.
In certain aspects, the inner polymeric liner 68 comprises one or more materials that are elastic and amenable to folding and/or pleating. For example,
Additionally, as shown in
In aspects having a plurality of folded regions 85, the regions can be equally displaced from each other around the circumference of the outer polymeric tubular layer 70. Alternatively, the folded regions can be off-center, different sizes, and/or randomly spaced apart from each other. While portions of the inner polymeric liner 68 and the outer polymeric tubular layer 70 can be adhered or otherwise coupled to one another, the folded regions 85 preferably are not adhered or coupled to the outer polymeric tubular layer 70. For example, adhesion between the inner polymeric liner 68 and the outer polymeric tubular layer 70 can be highest in areas of minimal expansion.
One particular aspect of the sheath, as illustrated in
In certain aspects, where the inner polymeric liner 68 comprises one or more folded portions, and as disclosed above, the inner liner can be selectively etched. In such aspects, at least a portion of the outer surface of the at least one folded portion of the inner liner is not etched along at least a portion of the sheath length. In still further aspects, the outer surface of the inner liner comprises one or more nonetched portions along the sheath length. Again, in the aspects where are a plurality of nonetched portions, such portions can be at any location on the sheath. In certain aspects, for example, and without limitation, each of the one or more nonetched portions is followed by an etched portion. While in other aspects, the one or more nonetched portions comprise the outer surface of the at least one folded portion.
In certain aspects, the sheaths disclosed herein can exhibit an insertion force of less than about 60 N, less than about 50 N, less than about 40 N, or less than about 30 N. In still further aspects, the sheath can exhibit a reduction in an insertion force of at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 100%, when compared to a substantially identical reference sheath that does not comprise the first compound composition and the selectively etched inner liner
In still further aspects, where the sheath comprises an inner liner that is selectively etched and has nonetched portions as disclosed above, such a sheath can exhibit even a substantial reduction in the insertion force when compared to a substantially identical sheath that does not comprise similar nonetched portions.
In some aspects, the outer polymeric tubular layer 70 comprises the same material or combination of materials along the entire length of the outer polymeric tubular layer 70. In alternative aspects, the material composition can change along the length of the outer polymeric tubular layer 70. For example, the outer polymeric tubular layer can be provided with one or more segments, where the composition changes from segment to segment. In one particular aspect, the Durometer rating of the composition changes along the length of the outer polymeric tubular layer 70 such that segments near the proximal end comprise a stiffer material or combination of materials, while segments near the distal end comprise a softer material or combination of materials. This can allow for a sheath 66 having a relatively stiff proximal end at the point of introducing a delivery apparatus while still having a relatively soft distal tip at the point of entry into the patient's vessel.
As with other disclosed aspects, the aspects of sheath 66 shown in
The sheath 66 can be provided with an unexpanded outer diameter of from about 3 Fr to about 30 Fr, including exemplary values of about 5 Fr, about 10 Fr, about 15 Fr, about 20 Fr, and about 25 Fr and, in some aspects has an unexpanded outer diameter of from about 18 Fr to about 19 Fr. In some aspects, the unexpanded outer diameter of the sheath 66 can range from about 3 Fr to about 28 Fr, including exemplary values of about 5 Fr, about 10 Fr, about 15 Fr, about 20 Fr, and about 25 Fr at or near the distal end of sheath 66, while the unexpanded outer diameter of the sheath 66 can range from about 3 Fr to about 30 Fr, including exemplary values of about 5 Fr, about 10 Fr, about 15 Fr, about 20 Fr, and about 25 Fr at or near the proximal end of sheath 66. For example, in one unexpanded aspect, the sheath 66 can transition from an unexpanded outer diameter of about 18 Fr at or near the distal end of the sheath 66 to an unexpanded outer diameter of about 28 Fr at or near the proximal end of the sheath 66.
The thickness of the inner polymeric liner 68 can vary, but in some preferred aspects is from about 0.002 inches to about 0.015 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.010 inches, about 0.011 inches, about 0.012 inches, about 0.013 inches, and about 0.014 inches. In some aspects, expansion of the sheath 66 can result in expansion of the unexpanded outer diameter of from about 10% or less to about 430% or more, for example, and without limitation about 1%, about 5%, about 10%, about 20%, about 50%, about 70%, about 100%, about 120%, about 150%, about 200%, about 250%, about 300%, about 350%, about 400%, about 450%, about 500%, or even more.
As with other illustrated and described aspects, the aspects shown in
In still further aspects, where the folded portions can be present, the at least one folded portion can comprise a first folded edge and a second folded edge and an overlapping portion extending circumferentially between the first and second folded edges, the overlapping portion comprising an overlap in a radial direction of at least two thicknesses of the inner liner, and wherein the first folded edge is configured to move closer to the second folded edge to shorten the overlapping portion at a local axial location during application of a radial outward force by passage of the medical device and wherein shortening of the overlapping portion corresponds with a local expansion of the lumen. Yet in other aspects, the at least one folded portion comprises a first folded edge and a second folded edge and an overlapping portion extending circumferentially between the first and second folded edges, the overlapping portion comprising an overlap in a radial direction of at least two thicknesses of the inner liner, wherein the first folded edge is configured to move closer to the second folded edge to shorten the overlapping portion at a local axial location during application of a radial outward force by passage of the medical device and wherein shortening of the overlapping portion corresponds with a local expansion of the lumen, and wherein the outer layer includes a first longitudinally extending edge and a second longitudinally extending edge configured to separate as the sheath expands, the first longitudinal extending edge and an overlapping portion of the outer layer extending over the second longitudinally extending edge when the sheath is not expanded.
In still further aspects, it is understood that the inner liner can be configured to expand to a substantially cylindrical tube.
In still further aspects, the sheath disclosed herein and comprising the elongated tube, as described herein, can further comprise an inner tubular layer comprising a longitudinal slit and partially defining an inner lumen, a first outer tubular layer enveloping the inner layer, the outer tubular layer comprising a longitudinally extending, folded flap that overlies a portion of an outer surface of the outer layer when the sheath is in an unexpanded state, and the elongated tube positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
Such exemplary aspects are described in detail below.
The folded flap 171 of the first outer tubular layer 170 has a base 173. The base 173 can be positioned radially outwardly from the longitudinal slit 169. In some aspects, the base 173 is centered over the longitudinal slit 169. The folded flap 171 further includes a longitudinally extending overlying portion 175 extending from the base 173 to a longitudinally extending crease 179 at the edge of the flap 171. The longitudinally extending overlying portion 175 overlies a longitudinally extending underlaying portion 177 and is separated from the underlaying portion 177 by the crease 179. Underlaying portion 177 contacts the outer surface 183 of the first outer tubular layer 170 when the sheath is in an unexpanded state, as shown in
Some aspects of sheath 166 can include multiple longitudinally extending folded flaps that overlie portions of the outer surface 183 of the first outer tubular layer 170, positioned at various locations around the circumference of sheath 166. For example, 2, 3, 4, 5, 6, 7, 8, 9, or 10 longitudinally extending folded flaps can be positioned around the circumference. In some aspects, these multiple folded flaps are equally spaced around the circumference of the sheath 166.
The folded flap 171 extends circumferentially around a portion of the sheath 166. In some aspects, the longitudinally extending flap 171 extends around about 20% to about 40% of the outer circumference of the first outer tubular layer 170 when the sheath 166 is unexpanded (including about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, and about 40% of the outer circumference of the first outer tubular layer 170). In one example, for a sheath having a 14 F (4.7 millimeters) unexpanded outer diameter, the folded flap extends around about 85 to about 120 degrees (including exemplary values of about 90, about 95, about 100, about 105, about 110, and 115 degrees), or about 23%-35%, (including exemplary values of about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, and about 34%) of the outer circumference (resulting in an inner lumen having an expanded diameter of about 7.6 millimeters to about 8.4 millimeters, including exemplary values of about 7.7 mm, about 7.8 nm, about 7.9 mm, about 8.0 mm, about 8.1 mm, about 8.2 mm, and about 8.3 mm, which can be used with a valve having a 6.4 millimeter crimped outer diameter, and a 26 millimeter expanded outer diameter).
In
The first outer tubular layer 170 is formed of a material having a low coefficient of friction, a high tensile modulus, and a high ultimate tensile strength in order to improve the push force transmission through the length of sheath 166 while reducing kinking. Good push force transmission means that the force applied by the practitioner to advance the sheath is predictable, responsive, and consistent along the length of the sheath. However, an excessively high tensile modulus may limit the ability of the longitudinally extending flap 171 to open, which could hamper push force transmission. A desirable range for the tensile modulus of the first outer tubular layer 170 is from about 300 MPa to about 2,000 MPa (including about 300 MPa, about 400 MPa, about 500 MPa, about 600 MPa, about 700 MPa, about 800 MPa, about 900 MPa, about 1000 MPa, about 1100 MPa, about 1200 MPa, about 1300 MPa, about 1400 MPa, about 1500 MPa, about 1600 MPa, about 1700 MPa, about 1800 MPa, about 1900 MPa, and about 2000 MPa). In some aspects, the tensile modulus may preferably be at least 700 MPa. High axial and radial stiffnesses enable the sheath to be easily inserted and to resist collapse within the body.
The ultimate tensile strength of the first outer tubular layer 170 can be at least 50 MPa. A high ultimate tensile strength helps to prevent the material from tearing while the prosthetic device is advancing through the sheath.
In some exemplary and unlimiting aspects, the first outer tubular layer 170 of the aspects shown in
In some aspects, the outer surface 183 of the first outer tubular layer 170 can include a hydrophilic coating. In some aspects, a bond can be created between the underlaying portion 177 of the folded flap 171 and the outer surface 183 of the first outer tubular layer 170. The bond can be a thermal bond (with portions of the contacting layers melted together), or it can be a separate layer of adhesive.
As discussed above, the inner tubular layer 168 of the aspects shown in
The inner tubular layer 168 forms a low friction barrier between a passing prosthetic device and the first higher friction outer tubular layer 170. The inner tubular layer 168 extends around at least 80% (or at least 85%, or at least 90%, or at least 95%) of the circumference of the inner lumen 172 when the sheath 166 is in an unexpanded state. This high degree of coverage limits contact between the passing prosthetic device and the first higher friction outer tubular layer 170. In some aspects, the coefficient of friction per ASTM D1894 of the inner tubular layer 168 (static or dynamic) is 0.30 or less, or 0.25 or less, or 0.20 or less, or 0.1 or less, or 0.05 or less. In other aspects, the coefficient of friction is 0.25 or less.
In some aspects, the low-friction inner tubular layer 168 comprises, or is formed of, a material having a tensile modulus of at least about 300 MPa (and up to about 1,400 MPa, including exemplary values of about 350 MPa, about 400 MPa, about 450 MPa, about 500 MPa, about 550 MPa, about 600 MPa, about 650 MPa, about 700 MPa, about 750 MPa, about 800 MPa, about 850 MPa, about 900 MPa, about 1,000 MPa, about 1,050 MPa, about 1,100 MPa, about 1,150 MPa, about 1,200 MPa, about 1,250 MPa, about 1,300 MPa, and about 1,350 MPa) to provide good push force transmission while providing kink resistance. This material could be, for example, high density polyethylene or a fluoropolymer. Exemplary fluoropolymers include polytetrafluoroethylene, ethylene fluorinated ethylene propylene, or perfluoro alkoxy.
A tie layer 174 can be positioned between the two layers, thereby adhering the inner tubular layer 168 to the first outer tubular layer 170. The tie layer 174 can be formed of polyurethane or functionalized polyolefin in some aspects. In some aspects, the contacting surface of the inner tubular layer 168 can be etched to improve bonding to the tie layer 174. For example, an inner tubular layer 168 that includes, or is formed of, a fluoropolymer might be etched on its outer surface to improve thermal bonding to the tie layer 174. In yet further aspects, the inner tubular layer 168 can be selectively etched as described above.
As shown in
As mentioned above, in some aspects, the first outer tubular layer 170 can be included or can be formed of a shape memory material (for example, a heat-set polymer such as PEBAX®) that facilitates refolding of the first outer tubular layer 170 after expansion. In aspects disclosed herein, the second outer layer (outer jacket) 181 can extend over and envelop the first outer tubular layer 170. The refolding of the first outer tubular layer 170 can preferably return the sheath 166 back to its original outer diameter or to a value close to the original outer diameter (for example, to within about 10%, about 20%, about 30%, about 40%, or about 50% of the original outer diameter).
Methods of using the sheath of
The outwardly directed radial force further unfolds the longitudinally extending flap 171 of the first outer tubular layer 170 to expand the expandable sheath. The unfolding of the flap 171 can include sliding a longitudinally extending overlying portion 175 circumferentially against a longitudinally extending underlaying portion 177 of flap 171. The underlaying portion 177 can slide circumferentially against an outer surface 183 of the first outer tubular layer 170. In some aspects, the unfolding of the longitudinally extending flap 171 occurs at a position radially outward from the longitudinal slit 169 of the inner tubular layer 168. The unfolding of the flap 171 can extend the full length of the expandable sheath 166 in some aspects.
The longitudinal slit 169 of the inner tubular layer 168 narrows once the outwardly directed radial force has ceased (i.e., once the prosthetic device has passed by). The slit 169 may narrow back to its original width or to a value close to the original width (for example, to a value within 10% of the original width). The narrowing can occur along the entire length of the sheath 166. The prosthetic device is then delivered to the procedure site.
The longitudinally extending flap 171 at least partially refolds once the prosthetic device ceases to apply the outwardly directed radial force (i.e., once it has passed by). In some aspects, the longitudinally extending flap 171 refolds itself due to a shape memory bias toward the folded state. In some aspects, an inwardly directed radial force is applied to the outer surface 183 of the first outer tubular layer 170 to refold the longitudinally extending flap 171 (for example, by the second outer layer (outer jacket) 181).
An example method of making the sheath is as follows. These steps are not meant to be limiting. The steps given can be reordered as needed. Other steps can be added, or in other examples, some steps may not be necessary. Sizes are approximate. Disclosed herein is an exemplary aspect of making a sheath where the elongated tube or recoverable outer jacket covers the whole length of the expandable sheath shaft assembly. In certain aspects, the elongate tube and the expandable sheath shaft assembly can be about 380 mm long (15 inches). 1) Start with a PTFE inner layer of about 0.200 inch inner diameter (ID), wall thickness about 0.004 inches, 2) load PTFE inner layer on to a tapering mandrel from about 0.200 inches to about 0.187 inches, 3) stretch on to an 0.187 inch outer diameter (OD) mandrel section under heat, 4) flare proximal end of 0.200 inch ID PTFE to 0.340 inches ID under heat, 5) by expanding with air pressure, load tie layer such as Tecoflex 80A having about 0.200 inch ID and 0.004 inch wall thickness over the PTFE inner layer along the body section, 6) adhere tie layer to inner layer, for example, by covering it with FEP (fluorinated ethylene propylene) heat shrink tubing and applying heat, 7) remove FEP thermal shrink tubing if it was used, 8) create a longitudinal slit along the body section of the assembly, 9) load the subassembly having a slit on to a 0.187 inch OD mandrel, 10) load outer layer over the body, 11) fold outer layer, 12) heat set the fold, for example, by inserting the subassembly with a fold inside a heat shrink tubing and placing the assembly into the oven, 13) remove the shrink tubing if it was used, 14) add the second outer layer; and 14) remove sheath from the mandrel.
The outer jacket can be expanded to a larger diameter by applying air pressure to the inner diameter of the outer jacket. The assembled sheath can then be inserted into the expanded outer jacket for the desired length. Air pressure can then be released to allow the outer jacket to decrease in diameter to the original diameter.
Also disclosed an exemplary aspect of making a sheath where the elongated tube or recoverable outer jacket covers the proximal side of the expandable sheath shaft assembly. In such exemplary aspects, the sheath shaft having about 380 mm (15 inches) length can be assembled. For example, a tapered mandrel can be inserted into the sheath shaft assembly's inner diameter. The outer jacket or strain relief tubing, as disclosed here, can be cut to about 105 mm +/− 10 mm (4.15″ +/− 0.40″) and positioned on the sheath shaft assembly. The outer jacket can have an inner diameter big enough to slide the outer jacket over the sheath shaft assembly, especially with the outer jacket comprised of the low friction PTFE incorporating layer. An FEP (fluoroethylene propylene) heat shrink tubing can then be flared on the proximal end. Flared FEP heat shrink tubing can be slid over the outer jacket. Heat can be used to fuse the outer jacket to the sheath shaft assembly. The distal end of the outer jacket can be heated to adhere to the distal end of the outer jacket to the sheath shaft assembly. FEP heat shrink tubing can then be removed.
Further, the mandrel can be removed. Still, further, the proximal end of the sheath and the outer jacket assembly can beflared over a heated flaring tool. It is understood that in some exemplary and unlimiting aspects, other manufacturing steps can be present such as the flushing tube and the housing bonding, hydrophilic coating, inspection, the valves, and the sleeve assembly, and leak test etc.
In preferred aspects, the first and second portions 90, 92 are not adhered to one another. In some aspects, and as best seen in
In some aspects, a sheath 66 can comprise a partial slit or score line along at least a portion of its length. For example, as shown in
Score line 77 can be substantially centrally located with respect to the folded region 85. In alternative aspects, score line 77 can be positioned in other locations relative to the folded region 85. Also, sheath 66 can comprise one or more score lines 77. For example, as shown in
In certain aspects, sheath 100 can include a plurality of layers. For example, sheath 100 can include an inner layer 108 and an outer layer 110 disposed around the inner layer 108. The inner layer 108 can define a lumen through which a delivery apparatus can travel into a patient's vessel in order to deliver, remove, repair, and/or replace a prosthetic device, moving in a direction along the longitudinal axis X. As the prosthetic device passes through the sheath 100, the sheath locally expands from a first resting diameter to a second, expanded diameter to accommodate the prosthetic device. After the prosthetic device passes through a particular location of the sheath 100, each successive expanded portion or segment of the sheath 100 at least partially returns to the smaller resting diameter. In this manner, the sheath 100 can be considered self-expanding in that it does not require the use of a balloon, dilator, and/or obturator to expand.
The inner and outer layers 108, 110 can comprise any suitable materials. Suitable materials for the inner layer 108 include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyether block amide (e.g., PEBAX®), and/or combinations thereof. In one specific aspect, the inner layer 108 can comprise a lubricious, low-friction, or hydrophilic material, such as PTFE. Such a low coefficient of friction materials can facilitate the passage of the prosthetic device through the lumen defined by the inner layer 108. In some aspects, the inner layer 108 can have a coefficient of friction of less than about 0.1. Some aspects of a sheath 100 can include a lubricious liner on the inner surface of the inner layer 108. Examples of suitable lubricious liners include materials that can further reduce the coefficient of friction of the inner layer 108, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for a lubricious liner also include other materials desirably having a coefficient of friction of about 0.1 or less.
Suitable materials for the outer layer 110 include nylon, polyethylene, PEBAX®, HDPE, polyurethanes (e.g., Tecoflex™), and other medical grade materials. In one aspect, the outer layer 110 can comprise high density polyethylene (HDPE) and Tecoflex™ (or other polyurethane material) extruded as a composite. In some aspects, the Tecoflex™ can act as an adhesive between the inner layer 108 and the outer layer 110 and may only be present along a portion of the inner surface of the outer layer 110. Other suitable materials for the inner and outer layers are also disclosed in U.S. Patent Application Publication No. 2010/0094392, which is incorporated herein by reference.
Additionally, some aspects of a sheath 100 can include an exterior hydrophilic coating on the outer surface of the outer layer 110. Such a hydrophilic coating can facilitate insertion of the sheath 100 into a patient's vessel. Examples of suitable hydrophilic coatings include the Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, Minn. DSM medical coatings (available from Koninklijke DSM N.V, Heerlen, the Netherlands), as well as other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride), are also suitable for use with the sheath 100. The elongate tube serving as an outer jacket can then be disposed on the outer layer of the sheath.
Best seen in
The C-shaped band 112 can serve as a radiopaque marker or filler to enable visibility of the sheath 100 under fluoroscopy during use within a patient. The C-shaped band 112 can comprise any suitable radiopaque material, such as barium sulfite, bismuth trioxide, titanium dioxide, bismuth subcarbonate, platinum, iridium, and combinations thereof. In one specific aspect, the C-shaped band can comprise 90% platinum and 10% iridium. In other aspects, the marker 112 needs not to be a C-shaped band. Other shapes, designs, and configurations are possible. For example, in some aspects, the marker 112 can extend around the entire circumference of the sheath 100. In other aspects, the marker 112 can comprise a plurality of small markers spaced around the sheath 100.
As shown in
As shown in
In this manner, the sheath 100 is configured to expand from a resting configuration (
The sheath 100 can be configured such that it locally expands at a particular location corresponding to the location of the medical device along the length of the lumen 116, and then locally contracts once the medical device has passed that particular location. Thus, a bulge may be visible, traveling longitudinally along the length of the sheath as a medical device is introduced through the sheath, representing continuous local expansion and contraction as the device travels the length of the sheath 100. In some aspects, each segment of the sheath 100 can locally contract after removal of any radial outward force such that it regains the original resting diameter of the lumen 116. In some aspects, each segment of the sheath 100 can locally contract after removal of any radial outward force such that it at least partially returns to the original resting diameter of the lumen 116.
The layers 108, 110 of sheath 100 can be configured, as shown in
As shown in
As described above, the sheath 100 includes an inner layer 108. The inner layer 108 can be surface-treated, such as by plasma etching, chemical etching, or other suitable methods of surface treatment. In certain aspects, the inner liner 108 is selectively etched, forming various etched and nonetched portions, as disclosed above. By treating the surface of the inner layer 108, the outer surface of the inner liner 108 can have areas with altered surface angles that can provide better adhesion between the inner layer 108 and the outer layer 110. As described above, the inner liner 108 can comprise polytetrafluoroethylene (PTFE), polyimide, polyetheretherketone (PEEK), polyurethane, nylon, polyethylene, polyamide, or combinations thereof. In an example, sheath 100, the inner layer 108 is composed of an etched PTFE material. It is contemplated that the inner layer 108 can have a fully etched outer surface or a partially etched outer surface. When partially etched, the unetched portions of the outer surface of the inner liner 108 can extend longitudinally along a length of the inner layer 108 and/or circumferentially around the circumference of the inner layer 108. For example, the desired unetched location on the inner layer 108 can be masked or otherwise covered during the etching process to prevent etching at that location. It is also contemplated that the entire outer surface of the inner liner 108 can be etched and the etching removed at the desired locations of the unetched surface.
In an example, sheath 100, unetched portions are provided along those surfaces of the inner layer 108 that come into contact with the outer surface of the outer layer 110. That is, those portions of the inner layer 108, excluding the tie layer 128, would not include etching. For example, it is contemplated that etching is not included between the inner surface of the folded portion 118 of the inner layer 108 and the underlaying portion 122 of the outer layer 110. By excluding etching on the portions where the inner layer 108 and the outer surface of the outer layer 110 are in direct contact helps to facilitate release of the inner surface of the folded portion 118 and the outer layer 110 during expansion of the sheath 100.
The wall thickness of the inner liner can vary, but in some examples, the wall thickness of the inner layer 108 ranges between about 0.002 inches and about 0.006 inches (including about 0.002 inches, about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches). In other examples, the wall thickness of the inner layer ranges between about 0.003 includes and about 0.005 inches. In a further example, the wall thickness of the inner layer (liner) 108 ranges between about 0.0035 inches and about 0.0045 inches (including about 0.0035 inches, about 0.0040 inches, about 0.0045 inches).
As described above, the sheath 100 includes an outer layer 110 exerting a radially inward force on the inner layer 108. In general, the outer layer 110 can comprise a polymeric material. As described above, the outer layer 110 can be comprised of PTFE, polyimide, PEEK, polyurethane, nylon, polyethylene, polypropylene, polyamide, polyether block amides, polyether block ester copolymer, thermoset silicone, latex, poly-isoprene rubbers, high density polyethylene (HDPE), Tecoflex™, or combinations thereof. In an exemplary aspect, the inner layer 108 can comprise PTFE, and the outer layer 110 can comprise a combination of HDPE and Tecoflex™. The outer layer 110 can have a wall thickness ranging between about 0.007 inches and about 0.013 inches (including 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.010 inches, about 0.011 inches, about 0.012 inches, about 0.013 inches),In another example, the outer layer 110 can have a wall thickness ranging between about 0.008 inches and about 0.012 inches. In another example, the outer layer 110 can have a wall thickness ranging between about 0.009 inches and about 0.011 inches.
As described above, the sheath 100 includes an outer jacket 140 that extends over and envelopes the outer layer 110. While the outer layer 110 can be discontinuous in that it includes a slit or a cut in order to form the overlapping and underlaying portions 120, 122 as described above, the outer jacket 140 comprises a continuous outer layer covering the inner and outer layers 108, 110. It is understood that the outer jacket is formed by the disclosed above elongated tube having a disclosed composition and characteristics.
Generally, the outer jacket 140 has a relatively low tensile modules compared to the inner and outer layers 108, 110. In certain aspects and as disclosed above, the outer jacket exhibits an elongation at break of ranging between about 40% and about 800% (including about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 150%, about 200%, about 250%, about 300%, about 350%, about 400%, about 450%, about 500%, about 550%, about 600%, about 650%, about 700%, about 800%).
The outer jacket 140 in this aspect, can have a first polymer layer and a second polymer layer, similar to the aspects disclosed above. For example, the first polymer layer can comprise a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65 wt % of an inorganic filler based on a total weight of the first compound composition; and up to about 20 wt % of a solid lubricant filler based on a total weight of the first compound composition. In yet further aspects, the first polymer layer can also comprise at least one tackiness reducing compound in an amount from about 1wt % to about 20 wt %. In still further aspects, the solid lubricant filler can comprise one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicones, talc, polytetrafluorethylene (PTFE), fluorinated ethylene propylene, and the like. In yet further aspects, the inorganic filler can comprise bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof. In still further aspects, and as disclosed above, the least one tackiness reducing compound comprises ProPell™.
In yet further aspects, the outer jacket 140 can comprise a second polymer layer. In such aspects, the second polymer layer can have any composition, as disclosed above. For example, and without limitation, the second polymer layer can comprise a second compound composition comprising from 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof. In still further aspects, the second compound composition is substantially free of inorganic filler. While in other aspects, the second compound composition is substantially free of the solid lubricant filler.
The outer jacket 140 can comprise the first and/or the second polymer layer with a wall thickness ranging between about 1 mil to about 5 mils, including exemplary values of about 1.5 mils, about 2 mils, about 2.5 mils, about 3 mils, about 3.5 mils, about 4 mils, about 4.5 mils, and about 4.9 mils. The wall thickness is measured radially between the inner surface of the outer jacket 140 and the outer surface of the outer jacket 140.
In alternative aspects, the first (and/or second) polymer layer composition and/or wall thickness can change along the length of the outer jacket 140. For example, the outer jacket (elongated tube) 140 can be provided with one or more segments where the composition and/or thickness changes from segment to segment. In an example aspect, the Durometer rating of the composition changes along the length of the outer jacket 140 such that segments near the proximal end comprise a stiffer material or combination of materials, while segments near the distal end comprise a softer material or combination of materials. Similarly, the wall thickness of the outer jacket 140 the wall thickness of the outer jacket 140 in segments near the proximal end can be thicker/greater than the wall thickness of the outer jacket 140 near the distal end.
As illustrated in
As illustrated in
The outer jacket (or elongated tube) 140 can be bonded to the outer layer 110 to prevent the outer jacket (elongated tube) 140 from sliding over the outer layer 110 and “bunching up” in response to the friction forces applied by the surrounding tissue during the insertion of the sheath 100 into the patient's vasculature. For example, the outer jacket (the elongated tube) 140 can be bonded at the proximal end and/or distal end of the outer layer 110. At the proximal and distal ends, the outer jacket 140 can be bonded to the outer layer 110 around the full circumference of the outer layer. At the distal end of the sheath 100, the outer jacket (the elongated tube) 140 can alternatively be bonded to the inner layer 108. For example, the outer jacket (the elongated tube) 140 can be bonded to the distal end surface of the inner layer 108.
As illustrated in
The outer jacket (elongated tube) 140 can be bonded to the outer layer 110 and/or inner layer 108 using any mechanical and/or chemical (e.g., adhesive) fastener known in the art. In one example, sheath 100, the outer jacket 140 and the outer layer 110 and/or inner layer 108 may have similar melting temperatures. Accordingly, an example bonding method includes a thermally bonded coupling between the outer jacket (elongated tube) 140, the outer layer 110, and/or inner layer 108. For example, the bond between the outer jacket 140 and the outer layer 110 can be achieved by laser welding and/or a heat compression (e.g., using a heat compression jaw), allowing the location of the bond line to be closely controlled.
As shown in
As illustrated in
The adhesive layer 128 can comprise a material having a Shore A hardness (durometer) less than about 90 A. For example, the adhesive layer 128 can comprise a thermoplastic polyurethane such as an aliphatic polyether-based thermoplastic polyurethane (TPU). An example of TPU includes Tecoflex™ 80A. The adhesive layer 128 can also be composed of an aromatic polyether or polyesters-based thermoplastic polyurethane such as, for example, Pellethane™ 80A. The adhesive layer can also be composed of a polyolefin or polyamide, including, for example, a polyolefin (PE, PP, or EVA) modified with maleic anhydride such as an Orevac™ resin.
The thickness (wall thickness) of the adhesive layer 128 can vary, but in some examples, the wall thickness of the adhesive layer ranges between about 0.002 inches and about 0.005 inches (including about 0.002 inches, about 0.003 inches, about 0.004 inches, about 0.005 inches). In other examples, the wall thickness of the adhesive layer 128 ranges between about 0.0025 and about 0.0040 (including about 0.0025 inches, about 0.0030 inches, about 0.0035 inches, about 0.0040 inches). In a further example, the wall thickness of the adhesive layer 128 ranges between about 0.0025 inches and about 0.0035 inches (including about 0.0025 inches, about 0.0030 inches, about 0.0035 inches).
In some examples, the sheath 100 can include a lubricant to reduce friction and facilitate expansion/contraction between the outer layer 110 and the outer jacket 140. The lubricant 142 allows the outer layer 110 and inner layer 108 to unroll easily under the outer jacket (elongated tube) 140, ensuring that the hemostasis and atraumatic benefits achieved by the addition of an outer jacket 140, do not compromise the push force performance of the sheath 100. That is, the lubricant 142 reduced the push force necessary to move the prosthetic device through the lumen 116 of the inner layer 108 during the delivery of the prosthetic device and the corresponding local expansion of the sheath 100.
As illustrated in
The lubricant is applied as a band (or spot) that extends both circumferentially and longitudinally along the outer layer 110 (and the protruding portion of the inner layer 108). In an example sheath 100, the lubricant 142 is applied as a band that extends both circumferentially around the outer layer 110 and longitudinally along a length of the outer layer 110. To prevent migration, the lubricant 142 can be composed of a heat-curable material, e.g., a material curable at room temperature. As a result, the material can be applied to a desired location along the outer layer 110 and does not migrate during assembly and/or use of the sheath 100. The lubricant 142 can be composed of a medical-grade lubricant, such as silicone. Example lubricants include medical-grade curable silicone lubricants, including a platinum catalyzed thermal curing silicone lubricant such as NuSil™ MED10-6670 (heat-curable), a PTFE lubricant such as Duraglide™ (curable at room temperature) and/or CHRISTO-LUBE™.
As illustrated in
The coiled wire 160 can be comprised of a metal or a polymer wire. For example, the coiled wire 160 can be composed of PET, PEEK, stainless steel, and/or nitinol. The coiled wire 160 can be comprised of a flat wire, a round wire, or a combination thereof. The individual wires of the coiled wire 160 can have a diameter/thickness ranging between about 0.002 inches and about 0.008 inches (including about 0.002 inches, about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches). In another example, the individual wires of the coiled wire 160 can have a diameter/thickness ranging between about 0.004 inches and about 0.007 inches. In a further example, the individual wires of the coiled wire 160 can have a diameter/thickness of about 0.006 inches. The pitch/distance between adjacent coils of the coiled wire 160 can correspond to the diameter/thickness of the coiled wire. For example, where the diameter/thickness of a single coil of the coiled wire is about 0.006 inches, the spacing/pitch between the wire and the next adjacent coiled wire is about 0.006 inches.
Methods of using the sheath of
As the sheath 100 expands at a particular location (i.e., locally expands at the location of the passing prosthetic device), the overlapping portion 120 of the outer layer 110 can move circumferentially with respect to the underlaying portion 122 as the folded portion 118 of the inner layer 108 least partially separate and/or unfold, causing the elongate gap(s) 132 provided in the outer layer 110 to widen/expand. The sheath thereby expands to accommodate a medical device having a diameter larger than that of lumen 116 in the resting (unexpanded) configuration. As shown in
In an unexpanded configuration, the sheath 100 can have an outer diameter less than about 0.30 inches (including less than about 0.29 inches, less than about 0.28 inches, less than about 0.27 inches, less than about 0.26 inches, less than about 0.25 inches, less than about 0.24 inches). Preferably, the unexpanded sheath has an outer diameter ranging between about 0.24 inches and about 0.26 inches. In a fully expanded configuration, the sheath 100 can have an inner diameter greater than 0.300 inches. Preferably, the expanded sheath 100 has an inner diameter ranging between 0.325 inches and 0.400 inches (including about 0.325 inches, about 0.327 inches, about 0.330 inches, about 0.333 inches, about 0.336 inches, about 0.340 inches, about 0.345 inches, about 0.350 inches, about 0.355 inches, about 0.360 inches, about 0.365 inches, about 0.370 inches, about 0.375 inches, about 0.380 inches, about 0.385 inches, about 0.390 inches, and about 0.395 inches).
As described above, the inner and outer layers 108, 110 can be bonded together using an adhesive layer 128. The adhesive layer 128 prevents movement, both longitudinal and radial, between the inner and outer layers 108, 110. As a result, expansion of the sheath 100 can be limited to only those regions excluding the adhesive layer 128. For example, as illustrated in
Once the prosthetic device is passed through the lumen 116 (or a particular location along the lumen), the lumen 116 of the sheath can at least partially contracts back to an unexpanded configuration. The outer layer 110 can exert an inwardly directed radial force on the inner layer 108 urging it back to its original folded configuration. Similarly, if a coiled wire 160 was included, the coiled wire can exert an inwardly directed radial force on the outer layer 110 and the inner layer 108 urging them back towards an unexpanded configuration. In still further aspects, the outer jacket 140 can exert an inwardly directed radial force on the outer layer 110 and the inner layer 108 urging them back to an unexpanded configuration.
The prosthetic device can be delivered through the distal end of the sheath 100 to the delivery site within the patient. The prosthetic device can include a self-expanding heart valve or a stent-mounted heart valve. The heart valve can be extended through the distal end of the elongate lumen 116 at the delivery site. Once outside the lumen 116, the heart valve can be expanded, and the sheath 100 removed from the treatment site.
As shown in
The elongated tube 702 can, in some aspects, provide hemostasis (e.g., prevent blood loss during implantation of the prosthetic device). For example, the elongated tube 702 can be sized or configured to form a seal with the patient's artery when inserted, such that blood is substantially prevented from flowing between the elongated tube 702 and the vessel wall. The elongated tube 702 can be inserted such that it passes the arteriotomy. For example, in aspects where the elongated tube 702 does not extend all the way to the distal end 709 of the sheath 700, the elongated tube 702 can extend distally far enough such that when the sheath 700 is fully inserted into the patient, at least part of the elastic outer cover extends through the ateriotomoy site.
The elongated tube 702 can be configured to expand as the sheath expands, as shown in the expanded configuration in
In some aspects, the folded portion 710 can include a weakened portion 716, such as a longitudinal perforation, score line, and/or slit along at least a portion of the length of the inner layer 704. The slit can allow for two adjacent ends 718, 720 of the folded portion 710, to move relative to one another as the sheath 700 expands to the expanded configuration shown in
Each folded portion 808, 810 can include a weakened portion 818, such as a slit, score line, and/or perforation. Weakened portion 818 can allow the expandable sheath 800 to expand easily without a high radial force. As the sheath 800 expands, segment 812 along the top of the folded portions 808, 810 of inner layer 804 can be configured to split apart from the rest of the folded portions 808, 810 and the first and second underlaying portions 814, 816 can move away from one another so as to create an enlarged lumen within the inner layer 804. Weakened portions 818 can allow for segment 812 to easily split apart from the inner layer 804 as the sheath 800 expands.
Inner layer 902 can be shaped to include one or more folded portions 906 arranged to form a generally horseshoe-shaped lumen 908 that extends longitudinally through sheath 900 along the inner surface of the inner layer 902. The folded portions 906 can be arranged to form an area 910 positioned with the lumen 908 and radially inward from the elongated tube 904. In some aspects, the area 910 can include one or more voids (e.g., smaller lumens or openings extending through area 910). In some aspects, the area 910 can be filled with material (e.g., HDPE) reflowed from an intermediate layer while the sheath is being made. In some aspects, area 910 can be filled with material reflowed from the elongated tube 904 during the sheath manufacturing process.
The inner layer 902 can include one or more weakened portions 912, such as score lines, perforations, or slits. The weakened portions 912 can be configured to split apart, separate, or widen as the sheath expands from its initial resting configuration (
The inner layers 1002, 1102 of the sheaths 1000, 1100, respectively, of
It is further understood that the aspects disclosed herein that describe the presence of the outer layer in addition to the inner layer and the elongated tube (the outer jacket) are exemplary. Also described herein are aspects where this outer layer is substituted fully by an elongated tube comprising the disclosed herein composition. In such aspects, the elongated tube can have a structure and characteristics of the as disclosed herein outer layer. It is further understood that in such exemplary and unlimiting aspects, the additional elongated tube can be present and behave as disclosed herein outer jacket or a strain relief jacket.
The elongated tube of this current disclosure can be used as an outer jacket 140 in various sheath configurations, as shown in
It is understood that the axial reinforcing members as used herein can also be used interchangeably with the term “at least one intermediate reinforcement layer.” In certain aspects, the at least one intermediate reinforcement layer can be presented as a strip. While in yet other aspects, the at least one intermediate reinforcement layer can be a thermally bondable layer. Yet, in still further aspects, this thermally bondable layer can be presented as a strip.
The reinforcing member 145 provides stiffness and prevents axial bunching of the outer jacket 140 during insertion into the patient's vasculature while not sacrificing the low radial expansion force of the outer jacket 140.
As illustrated in
As disclosed herein, the elongated tube or an outer jacket can have the same diameter across the length of the sheath or can have varying diameters across the length of the sheath.
As provided in
Additional aspects of the sheath comprising the disclosed herein elongated tube are shown in
In still further aspects, the sheath, as disclosed herein, does not comprise the braid. In such exemplary and unlimiting aspects, the elongated tube 206 alone, without the braid, forms the outer layer of the sheath.
In still further exemplary and unlimiting aspects, an additional outer layer can be optionally positioned in between the inner liner and the elongated tube.
The inner liner 202 defines a lumen 201 through which a delivery apparatus can travel into a patient's vessel in order to deliver, remove, repair, and/or replace a prosthetic device. The disclosed sheath can also be useful for other types of minimally invasive surgery, such as any surgery requiring introduction of an apparatus into a subject's vessel. For example, the disclosed sheath also can be used to introduce other types of delivery apparatus for placing various types of intraluminal devices (e.g., stents, stented grafts, etc.) into many types of vascular and non-vascular body lumens (e.g., veins, arteries, esophagus, ducts of the biliary tree, intestine, urethra, fallopian tube, other endocrine or exocrine ducts, etc.). In still further exemplary aspects, the sheath can contract to the predetermined rest diameter dr after passage of the medical device through the lumen.
In still further aspects, the sheet used to make the inner liner 202 can comprise a high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In still further aspects, the sheet can comprise one or more layers. In some aspects, if one or more layers are present, each layer can comprise the same or different polymer. In still further aspects, the sheet can have a predetermined thickness, wherein the predetermined thickness can be defined by one of ordinary skill in the art depending on the specific application. In certain aspects, the predetermined thickness of the inner liner can be from about 0.002 inches to about 0.0025 inches, including exemplary values of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. It is further understood that the predetermined thickness of the sheet forming the inner liner 202 can be varied depending on the desired amount of radial expansion, as well as the strength required.
In still further aspects, the internal surface of the sheet can be at least partially ribbed. In yet further aspects, the sheet can also be lubricious. In some exemplary aspects, the sheet that forms the inner liner can have a coefficient of friction less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. It is further understood that the sheet can have a coefficient of friction having any value between any two foregoing values. Such a liner can facilitate the passage of a delivery apparatus through the lumen 201 of the disclosed sheath. In some further exemplary aspects, materials that can be used to form suitable lubricious inner liners include materials that can reduce the coefficient of friction of the inner liner 202, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for a lubricious liner also include other materials desirably having a coefficient of friction of about 0.1 or less, of about 0.09 or less, about 0.08 or less, about 0.07 or less, about 0.05 or less, about 0.04 or less, about 0.03 or less, about 0.02 or less, or about 0.01 or less.
In yet further aspects, the elongated tube can have any predetermined thickness. It is understood that the predetermined thickness of the elongated tube can be dependent on the specific application of the sheath. For example, and without limitation, the thicknesses of the inner liner 202, the elongated tube 206, and the braid 204 can also be varied depending on the particular application of the disclosed sheath. In some aspects, the thickness of the inner liner 202 ranges from about 0.0005 inches to about 0.010 inches, including exemplary values of about 0.0006, about 0.0007, about 0.0008, about 0.0009, about 0.001, about 0.002, about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009 inches, and in one particular aspect, the thickness can be about 0.002 inches. In yet other aspects, a total thickness of the elongated tube 206 and the braid 204 can have a thickness of from about 0.002 inches to about 0.015 inches, including exemplary values of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, and about 0.01 inches.
It is understood that the inner liner can have any shape or configuration depending on the desired application and the size of the delivery apparatus and prosthetic device. It is further understood that the inner liner is not limited to a specific shape or configuration. In certain aspects, the sheath disclosed herein is defined by the rest diameter dr, and the outer diameter do. As disclosed herein, the rest diameter dr is defined by the inner liner, while the outer diameter can be defined by the inner liner and the outer layer, wherein the outer layer comprises the braid and the elongated tube.
The resting diameter dr of the inner liner 202 can vary depending on the application and size of the delivery apparatus and prosthetic device. It is understood that in some aspects, the rest diameter dr is substantially uniform along the longitudinal axis of the lumen without changing from the proximal end to the distal end. In yet other aspects, the rest diameter dr can vary along the longitudinal axis of the lumen. In certain aspects, the rest diameter dr at the proximal end is larger than the rest diameter drat the distal end. In yet further aspects, where the outer layer comprising the braid and the elongated tube conforms to the shape of the inner liner, the outer diameter do (not shown) comprises the overall diameter of the inner liner and the outer layer. In such aspects, the outer diameter do is defined by the specific application of the sheath.
Similar to the rest diameter dr, the outer diameter do of the unexpended sheath disclosed herein can be substantially uniform (constant) along the longitudinal axis of the lumen without changing from the proximal end to the distal end (not shown). In alternative aspects, the original unexpanded outer diameter do of the disclosed sheath, similarly to the rest diameter dr, can decrease from the proximal end to the distal end. In some aspects, and similarly to the rest diameter dr, the original unexpanded outer diameter can decrease along a gradient, from the proximal end to the distal end; or it can incrementally step down along the length of the sheath having the largest original unexpanded outer diameter is near do the proximal end, and the smallest original unexpanded outer diameter do is near the distal end.
In some aspects, the rest diameter dr can range from about 0.005 inches to about 0.400 inches, including exemplary values of about 0.01 about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, and about 0.3 inches. As described above, in certain aspects, the sheath can comprise the inner liner having various dr. In such aspects, the dr can have any value between any two foregoing values and can depend on the specific application and the size and shape of the delivery apparatus and prosthetic device. Different sheaths can be provided with different expanded and unexpanded rest diameter dr and outer diameter do, depending on the size requirements of the delivery apparatus for various applications. Additionally, some aspects can provide more or less expansion depending on the particular design parameters, the materials, and/or configurations used.
As disclosed herein, the outer layer comprises a braid 204 and the elongated tube 206 having a predetermined thickness and having an inner surface and outer surface (as shown in
It is understood that the braid can have any configurations known in the art. In certain aspects, the braid 204 is generally a thin, hollow, substantially cylindrical tube comprising an arrangement, pattern, structure, or configuration of filaments or struts, however, other geometries can also be used. Suitable filaments can be round, having a diameter less than about 0.015,″ less than about 0.01″, less than about 0.008″, less than about 0.005″, less than about 0.002″, less than about 0.001″, less than about 0.0008″, or less than about 0.0005″. In yet other aspects, suitable filaments can be round and having a diameter ranging from about 0.0005″ inches thick to about 0.015″ thick, including exemplary values of about 0.0006″, about 0.0007″, about 0.0008″, about 0.0009″, about 0.001″, about 0.002″, about 0.003″, about 0.004″, about 0.005″, about 0.006″, about 0.007″, about 0.008″, about 0.009″, about 0.01″, about 0.012″, about 0.013″, and about 0.014″. In yet other aspects, the suitable filaments can be flat filaments having a height of less than about 0.006″, less than about 0.005″, less than about 0.004″, less than about 0.003″, less than about 0.001″, less than about 0.0009″, less than about 0.0008″, less than about 0.0007″, less than about 0.0006″, and about 0.0005″. In yet other aspects, the flat filaments can have a width from greater than about 0.003″ to about 0.015″, including exemplary values of about 0.004″, about 0.005″, about 0.006″, about 0.007″, about 0.008″, about 0.009″, about 0.01″, about 0.012″, about 0.013″, and about 0.014″. However, other geometries and sizes are also suitable for certain aspects.
In yet further aspects, the braid can have a per-inch crosses (PIC) count of less than 50, less than 40, less than 30, less than 20, or less than 10. In yet other aspects, the braid can have a PIC count from 10 to 2, including exemplary values of 9, 8, 7, 6, 5, 4, and 3. In still further aspects, the PIC can vary along the longitudinal axis of the lumen. In yet other aspects, the braid pattern can vary along the longitudinal axis of the lumen. In the aspects where the braid comprises filament that is nitinol, the nitinol is heat-set at the expanded diameter de. In yet further aspects, where the filament comprises stainless steel or nitinol, the filament is configured to be atraumatic, at least at the distal end of the sheath.
It is understood that the elongated tube 206, as shown in
Alternative aspects of a sheath for introducing a prosthetic device are also described. For example,
In certain aspects, an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer that comprises the braid and the disclosed elongated tube. In yet other aspects, an amount of a second lubricant is disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portions of the sheet. It is understood that the first lubricant and the second lubricant can be the same or different. In certain and unlimiting aspects, the first and/or second lubricants can comprise Christo Lube supplied by ECL or MED10/6670 supplied by Nusil. In still further aspects, it is understood that the amount of the first and/or second lubricant can be easily determined by one of ordinary skill in the art.
In still further aspects, the outer surface of the elongated tube defines at least a portion of the outer surface of the outer layer. In yet other aspects, at least a portion of the inner surface of the elongated tube is at least partially bonded to at least a portion of the outer surface of the sheet of the inner liner. It is understood that the outer layer of the disclosed sheath is configured to provide hemostasis and prevent bleeding of the patient during the procedure.
In still further aspects, the sheath of the instant disclosure can comprise a hemostasis valve inside the lumen of the sheath, at or near the proximal end of the sheath (not shown). Additionally, the exemplary sheaths disclosed herein can comprise a soft tip at the distal end of the sheath (not shown). Such a soft tip can be provided with a lower hardness than the other portions of the sheath. In some aspects, the soft tip can have a Shore hardness from about 25 D to about 40 D, including exemplary values of about 26 D, about 27 D, about 28 D, about 29 D, about 30 D, about 31 D, about 32 D, about 33 D, about 34 D, about 35 D, about 36 D, about 37 D, about 38 D, and about 39 D. In yet other aspects, the soft tip can have a Shore hardness from about 25 A to about 40 A, including exemplary values of about 26 A, about 27 A, about 28 A, about 29 A, about 30 A, about 31 A, about 32 A, about 33 A, about 34 A, about 35 A, about 36 A, about 37 A, about 38 A, and about 39 A.
In certain aspects, the elongated tube and the inner liner can be bonded together or otherwise physically associated with one another. It is understood that the amount of adhesion between the inner liner 602 and the outer polymer layer that comprises braid 604 and the elongated tube 606 can be variable over the surfaces of the layers. The bonding between the layers can be created by, for example, thermal bonding. In certain aspects, the bonding can be facilitated by the presence of an additional portion of the elastomeric polymer. For example, in certain aspects, the sheath, as described herein and as shown in
Applications can utilize a sheath of the present disclosure with the rest diameter dr of the lumen formed by the inner liner 602 that is expandable to an expanded diameter de of from about 3 Fr to about 26 Fr, including exemplary values of about 5 Fr, about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, about 22 Fr, about 25 Fr. The expanded diameter can vary slightly along the length of the disclosed sheath. For example, the expanded outer diameter at the proximal end of the sheath can range from about 3 Fr to about 28 Fr, including exemplary values of about 5 Fr, about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, about 22 Fr, about 25 Fr, while the expanded outer diameter at the distal end of the sheath can range from about 3 Fr to about 25 Fr, including exemplary values of about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, and about 22 Fr. Aspects of the disclosed sheath can expand to an expanded outer diameter that is from about 10% greater than the original unexpanded outer diameter to about 100% greater than the original unexpanded outer diameter, including exemplary values of about 15% greater, about 20% greater, about 25% greater, about 30% greater, about 35% greater, about 40% greater, about 45% greater, about 50% greater, about 55% greater, about 60% greater, about 65% greater, about 70% greater, about 75% greater, about 80% greater, about 85% greater, about 90% greater, and about 95% greater than the original unexpanded outer diameter.
It is understood, and as described above, the disclosed sheath can expand from its rest position. The expansion of the disclosed sheath can result in an expansion of the rest diameter dr of from about 10% or less to about 430% or more. In certain aspects, expansion of the sheath can result in expansion of the rest diameter dr to about 10% or less, to about 9% or less, to about 8% or less, to about 7% or less, to about 6% or less, to about 5% or less, to about 4% or less, to about 3% or less, to about 2% or less, to about 1% or less. In yet other aspects, expansion of the disclosed sheath can result in expansion of the rest diameter dr to about 10% or more, about 20% or more, about 30% or more, about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 100% or more, about 125% or more, about 150% or more, about 175% or more, about 200% or more, about 225% or more, or about 250% or more.
As with previously disclosed aspects, the aspects illustrated in
In some aspects, the braid and/or the elongated tube can comprise the same material or combination of materials along the entire length. In alternative aspects, the material composition of each layer can change along the length of the sheath. For example, the outer layer comprising both the braid and the elongated tube can be provided with one or more segments, where the composition changes from segment to segment. For example, in one segment, the braid can comprise nitinol having a different PIC count than another segment. In yet another exemplary aspect, the elongated tube in one segment can be different from the layer of the elastomeric material in another segment. In still further exemplary aspects, one segment of the sheath can comprise the braid embedded within the elongated tube, while another segment can comprise the braid that is not embedded within the elongated tube. It is understood that the exemplary sheath disclosed herein is not limiting. In certain exemplary aspects, the sheath can comprise an n number of segments, wherein each segment can be the same or different. In still further exemplary aspects, the Durometer rating of the composition of the outer layer can also change along the length of the sheath such that segments near the proximal end comprise a stiffer material or combination of materials, while segments near the distal end comprise a softer material or combination of materials. This can allow for a sheath having a relatively stiff proximal end at the point of introducing a delivery apparatus while still having a relatively soft distal tip at the point of entry into the patient's vessel.
Additionally, some aspects of the sheath, as disclosed herein, can include an exterior hydrophilic coating on the outer surface of the elongated tube. Such a hydrophilic coating can facilitate insertion of the sheath into a patient's vessel. Examples of suitable hydrophilic coatings include the Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, Minn. DSM medical coatings (available from Koninklijke DSM N.V, Heerlen, the Netherlands), as well as other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride), are also suitable for use with the sheath. This exemplary sheath, similarly to other sheaths disclosed herein in some aspects, can comprise a soft tip portion comprising, in some aspects, low-density polyethylene (LDPE) and can be configured to minimize trauma or damage to the patient's vessels as the sheath is navigated through the vasculature. Any materials described herein for a soft tip can be used to form the soft tip of this exemplary sheath.
In certain aspects, the exemplary sheath, as described herein, can also be generally represented, as shown in
Some exemplary aspects of these additional sheaths are also shown in
In yet further aspects, as shown in
Now referring to
The wall thickness of the outer jacket can range from 0.0040 inches to 0.0066 inches. In some examples, the thickness of the outer jacket is about 0.0055 inches. The wall thickness of the outer jacket 140 can remain constant along the entire length of the outer jacket 140. However, in some examples, the thickness of the outer jacket 140 at the proximal end (T1) is greater than the thickness of the outer jacket 140 at the distal end (T2).
In still further aspects, the outer jacket 140 can comprise two or more reinforcing members 145. In such aspects, the two or more reinforcing members 145 can be disposed, as individual strips, disposed circumferentially in the first polymer layer, in the second polymer layer, or between the first and second layers at a predetermined distance from each other.
In further aspects, the reinforcing member 145 has a finite width that is smaller than the circumference of the outer jacket 140. The total combined width (w) of the reinforcing members 145 can range from 5% to 50% of the circumference of the outer jacket 140. In still further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the elongated tube.
It is further understood that in the aspects where the reinforcing member 145 is present as one or more strips disposed circumferentially along the length of the outer jacket 140, the width of the reinforcing member 145 can be the same along the length, or it can vary along the length. In aspects where the reinforcing member 145 width varies along the length of the outer jacket 140, such a reinforcing member 145 can have any of the disclosed above width values.
In still further aspects, at least one reinforcing member 145 is configured to provide an axial reinforcement to the outer jacket 140 and, as a result, to the sheath where the outer jacket 140 can be used. In such exemplary aspects, the at least one reinforcing member 145 can be disposed along the length of the outer jacket 140 or along a portion of the length of the outer jacket 140. In some aspects, the portion of the length of the outer jacket 140 where the at least reinforcing member 145 is disposed at the distal end and/or proximal end of the outer jacket 140. In yet other aspects, the reinforcing member 145 can also be positioned anywhere along the length of the outer jacket 140.
As described above, and as illustrated in
In some examples, the inner layer 146 can be composed of Pebax or polyurethane, having Shore 25 D to 35 D. In some examples, the inner layer 146 includes a PTFE powder, an optional inorganic filler, and an optional tackiness reducing additive to lower friction when outer layer 147 of the sheath expanding by sliding against the outer jacket 140. In some examples, the outer layer 147 of the outer jacket 140 is composed of polyurethane or polyurethane/Styrene Block Copolymer (SBC) having Shore A durometer lower than about 60, e.g., Neusoft 597-50A having Shore A hardness of about 55 A. In certain examples, the inner layer 146 is constructed from Polyether Block Amide, such as Pebax having a Shore D durometer of less than about 35.
As provided in
As described above, the reinforcing members 145 are constructed from a stiffer material than the main body portion of the outer jacket 140 (inner layer 146, outer layer 147) and also a material having a low coefficient of friction (e.g., high density polyethylene). In some examples, the reinforcing members 145 are constructed from a polymer compatible with the inner layer and outer layer, including, for example, high durometer Pebax or polyurethane. The reinforcing member 145 can also be constructed from a material having a Shore D durometer ranging from 45 D to 76 D.
Additional examples of the sheath that can be used with the disclosed herein elongated tube can be found in U.S. application No. 63/021,945, the content of which is incorporated herein in whole entirety.
The disclosed herein sheath can be configured such that it locally expands at a particular location corresponding to the location of the medical device along the length of the lumen and then locally contracts once the medical device has passed that particular location. Thus, a bulge may be visible, traveling longitudinally along the length of the sheath as a medical device is introduced through the sheath, representing continuous local expansion and contraction as the device travels the length of the sheath. In some aspects, each segment of the sheath can locally contract after removal of any radial outward (insertion) force such that it regains the original resting diameter of lumen dr.
In some aspects, each segment of the sheath can locally contract after removal of any radial outward force such that it at least partially returns to the original resting diameter of lumen dr.
An example method of making the sheath is as follows. These steps are not meant to be limiting. The steps given can be reordered as needed. Other steps can be added, or in other examples, some steps may not be necessary.
Disclosed herein are the methods of making a sheath having a proximal end and a distal end and comprising: a) extruding a tubular body to form an elongated tube comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65 wt % of an inorganic filler based on a total weight of the first compound composition; and up to about 20 wt % of a solid lubricant filler based on a total weight of the first compound composition; b) disposing the elongated tube on the sheath such that the elongated tube forms an outer layer of the sheath, and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the formed sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
It is understood that any known in the art methods can be utilized to form the composition of the elongated tube. In certain aspects, the components that are present in the elongated tube are provided to form a compound. The compound is then mixed to form a substantially homogeneous mixture. Yet, in other aspects, the mixture is homogeneous. In still further aspects, the mixture is extruded to form an elongated tube having a first polymer layer. The formed first polymer layer can comprise any (and in any combination) of the compositions and characteristics disclosed above.
In yet further aspects, the methods also comprise steps of forming the elongated tube comprising two or more layers, as disclosed above. In such aspects, for example, when the elongated tube comprises any of the disclosed above first polymer and the second polymer layers, such layers can be coextruded to form the elongated tube as disclosed. Any of the known in the art extrusion devices can be used to obtain the desired elongated tube.
The methods disclosed herein produce any of the disclosed above elongated tubes.
In still further aspects, also disclosed are the methods of forming additional parts of the sheath. In certain aspects, the elongated tube can behave as an outer jacket of the sheath. While yet in other aspects, the elongated tube can form an outer layer of the sheath without an additional outer jacket being present.
For example, and without limitation, the inner layer 108, as shown in one of the exemplary sheaths, can be formed to include a first fold and a second fold and an overlapping folded portion 118 extending circumferentially between the first and second folds. The overlapping folded portion 118 can be formed to include overlap in a radial direction of at least two thicknesses of the inner layer 108. The inner layer 108 can be extruded, including the folded portion 118. Alternatively, the folded portion 118 can be formed after the inner layer 108 is extruded (e.g., formed on a cylindrical tubular structure).
A discontinuous outer layer 110 can be further provided (at least partially) around the inner layer 108. The outer layer 110 is formed to include an overlapping portion 120 and an underlaying portion 122 such that at least a portion of the folded portion 118 of the inner layer 108 is positioned between the overlapping portion 120 and the underlaying portion 122. In some aspects, the inner layer 108 and the outer layer 110 are coextruded. In alternative aspects, the inner layer 108 and the outer layer 110 are separately formed and joined together.
An adhesive layer 128 can be provided between the inner layer 108 and the outer layer 110 for bonding (at least partially) the inner layer 108 to the outer layer 110. The adhesive layer 128 can be applied to and bond the inner and outer layers 108, 110 axially along a length of the sheath, e.g., along a portion of the entire length of the sheath or along the entire length of the sheath. In an example, the adhesive layer 128 is coextruded with the outer layer 110. In a further example, the adhesive tie layer 128 is coextruded with the inner layer 108. In an alternate example method, the adhesive layer 142 can be applied to the outer surface of the inner liner 108 and/or an inner surface of the outer layer 110.
After the adhesive layer 128 is applied to the desired locations along the inner and/or outer layer 110, the outer layer 110 is applied over the inner layer 108. The outer layer 110 can then be bonded to the inner layer 108 by heat curing the adhesive layer 128. The adhesive layer 128 can comprise a material curable at a temperature above room temperature, in which case a heat treatment may be applied to the assembled inner layer 108/outer layer 110. The adhesive layer 128 may also be composed of a material that cures at room temperature. Accordingly, after the application of the adhesive layer 128 and assembly of the outer layer 110 over the inner layer 108 (at a temperature below room temperature), the temperature of the combined layers may be increased to room temperature.
As illustrated in
As described above, the lubricant 142 can be provided on an outer surface of the outer layer 110 proximate to a longitudinally extending edge 126 of the overlapping portion 120, on any portion of the folded portion 118 extending/protruding beyond edge 126, and/or on any portion of the outer surface of the outer layer 110 adjacent the protruding portion of the folded portion 118. The lubricant 142 can be applied as a band extending around a portion of the circumference of the outer layer, the band of lubricant 142 also extending longitudinally along a length of the outer layer 110. After the lubricant 142 is selectively applied to the outer surface of the outer layer 110, the outer jacket 140 can be applied over the outer layer 110. As outlined above, the lubricant 142 can comprise a heat-curable material, in which case a heat treatment can be applied to the outer layer 110/outer jacket (elongated tube) 140. The lubricant 142 may also be composed of a material that cures at room temperature. Accordingly, after application of the lubricant 142 (at a temperature below room temperature), the temperature of the outer layer 110 (separately or in combination with the outer jacket (elongated tube) 140) can be increased to room temperature.
The outer jacket 140, formed by any of the methods disclosed above, can then be applied over/around the outer layer 110 and bonded to the outer layer 110 at at least one of the proximal and distal ends of the outer layer 110. The outer jacket 140 can also be bonded to the outer layer 110 along a length of the outer layer 110. The outer jacket 140 can be bonded to the outer layer 110 via a heat treatment process, e.g., a reflow process where the outer layer 110 and the outer jacket are headed to a temperature high enough such that the outer layer 110 and the outer jacket 140 are at least partially melted and are then fused together are the heat is removed, and the assembly cools. The entire sheath 100 assembly may be reflowed to reduce the overall outer diameter and regain/ensure a circular shape in cross-section.
As described above, select portions of the outer surface of the inner liner 108 can include a surface treatment such as surface etching. In an example method, surface treatment of the inner layer 108 would occur before application of the outer layer 110. It is contemplated that it may be desirable to exclude etching from those surfaces of the inner layer 108 that come into contact with the outer surface of the outer layer 110. For example, etching may not be included between the inner surface of the folded portion 118 of the inner layer 108 and the underlaying portion 122 of the outer layer 110. By excluding etching on the portions where the inner layer 108 and the outer surface of the outer layer 110 are in direct contact helps to facilitate release of the inner surface of the folded portion 118 and the outer layer 110 during expansion of the sheath 100.
In some instances, it may be necessary to release (“break”) any undesirable bonding that occurs between the outer layer 110 and the inner layer 108. This bonding can occur due to the etching on the outer surface of the inner liner 108 that allows it to stick directly to the outer layer 110 (with/without the adhesive layer 128). Undesirable bonding can also occur if the outer layer 110 can flows on top of the folded inner layer 108 and “grabs” it during the reflow process.
However, when the inner layer 108 is unetched along those locations excluding the adhesive layer 128, e.g., those portions adjacent the underlaying portion of the outer layer 110, undesirable bonding between the outer layer 110 and the inner layer 108 at this location is limited. Therefore, it may not be necessary to precondition the sheath to release undesirable bonding between the inner layer 108 and the outer layer 110 because the bonding has not occurred (or is less likely to occur).
Nonetheless, undesirable bonding between the inner layer 108 and the underlaying portion 122 of the outer layer 110 can be released while maintaining desirable bonding at the proximal and distal ends of the sheath 100. For example, a mandrel can be passed at least partially through the lumen 116 of the inner layer 108, expanding the inner layer 108 and the outer layer 110, and breaking/releasing any undesirable bonding between the inner layer 108 and the underlaying portion 122 of the outer layer 110.
Various methods can be used to produce the sheaths discussed above and below throughout the present disclosure. For example, a method of making the sheath shown in
In some aspects of methods of making a sheath, such as the sheaths illustrated in
A layer of material that will become the outer polymeric tubular layer, such as a layer comprising polyurethane or polyolefin, can be cut or notched through all, substantially all, or a part of the thickness of the layer (step 3304). Such a cut or notch can extend longitudinally along the length of the layer and can extend along substantially the entire length of the outer polymeric tubular layer. In alternative aspects, the cut or notch can be provided along only a portion of the outer polymeric tubular layer. For example, the outer polymeric tubular layer can be cut starting at the distal end of the outer polymeric tubular layer, with the cut ending before the proximal end of the outer polymeric tubular layer. In one aspect, the cut can end at a transition, where the outer diameter of the outer polymeric tubular layer increases or decreases. In one specific aspect, the cut or notch can extend longitudinally along about 75% of the length of the sheath.
The cut or notched outer polymeric tubular layer can be applied, positioned, adhered, mounted, thermally fused or bonded, dip coated, and/or otherwise coupled to the etched inner liner (step 3306).
In alternative aspects, the outer polymeric tubular layer can be notched or cut after being mounted on the inner liner/mandrel assembly. The outer polymeric tubular layer can optionally be provided with a hydrophilic coating and/or provided with additional layers, such as being dip coated with polyurethane. Some portion of the inner liner can protrude through the cut in the outer polymeric tubular layer after such an outer polymeric tubular layer is mounted onto the inner liner/mandrel arrangement. Using, for example, a split tool, the protruding portion of the inner liner can be folded down onto the outer surface of the outer polymeric tubular layer (step 3308). In some aspects, the protruding portion of the inner liner is folded down along the entire length of the resulting sheath, while in other aspects, the protruding portion of the inner liner is only present along a portion of the length of the sheath or is only folded down along a portion of the length of the resulting sheath.
A soft, atraumatic tip can be provided at the distal end of the resulting sheath (step 3310). Additional outer layers can also be applied if desired. Then, a layer of heat shrink tubing, such as fluorinated ethylene propylene (FEP) heat shrink tubing, can be positioned over the entire assembly (step 3312). An appropriate amount of heat is applied, thus shrinking the heat shrink tubing and compressing the layers of the sheath together, such that components of the sheath can be thermally bonded or fused together where desired. Once the components of the sheath have been bonded together, the heat shrink tubing can be removed (step 3314). The proximal end of the sheath can be adhered or otherwise attached to a housing of a catheter assembly, and the sheath can be removed from the mandrel (step 3316). The disclosed herein elongated tube is then positioned (step 3320) on the sheath to form an outer jacket or strain relief jacket. It is understood that the disclosed tube can be positioned at at least a portion of the sheath, for example, and without limitation, the proximal end of the sheath, or it can be positioned along the entire length of the sheath.
A notched or cut outer polymeric tubular layer, such as high-density polyethylene tubing that has been notched or cut longitudinally, can be slid onto the tapered mandrel and a portion of the inner liner, starting at the distal end of the tapered mandrel (step 2004). The second mandrel can then be removed (step 2006).
A split tool can be inserted into the portion of the lumen of the inner liner that was previously occupied by the second mandrel (step 2008). The split tool can then be used to form folds and/or pleats in the excess portion of the inner liner, which now extends through the longitudinal cut in the outer polymeric tubular layer (step 2010). A radiopaque marker band can optionally be applied at the distal end of the sheath (step 2012). Heat shrink tubing, such as FEP heat shrink tubing, can be applied over the entire sheath, and heat can be applied to compress the components of the sheath and bond or fuse them together (step b). The split tool, heat shrink tubing, and second mandrel can then be removed (step 2016). The sheath can then be utilized with a delivery apparatus, such as by bonding the proximal end of the sheath to a polycarbonate housing of a delivery apparatus or catheter assembly (step 2018).
In another example, disclosed expandable sheaths can be made using a reflowed mandrel process. A mandrel can be provided, with the size of the mandrel defining the inner diameter of the sheath lumen in its resting configuration. A tube of material, such as a PTFE tube that will become the sheath's inner liner, can be provided with an inner diameter greater than that of the mandrel (e.g., a 9 mm PTFE tube can be mounted on a 6 mm mandrel). The PTFE tube can be mounted on the mandrel and prepared into the final folded configuration by folding the excess material of the PTFE tube over to one or both sides. An HDPE tube that will serve as the outer layer can then be placed over the PTFE liner. The two-layer assembly can then be thermally fused together. For example, a reflow process can be performed where the assembly is heated to a temperature high enough such that the inner and/or outer layers are at least partially melted and are then fused together as the heat is removed and the assembly cools.
An elongated tube, as described herein, is then placed over at least part of the fused layers (e.g., over a proximal section of the sheath) and held in place using a thermal process (step 2020) to form an outer jacket or a strain relief jacket. In some aspects, the same thermal process can bond the layers of the sheath and the elongated tube. In other aspects, a first thermal process can be used to fuse the layers of the sheath, and a second thermal process can be used to secure the elongated tube to other layers of the sheath. In still further aspects, the elongated tube can cover the whole length of the sheath or at least a portion of the sheath. In some aspects, a distal soft tip can then be attached to the shaft of the expandable sheath.
In some aspects, the outer layer can be co-extruded with an adhesive layer, such as a layer formed from Tecoflex™, such that the Tecoflex™ is positioned on an inner surface of the outer layer—in this manner, the Tecoflex™ will be positioned between the inner and outer layers in the completed sheath. In these aspects, an HDPE tube can be provided with a coating of Tecoflex™ on the inner surface. The HDPE tube can be slit along the length of the tube to open and flatten it and then cut using a template in some aspects. For example, for specific applications, portions of the outer layer can be cut and removed using a template. The cut HDPE can then be placed on the inner layer on the mandrel. In some aspects, only a portion of the outer layer will have the adhesive Tecoflex™. In these aspects, the sections without Tecoflex™ will only be partially fused to the inner layer. In some aspects, the entire inner surface of the outer layer will have the Tecoflex™, and the inner surface of the outer layer can be positioned so that it contacts the inner layer on the mandrel. To position the inner and outer layers, as shown in the sheath of
Some additional sheaths, as disclosed herein, can also be prepared according to the methods disclosed below. For example, also disclosed are aspects where the sheath is formed by forming a variable diameter inner liner by rolling a sheet having a first edge and a second edge and wherein the sheet is defined by an inner surface and an outer surface in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet thereby forming an overlying portion and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis. The elongated tube formed as disclosed above can be used to form an outer layer of the sheath. In such aspects, the outer layer will comprise and the disclosed herein elongated tube and a braid.
In still further aspects, one or more mandrels can be provided (step 7700 or 8800 in
In still further exemplary aspects, in steps 7705 and 8805 (
In still further aspects, the methods can further comprise a step of providing a braid (steps 7704 and 8804). It is understood that any of the described above braids can be used in this step. In still further aspects, and as shown in step 7706 of
In yet further aspects and as shown in step 7708, the method can further comprise a step of providing the disclosed herein elongated tube. In certain and unlimiting aspects, the elongated tube is extruded from the disclosed herein compositions and is provided as a cylindrical tube 1906 (
In yet further aspects, the disclosed method can comprise a step of embedding (step 7711,
In still further aspects, a soft, atraumatic tip can be provided at the distal end of the resulting sheath (step 7712). In yet further aspects, the outer layer comprising the braid and the layer of the elastomeric polymer is at least partially bonded to the inner liner. It is understood that this bonding can also be achieved by any known in the art methods. In certain aspects, and as shown in step 7714, a heat shrink is applied to the portion that is being bound and heated to form a bonding between the inner liner and the outer layer. In yet other aspects, the bonding between the inner liner and the outer layer can be achieved by placing the assembly in an oven or otherwise heating it. In still further aspects, the bonding is performed by heating at a temperature from about 350° F. to about 550° F. for a time period effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner. In yet further aspects, the heating can be done at a temperature of about 375° F., about 400° F., about 425° F., about 450° F., about 475° F., about 500° F., or about 525° F. In yet other aspects, the time period effective to form a bond can comprise from about 1 second to about 60 seconds, including exemplary values of about 5 seconds, about 10 seconds, about 15 seconds, about 20 seconds, about 25 seconds, about 30 seconds, about 35 seconds, about 40 seconds, about 45 seconds, about 50 seconds, and about 55 seconds. However, it is further understood that this time period is not limiting, and it can have any value needed to provide for an effective bond, for example, it can have any value from about 1 second to about 5 hours. It is further understood that if the heat shrink tubing is used to obtain the desired bonding, the heat shrink tubing is removed (step 7716,
In still further aspects and as shown in
In still further exemplary aspects, the methods can comprise applying a second strip 1922a of a polymer to at least a portion of the outer surface of the sheet at the proximal end of the sheath prior to or during the step of bonding the at least a portion of the inner surface of the disclosed herein elongated tube to at least a portion of the outer surface of the sheet of the inner liner. It is understood that in some aspects, the second strip of the polymer can be made of the same material as the elongated tube itself. While in other aspects, the second strip of the polymer can be made of any material that allows an efficient bonding between the inner liner and the elongated tube. It is further understood that the first and the second strips can be made from the same or different polymers.
It is understood that in some exemplary aspects and as shown in the
It is understood that in some exemplary aspects and as shown in the
Some alternative aspects are shown in
In still further aspects, and as shown in
It is also understood that these alternative aspects can also include a step where a second strip 1922a can be applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath prior to or during the step of bonding the at least a portion of the inner surface of the elongated tube to at least a portion of the outer surface of the sheet of the inner liner. It is understood that in some exemplary aspects and as shown in the
Again, it is understood that the method that does not include the application of the braid is also disclosed. In such methods, the elongated braid as disclosed herein forms the outer layer of the sheath, and the braid is not present.
Also disclosed herein are aspects where the disclosed herein methods can comprise a step of disposing a hydrophilic coating layer on the outer surface of the elongated tube of any of the exemplary sheaths. Any disclosed herein hydrophilic coating can be used.
Any of the disclosed herein sheaths can also be attached to the housing 101, as shown in
Sheaths of the present disclosure can be used with various methods of introducing a prosthetic device into a patient's vasculature. One such method comprises positioning an expandable sheath in a patient's vessel, passing a device through the introducer sheath, which causes a portion of the sheath surrounding the device to expand and accommodate the profile of the device, and automatically retracting the expanded portion of the sheath to its original size after the device has passed through the expanded portion. In some methods, the expandable sheath can be sutured to the patient's skin at the insertion site so that once the sheath is inserted the proper distance within the patient's vasculature, it does not move once the implantable device starts to travel through the sheath.
Disclosed aspects of an expandable sheath can be used with other delivery and minimally invasive surgical components, such as an introducer and loader. In one aspect, the expandable sheath can be flushed to purge any air within the sheath, using, for example, flush port 103 (
The introducer can then be removed, and a medical device, such as a transcatheter heart valve, can be inserted into the sheath, in some instances, using a loader. Such methods can additionally comprise placing the tissue heart valve in a crimped state on the distal end portion of an elongated delivery apparatus and inserting the elongated delivery device with the crimped valve into and through the expandable sheath. Next, the delivery apparatus can be advanced through the patient's vasculature to the treatment site, where the valve can be implanted.
Typically, the medical device has a greater outer diameter than the diameter of the sheath in its original configuration. The medical device can be advanced through the expandable sheath towards the implantation site, and the expandable sheath can locally expand to accommodate the medical device as the device passes through. The radial force exerted by the medical device can be sufficient to locally expand the sheath to an expanded diameter (e.g., the expanded configuration) just in the area where the medical device is currently located. Once the medical device passes a particular location of the sheath, the sheath can at least partially contract to the smaller diameter of its original configuration. The expandable sheath can thus be expanded without the use of inflatable balloons or other dilators. Once the medical device is implanted, the sheath and any sutures holding in place can be removed. In some aspects, it is preferable to remove the sheath without rotating it.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises an elongated tube forming an outer layer of the sheath that is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, having an inner surface and an outer surface, and wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
The sheath of any examples herein, particularly example 1, wherein the first polymer has a substantially same durometer along a total length of the elongated tube.
The sheath of any examples herein, particularly example 1, wherein a durometer of the first polymer at a proximal end of the elongated tube is different from a durometer of the first polymer at a distal end of the elongated tube.
The sheath of any one of examples herein, particularly examples 1-3, wherein the first polymer has a Shore D from about 20 D to about 35 D.
The sheath of any examples herein, particularly examples 1-4, wherein the first polymer comprises PEBAX®.
The sheath of any examples herein, particularly examples 1-4, wherein the first polymer comprises polyurethane.
The sheath of any examples herein, particularly examples 1-6, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof.
The sheath of any examples herein, particularly examples 1-7, wherein the inorganic filler is present in an amount of at least about 10% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 1-8, wherein the inorganic filler is present in an amount of less than about 50% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 1-9, wherein the solid lubricant comprises a PTFE filler.
The sheath of any examples herein, particularly example 10, wherein the PTFE filler is a powder.
The sheath of any examples herein, particularly examples 1-11, wherein the first compound composition further comprises at least one tackiness reducing compound.
The sheath of any examples herein, particularly example 12, wherein the at least one tackiness reducing compound is present in an amount from about 1% to about 20% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly example 12 or 13, wherein the at least one tackiness reducing compound comprises ProPell™.
The sheath of any examples herein, particularly examples 1-14, wherein the elongated tube comprises two or more polymer layers.
The sheath of any examples herein, particularly example 15, wherein the elongated tube comprises at least a second polymer layer comprising a second compound composition comprising from greater than 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof.
The sheath of any examples herein, particularly example 16, wherein the second compound composition further comprises up to 20% of tackiness reducing additive based on a total weight of the second compound composition.
The sheath of any examples herein, particularly examples 15-17, wherein the second polymer layer comprises PEBAX®.
The sheath of any examples herein, particularly examples 15-17, wherein the second polymer layer comprises polyurethane.
The sheath of any examples herein, particularly examples 15-19, wherein the second polymer has a Shore A Durometer from about 20 A to about 60 A.
The sheath of any examples herein, particularly examples 15-20, wherein the second compound composition is substantially free of an inorganic filler.
The sheath of any examples herein, particularly examples 15-21, wherein the second compound composition is substantially free of a lubricant solid.
The sheath of any examples herein, particularly examples 15-22, wherein the elongated tube has a predetermined thickness and wherein at least about 50% of the predetermined thickness comprises the first and/or the second compound composition comprising the first and/or the second polymer having a Shore D Durometer from about 20 D to about 35 D.
The sheath of any examples herein, particularly example 23, wherein the predetermined thickness is up to 6 mils.
The sheath of any examples herein, particularly example 24, wherein the predetermined thickness of the elongated tube varies along a length of the sheath.
The sheath of any examples herein, particularly example 25, wherein the predetermined thickness of the elongated tube is greater at the proximal end.
The sheath of any examples herein, particularly example 25 or 26, wherein the predetermined thickness of the elongated tube is smaller at the distal end as compared to the predetermined thickness of the elongated tube at the proximal end.
The sheath of any examples herein, particularly examples 1-27, wherein the first polymer layer has a thickness of about 1 mil to about 3 mils.
The sheath of any examples herein, particularly examples 15-28, wherein the second polymer layer has a thickness of about 2 mils to about 4 mils.
The sheath of any examples herein, particularly examples 15-29, wherein the first polymer layer defines the inner surface of the elongated tube.
The sheath of any examples herein, particularly examples 15-30, wherein the second polymer layer defines the outer surface of the elongated tube.
The sheath of any examples herein, particularly examples 15-31, wherein the first polymer layer defines the outer surface of the elongated tube.
The sheath of any examples herein, particularly example 32, wherein the second polymer layer defines the inner surface of the elongated tube.
The sheath of any examples herein, particularly examples 15-33, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.
The sheath of any examples herein, particularly examples 1-34, wherein the sheath exhibits at least about 20% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
The sheath of any examples herein, particularly examples 1-35, wherein the elongated tube is extruded.
The sheath of any examples herein, particularly example 36, wherein the first polymer layer and the second polymer layer are co-extruded.
The sheath of any examples herein, particularly examples 16-37, wherein the first polymer layer is substantially bonded to the second polymer layer.
The sheath of any examples herein, particularly examples 1-38, wherein the elongated tube exhibits a friction force of less than about 10 N in the dry state against a substrate surface comprising one or more of polytetrafluoroethylene, fluorinated ethylene propylene, or high-density polyethylene.
The sheath of any examples herein, particularly examples 1-39, wherein the elongated tube exhibits a friction force of less than about 7 N in the dry state against a substrate surface comprising one or more of polytetrafluoroethylene, fluorinated ethylene propylene, or high-density polyethylene.
The sheath of any examples herein, particularly examples 1-40, wherein the elongated tube exhibits a hoop direction force at a 10 mm extension of less than about 8 N.
The sheath of any examples herein, particularly examples 1-41, the elongated tube exhibits an elongation at break ranging between about 650% and about 800%.
The sheath of any examples herein, particularly examples 1-42, wherein the elongated tube is substantially kink resistant.
The sheath of any examples herein, particularly examples 1-43, where the elongated tube extends along the length of the sheath.
The sheath of any examples herein, particularly examples 1-44, wherein the elongated tube is positioned at the proximal end of the sheath and extends to the distal end of the sheath.
The sheath of any examples herein, particularly examples 1-45, further comprising an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; and a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; wherein the elongated tube is positioned such that at least a portion of the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
The sheath of any examples herein, particularly example 46, wherein the sheath exhibits an insertion force of less than about 55 N when a medical device is pushed through the sheath.
The sheath of any examples herein, particularly examples 46-47, wherein the expandable tubular inner liner comprises polytetrafluoroethylene.
The sheath of any examples herein, particularly examples 46-48, wherein the first outer tubular layer comprises a high-density polyethylene.
The sheath of any examples herein, particularly examples 46-49, wherein the outer surface of the first outer tubular layer is at least partially selectively etched.
The sheath of any examples herein, particularly example 50, wherein the outer surface of the inner liner is selectively etched around the circumference, linearly along at least a portion of the length of the sheath, or a combination thereof.
The sheath of any examples herein, particularly examples 50-51, wherein at least a portion of the outer surface of the at least one folded portion of the inner liner is not etched along at least a portion of the sheath length.
The sheath of any examples herein, particularly examples 50-52, wherein the outer surface of the inner liner comprises one or more nonetched portions along the sheath length.
The sheath of any examples herein, particularly example 53, wherein each of the one or more nonetched portions is followed by an etched portion.
The sheath of any examples herein, particularly example 53 or 54, wherein the one or more nonetched portions comprise the outer surface of the at least one folded portion.
The sheath of any examples herein, particularly examples 50-55, wherein the sheath exhibits an insertion force of less than about 55 N.
The sheath of any examples herein, particularly examples 50-56, wherein the sheath exhibits a reduction in an insertion force of at least about 25% when compared to a substantially identical reference sheath that does not comprise the first compound composition and the selectively etched inner liner.
The sheath of any examples herein, particularly examples 46-57, wherein the inner liner comprises two or more folded portions.
The sheath of any examples herein, particularly examples 46-58, wherein the at least one folded portion comprises a first folded edge and a second folded edge and an overlapping portion extending circumferentially between the first and second folded edges, the overlapping portion comprising an overlap in a radial direction of at least two thicknesses of the inner liner, and wherein the first folded edge is configured to move closer to the second folded edge to shorten the overlapping portion at a local axial location during application of a radial outward force by passage of the medical device and wherein shortening of the overlapping portion corresponds with a local expansion of the lumen.
The sheath of any examples herein, particularly examples 46-59, wherein the at least one folded portion comprises a first folded edge and a second folded edge and an overlapping portion extending circumferentially between the first and second folded edges, the overlapping portion comprising an overlap in a radial direction of at least two thicknesses of the inner liner, wherein the first folded edge is configured to move closer to the second folded edge to shorten the overlapping portion at a local axial location during application of a radial outward force by passage of the medical device and wherein shortening of the overlapping portion corresponds with a local expansion of the lumen, and wherein the outer layer includes a first longitudinally extending edge and a second longitudinally extending edge configured to separate as the sheath expands, the first longitudinal extending edge and an overlapping portion of the outer layer extending over the second longitudinally extending edge when the sheath is not expanded.
The sheath of any examples herein, particularly examples 46-60, wherein the inner liner is configured to expand to a substantially cylindrical tube.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion and wherein the outer surface of the inner liner is selectively etched; a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the outer layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the outer layer is positioned adjacent to at least a portion of the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 1-45, further comprising a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and wherein the elongated tube is positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner.
The sheath of any examples herein, particularly example 64, further comprising a braid positioned between the inner liner and the elongated tube.
The sheath of any examples herein, particularly example 64 or 65, further comprising an additional outer layer positioned in between the inner liner and the elongated tube.
The sheath of any examples herein, particularly example 66, wherein the sheath contracts to the predetermined rest diameter dr after passage of the medical device through the lumen.
The sheath of any examples herein, particularly examples 64-67, wherein the sheet comprises a high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.
The sheath of any examples herein, particularly example 68, wherein the sheet has a multilayer structure.
The sheath of any examples herein, particularly examples 64-69, wherein the internal surface of the sheet is at least partially ribbed.
The sheath of any examples herein, particularly examples 64-70, wherein the sheet is lubricious and has a coefficient of friction less than about 0.5.
The sheath of any examples herein, particularly examples 64-71, wherein an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the inner surface of the elongated tube.
The sheath of any examples herein, particularly examples 64-72, wherein an amount of a second lubricant is disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portions of the sheet.
The sheath of any examples herein, particularly examples 65-73, wherein the braid comprises at least one filament comprising stainless steel, nitinol, a polymer material, or a composite material.
The sheath of any examples herein, particularly examples 65-7, wherein the braid has a per-inch crosses (PIC) count of less than 50.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and an elongated tube forming an outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 1-45, further comprising an inner tubular layer comprising a longitudinal slit and partially defining an inner lumen, a first outer tubular layer enveloping the inner layer, the outer tubular layer comprising a longitudinally extending, folded flap that overlies a portion of an outer surface of the outer layer when the sheath is in an unexpanded state, and the elongated tube positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
The sheath of any examples herein, particularly example 77, wherein a base of the folded flap is positioned radially outwardly from the longitudinal slit.
The sheath of any examples herein, particularly example 77 or 78, wherein the folded flap includes a longitudinally extending overlying portion separated from a longitudinally extending underlaying portion by a longitudinally extending crease.
The sheath of any examples herein, particularly example 79, wherein the underlaying portion contacts an outer surface of the outer tubular layer when the sheath is in the unexpanded state.
The sheath of any examples herein, particularly examples 78-80, wherein a base of the folded flap extends the length of the outer tubular layer and wherein the overlying portion and the underlaying portion extend between the base and the crease.
The sheath of any examples herein, particularly examples 78-81, wherein the overlying portion, the underlaying portion, or both have a wall thickness that is thinner than the remainder of the outer tubular layer.
The sheath of any examples herein, particularly examples 78-82, wherein the longitudinally extending flap extends around about 20% to about 40% of an outer circumference of the outer tubular layer when the sheath is in an unexpanded state.
The sheath of any examples herein, particularly examples 76-83, wherein the first outer tubular layer comprises a material having a tensile modulus of at least 300 MPa.
The sheath of any examples herein, particularly example 84, wherein the first outer tubular layer comprises a material having a tensile modulus from 300 MPa to 2,000 MPa.
The sheath of any examples herein, particularly examples 77-85, wherein the first outer tubular layer comprises a material having an ultimate tensile strength of at least 50 MPa.
The sheath of any examples herein, particularly examples 77-86, wherein the first outer tubular layer comprises a shape memory material.
The sheath of any examples herein, particularly examples 77-87, wherein the first outer tubular layer comprises a polyamide, co-polyamide, polyether block amide (PEBAX®), or a blend.
The sheath of any examples herein, particularly examples 76-88, wherein the first outer tubular layer further comprises at least one additional longitudinally extending folded flap that overlies a portion of the outer surface of the outer layer when the sheath is in an unexpanded state.
The sheath of any examples herein, particularly examples 76-89, wherein the longitudinal slit extends the full length of the inner tubular layer.
The sheath of any examples herein, particularly examples 76-90, wherein the inner tubular layer comprises a first longitudinally extending end and a second longitudinally extending end, the first and second longitudinally extending ends defining the longitudinal slit.
The sheath of any examples herein, particularly examples 76-91, wherein the inner tubular layer comprises a material with a static or dynamic coefficient of friction less than 0.3.
The sheath of any examples herein, particularly examples 76-92, wherein the inner tubular layer extends around at least 80% of a circumference of the inner lumen when the sheath is in an unexpanded state.
The sheath of any examples herein, particularly examples 76-93, wherein the inner tubular layer is formed of a material having a tensile modulus of at least 300 MPa.
The sheath of any examples herein, particularly examples 76-94, wherein the inner tubular layer comprises HDPE or a fluoropolymer.
The sheath of any examples herein, particularly examples 76-95, further comprising a tie layer positioned between and adhering the inner tubular layer to the first outer tubular layer.
The sheath of any examples herein, particularly example 96, wherein the tie layer comprises a polyurethane or functionalized polyolefin.
An expandable sheath comprising: an inner tubular layer comprising a longitudinal slit and partially defining an inner lumen, a first outer tubular layer enveloping the inner layer, the outer tubular layer comprising a longitudinally extending, folded flap that overlies a portion of an outer surface of the outer layer when the sheath is in an unexpanded state, and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein an outwardly directed radial force from a prosthetic device moving through the inner lumen widens the longitudinal slit and unfolds the folded flap to allow expansion of the sheath.
The sheath of any examples herein, particularly examples 1-45, further comprising a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; and wherein the elongated tube is positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the discontinuous first outer tubular layer ; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
The sheath of any examples herein, particularly example 99, wherein the first fold is configured to move closer to the second fold to shorten the folded portion at a local axial location during passage of the medical device through the lumen and wherein shortening of the folded portion corresponds with a local expansion of the lumen.
The sheath of any examples herein, particularly examples 99-100, wherein the inner layer extends through a longitudinally extending opening provided in the outer layer when the outer layer is expanded.
The sheath of any examples herein, particularly example 101, wherein the longitudinally extending opening is provided between a longitudinally extending edge of the overlapping portion and a longitudinally extending edge of the underlaying portion.
The sheath of any examples herein, particularly examples 99-102, wherein the inner layer comprises at least partially etched PTFE.
The sheath of any examples herein, particularly example 103, wherein the inner layer comprises a fully etched PTFE.
The sheath of any examples herein, particularly example 104, wherein unetched portions of an outer surface of the inner liner extend longitudinally along a length of the inner layer and/or circumferentially around a length of a circumference of the inner layer.
The sheath of any examples herein, particularly examples 103 or 105, wherein unetched portions of the inner layer are provided along portions of the inner layer that contact an outer surface of the outer layer.
The sheath of any examples herein, particularly examples 99-106, wherein the sheath further comprises a tie layer disposed between the inner layer and the first outer tubular layer and at least partially adhering the inner layer to the first outer tubular layer.
The sheath of any examples herein, particularly example 107, wherein unetched portions of the inner layer are provided along those locations excluding the tie layer, wherein the surface of the inner layer adjacent the underlaying portion of the outer layer when the sheath is not expanded, are unetched.
The sheath of any examples herein, particularly examples 99-108, wherein the inner layer has a wall thickness ranging between about 0.002 inches and about 0.006 inches.
The sheath of any one of any examples herein, particularly examples 107-109, wherein the tie layer extends at least partially around an outer surface of the inner liner.
The sheath of any examples herein, particularly example 110, wherein the tie layer extends around an entirety of the outer surface of the inner liner.
The sheath of any one of any examples herein, particularly examples 107-111, wherein the tie layer extends at least partially around an inner surface of the first outer tubular layer.
The sheath of any one of any examples herein, particularly example 112, wherein the tie layer extends around an entirety of an inner surface of the first outer tubular layer.
The sheath of any one of any examples herein, particularly examples 107-113, wherein the tie layer extends between the first outer tubular layer and the overlapping folded portion of the inner layer.
The sheath of any examples herein, particularly example 114, wherein the tie layer extends between an outer surface of the overlapping folded portion of the inner layer and a corresponding surface of the overlapping portion of the first outer tubular layer.
The sheath of any examples herein, particularly examples 114-115, wherein the tie layer does not extend between an inner surface of the overlapping folded portion of the inner layer and a corresponding surface of the underlaying portion of the outer surface of the first outer tubular layer.
The sheath of any one of any examples herein, particularly examples 107-116, wherein the tie layer adheres at least a portion of the inner layer to a corresponding portion of the first outer tubular layer.
The sheath of any one of any examples herein, particularly examples 107-117, wherein the tie layer comprises a material having a Shore A durometer less than about 90 Shore A.
The sheath of any examples herein, particularly examples 107-118, wherein the tie layer comprises thermoplastic polyurethane.
The sheath of any examples herein, particularly example 119, wherein the tie layer comprises an aliphatic polyether-based thermoplastic polyurethane (TPU).
The sheath of any examples herein, particularly example 120, wherein the tie layer comprises of Tecoflex™ 80A.
The sheath of any examples herein, particularly example 118, wherein the tie layer comprises an aromatic polyether or polyester-based thermoplastic polyurethane.
The sheath of any examples herein, particularly example 124, wherein the tie layer comprises of Pellethane™ 80A.
The sheath of any one of any examples herein, particularly examples 107-118, wherein the tie layer comprises a polyolefin or polyamide.
The sheath of any examples herein, particularly example 124, wherein the tie layer comprises a polyolefin comprising polyethylene, polypropylene, or ethylene vinyl acetate PE, PP, or EVA modified with maleic anhydride.
The sheath of any examples herein, particularly example 125, wherein the tie layer comprises an Orevac™ resin.
The sheath of any one of any examples herein, particularly examples 107-126, wherein the tie layer has a wall thickness ranging between about 0.002 inches and about 0.005 inches.
The sheath of any examples herein, particularly examples 99-127, wherein the first outer tubular layer exerts a radially inward force on the inner layer.
The sheath of any examples herein, particularly examples 99-128, wherein the first outer tubular layer comprises of at least one polymeric material.
The sheath of any examples herein, particularly examples 99-129, wherein the first outer tubular layer comprises at least one of HDPE, nylon, and polypropylene.
The sheath of any examples herein, particularly examples 99-130, wherein the first outer tubular layer has a wall thickness ranging between about 0.007 inches and about 0.013 inches.
The sheath of any examples herein, particularly examples 99-131, wherein the elongated tube is bonded to the first outer tubular layer.
The sheath of any examples herein, particularly examples 99-132, wherein the elongated tube is bonded to the first outer tubular layer at a proximal end of the first outer tubular layer.
The sheath of any examples herein, particularly examples 99-133, wherein the elongated tube is bonded to the outer layer at a distal end of the first outer tubular layer.
The sheath of any examples herein, particularly examples 99-134, wherein the elongated tube is bonded to the first outer tubular layer along a length of the first outer tubular layer between the proximal and distal ends of the first outer tubular layer.
The sheath of any examples herein, particularly examples 99-135, wherein a distal end of the elongated tube is bonded to the inner layer.
The sheath of any examples herein, particularly example 136, wherein the elongated tube is bonded to a distal end surface of the inner layer.
The sheath of any examples herein, particularly examples 99-137, wherein the elongated tube is bonded to at least one of a proximal end of the first outer tubular layer, a distal end of the first outer tubular layer, and a distal end of the inner layer by a chemical and/or mechanical fastener.
The sheath of any examples herein, particularly example 138, wherein the mechanical fastener includes thermally-bonded coupling between the elongated tube and at least one of the first outer tubular layer and the inner layer.
The sheath of any examples herein, particularly examples 99-139, wherein the elongated tube extends over an entire length of the first outer tubular layer.
The sheath of any examples herein, particularly examples 99-140, further comprising a lubricant disposed between the elongated tube and the first outer tubular layer.
The sheath of any examples herein, particularly example 141, wherein the lubricant is provided along the portion of the folded portion of the inner layer extending along the outer surface of the first outer tubular layer.
The sheath of any examples herein, particularly example 141, wherein the lubricant is applied as a band around a portion of the circumference of the first outer tubular layer, the band of lubricant extending longitudinally along a length of the first outer tubular layer.
The sheath of any examples herein, particularly examples 141-143, wherein the lubricant comprises a curable material.
The sheath of any examples herein, particularly examples 141-143, wherein the lubricant comprises a medical-grade silicone.
The sheath of any examples herein, particularly examples 141-143 wherein the lubricant comprises at least one of Med10-6670, Duraglide™, and/or Christo-Lube™.
A sheath for delivering a medical device, the sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
A sheath of any examples herein, particularly examples 1-45, further comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; a coiled wire along a length of the sheath, the coil wire providing uniform bending of the sheath to prevent kinking: and wherein the elongated tube is positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, and wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpended configuration as the prosthetic device passes through the lumen.
The sheath of any examples herein, particularly example 148, further comprising a tie layer provided between the inner layer and the first outer tubular layer and at least partially adhering the inner layer to the first outer tubular layer,
The sheath of any examples herein, particularly example 148 or 149, wherein the coiled wire is embedded in the first outer tubular layer.
The sheath of any examples herein, particularly examples 148-150, wherein the coiled wire is co-extruded with the first outer tubular layer.
The sheath of any examples herein, particularly example 151, wherein the coiled wire is provided between the first outer tubular layer and the tie layer.
The sheath of any examples herein, particularly example 152, wherein the coiled wire is embedded at least partially within both the first outer tubular layer and the tie layer.
The sheath of any examples herein, particularly example 153, wherein the coiled wire is provided to an outer surface of the tie layer, and the first outer tubular layer is reflowed over.
The sheath of any examples herein, particularly examples 148-154, wherein the coiled wire is composed of a metal or a polymer wire.
The sheath of any examples herein, particularly examples 148-155, wherein the coiled wire is composed of at least one of PET, PEEK, stainless steel, or nitinol.
The sheath of any examples herein, particularly examples 148-156, wherein the coiled wire defines a helical-shaped path around the longitudinal axis of the sheath.
The sheath of any examples herein, particularly examples 148-157, wherein the coiled wire defines an overlapping helical-shaped path around the longitudinal axis of the sheath.
The sheath of any examples herein, particularly example 158, wherein the overlapping helical-shaped path defines a continuous diamond pattern along a length of the sheath.
The sheath of any examples herein, particularly examples 148-159, wherein the coiled wire is a flat wire.
The sheath of any examples herein, particularly examples 148-160, wherein the coiled wire is a round wire.
The sheath of any examples herein, particularly examples 148-161, wherein the coiled wire has a thickness of about 0.002″ to about 0.008″.
The sheath of any examples herein, particularly examples 148-162, wherein a distance between adjacent coils of the coiled wire corresponds to a diameter of the coiled wire.
The sheath of any examples herein, particularly examples 148-163, wherein a distance between adjacent coils of the coiled wire is about 0.006″.
The sheath of any examples herein, particularly example 164, wherein the coiled wire has a diameter of about 0.006″.
The sheath of any one of any examples herein, particularly examples 148-165, wherein a lubricant is provided between the elongated tube and the first outer tubular layer for reducing friction during expansion of the sheath.
The sheath of any examples herein, particularly example 166, wherein the lubricant is provided on an outer surface of the outer layer proximate to a longitudinally extending edge of the overlapping portion.
The sheath of any examples herein, particularly example 167, wherein at least a portion of the folded portion of the inner layer extends beyond the longitudinally extending edge of the overlapping portion, and along an outer surface of the first outer tubular layer, wherein the lubricant is provided along the portion the folded portion of the inner layer extending along the outer surface of the first outer tubular layer for reducing friction between the inner layer and the elongated tube during expansion of the sheath.
A sheath for delivering a medical device, the sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; a coiled wire along a length of the sheath, the coil wire providing uniform bending of the sheath to prevent kinking; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpended configuration as the prosthetic device passes through the lumen,
The sheath of any examples herein, particularly examples 1-159, further comprising a hydrophilic coating disposed on an outer surface of the elongated tube.
The sheath of any examples herein, particularly examples 1-170, wherein the sheath comprises a radiopaque material.
A method of making a sheath having a proximal end and a distal end and comprising: a) extruding a tubular body to form an elongated tube comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; b) disposing the elongated tube on the sheath such that the elongated tube forms an outer layer of the sheath, and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the formed sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
The method of any examples herein, particularly example 172, wherein the elongated tube comprises a second polymer layer comprising a second compound composition comprising from 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof.
The method of any examples herein, particularly example 173, wherein a step of extruding comprises co-extruding the first polymer layer and the second polymer layer.
The method of any examples herein, particularly example 173 or 174, wherein the second polymer layer is substantially free of an inorganic filler.
The method of any examples herein, particularly examples 173-175, wherein the second polymer layer is substantially free of a solid lubricant filler.
The method of any examples herein, particularly examples 173-176, wherein the second polymer layer has an average durometer larger than the first polymer layer.
The method of any examples herein, particularly examples 173-177, wherein the first polymer layer defines the inner surface of the elongated tube.
The method of any examples herein, particularly examples 173-178, wherein the second polymer layer defines the outer surface of the elongated tube.
The method of any examples herein, particularly examples 173-179, wherein the first polymer layer defines the outer surface of the elongated tube.
The method of any examples herein, particularly examples 173-180, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.
The method of any examples herein, particularly examples 172-181, further comprising providing a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner and forms the outer layer of the sheath.
The method of any examples herein, particularly examples 172-182, further comprising: providing an inner tubular layer comprising a longitudinal slit and partially defining an inner lumen and a first outer tubular layer enveloping the inner layer, the outer tubular layer comprising a longitudinally extending, folded flap that overlies a portion of an outer surface of the outer layer when the sheath is in an unexpanded state, and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer.
The method of any examples herein, particularly examples 172-182, further comprising: providing a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer and a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the discontinuous first outer tubular layer ; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
The method of any examples herein, particularly examples 172-182, further comprising: providing: a) a continuous inner layer defining a lumen therethrough, the inner layer including a first fold and a second fold and an overlapping folded portion extending circumferentially between the first and second folds, the folded portion comprising overlap in a radial direction of at least two thicknesses of the inner layer; b) a discontinuous first outer tubular layer extending at least partially around the inner layer, the first outer tubular layer having an overlapping portion and an underlaying portion, at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlaying portion; and c) a coiled wire along a length of the sheath, the coil wire providing uniform bending of the sheath to prevent kinking; and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, and wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
The method of any examples herein, particularly examples 173-182, further comprising providing: a) an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; b) a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; and disposing the elongated tube such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, and wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second diameter larger than the first diameter due to an outwardly directed radial force exerted by a medical device against the inner layer, and then locally contract at least partially back to the unexpanded configuration as the prosthetic device passes through the lumen.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises an elongated tube forming an outer layer of the sheath that is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, having an inner surface and an outer surface, and wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0 wt % to less than 100 wt % of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer; and wherein the elongated tube is substantially kink resistant.
The sheath of any examples herein, particularly example 187, wherein a durometer of the first polymer at a proximal end of the elongated tube is different from a durometer of the first polymer at a distal end of the elongated tube and has a Shore D from about 20 D to about 35 D.
The sheath of any examples herein, particularly examples 187-188, wherein the first polymer comprises polyether block amide elastomer.
The sheath of any examples herein, particularly examples 187-188, wherein the first polymer comprises polyurethane.
The sheath of any examples herein, particularly examples 187-191, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof and is present in an amount of at least about 10% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 187-191, wherein the inorganic filler is present in an amount of less than about 50% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 187-192, wherein the solid lubricant comprises a PTFE filler.
The sheath of any examples herein, particularly examples 187-193, wherein the first compound composition further comprises at least one tackiness reducing compound present in an amount from about 1% to about 20% based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 187-194, wherein the elongated tube comprises two or more polymer layers.
The sheath any examples herein, particularly example 195, wherein the elongated tube comprises at least a second polymer layer comprising a second compound composition comprising from greater than 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof; and wherein the second polymer has a Shore A Durometer from about 20 A to about 65 A.
The sheath of any examples herein, particularly example 196, wherein the second compound composition further comprises up to 20% of tackiness reducing additive based on a total weight of the second compound composition.
The sheath of any examples herein, particularly examples 196-197, wherein the second polymer layer comprises polyurethane.
The sheath of any examples herein, particularly examples 196-198, wherein the elongated tube has a predetermined thickness and wherein at least about 50% of the predetermined thickness comprises the first and/or the second compound composition.
The sheath of any examples herein, particularly examples 196-199, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.
The sheath of any examples herein, particularly example 200, wherein the one or more additional polymer layers comprise at least one intermediate reinforcement layer extending axially at at least a portion of a length of the elongated tube.
The sheath of any examples herein, particularly example 201, wherein the at least one intermediate reinforcement layer comprises the first polymer, the second polymer, a polyolefin-based polymer, or a combination thereof.
The sheath of any examples herein, particularly example 201 or 202, wherein the at least one intermediate reinforcement layer comprises a material having a Shore D durometer from about 45 D to about 76 D.
The sheath of any examples herein, particularly examples 201-203, wherein the at least one intermediate reinforcement layer is configured to thermally bond with the first polymer layer, the second polymer layer, or a combination thereof.
The sheath of any examples herein, particularly examples 187-204, wherein the elongated tube exhibits a friction force of less than about 7 N in the dry state against a substrate surface comprising one or more of polytetrafluoroethylene or high-density polyethylene.
The sheath of any examples herein, particularly examples 187-205, wherein the elongated tube exhibits a hoop direction force at a 10 mm extension of less than about 8 N.
The sheath of any examples herein, particularly examples 187-206, the elongated tube exhibits an elongation at break of ranging between about 600% and about 800%.
The sheath of any examples herein, particularly examples 187-207, further comprising an expandable tubular inner liner extending along the length of the sheath and comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; and a first outer tubular layer extending at least partially along the length of the sheath and having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer further extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; wherein the elongated tube is positioned such that at least a portion of the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer; and wherein the sheath exhibits an insertion force of less than about 55 N when a medical device is pushed through the sheath.
The sheath of any examples herein, particularly example 208, wherein the expandable tubular inner liner comprises polytetrafluoroethylene; or wherein the first outer tubular layer comprises a high-density polyethylene.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion; a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the first outer tubular layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the first outer tubular layer is positioned adjacent to the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: an expandable tubular inner liner comprising at least one folded portion, wherein the expandable inner liner has an inner surface, and an outer surface, wherein the inner surface of the expandable inner liner defines a lumen and forms an inner surface of the at least one folded portion, and wherein the outer surface extends circumferentially to form an outer surface of the at least one folded portion and wherein the outer surface of the inner liner is selectively etched; a first outer tubular layer having an inner surface and an outer surface, wherein the inner surface of the outer layer extends at least partially around the outer surface of the inner liner such that at least a portion of the inner surface of the outer layer is positioned adjacent to at least a portion of the outer surface of the at least one folded portion of the inner liner; and an elongated tube forming a second outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the first outer tubular layer, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
The sheath of any examples herein, particularly examples 187-211, further comprising a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and wherein the elongated tube is positioned such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner.
The sheath of any examples herein, particularly example 212, further comprising a braid positioned between the inner liner and the elongated tube.
The sheath of any examples herein, particularly examples 212 or 213, further comprising an additional outer layer positioned in between the inner liner and the elongated tube.
The sheath of any examples herein, particularly examples 212-214, wherein the sheet comprises a high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.
The sheath of any examples herein, particularly examples 212-215, wherein an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the inner surface of the elongated tube.
The sheath of any examples herein, particularly examples 212-216, wherein an amount of a second lubricant is disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portions of the sheet.
The sheath of any examples herein, particularly examples 213-217, wherein the braid comprises at least one filament comprising stainless steel, nitinol, a polymer material, or a composite material.
A sheath for delivering a medical device, wherein the sheath has a proximal and a distal end and comprises: a variable diameter inner liner comprising a sheet having a first edge and a second edge and is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet and wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the cylinder having a longitudinal axis; wherein the variable diameter inner liner is configured to reversible expand from a predetermined rest diameter dr to an expanded diameter d1 by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of outer surface, during application of a radial outward force by passage of a medical device through the lumen of the inner liner; and an elongated tube forming an outer layer having an inner surface and an outer surface and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, such that the inner surface of the elongated tube overlies at least a portion of the outer surface of the inner liner, wherein the elongated tube comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition.
A method of making a sheath having a proximal end and a distal end and comprising: a) extruding a tubular body to form an elongated tube comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising from greater than 0% to less than 100% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65% of an inorganic filler based on a total weight of the first compound composition; and up to about 20% of a solid lubricant filler based on a total weight of the first compound composition; b) disposing the elongated tube on the sheath such that the elongated tube forms an outer layer of the sheath, and wherein the elongated tube is positioned at at least the proximal end of the sheath and extending along at least a portion of a length of the sheath, wherein the elongated tube is configured to reversibly expand from an initial diameter do in an unexpended position to an expanded diameter de in an expanded position upon passage of a medical device; and wherein the formed sheath exhibits at least a 10% reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer.
The method of any examples herein, particularly example 220, wherein the elongated tube comprises a second polymer layer comprising a second compound composition comprising from 0 wt % to 100 wt % of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof.
The method of any examples herein, particularly example 221, wherein a step of extruding comprises co-extruding the first polymer layer and the second polymer layer.
The method of any examples herein, particularly examples 220-222, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.
In view of the many possible aspects to which the principles of the disclosed disclosure can be applied, it should be recognized that the illustrated aspects are only preferred examples of the disclosure and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is defined by the following claims. We, therefore, claim as our disclosure all that comes within the scope and spirit of these claims.
This application is a continuation of International Application No. PCT/US2021/031275, filed May 7, 2021, which claims the benefit of U.S. Provisional Application No. 63/059,772, filed Jul. 31, 2020, the content of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63059772 | Jul 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2021/031275 | May 2021 | US |
| Child | 18103361 | US |
