Patent Application
20250229057
The present application relates to expandable introducer sheaths for prosthetic devices such as transcatheter heart valves and methods of making the same.
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.
Aspects of the present 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 prior art introducer sheaths. Furthermore, certain aspects can reduce the length of time a procedure takes and the risk of a longitudinal or radial vessel tear or plaque dislodgement because only one sheath is required rather than several different sizes. Aspects of the present expandable sheath can require only a single vessel insertion instead of requiring multiple insertions to dilate the vessel.
According to some aspects, a sheath for introducing a prosthetic device wherein the sheath comprises an inner liner and an outer layer is disclosed. At least a portion of the sheath can be designed or configured to locally expand from a first diameter (rest diameter) to a second diameter (expanded diameter) as the prosthetic device is pushed through a lumen of the sheath, and then at least partially return to the first diameter once the prosthetic device has passed through.
According to some aspects, an expandable sheath for deploying a medical device is disclosed. The expandable sheath has a proximal end and a distal end, an inner surface and an outer surface and comprising: an inner liner comprising one or more polymer layers; wherein the inner liner has a first surface and an opposite second surface, wherein the first surface of the inner liner defines the inner surface of the sheath; a first polymeric layer surrounding radially outward of the inner liner, such that it is positioned at the second surface of the inner liner and wherein the first polymeric layer comprises one or more sublayers; a braided layer disposed radially outward of the first polymeric layer; a second polymeric layer surrounding radially outward of the braided layer, wherein the second polymeric layer comprises one or more sublayers; an outer liner comprising one or more polymer layers; wherein the outer liner has a first surface and an opposite second surface, wherein the first surface of the outer liner overlies the second polymeric layer, and wherein the second surface of the liner layer defines the outer surface of the sheath; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; and wherein when a medical device is passed through the sheath, a diameter of the sheath locally expands from a first unexpended diameter around the medical device to a second expanded diameter, while the first and second polymeric layers resist axial elongation of the sheath such that a length of the sheath remains substantially constant; and wherein the sheath resiliently returns to a third diameter after the passage of the medical device.
In some implementations, the first polymeric layer can be provided as a film or as a coating. In some aspects, the second polymeric layer can be provided as a film or as a coating.
Also disclosed are implementations where a portion of the proximal end of the expandable sheath further comprises a third polymeric layer comprising one or more layers and surrounding radially outward of the outer layer.
According to some aspects, the sheath comprises a plurality of longitudinally extending pleats. In such exemplary and unlimiting aspects, the plurality of pleats can extend around at least a portion of a circumference of the sheath. In addition or in the alternative, disclosed are aspects where the plurality of pleats can form a plurality of circumferentially spaced ridges and a plurality of circumferentially spaced valleys and wherein, as the medical device is passed through the sheath, the ridges and valleys at least partially level out to allow a sheath wall to radially expand.
Also disclosed are aspects of an expandable sheath for deploying a medical device having a proximal end and a distal end, an inner surface and an outer surface and comprising: an inner liner comprising one or more polymer layers; wherein the inner liner has a first surface and an opposite second surface, wherein the first surface of the inner liner defines the inner surface of the sheath; a first polymeric layer surrounding radially outward of the inner liner, such that it is positioned at the second surface of the inner liner and wherein the first polymeric layer comprises one or more sublayers; a braided layer disposed radially outward of the first polymeric layer; a second polymeric layer surrounding radially outward of the braided layer, wherein the second polymeric layer comprises one or more sublayers; an outer liner comprising one or more polymer layers; wherein the outer liner has a first surface and an opposite second surface, wherein the first surface of the outer liner overlies the second polymeric layer, and wherein the second surface of the liner layer defines the outer surface of the sheath; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; and wherein when a medical device is passed through the sheath, the diameter of the sheath locally expands from a first unexpended diameter around the medical device to a second expanded diameter, while the first and second polymeric layers resist axial elongation of the sheath such that a length of the sheath remains substantially constant; and wherein the sheath resiliently returns to a third diameter after the passage of the medical device.
Also disclosed herein are methods of making an expandable sheath, the method comprising: forming an inner liner; wherein the inner liner comprises one or more polymer layers and wherein the inner liner has a first surface and an opposite second surface; forming a first polymeric layer, wherein the first polymeric layer is positioned radially outward of the inner liner; wherein the first polymeric layer comprises one or more sublayers; and wherein the first polymeric layer overlies the second surface of the inner liner; positioning a braided layer radially outward of a first polymeric layer; forming a second polymeric layer such that it is positioned radially outward of the braided layer; wherein the second polymeric layer comprises one or more sublayers; forming an outer liner radially outward of the second polymeric layer; wherein the outer liner comprises one or more polymer layers; and wherein the outer liner has a first surface and an opposite second surface and wherein the first surface of the outer liner is in contact with at least a portion of the second polymeric layer; heating the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, and the outer liner to form a laminate structure; and crimping the laminate structure to form a plurality of longitudinally-extending pleats, wherein the plurality of longitudinally-extending pleats are configured to expand upon passage of a medical device through the sheath laminate.
According to some aspects, a method of making an expandable sheath is disclosed, the method comprising: forming an inner liner; wherein the inner liner comprises one or more polymer layers and wherein the inner liner has a first surface and an opposite second surface; forming a first polymeric layer, wherein the first polymeric layer is positioned radially outward of the inner liner; wherein the first polymeric layer comprises one or more sublayers; and wherein the first polymeric layer overlies the second surface of the inner liner; positioning a braided layer radially outward of a first polymeric layer; forming a second polymeric layer such that it is positioned radially outward of the braided layer; wherein the second polymeric layer comprises one or more sublayers; forming an outer liner radially outward of the second polymeric layer; wherein the outer liner comprises one or more polymer layers, and wherein the outer liner has a first surface and an opposite second surface, and wherein the first surface of the outer liner is in contact with at least a portion of the second polymeric layer; heating the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, and the outer liner to form a laminate structure; and crimping the laminate structure to form a plurality of longitudinally-extending pleats, wherein the plurality of longitudinally-extending pleats are configured to expand upon passage of a medical device through the sheath; and then forming a third polymeric layer radially outward of at least a portion of the outer liner; wherein the third polymeric layer comprises one or more polymer layers.
In some aspects disclosed is also a method of delivering a prosthetic device to a procedure site, the method comprising inserting an expandable sheath at least partially into the vasculature of the patient, the expandable sheath comprising a plurality of radially arranged layers including an inner liner, a first polymeric layer radially outward of the inner liner, a braided layer radially outward of the first polymeric layer, a second polymeric layer radially outward of the braided layer, and an outer liner, and wherein the sheath comprises a plurality of longitudinally-extending pleats; advancing a medical device through an inner lumen defined by a first surface of the inner liner of the sheath, the medical device applying an outward radial force on the inner liner of the sheath; locally expanding the sheath from an unexpanded state to a locally expanded state; at least partially unfolding the plurality of longitudinally-extending pleats during a local expansion of the sheath, wherein each of the plurality of longitudinally-extending pleats incorporates at least a portion of the plurality of radially arranged layers; locally collapsing the sheath from the locally expanded state at least partially back to the unexpanded state after passage of the medical device.
According to some aspects, disclosed is a method of delivering a prosthetic device to a procedure site, the method comprising: inserting an expandable sheath at least partially into the vasculature of the patient, the expandable sheath comprising a plurality of radially arranged layers including an inner liner, a first polymeric layer radially outward of the inner liner, a braided layer radially outward of the first polymeric layer, a second polymeric layer radially outward of the braided layer, an outer liner, and a third polymer layer disposed radially outward of at least a portion of the outer liner, and wherein the sheath comprises a plurality of longitudinally-extending pleats; advancing a medical device through an inner lumen defined by a first surface of the inner liner of the sheath, the medical device applying an outward radial force on the inner liner of the sheath; locally expanding the sheath from an unexpanded state to a locally expanded state; at least partially unfolding the plurality of longitudinally-extending pleats during a local expansion of the sheath, wherein each of the plurality of longitudinally-extending pleats incorporates at least a portion of the plurality of radially arranged layers; and locally collapsing the sheath from the locally expanded state at least partially back to the unexpanded state after passage of the medical device.
Aspects of the disclosure will be set forth, in part, in the detailed description, figures, and claims which follow, and in part will be derived from the detailed description or can be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as disclosed.
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.
The present disclosure relates to introducer sheaths. Such introducer sheaths may be radially expandable. However, currently known sheaths tend to have complex mechanisms, such as ratcheting mechanisms that maintain the sheath in an expanded configuration once a device with a larger diameter than the sheath's original diameter is introduced. Existing expandable sheaths can also be prone to axial elongation as a consequence of the application of longitudinal force attendant to passing a prosthetic device through the sheath. Such elongation can cause a corresponding reduction in the diameter of the sheath, increasing the force required to insert the prosthetic device through the narrowed sheath.
Accordingly, there remains a need in the art for an improved introducer sheath for endovascular systems used for implanting valves and other prosthetic devices.
As used in this application and 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 denote 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, including 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, some aspects include from 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.”
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It is also understood that the term “and/or” includes where one or another of the associated listed items is present and the aspects where both of the associated listed items are present or any combinations of the associated listed items are present.
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, a 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 “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 or a compound, 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 sections, and/or steps. These elements, components, regions, layers, sections, and/or steps 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, section, or step. Thus, a first element, component, region, layer, section, or step discussed below could be termed a second element, component, region, layer, section, or step without departing from the teachings of example aspects.
It is understood that the terms “layer” and “liner” can be used interchangeably. For example, the aspects describing an “inner liner” also include aspects describing an “inner layer.” Similarly, the aspects describing an “outer layer” also include aspects describing an “outer liner.”
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.
Some of the aspects disclosed herein comprise a plurality of longitudinally-extending creases. It is understood that the terms “creases,” “folds,” and “pleats” as used in reference to these aspects can be used interchangeably. It is understood that the pleats or creases can be arranged in a specific pattern, or they can be randomly formed along a length of the sheath. For example, pleats formed along the length of the sheath are formed as a result of the manufacturing process where the various polymer layers encapsulate a braid (or braided layer; it is understood that braid and braided layer can be used interchangeably) and form creases that can be flattened out during expansion process of the valve. In some aspects, pleats can have an arranged pattern. For example, and without limitation, pleats can have an arranged pattern at a tip of the sheath. In some implementations, the pleats can have an even area in an arc length of a cross section. In such aspects, each of the formed pleats can have a substantially identical area, whether there are 2 pleats, or 3 pleats, or 4 pleats, or 5 pleats, and so on. In some implementations, the pleats can have a predetermined design for the desired application.
It is understood that the term “collapsed” as used herein, refers to a natural unexpanded state of the sheath.
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 the 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 wherein 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 wherein and to the Figures and their previous and following description.
The expandable introducer sheaths described herein can be used to deliver a prosthetic device through a patient's vasculature to a procedure site within the body. The sheath can be constructed to be highly expandable and collapsible in the radial direction while limiting axial elongation of the sheath and, thereby, undesirable narrowing of the lumen. In one aspect, the expandable sheath includes a braided layer, one or more relatively thin, non-elastic polymeric layers, and an elastic layer. The sheath can resiliently expand from its natural diameter to an expanded diameter as a prosthetic device is advanced through the sheath and can return to its natural diameter upon passage of the prosthetic device under the influence of the elastic layer. In certain aspects, the one or more polymeric layers can engage the braided layer and can be configured to allow radial expansion of the braided layer while preventing axial elongation of the braided layer, which would otherwise result in elongation and narrowing of the sheath.
The prosthetic heart valve 12 can be delivered into a patient's body in a radially compressed configuration and radially expanded to a radially expanded configuration at the desired deployment site. In the illustrated aspect, the prosthetic heart valve 12 is a plastically expandable prosthetic valve that is delivered into a patient's body in a radially compressed configuration on a balloon of the balloon catheter 16 (as shown in
Some details regarding a mechanically expandable heart valve that can be implanted using the devices disclosed herein are disclosed in U.S. Publication No. 2018/0153689, which is incorporated herein by reference. In some aspects, a prosthetic valve can incorporate two or more of the above-described technologies. For example, a self-expandable heart valve can be used in combination with an expansion device to assist in the expansion of the prosthetic heart valve.
In alternative aspects, the introducer device 90 need not include a housing 92. For example, the sheath 100 can be an integral part of a component of the delivery apparatus 10, such as the guide catheter. For example, the sheath can extend from the handle 18 of the guide catheter. Some examples of introducer devices and expandable sheaths can be found in U.S. patent application Ser. No. 16/378,417 and U.S. Provisional Patent Application No. 62/912,569, which are incorporated by reference in their entireties.
Referring to
In certain aspects, the inner layer (liner) 102 and/or the outer layer (liner) 108 can comprise a relatively thin layer of polymeric material. For example, in some aspects, the thickness of the inner layer 102 can be from 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm. In certain aspects, the thickness of the outer layer 108 can be from 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm. In yet some aspects, the inner liner 102 and the outer liner 108 can comprise at least one polymer layer. In some aspects, the inner liner and the outer liner each can comprise two or more layers of polymeric material.
In certain examples, the inner layer 102 and/or the outer layer 108 can comprise a lubricious, low-friction, and/or relatively non-elastic material. In particular aspects, the inner layer 102 and/or the outer layer 108 can comprise a polymeric material having a modulus of elasticity of 400 MPa or greater. Exemplary materials can include ultra-high-molecular-weight polyethylene (UHMWPE) (e.g., Dyneema®), high-molecular-weight polyethylene (HMWPE), or polyether ether ketone (PEEK). With regard to the inner layer 102 in particular, such a low coefficient of friction materials can facilitate the passage of the prosthetic device through the lumen 112. Some suitable materials for the inner and outer layers can include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene (such as, for example, low-density polyethylene (LDPE), high density polyethylene (HDPE)), polyether block amide (e.g., Pebax), bi-oriented polypropylene, cast polypropylene, thermoplastic polyurethane, and/or combinations of any of the above. Some aspects of a sheath 100 can include an additional lubricious liner on the inner surface of the inner layer 102. Examples of such suitable lubricious liners include materials that can further reduce the coefficient of friction of the inner layer 102, such as PTFE, polyethylene (such as, for example, HMWPE, UHMWPE, LDPE, HDPE), polyvinylidine fluoride, and combinations thereof. Suitable materials for a lubricious liner also include some materials desirably having a coefficient of friction of 0.1 or less.
Some aspects of the sheath 100 can include an exterior hydrophilic coating on the outer surface of the outer layer (liner) 108. Such a hydrophilic coating can facilitate the insertion of the sheath 100 into a patient's vessel, reducing potential damage. Examples of suitable hydrophilic coatings include the Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, MN. DSM medical coatings (available from Koninklijke DSM N. V, Heerlen, the Netherlands), as well as other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidine fluoride), are also suitable for use with the sheath 100. Such hydrophilic coatings may also be included on the inner surface of the inner layer 102 to reduce friction between the sheath and the delivery system, thereby facilitating the use and improving safety. In some aspects, a hydrophobic coating, such as Perylene, may be used on the outer surface of the outer layer 108 or the inner surface of the inner layer 102 in order to reduce friction.
In certain aspects, the second layer 104 can be braided.
The braided layer 104 can extend along substantially the entire length L of the sheath 100, or alternatively, it can extend only along a portion of the length of the sheath. In particular aspects, the filaments 110 can be wires made from metal (e.g., Nitinol, stainless steel, etc.) or any of various polymers or polymer composite materials, such as carbon fiber. In certain aspects, the filaments 110 can be round and can have a diameter of from 0.01 mm to 0.5 mm, 0.03 mm to 0.4 mm, or 0.05 mm to 0.25 mm. In some implementations, the filaments 110 can have a flat cross-section with dimensions of 0.01 mm×0.01 mm to 0.5 mm×0.5 mm, or 0.05 mm×0.05 mm to 0.25 mm×0.25 mm. In one aspect, filaments 110 having a flat cross-section can have dimensions of 0.1 mm×0.2 mm. 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 ten picks per inch to eighty picks per inch and can include eight wires, sixteen wires, or up to fifty-two wires in various braid patterns. In some implementations, the second layer 104 can be laser cut from a tube, or laser-cut, stamped, punched, etc., from sheet stock and rolled into a tubular configuration. Layer 104 can also be woven or knitted, as desired. In some aspects, the braided layer can have a weave pattern of, for example, 1×1 (one over, one under), 2×2 (two over, two under), or 2×1 (two over, one under).
A braided layer 104 can comprise any known in the art material that can be provided for the desired expansion of the sheath. For example, and without limitations, the braided layer 104 can comprise Nitinol or some other shape memory metal or material that can exhibit superelastic properties. In such aspects, these materials can have the advantage of allowing for austenitic finishing (AF) at a certain temperature. For example, a nitinol braided layer having AF at 15 degrees Celsius or less allows for its use in relatively cold operating rooms while still exhibiting superelastic properties. In some implementations, the materials used to form the braided layer can exhibit superelastic properties at temperatures at or above about 15 degrees Celsius.
The third layer 106 can be a resilient, elastic layer (also referred to as an elastic material layer). In certain aspects, the elastic layer 106 can be configured to apply force to the underlying layers 102 and 104 in a radial direction (e.g., toward the central axis 114 of the sheath) when the sheath expands beyond its natural diameter by the passage of the delivery apparatus through the sheath. Stated differently, the elastic layer 106 can be configured to apply encircling pressure to the layers of the sheath beneath the elastic layer 106 to counteract expansion of the sheath. The radially inwardly directed force is sufficient to cause the sheath to collapse radially back to its unexpanded state after the delivery apparatus is passed through the sheath. It is understood, however, that layer 106 can be optional. And also described herein are the aspects where this third elastic layer is not present, while all other layers described herein are. It is also understood that this description includes all various combinations of the layers, and unless it is stated otherwise, some of the described herein layers (liners) can be present while others can be absent. In some implementations, and as shown below, additional layers can also be present.
In the illustrated aspect, the elastic layer 106 can comprise one or more members configured as strands, ribbons, or bands 116 helically wrapped around the braided layer 104. For example, in the illustrated aspect, the elastic layer 106 comprises two elastic bands, 116A and 116B, wrapped around the braided layer with opposite helicity, although the elastic layer may comprise any number of bands depending upon the desired characteristics. The elastic bands 116A and 116B can be made from, for example, any of a variety of natural or synthetic elastomers, including silicone rubber, natural rubber, any of various thermoplastic elastomers, polyurethanes such as polyurethane siloxane copolymers, urethane, plasticized polyvinyl chloride (PVC), styrenic block copolymers, polyolefin elastomers, etc. In some aspects, the elastic layer can comprise an elastomeric material having a modulus of elasticity of 200 MPa or less. In some aspects, the elastic layer 106 can comprise a material exhibiting an elongation to break of 200% or greater or an elongation to break of 400% or greater. The elastic layer 106 can also take other forms, such as a tubular layer comprising an elastomeric material, a mesh, a shrinkable polymer layer such as a heat-shrink tubing layer, etc. In lieu of, or in addition to, the elastic layer 106, the sheath 100 may also include an elastomeric or heat-shrink tubing layer around the outer layer 108. Examples of such elastomeric layers are disclosed in U.S. Publication No. 2014/0379067, U.S. Publication No. 2016/0296730, and U.S. Publication No. 2018/0008407, which are incorporated herein by reference. In some aspects, the elastic layer 106 can also be radially outward of the polymeric layer 108.
In certain aspects, one or both of the inner layer 102 and/or the outer layer 108 can be configured to resist axial elongation of the sheath 100 when the sheath expands. More particularly, one or both of the inner layer 102 and/or the outer layer 108 can resist stretching against longitudinal forces caused by friction between a prosthetic device and the inner surface of the sheath such that the length L remains substantially constant as the sheath expands and contracts. As used herein with reference to the length L of the sheath, the term “substantially constant” means that the length L of the sheath increases by not more than 1%, by not more than 5%, by not more than 10%, by not more than 15%, or by not more than 20%. Meanwhile, with reference to
For example, in some aspects, the inner layer 102 and the outer layer 108 can be heat-bonded during the manufacturing process, such that the braided layer 104 and the elastic layer 106 are encapsulated between the layers 102 and 108. More specifically, in certain aspects, the inner layer 102 and the outer layer 108 can be adhered to each other through the spaces between the filaments 110 of the braided layer 104 and/or the spaces between the elastic bands 116. Layers 102 and 108 can also be bonded or adhered together at the proximal and/or distal ends of the sheath. In certain aspects, layers 102 and 108 are not adhered to the filaments 110. This can allow the filaments 110 to move angularly relative to each other and relative to the layers 102 and 108, allowing the diameter of the braided layer 104, and thereby the diameter of the sheath, to increase or decrease. As the angle θ between the filaments 110A and 110B changes, the length of the braided layer 104 can also change. For example, as the angle θ increases, the braided layer 104 can foreshorten, and as the angle θ decreases, the braided layer 104 can lengthen to the extent permitted by the areas where the layers 102 and 108 are bonded. However, because the braided layer 104 is not adhered to layers 102 and 108, the change in length of the braided layer that accompanies a change in the angle θ between the filaments 110A and 110B does not result in a significant change in the length L of the sheath.
Meanwhile, the angle θ between the filaments 110A and 110B can increase as the sheath expands to the second diameter D2 to accommodate the prosthetic valve. This can cause the braided layer 104 to be foreshortened. However, because the filaments 110 are not engaged or adhered to the layers 102 or 108, the shortening of the braided layer 104 attendant to an increase in the angle θ does not affect the overall length L of the sheath. Moreover, because of the longitudinally-extending folds 126 formed in the layers 102 and 108, the layers 102 and 108 can expand to the second diameter D2 without rupturing, despite being relatively thin and relatively non-elastic. In this manner, the sheath 100 can resiliently expand from its natural diameter D1 to a second diameter D2 that is larger than the diameter D1 as a prosthetic device is advanced through the sheath, without lengthening and without constricting. Thus, the force required to push the prosthetic implant through the sheath is significantly reduced.
In some examples, because of the radial force applied by the elastic layer 106, the radial expansion of the sheath 100 can be localized to the specific portion of the sheath occupied by the prosthetic device. For example, with reference to
In addition to the advantages above, the expandable sheath aspects described herein can provide surprisingly superior performance relative to known introducer sheaths. For example, it is possible to use a sheath configured as described herein to deliver a prosthetic device having a diameter that is two times larger, 2.5 times larger, or even three times larger than the natural outer diameter of the sheath. For example, in one aspect, a crimped prosthetic heart valve having a diameter of 7.2 mm was successfully advanced through a sheath configured as described above and having a natural outer diameter of 3.7 mm. As the prosthetic valve was advanced through the sheath, the outer diameter of the portion of the sheath occupied by the prosthetic valve increased to 8 mm. In other words, it was possible to advance a prosthetic device having a diameter more than two times the outer diameter of the sheath through the sheath, during which the outer diameter of the sheath resiliently increased by 216%. In some examples, a sheath with an initial or natural outer diameter of 4.5 mm to 5 mm can be configured to expand to an outer diameter of 8 mm to 9 mm.
In alternative aspects, the sheath 100 may optionally include layer 102 without layer 108, or layer 108 without layer 102, depending upon the particular characteristics desired.
In the illustrated aspects, the braided layer 104 is disposed between the polymeric layers 102 and 108, as described above. For example, the polymeric layers 102 and 108 can be adhered or laminated to each other at the ends of the sheath 100 and/or between the filaments 110 in the open spaces 136 defined by the unit cells 134. Thus, with reference to
Turning now to methods of making expandable sheaths,
With reference to
In particular aspects, the elastic bands 116 can be applied to the braided layer 104 in a stretched, taut, or extended condition. For example, in certain aspects, the bands 116 can be applied to the braided layer 104 stretched to a length that is twice their natural, relaxed length. This will cause the completed sheath to radially collapse under the influence of the elastic layer when removed from the mandrel, which can cause corresponding relaxation of the elastic layer, as described below. In some implementations, the layer 102 and the braided layer 104 can be removed from the mandrel, the elastic layer 106 can be applied in a relaxed state or moderately stretched state, and then the assembly can be placed back on the mandrel such that the elastic layer is radially expanded and stretched to a taut condition prior to application of the outer layer 108.
The assembly can then be heated to a sufficiently high temperature that the heat-shrink layer 124 shrinks and compresses the layers 102-108 together. In certain aspects, the assembly can be heated to a sufficiently high temperature such that the polymeric inner and outer layers 102 and 108 become soft and tacky and bond to each other in the open spaces between the braided layer 104 and the elastic layer 106 and encapsulate the braided layer and the elastic layer. In some implementations, the inner and outer layers 102, 108 can be reflowed or melted such that they flow around and through the braided layer 104 and the elastic layer 106. In an exemplary aspect, the assembly can be heated at 150° C. for 20-30 minutes.
After heating, the sheath 100 can be removed from the mandrel 118, and the heat-shrink tubing 124 and the ePTFE layers 120 and 122 can be removed. In such exemplary aspects, these ePTFE layers can behave as sacrificial layers. Upon being removed from the mandrel 118, the sheath 100 can at least partially radially collapse to the natural design diameter D1 under the influence of the elastic layer 106. In certain aspects, the sheath can be radially collapsed to the design diameter with the optional aid of a crimping mechanism. The attendant reduction in circumference can buckle the filaments 110, as shown in
In certain aspects, a layer of PTFE can be interposed between the ePTFE layer 120 and the inner layer 102, and/or between the outer layer 108 and the ePTFE layer 122, in order to facilitate separation of the inner and outer polymeric layers 102, 108 from the respective ePTFE layers 120 and 122. In some implementations, one of the inner layer 102 or the outer layer 108 may be omitted, as described above.
The expandable sheath 100 can also be made in other ways. For example,
The containment vessel 202 can define an interior volume or chamber 204. In the illustrated aspect, vessel 202 can be a metal tube, including a closed-end 206 and an open-end 208. The vessel 202 can be at least partially filled with a thermally-expandable material 210 having a relatively high coefficient of thermal expansion. In particular aspects, the thermally-expandable material 210 may have a coefficient of thermal expansion of 2.4×10−4/° C. or greater. Exemplary thermally-expandable materials include elastomers, such as silicone materials. Silicone materials can have a coefficient of thermal expansion of from 5.9×10−4/° C. to 7.9×10−4/° C.
A mandrel, similar to the mandrel 118 of
The open end 208 of vessel 202 can be closed with a cap 212. The vessel 202 can then be heated by the heating system 214. Heating by the heating system 214 can cause the material 210 to expand within chamber 204 and apply radial pressure against the layers of material on the mandrel 118. The combination of the heat and pressure can cause the layers on the mandrel 118 to bond or adhere to each other to form a sheath. In certain aspects, it is possible to apply radial pressure of 100 MPa or more to the mandrel 118 using apparatus 200. The amount of radial force applied to the mandrel can be controlled by, for example, the type and quantity of the material 210 selected and its coefficient of thermal expansion, the thickness of the material 210 surrounding the mandrel 118, the temperature to which the material 210 is heated, etc.
In some aspects, the heating system 214 can be an oven into which the vessel 202 is placed. In some aspects, the heating system can include one or more heating elements positioned around vessel 202. In some aspects, vessel 202 can be an electrical resistance heating element or an induction heating element controlled by the heating system 214. In some aspects, heating elements can be embedded in the thermally-expandable material 210. In some aspects, the material 210 can be configured as a heating element by, for example, adding electrically conductive filler materials, such as carbon fibers or metal particles.
The apparatus 200 can provide several advantages over known methods of sheath fabrication, including uniform, highly controllable application of radial force to the mandrel 118 along its length and high repeatability. The apparatus 200 can also facilitate fast and accurate heating of the thermally-expandable material 210 and can reduce or eliminate the need for heat-shrink tubing and/or tape, reducing material costs and labor. The amount of radial force applied can also be varied along the length of the mandrel by, for example, varying the type or thickness of the surrounding material 210. In certain aspects, multiple vessels 202 can be processed in a single fixture, and/or multiple sheaths can be processed within a single vessel 202. The apparatus 200 can also be used to produce other devices, such as shafts or catheters.
In one specific method, the sheath 100 can be formed by placing layers 102, 104, 106, 108 on the mandrel 118 and placing the mandrel with the layers inside of the vessel 202 with the thermally-expandable material 210 surrounding the outermost layer 108. If desired, one or more inner layers 120 of ePTFE (or similar material) and one or more outer layers 122 of ePTFE (or similar material) can be used (as shown in
Referring to
Referring to
The vessel dilator 300 can include a variety of active and/or passive mechanisms for engaging and retaining the sheath 100. For example, in certain aspects, the retaining member 306 can comprise a polymeric heat-shrink layer that can be collapsed around the distal end portion of the sheath 100. In the aspect illustrated in
Referring to
Referring to
In some aspects, an expandable sheath configured as described above can further comprise a shrinkable polymeric outer cover, such as a heat-shrink tubing layer 400 shown in
In some aspects, the heat-shrink tubing layer 400 can extend distally beyond the distal end portion 140 of the sheath as the distal overhang 408 is shown in
In some aspects, the heat-shrink tubing layer can be configured to split open as a delivery apparatus, such as the delivery apparatus 10 is advanced through the sheath. For example, in certain aspects, the heat-shrink tubing layer can comprise one or more longitudinally extending openings, slits, or weakened, elongated scorelines 406, such as those shown in
In some aspects, splitting or tearing of the heat-shrink tubing layer may be induced in a variety of other ways, such as by forming weakened areas on the tubing surface by, for example, applying chemical solvents, cutting, scoring, or ablating the surface with an instrument or laser, and/or by decreasing the wall thickness or making cavities in the tubing wall (e.g., by femtosecond laser ablation).
In some aspects, the heat-shrink tubing layer may be attached to the body of the sheath by adhesive, welding, or any other suitable fixation means.
In some aspects, the expandable sheath can have a distal end or tip portion comprising an elastic thermoplastic material (e.g., Pebax), which can be configured to provide an interference fit or interference geometry with the corresponding portion of the vessel dilator 300. In certain configurations, the outer layer of the sheath may comprise polyamide (e.g., nylon) in order to provide for welding the distal end portion to the body of the sheath. In certain aspects, the distal end portion can comprise a deliberately weakened portion, scoreline, slit, etc., to allow the distal end portion to split apart as the delivery apparatus is advanced through the distal end portion.
In some implementations, the entire sheath could have an elastomeric outer cover that extends longitudinally from the handle to the distal end portion 140 of the sheath, optionally extending onward to create an overhang similar to overhang 408 shown in
In some aspects, the distal end portion of the expandable sheath can comprise a polymer such as Dyneema®, which can be tapered to the diameter of the vessel dilator 300. Weakened portions, such as dashed cuts, scoring, etc., can be applied to the distal end portion such that it will split open and/or expand in a repeatable way. In some implementations and as also described in detail below, the distal end portion of the expandable sheath can comprise any of the disclosed herein layers.
Crimping of the expandable sheath aspects described herein can be performed in a variety of ways, as described above. According to some aspects, the sheath can be crimped using a conventional short crimper several times longitudinally along the longer sheath. In some aspects, the sheath may be collapsed to a specified crimped diameter in one or a series of stages in which the sheath is wrapped in heat-shrink tubing and collapsed under heating. For example, a first heat shrink tube can be applied to the outer surface of the sheath, the sheath can be compressed to an intermediate diameter by shrinking the first heat shrink tube (via heat), the first heat shrink tube can be removed, a second heat shrink tube can be applied to the outer surface of the sheath, the second heat shrink tube can be compressed via heat to a diameter smaller than the intermediate diameter, and the second heat shrink tube can be removed. This can go on for as many rounds as necessary to achieve the desired crimped sheath diameter.
Crimping of the expandable sheath aspects described herein can be performed in a variety of ways, as described above. A roller-based crimping mechanism 602, such as the one shown in
Each disc-shaped roller 606 is held in place in the radially arranged configuration by a connector 608 that is attached to crimping mechanism 602 via one or more fasteners 619, such that the location of each of the plurality of connectors is fixed with respect to the first end surface of the crimping mechanism 602. In the depicted aspect, fasteners 619 are positioned adjacent an outer portion of the crimping mechanism 602, radially outwardly of the disc-shaped rollers 606. Two fasteners 619 are used to position each connector 608, in the aspect shown, but the number of fasteners 619 can vary. As shown in
During use, an elongated sheath is advanced from the first side 604 of the crimping mechanism 602 through the axial passage between the rollers and out the second side 605 of the crimping mechanism 602. The pressure from the circular edge 610 of the disc-shaped rollers 606 reduces the diameter of the sheath to a crimped diameter as it rolls along the outer surface of the elongated sheath.
The first tapered portion 713 of the narrowing lumen 714 opens toward a second end piece 711 of the holding mechanism 708, such that the widest side of the taper is located on an inner surface 722 of the first end piece 710. In the aspect shown, the first tapered portion 713 narrows to a narrow end 715 that connects with a narrow cylindrical portion 716 of the narrowing lumen 714. In this aspect, the narrow cylindrical portion 716 defines the narrowest diameter of the narrowing lumen 714. The cylindrical end portion 724 of the mandrel 706 may nest loosely within the narrow cylindrical portion 716 of the narrowing lumen 714, with enough space or clearance between the cylindrical end portion 724 and the narrow cylindrical portion 716 of the lumen to allow for passage of the elongated sheath. The elongated nature of the narrow cylindrical portion 716 may facilitate the smoothing of the crimped sheath after it has passed over the conical end portion 712 of the mandrel. However, the length of the cylindrical portion 716 of the narrowing lumen 714 is not meant to limit the disclosure, and in some aspects, the crimping mechanism 702 may only include a first tapered portion 713 of the narrowing lumen 714 and still be effective to crimp an elongated sheath.
At the opposite end of the first end piece, 710, shown in
The holding mechanism 708 further includes a second end piece 711 positioned opposite the elongated base 704 from the first end piece 710. The second end piece 711 is movable with respect to elongated base 704, such that the distance between the first end piece 710 and the second end piece 711 is adjustable and, therefore, able to support mandrels of varying sizes. In some aspects, elongated base 704 may include one or more elongated sliding tracks 728. The second end piece 711 can be slidably engaged to the sliding track 728 via at least one reversible fastener 730, such as, but not limited to, a bolt that extends into or through the second end piece 711 and the elongated sliding track 728. To move the second end piece 711, the user would loosen or remove the reversible fastener 730, slide the second end piece 711 to the desired location, and replace or tighten the reversible fastener 730.
In use, a sheath in an uncrimped diameter can be placed over the elongated mandrel 706 of the crimping device 700, shown in
In some aspects, the crimping mechanism 602 shown in
However, there are also aspects where the distal end portion of the sheath can include additional materials that are used in addition or instead of the material similar to the one used in the outer liner. For example, and without limitation, the distal portion of the sheath can include layers of materials that exceed the number of layers in other parts of the sheath. In some aspects, the distal end portion 902 includes an extension of the outer layer of the sheath, with or without one more additional layer added by separate processing techniques. The distal end portion can include anywhere from 1 to 8 layers of material (including 1, 2, 3, 4, 5, 6, 7, and 8 layers of material). In some aspects, the distal end portion comprises multiple layers of a Dyneema® material. The distal end portion 902 can extend distally beyond a longitudinal portion of the sheath that includes braided layer 904 and elastic layer 906. In fact, in some aspects, the braided layer 904 may extend distally beyond the elastic layer 906, and the distal end portion 902 may extend distally beyond both the braided layer 904 and elastic layer 906, as shown in
The distal end portion 902 may have a smaller collapsed diameter than the more proximal portions of the sheath, giving it a tapered appearance. This smooths the transition between the introducer/dilator and the sheath, ensuring that the sheath does not get lodged against the tissue during insertion into the patient. The smaller collapsed diameter can be a result of multiple folds (for example, 1, 2, 3, 4, 5, 6, 7, or 8 folds) positioned circumferentially (evenly or unevenly spaced) around the distal end portion. For example, a circumferential segment of the distal end portion can be brought together and then laid against the adjacent outer surface of the distal end portion to create an overlapping fold. In the collapsed configuration, the overlapping portions of the fold extend longitudinally along the distal end portion 902. Exemplary folding methods and configurations are described in U.S. Application Number 14/880,109 and U.S. application Ser. No. 14/880,111, each of which are hereby incorporated by reference in their entirety. Scoring can be used as an alternative or in addition to folding of the distal end portion. Both scoring and folding of the distal end portion 902 allow for the expansion of the distal end portion upon the passage of the delivery system and ease the retraction of the delivery system back into the sheath once the procedure is complete. In some aspects, the distal end portion of the sheath (and/or of the vessel dilator) can decrease from the initial diameter of the sheath (e.g., 8 mm) to 3.3 mm (10F) and may decrease to the diameter of a guidewire, allowing the sheath and/or the vessel dilator 300 to run on a guidewire.
In some aspects, a distal end portion can be added, the sheath and tip can be crimped, and the crimping of the distal end portion and sheath can be maintained by the following method. As mentioned above, the distal end portion 902 can be an extension of the outer layer (liner) of the sheath. It can also be a separate, multilayer tubing that is heat bonded to the remainder of the sheath prior to the tip crimping processing steps. In some aspects, the separate, multilayer tubing is heat bonded to a distal extension of the outer layer of the sheath to form the distal end portion 902. For crimping of the sheath after tip attachment, the sheath is heated on a small mandrel. The distal end portion 902 can be folded around the mandrel to create the folded configuration shown in
This method advantageously avoids risks that a tear initiated at a score or split line (such as perforation 813 shown in
The crimping of the inner and outer polymeric layers (liners) 513, 517 and the external covering layer 561 can be, for example, from a pre-compressed diameter of about 8.3 mm to a compressed diameter of about 3 mm.
The method of compressing the distal portion of the expandable sheath can include a step of covering the expandable sheath 501 and the external covering layer 561 with a heat-shrink tube (HST) prior to, during, or following the heating to the second temperature, wherein the second temperature acts to shrink the HST in order to retain the external covering layer 561 and the expandable sheath 501 in a compressed state. The HST can be removed from the expandable sheath 501, and the external covering layer 561 after the folds 563 of the covering layer 563 are sufficiently attached to each other in the desired compressed state and cooled down for a sufficient period of time.
According to some aspects, the HST is utilized as a heat shrink tape to apply the external radial pressure by wrapping and heating it over the external covering layer 561 and the expandable sheath 501.
According to some aspects, a non-heat-shrink tape can be used instead of a heat-shrink tube.
The external covering layer 561 is chosen such that its melting temperature TM1 is lower than the melting temperature TM2 of the polymeric layers of the expandable sheath 100 in order to promote folds' 563 formation with moderate attachment in the external covering layer 561 while avoiding melting and attaching similar folds in the polymeric layers 513 and 517 of the expandable sheath 501.
According to some aspects, the external covering layer 561 is low-density polyethylene. Other suitable materials, as known in the arts, such as polypropylene, thermoplastic polyurethane, and the like, may be utilized to form the external covering layer 561.
According to some aspects, the external covering layer 561 is attached to different attachment regions, such as along a longitudinally oriented attachment line, to the external surface of the expandable sheath 501 (e.g., the outer polymeric layer). According to some aspects, the external covering layer 561 is attached to the external surface of the expandable sheath 501 by a plurality of circumferentially spaced attachment regions 569, wherein the circumferential distance between adjacent attachment regions is chosen to allow formation of folds (or pleats) 563 therebetween. Attachment regions 569 ensure that the external covering layer 561 always remains attached to the expandable sheath 501, either during the compressed or expanded states thereof.
According to some aspects, the covering with an external covering layer 561 is performed after crimping the expandable sheath 501, such that the external layer 561 covers pre-formed folds of inner 513 and/or outer 517 layers of the sheath 501.
According to some aspects, the bond between the folds 563 is based on the adhesive with moderate adhesion strength.
Aspects of the sheaths described herein may comprise a variety of lubricious outer coatings, including hydrophilic or hydrophobic coatings and/or surface blooming additives or coatings.
In some aspects, the scorelines 504 can be configured as openings or cutouts, having various geometrical shapes, such as rhombuses, hexagons, etc., or combinations thereof. In the case of hexagonal openings, the openings can be irregular hexagons with relatively long axial dimensions to reduce foreshortening of the sheath when expanded.
The sheath 500 can comprise an outer layer (not shown), which can comprise a relatively low durometer, elastic thermoplastic material (e.g., Pebax, polyurethane, etc.), and which can be bonded (e.g., by adhesive or welding, such as by heat or ultrasonic welding, etc.) to the inner nylon layer. Attaching the outer layer to the inner layer 502 can reduce the axial movement of the outer layer relative to the inner layer during radial expansion and collapse of the sheath. The outer layer may also form the distal tip of the sheath.
The expandable sheath 601 is configured for advancement in a pre-compressed state up to a target area, for example, along the abdominal aorta or the aortic bifurcation, at which point the clinician should cease further advancement thereof and introduce the DS through its lumen, to facilitate expansion thereof. To that end, the clinician should receive a real-time indication of the expandable sheath's position during the advancement thereof. According to an aspect of the disclosure, there is provided at least one radio-opaque marker at or along at least one region of the expandable braided layer 621, configured to enable visualization of the expandable sheath's position under radio fluoroscopy.
According to one aspect, at least one of the distal crowns 633 comprises a radio-opaque marker. According to some aspects, the distal crowns 633 comprise at least one gold-plated crown 635 (
Since the expandable sheath 601 comprises an expandable braided layer 621 having a plurality of crossing struts 623 disposed along its length, this structure can be advantageously utilized for more convenient incorporation of radio-opaque elements.
According to some aspects, the struts 623 further comprise at least one radio-opaque strut 625, having a radio-opaque core. For example, a drawn-filled tubing (DFT) wire comprising a gold core (as may be provided by, for example, Fort Wayne Metals Research Products Corp.) may serve as a radio-opaque strut 625.
Since radio-opaque wires, such as a DFT wire, can be costly, the expandable braided layer 621 can comprise a plurality of non-radio-opaque or less radio-opaque struts 623, for example, made of a shape-memory alloy such as Nitinol and polymer wire such as PET respectively, intertwined with at least one radio-opaque strut 625 (
According to some aspects, radio-opaque wires are embedded within the polymer braid, such as the outer polymeric layer 617 or the inner polymeric layer 615, which are made of less-opaque materials.
Advantageously, the expandable braid embedded within the expandable sheath is utilized according to the disclosure for incorporating radio-opaque markers along specific portions thereof to improve visualization of the sheath's position in real-time under radio fluoroscopy.
According to yet some aspects of the disclosure, radiopaque tubes can be threaded on the distal crowns or loops 633, or radiopaque rivets can be swaged on the distal crowns or loops 633 to improve their visibility under fluoroscopy.
In order to mitigate uneven surface formations, cushioning polymeric layers 61a, 61b are added between the inner 31 and outer 41 layers of the sheath 11, configured to evenly spread the forces acting in the radial direction during sheath compression. A first cushioning layer 61a is placed between the inner polymeric layer 31 and the braided layer 21, and a second cushioning layer 61b is placed between the outer polymeric layer 41 and the braided layer 21. In some aspects, the cushioning polymeric layers 61a and 61b are sacrificial and are removed in a later processing step.
The cushioning layers 61a, 61b can comprise a porous material having a plurality of micropores of nanopores 63 (
However, when cushioning layers comprise a plurality of micropores of nanopores 63 (
While advantageous for the reasons described above, the addition of the cushioning and sealing can increase the complexity and time required to assemble the sheath 11. Advantageously, providing a single sealed cushioning member configured to provide both cushioning and sealing functionalities (instead of providing two separate cushioning and sealing layers, each configured to provide one functionality) reduces sheath assembly time and significantly simplifies the process. According to an aspect of the disclosure, there is provided a single sealed cushioning member configured for placement between the inner and outer polymeric layers of the sheath and the central braided layer. The single sealed cushioning member includes a cushioning layer and a sealed surface configured to prevent leakage/melting into the pores in the radial direction.
According to some aspects of the disclosure, and as mentioned above, with respect to
The sheath does not necessarily return to an initial diameter but may rather remain in an expanded diameter upon passage of the valve in the absence of the elastic layer.
In some aspects, provided herein is an expandable sheath for deploying a medical device, comprising a first polymeric layer, a braided layer radially outward of the first polymeric layer, and a second polymeric layer radially outward of the braided layer. The braided layer includes a plurality of filaments braided together. The second polymeric layer can be bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers. When a medical device is passed through the sheath, the diameter of the sheath expands from a first diameter to a second diameter around the medical device, while the first and second polymeric layers resist axial elongation of the sheath such that the length of the sheath remains substantially constant. However, according to some aspects, the first and second polymeric layers are not necessarily configured to resist axial elongation.
According to some aspects of the disclosure, the expandable sheath does include an elastic layer. But, unlike elastic layer 106, shown in
In some optional aspects, the elastic layer can be applied by dip coating in the elastic material (such as, but not limited to) silicone or TPU. The dip coating can be applied to the polymeric outer layer or to the braided layer.
Thus, there is provided an expandable sheath for deploying a medical device, comprising a first polymeric layer, a braided layer radially outward of the first polymeric layer, an elastic layer radially outward of the braided layer, and a second polymeric layer radially outward of the braided layer. The braided layers comprise a plurality of filaments braided together. The elastic layer is configured to provide the expandable sheath with sufficient column strength to resist buckling of spontaneous expansion due to friction forces applied thereto by a surrounding anatomical structure during the sheath's movement in an axial direction. The second polymeric layer is bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers. When a medical device is passed through the sheath, the diameter of the sheath expands from a first diameter to a second diameter around the medical device, optionally, while the first and second polymeric layers resist axial elongation of the sheath such that the length of the sheath remains substantially constant.
According to an aspect of the disclosure, there is provided a three-layered expandable sheath comprising an inner polymeric layer, an outer polymeric layer bonded to the inner polymeric layer, and a braided layer encapsulated between the inner and outer polymeric layers, wherein the braided layer comprises an elastic coating.
In some aspects, the second outer polymeric layer 209 is bonded to the first, inner polymeric layer 203, such that the braided layer 205 and the elastic coating 207 are encapsulated between the first and second polymeric layers. Moreover, the elastic coating applied directly to the braided filaments is configured to serve the same function as that of the elastic layer 106 (that is, to apply radial force on the braided layer and the first polymeric layer).
While the aspect of
Alternatively, or additionally, an elastic coating can be applied to other layers of the sheath.
In some aspects, a braided layer 105, such as the one shown in
According to some aspects, an expandable sheath can include a braided expandable layer attached to at least one expandable sealing layer. In some aspects, the braided layer and the sealing layer are the only two layers of the expandable sheath. The braided layer is passively or actively expandable relative to a first diameter, and the at least one expandable sealing layer is passively or actively expandable relative to a first diameter. An expandable sealing layer can be useful with any of the aspects described above and may be particularly advantageous for braids having self-contracting frames or filaments.
The braided layer can be attached or bonded to the expandable sealing layer along its entire length, advantageously decreasing the risk of the polymeric layer being peeled off the braided layer due to frictional forces that may be applied thereon either during entry or exit through the surgical incision. The at least one sealing layer can comprise a lubricious, low-friction material so as to facilitate passage of the sheath within the blood vessels and or to facilitate passage of the delivery apparatus carrying a valve through the sheath.
A sealing layer is defined as a layer that is not permeable to the blood flow. The sealing layer can comprise a polymeric layer, a membrane, a coating, and/or a fabric, such as a polymeric fabric. According to some aspects, the sealing layer comprises a lubricious, low-friction material. According to some aspects, the sealing layer is radially outward to the braided layer so as to facilitate passage of the sheath within the blood vessels. According to some aspects, the sealing layer is radially inward to the braided layer so as to facilitate passage of the medical device through the sheath.
According to some aspects, the at least one sealing layer is passively expandable and/or contractible. In some aspects, the sealing layer is thicker at certain longitudinal positions of the sheath than at others, which can hold a self-contracting braided layer open at a wider diameter than at other longitudinal positions where the sealing layer is thinner.
Attaching the braided layer to at least one expandable sealing layer instead of encapsulating it between two polymeric layers bonded to each other may simplify the manufacturing process and reduce costs.
According to some aspects, the braided layer can be attached to both an outer expandable sealing layer and an inner expandable sealing layer so as to seal the braided layer from both sides while facilitating passage of the sheath along the blood vessels and facilitating passage of a medical device within the sheath. In such aspects, the braided layer can be attached to a first sealing layer, while the other sealing layer may also be attached to the first sealing layer. For example, the braided layer and the inner sealing layer can be each attached to the outer sealing layer, or the braided layer and the outer sealing layer can be each attached to the inner sealing layer.
According to some aspects, the braided layer is further coated by a sealing coating. This may be advantageous in configurations of a braided layer being attached only to a single expandable layer, wherein the coating ensures that the braided layer remains sealed from the blood flow or other surrounding tissues, even along regions that are not covered by the expandable layer. For example, if a braided layer is attached to a sealing layer on one side, the other side of the braided layer may receive a sealing coating. In some aspects, the sealing coating can be used instead of, or in addition to, one or both of the sealing layers.
According to some aspects, an expandable sheath for deploying a medical device are also disclosed. It is understood that in these exemplary aspects, the sheath can comprise any of the layers, elements, or materials described above. It is also understood that any of the described above methods of making the sheath can also be applied to disclosed below exemplary sheaths. Similarly, the methods of making the pleats (folds), such as crimping procedures, are also applicable to the disclosed below exemplary sheaths.
Some exemplary aspects are shown in
In some aspects, an expandable sheath 901 shown in
In some implementations, if desired, an additional low friction polymer layer, such as PTFE, for example (not shown), can be disposed on the first surface of the inner liner. In such an exemplary aspect, the PTFE layer would define the inner surface of the sheath.
In some implementations, the exemplary sheath 901 further comprises an outer low-friction liner 911 having a first surface and an opposite second surface, wherein the second surface of the outer liner defines the outer surface 915 of the sheath 901. It is also understood that similar to the inner liner 903, the outer liner 911 can comprise one or more polymer layers. Yet, in some implementations, the outer liner 911 can comprise two or more polymer layers. In some implementations, the outer liner can comprise from 1 to 8 layers, including an exemplary amount of 2, 3, 4, 5, 6, and 7 layers. It is understood that the outer liner can also comprise more than 8 layers, for example, and without limitation, it can comprise 9, 10, 15, 20, or more than 25 layers. It is understood that in some aspects, the layers of the polymers can be melted together during manufacturing processes.
In some implementations, the outer liner 911 can further comprise any of the disclosed herein hydrophilic coatings.
The sheath 901 can further comprise a first polymeric layer 905 that surrounds radially outward of the inner liner 903, such that it overlies the second surface of the inner liner 903. In the aspects disclosed herein, the first polymeric layer can comprise one or more sublayers. Yet, in some implementations, the first polymeric layer can comprise two or more polymeric sublayers. For example, the first polymeric layer can comprise from 1 to 8 sublayers, including an exemplary amount of 2, 3, 4, 5, 6, and 7 sublayers. It is understood that the first polymeric layer can also comprise more than 8 sublayers, for example, and without limitation, it can comprise 9, 10, 15, 20, or more than 25 sublayers. It is understood that in some aspects, the sublayers of the first polymeric layer can be melted together during manufacturing processes.
In some implementations, the sheath 901 can further comprise a braided layer 907 that is disposed radially outward of the first polymer layer 905.
In some implementations, the sheath 901 can further comprise a second polymeric layer 909 that surrounds radially outward of the braided layer 907. In the aspects disclosed herein, the second polymeric layer can comprise at least one sublayer or two or more polymeric sublayers. For example, the second polymeric layer can comprise from 1 to 8 sublayers, including an exemplary amount of 2, 3, 4, 5, 6, and 7 sublayers. It is understood that the second polymeric layer can also comprise more than 8 sublayers, for example, and without limitation, it can comprise 9, 10, 15, 20, or more than 25 sublayers. It is understood that in some aspects, the sublayers of the second polymeric layer can be melted together during manufacturing processes. As disclosed herein, the first surface of the outer liner 911 overlies the second polymeric layer 909.
For example, and without limitations, any of the disclosed herein braided layers can be used as the braided layer 907. In certain exemplary aspects, the braided layer can comprise a plurality of helical multifilar filaments braided together. In such aspects, the first and second polymeric layers 905, 909 can be thermally bonded to each other through the open spaces of the braided layer 907 such that the braided layer is encapsulated between these two polymeric layers. In some implementations, the first and second polymeric layers 905, 909 can also be thermally bonded to the adjacent inner and outer liners 903, 911. In such aspects, the braided layer is encapsulated between all the layers of the sheath. In some aspects, and as disclosed herein, the inner and outer liners can comprise various polymeric materials. In certain aspects, these polymeric materials can be porous. In such exemplary aspects, the first and second polymeric layers can penetrate at least a portion of the pores present in the porous material of the inner and/or outer liners during the manufacturing process. As a result, the sheath is more mechanically stable than any other known in the art sheaths.
As disclosed in detail above, when the first polymeric layer, second polymeric layer, inner liner, and outer liner encapsulate the braided layer, they can connect (adhere or penetrate if the porous materials are present) to each other through the spaces between the filaments of the braided layer as shown above (for example as shown in
In some implementations, it is understood that the filaments of the braided layer are not adhered to the polymeric layers of the sheath. This can allow the filaments, similarly to the aspects disclosed above, to move angularly relative to each other and relative to the first and the second polymeric layers, as well as relatively to all polymeric layers of the laminate structure, allowing the diameter of the braided layer, and thereby the diameter of the sheath, to increase or decrease upon the passage of the medical device. Again, as disclosed above, in this exemplary sheath, the angle θ between the filaments can change, and the length of the braided layer can also change. For example, as the angle θ increases, the braided layer can foreshorten, and as the angle θ decreases, the braided layer can lengthen to the extent permitted by the areas where the polymeric layers of the laminate structure are bonded. However, because the braided layer is not adhered to the polymeric layers of the sheath, the change in length of the braided layer that accompanies a change in the angle θ between the filaments does not result in a significant change in the length L of the sheath.
In some implementations, the laminate structure of this exemplary sheath can facilitate resistance to kinking and ballooning.
In some implementations, the inner and outer liners can comprise any of the disclosed above materials. In certain aspects, the inner liner comprises a first material. In some implementations, the outer liner can comprise a fourth material. In certain exemplary aspects, the first and fourth materials can be the same or different.
In some aspects, the material (the first and the fourth) of a low friction inner and outer liners 903, 911 can be a material with a relatively low coefficient of friction yet a relatively high tensile strength. The inner and/or outer liners can have a coefficient of friction of less than about 0.3, less than about 0.2, less than about 0.1, less than about 0.09, less than about 0.08, less than about 0.07, less than about 0.06, less than about 0.05, less than about 0.04, less than about 0.03, less than about 0.02, or even less than about 0.01.
In some exemplary aspects, materials for the inner and outer liners (the first and the fourth) can comprise ultra-high molecular weight polyethylene (UHMWPE). In some implementations, the UHMWPE can be present as a fabric, a laminate, or a porous film or membrane. For example, the inner and outer liners can comprise or be formed of Dyneema® UHMWPE. In some aspects, the inner and outer liner can comprise, or be formed of, the Dyneema Purity® membrane, which has a tensile strength of about 20 MPa. In some exemplary and unlimiting aspects, the inner and outer liner can also be formed by coating. In such aspects, the UHMWPE can be provided as a polymeric solution, for example. Any known in the art coating methods can be utilized. For example, the coating methods can include dipping, doctor blade coating, spraying, and the like.
Other suitable materials for the inner and outer liners (in addition or instead of those disclosed above) can include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyether block amide (e.g., Pebax), and/or combinations of any of the above. Again, it is understood that these materials can also be provided in any known in the art form.
In some implementations, the first polymeric layer and the second polymeric layer can also comprise any of the disclosed herein materials. In some aspects, the first polymeric layer and the second polymeric layer can be the same or different. In some aspects, the first polymer layer can comprise a second material, while the second polymeric layer can comprise a third material. Again, as mentioned above, the second material and the third materials can be the same or different. In certain aspects, the second material and/or the third material can comprise polyolefin or polyurethane. In some implementations, the polyolefin can comprise polyethylene, polypropylene, or a combination thereof. In some implementations, where the second material and/or the third material are polyolefin, such a polyolefin can comprise a bi-oriented polypropylene, cast polypropylene, a low-density polyethylene (LDPE), or a high density polyethylene (HDPE), or any combination thereof. In some implementations, where the second material and/or the third material are polyurethane, such aspects comprise a thermoplastic polyurethane.
It is understood that the second and/or the third materials can be provided in any form known in the art. In some aspects, they can be provided as a film or as a solution. In such aspects, if the materials are provided as a solution, the first and the second polymeric materials can be formed by coating, for example, dipping, spraying, doctor blade coating, and the like.
In some implementations, the tensile strength of the first polymeric layer and/or the second polymeric layer is substantially the same or different from the tensile strength of the inner liner and/or outer liner. In some implementations, the tensile strength of the first polymeric layer and/or the second polymeric layer can be larger than the tensile strength of the inner liner and/or outer liner. In some implementations, the tensile strength of the first polymeric layer and/or the second polymeric layer can be smaller than the tensile strength of the inner liner and/or outer liner.
In some exemplary aspects, the porous structure of inner and outer liners, the liner 903, 911 can enable the first and second polymeric layers 905, 909 to flow into the pores during processing to mechanically bond the layers together. Such a laminate structure allows the sheath to be more mechanically stable and durable. In such exemplary aspects, the inner liner and the outer liner can exhibit a mechanical strength higher than a mechanical strength of a reference sheath that does not comprise a substantially identical laminated structure. In some implementations, the disclosed herein sheath can exhibit an improved column strength when compared with a substantially identical reference sheath in the absence of a laminate structure.
In some aspects, liners 903, 911 can be relatively thin compared to the radial thickness of the adjacent first and second polymeric layers, having the appearance of a liner or a membrane. For example, the liner can have a radial thickness ranging from about 0.5 microns to about 40 microns, including about 1 micron, about 2 microns, about 3 microns, about 4 microns, 5 microns, about 10 microns, about 15 microns, about 20 microns, about 25 microns, about 30 microns, about 35 microns, and about 40 microns.
In some implementations and as illustrated in
The plurality of pleats, as shown in
Yet, in some implementations, the pleats can be structured circumferentially or longitudinally in any desired pattern. It is also understood that these pleats along the length of the sheath are formed as the various polymer layers encapsulate the braid during the manufacturing proceedings and are flattening out or shortened as a result of braid expansion.
In other words, in some aspects, the plurality of pleats can be uniformly distributed along at least a portion of a length of the sheath and at least a portion of a circumference of the sheath; while in some implementations, the plurality of pleats can be randomly distributed along at least a portion of a length of the sheath and at least a portion of a circumference of the sheath.
In some implementations, as the medical device is passed through the sheath, the ridges and valleys of the pleats can at least partially level out to allow a sheath wall to radially expand and allow the medical device to pass through without damaging the sheath or vascular system of the patient. The photograph of the locally collapsed and locally expanded sheath is shown in
It can be seen in
The folds can be arranged in an orderly fashion, as shown in
As a medical device passes through the inner lumen of the tip, it applies an outward radial force on the sheath wall 703. This causes the plurality of longitudinally-extending pleats 763 to partially or fully unfold (or at least partially smooth out) (that is, a single longitudinally-extending pleat may partially or fully unfold, and several of the longitudinally-extending pleats may partially or fully unfold, or all of the longitudinally-extending pleats may partially or fully unfold).
In some implementations, an additional lubricious liner can be used. In such aspects, this liner can be applied to the first surface of the sheath and becomes the most inner surface of the sheath. In such aspects, this additional lubricious liner can comprise a low coefficient of friction materials that can facilitate the passage of the medical device through the inner lumen.
An example of a method of making an expandable sheath is depicted in
Next, in reference to
Continuing to refer to
The layers are then covered by a heat shrink wrap and laminated by heating. This step allows the polymeric layers to flow into the unit cells of the braided layer. The sacrificial outer layers do not adhere to the sheath layers or the heat shrink wrap, thus assisting with the removal of the heat shrink wrap.
Continuing to refer to
An example aspect of the disclosed sheath is shown in
In some implementations, the fifth material can be any material that is suitable for the desired application. Yet, in some implementations, the fifth material can comprise ultra-high molecular weight polyethylene (UHMWPE). In some implementations, the UHMWPE can be present as a fabric, a laminate, or a porous film or membrane. For example, the fifth material forming the third polymeric layer can comprise or be formed of Dyneema® UHMWPE. In some aspects, the third polymeric layer can comprise, or be formed of, the Dyneema Purity® membrane, which has a tensile strength of about 20 MPa.
In some exemplary and unlimiting aspects, the third polymeric layer can also be formed by coating. In such aspects, the UHMWPE can be provided as a polymeric solution, for example. Any known in the art coating methods can be utilized. For example, the coating methods can include dipping, doctor blade coating, spraying, and the like.
It is understood that in aspects where the third polymeric layer is present, such a layer is formed after the laminate structure described herein and comprising the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, and the outer liner is formed.
In some implementations, after the third polymeric layer is formed either by wrapping the fifth material or by coating, a structure is heated to a temperature from about 120° C. to about 150° C., including exemplary values of about 125° C., about 130° C., about 135° C., about 140° C., and about 145° C. It is understood that at such temperatures, the third material is not fully melted and, therefore, is not expected to penetrate all the layers beneath it, and more specifically, it is not expected to be bound to the braided layer. In some implementations, at such temperatures, the third polymeric layer is at least partially bonded to the outer liner.
In certain aspects, prior to the exposure of the third polymeric layer to the described above temperature, a sacrificial heat tubing is first disposed on the third polymeric layer, and then the sheath is exposed to elevated temperatures. Yet, in some implementations, the heating of the third polymeric layer to form the described herein sheath can be performed without the presence of the sacrificial heath tubing.
In some implementations, where the third polymeric layer is laminated to at least a portion of the outer liner, an outer surface of the third polymeric layer is smoother than an outer surface of the outer liner anywhere on the sheath. In some implementations, an outer surface of the third polymeric layer exhibits less roughness than an outer surface of the outer liner anywhere on the sheath.
In yet some implementations, the third polymeric layer exhibits higher porosity than the outer liner.
In some implementations, the at least portion of the proximal end of the sheath that is covered by the third polymeric layer is up to about 15 cm, including exemplary values of about 1 cm, about 2 cm, about 3 cm, about 4 cm, about 5 cm, about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, and about 14 cm.
In some implementations, at least a portion of the sheath with the third polymeric layer is inserted into a patient's body. In such aspects, the third polymeric sheath can form a substantial seal with the patient's natural anatomy to prevent unnecessary blood loss.
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices, and/or methods claimed herein are made and evaluated and are intended to be purely exemplary and are not intended to limit the disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, specific conditions, etc.), but some errors and deviations should be accounted for.
The performance of the disclosed herein sheath was evaluated in an animal model with small bold vessels. Push and pull forces needed to operate the disclosed herein sheath were compared with the push and pull forces needed to operate other conventional and commercially available sheaths. The damage to the artery and the surrounding areas were evaluated.
The sheaths used herein comprised Dyneema@ inner and outer liners and cast polypropylene or low-density polyethylene as the first and the second polymeric layers. The sheath inner diameter ranged from 12 F to 14 F. The sheath was inserted either in the right or left femoral artery, and the results were compared.
Animals used in the study had an average weight of about 105-110 kg and had a femoral artery size of about 4.5-5.5 mm. It was found that disclosed herein, sheaths require significantly lower push force (25-55 N) when compared with a commercially available sheath having a different design (>60N).
In view of the described processes and compositions, hereinbelow are described certain more particularly described aspects of the disclosures. These particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.
EXAMPLE 1: An expandable sheath for deploying a medical device having a proximal end and a distal end, an inner surface and an outer surface and comprising: an inner liner comprising one or more polymer layers; wherein the inner liner has a first surface and an opposite second surface, wherein the first surface of the inner liner defines the inner surface of the sheath; a first polymeric layer surrounding radially outward of the inner liner, such that it positioned at the second surface of the inner liner and wherein the first polymeric layer comprises one or more sublayers; a braided layer disposed radially outward of the first polymeric layer; a second polymeric layer surrounding radially outward of the braided layer, wherein the second polymeric layer comprises one or more sublayers; an outer liner comprising one or more polymer layers; wherein the outer liner has a first surface and an opposite second surface, wherein the first surface of the outer liner overlies the second polymeric layer, and wherein the second surface of the liner layer defines the outer surface of the sheath; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; and wherein when a medical device is passed through the sheath, a diameter of the sheath locally expands from a first unexpended diameter around the medical device to a second expanded diameter, while the first and second polymeric layers resist axial elongation of the sheath such that a length of the sheath remains substantially constant; and wherein the sheath resiliently returns to a third diameter after the passage of the medical device.
EXAMPLE 2: The expandable sheath of any one of examples herein, particularly example 1, wherein the third diameter is substantially similar to the first unexpanded diameter.
EXAMPLE 3: The expandable sheath of any examples herein, particularly examples 1-2, wherein the inner liner comprises two or more polymer layers, wherein each of the polymer layers has a thickness from about 0.5 microns to about 40 microns.
EXAMPLE 4: The expandable sheath of any one of examples herein, particularly example 3, wherein the two or more polymer layers are laminated together.
EXAMPLE 5: The expandable sheath of any one of examples herein, particularly examples 1-4, wherein the outer liner comprises two or more polymer layers, wherein each of the polymer layers has a thickness from about 0.5 microns to about 40 microns.
EXAMPLE 6: The expandable sheath of any one of examples herein, particularly example 5, wherein the two or more polymer layers are laminated together.
EXAMPLE 7: The expandable sheath of any one of examples herein, particularly examples 1-6, wherein the first polymeric layer comprises two or more polymer sublayers, wherein each of the polymer sublayers has a thickness from about 0.5 microns to about 40 microns.
EXAMPLE 8: The expandable sheath of any one of examples herein, particularly example 7, wherein the two or more polymer sublayers are laminated together.
EXAMPLE 9: The expandable sheath of any one of examples herein, particularly examples 1-8, wherein the second polymeric layer comprises two or more polymer sublayers, wherein each of the polymeric layers has a thickness from about 0.5 microns to about 40 microns.
EXAMPLE 10: The expandable sheath of any one of examples herein, particularly example 9, wherein the two or more polymer sublayers are laminated together.
EXAMPLE 11: The expandable sheath of any one of examples herein, particularly examples 1-10, wherein the first polymeric layer is provided as a film or as a coating.
EXAMPLE 12: The expandable sheath of any one of examples herein, particularly example 11, wherein the one or more layers of the first polymeric layer are one or more layers of the film.
EXAMPLE 13: The expandable sheath of any one of examples herein, particularly example 12, wherein the one or more layers of the first polymeric layer are one or more layers of the coating.
EXAMPLE 14: The expandable sheath of any one of examples herein, particularly examples 1-13, wherein the second polymeric layer is provided as a film or as a coating.
EXAMPLE 15: The expandable sheath of any one of examples herein, particularly example 14, wherein the one or more layers of the second polymeric layer are one or more layers of the film.
EXAMPLE 16: The expandable sheath of any one of examples herein, particularly example 14, wherein the one or more layers of the second polymeric layer are one or more layers of the coating.
EXAMPLE 17: The expandable sheath of any one of examples herein, particularly examples 1-16, wherein a portion of the proximal end of the expandable sheath further comprises a third polymeric layer comprising one or more layers and surrounding radially outward of the outer layer.
EXAMPLE 18: The expandable sheath of any one of examples herein, particularly example 17, wherein the third polymeric layer is provided as a film or as a coating.
EXAMPLE 19: The expandable sheath of any one of examples herein, particularly examples 17 or 18, wherein the third polymeric layer is applied to the outer liner, after the inner liner, the first polymeric layer, the second polymeric layer, and the outer liner form the laminate structure.
EXAMPLE 20: The expandable sheath of any one of examples herein, particularly examples 17-19, wherein an outer surface of the third polymeric layer is substantially smoother than an outer surface of the outer liner.
EXAMPLE 21: The expandable sheath of any one of examples herein, particularly examples 17-20, wherein an outer surface of the third polymeric layer has a roughness substantially smaller than an outer surface of the outer liner.
EXAMPLE 22: The expandable sheath of any one of examples herein, particularly examples 17-21, wherein the third polymeric layer has a porosity substantially larger than a porosity of the outer liner.
EXAMPLE 23: The expandable sheath of any one of examples herein, particularly examples 17-22, wherein the third polymeric layer is bonded to at least a portion of the outer liner.
EXAMPLE 24: The expandable sheath of any one of examples herein, particularly examples 17-23, wherein the third polymeric layer is not bonded to the braided layer.
EXAMPLE 25: The expandable sheath of any one of examples herein, particularly examples 17-24, wherein the portion of the proximal end is from about 10 mm to about 150 mm from a proximal edge of the sheath.
EXAMPLE 26: The expandable sheath of any one of examples herein, particularly examples 17-25, wherein the third polymeric layer comprises from about 2 to about 10 layers.
EXAMPLE 27: The expandable sheath of any one of examples herein, particularly examples 17-26, wherein the third polymeric layer forms a substantial seal with a patient's natural anatomy upon insertion into a patient's body.
EXAMPLE 28: The expandable sheath of any one of examples herein, particularly examples 1-27, wherein the one or more polymer layers of the inner liner and/or outer liner comprise an ultra-high-molecular-weight polyethylene (UHMWP) polymer layer.
EXAMPLE 29: The expandable sheath of any one of examples herein, particularly example 28, wherein the UHMWP polymer layer is a porous film.
EXAMPLE 30: The expandable sheath of any one of examples herein, particularly example 28 or 29, wherein the UHMWP polymer is Dyneema®.
EXAMPLE 31: The expandable sheath of any one of examples herein, particularly examples 1-30, wherein the first polymeric layer comprises at least one sublayer comprising a polyolefin or a polyurethane.
EXAMPLE 32: The expandable sheath of any one of examples herein, particularly examples 1-31, wherein the second polymeric layer comprises at least one sublayer comprising a polyolefin or a polyurethane.
EXAMPLE 33: The expandable sheath of any one of examples herein, particularly example 31 or 32, wherein the polyolefin comprises polyethylene, polypropylene, or a combination thereof.
EXAMPLE 34: The expandable sheath of any one of examples herein, particularly example 33, wherein the polypropylene comprises a bi-oriented polypropylene, a cast polypropylene, or a combination thereof.
EXAMPLE 35: The expandable sheath of any one of examples herein, particularly example 33, wherein the polyethylene comprises a low-density polyethylene (LDPE), a high density polyethylene (HDPE), or a combination thereof.
EXAMPLE 36: The expandable sheath of any one of examples herein, particularly example 33, wherein the polyolefin comprises a bi-oriented polypropylene, a cast polypropylene, a low-density polyethylene (LDPE), a high density polyethylene (HDPE), or a combination thereof.
EXAMPLE 37: The expandable sheath of any one of examples herein, particularly example 32, wherein the polyurethane comprises a thermoplastic polyurethane.
EXAMPLE 38: The expandable sheath of any one of examples herein, particularly examples 17-37, wherein the third polymeric layer comprises an ultra-high-molecular-weight polyethylene (UHMWP) polymer layer.
EXAMPLE 39: The expandable sheath of any one of examples herein, particularly example 38, wherein the UHMWP polymer layer is a porous film.
EXAMPLE 40: The expandable sheath of any one of examples herein, particularly example 38 or 39, wherein the UHMWP polymer is Dyneema®.
EXAMPLE 41: The expandable sheath of any one of examples herein, particularly examples 1-40, wherein the tensile strength of the first polymeric layer and/or the second polymeric layer is substantially the same or different from the tensile strength of the inner liner and/or outer liner.
EXAMPLE 42: The expandable sheath of any one of examples herein, particularly examples 1-41, wherein the tensile strength of the first polymeric layer and/or the second polymeric layer is larger than the tensile strength of the inner liner and/or outer liner.
EXAMPLE 43: The expandable sheath of any one of examples herein, particularly examples 1-41, wherein the tensile strength of the first polymeric layer and/or the second polymeric is smaller than the tensile strength of the inner liner and/or outer liner.
EXAMPLE 44: The expandable sheath of any one of examples herein, particularly examples 1-43, wherein the inner surface of the sheath is substantially smooth.
EXAMPLE 45: The expandable sheath of any one of examples herein, particularly examples 1-44, wherein the sheath comprises a plurality of longitudinally extending pleats.
EXAMPLE 46: The expandable sheath of any one of examples herein, particularly example 45, wherein the plurality of pleats extend around at least a portion of a circumference of the sheath.
EXAMPLE 47: The expandable sheath of any one of examples herein, particularly example 45 or 46, wherein each of the plurality of pleats comprises at least a portion of the inner liner, at least a portion of the first polymeric layer, at least a portion of the second polymeric layer, and at least a portion of the outer liner.
EXAMPLE 48: The expandable sheath of any one of examples herein, particularly examples 45-47, wherein the plurality of pleats extend along at least a portion of a length of the sheath.
EXAMPLE 49: The expandable sheath of any one of examples herein, particularly examples 45-48, wherein the plurality of pleats are uniformly distributed along at least a portion of a length of the sheath and at least a portion of a circumference of the sheath.
EXAMPLE 50: The expandable sheath of any one of examples herein, particularly examples 45-49, wherein the plurality of pleats are randomly distributed along at least a portion of a length of the sheath and at least a portion of a circumference of the sheath.
EXAMPLE 51: The expandable sheath of any one of examples herein, particularly examples 45-50, wherein the plurality of pleats form a plurality of circumferentially spaced ridges and a plurality of circumferentially spaced valleys, and wherein, as the medical device is passed through the sheath, the ridges and valleys at least partially level out to allow a sheath wall to radially expand.
EXAMPLE 52: The expandable sheath of any one of examples herein, particularly examples 1-51, wherein the first polymeric layer is bonded or adhered to at least a portion of the second surface of the inner liner, and the second polymeric layer is bonded or adhered to at least a portion of the first surface of the outer liner.
EXAMPLE 53: The expandable sheath of any one of examples herein, particularly example 52, when the one or more polymer layers of the inner liner comprise the porous film, at least a portion of the first polymeric layer extends within at least a portion of the porous film of the inner liner.
EXAMPLE 54: The expandable sheath of any one of examples herein, particularly example 52 or 53, when the one or more polymer layers of the outer liner comprises the porous film, at least a portion of the second polymeric layer extends within at least a portion of the porous film of the outer liner.
EXAMPLE 55: The expandable sheath of any one of examples herein, particularly examples 52-54, wherein the inner liner and the outer liner exhibit a mechanical strength higher than a mechanical strength of a substantially identical reference sheath in the absence of the laminate structure.
EXAMPLE 56: The expandable sheath of any one of examples herein, particularly examples 1-55, wherein the braided layer comprises a plurality of helical multifilar filaments braided together.
EXAMPLE 57: The expandable sheath of any one of examples herein, particularly example 56, wherein the plurality of helical multifilar filaments comprise nitinol.
EXAMPLE 58: The expandable sheath of any one of examples herein, particularly example 56 or 57, wherein the braided layer has a proximal end and a distal end.
EXAMPLE 59: The expandable sheath of any one of examples herein, particularly example 58, wherein the braided layer comprises a plurality of closed loops at the distal end of the braid.
EXAMPLE 60: The expandable sheath of any one of examples herein, particularly examples 58-59, wherein the proximal end of the braided layer is positioned along the proximal end of the sheath.
EXAMPLE 61: The expandable sheath of any one of examples herein, particularly examples 58-60, wherein the braided layer has a length extending from the proximal end of the braided layer to the distal end of the braided layer and wherein the braided layer length is shorter than a length of the sheath measured from proximal end of the sheath to the distal end of the sheath.
EXAMPLE 62: The expandable sheath of any one of examples herein, particularly examples 56-61, wherein the braided layer has a weave pattern of 1×1.
EXAMPLE 63: The expandable sheath of any one of examples herein, particularly examples 56-61, wherein the braided layer has a weave pattern of 2×2.
EXAMPLE 64: The expandable sheath of any one of examples herein, particularly examples 56-61, wherein the braided layer has a weave pattern of 2×1.
EXAMPLE 65: The expandable sheath of any one of examples herein, particularly examples 56-64, wherein the braided layer comprises a self-contracting material.
EXAMPLE 66: The expandable sheath of any one of examples herein, particularly examples 56-65, wherein the braided layer comprises a shape memory material exhibiting superelastic properties at temperatures at or above 15 degrees Celsius.
EXAMPLE 67: The expandable sheath of any one of examples herein, particularly examples 56-66, wherein a portion of the plurality of filaments comprises an elastic coating.
EXAMPLE 68: The expandable sheath of any one of examples herein, particularly examples 56-67, wherein the filaments of the braided layer are movable between the first and second polymeric layers such that the braided layer is configured to radially expand as a medical device is passed through the sheath while the length of the sheath remains substantially constant.
EXAMPLE 69: The expandable sheath of any one of examples herein, particularly examples 56-68, wherein the filaments of the braided layer are resiliently buckled when the sheath is in a collapsed configuration, and the first and second polymeric layers are attached to each other at a plurality of open spaces between the filaments of the braided layer.
EXAMPLE 70: The expandable sheath of any one of examples herein, particularly examples 1-69, further comprising an outer cover formed of a heat shrink material and extending over at least a longitudinal portion of the first polymeric layer and the second polymeric layer, the outer cover comprising one or more longitudinally extending slits, weakened portions, or scorelines.
EXAMPLE 71: The expandable sheath of any one of examples herein, particularly examples 1-70, wherein the sheath further comprises an elastic outer layer that applies an inward radial force on a sheath wall, biasing the sheath toward the unexpanded state.
EXAMPLE 72: The expandable sheath of any one of examples herein, particularly examples 1-71, wherein the sheath exhibits an improved column strength when compared with a substantially identical reference sheath in the absence of a laminate structure.
EXAMPLE 73: The expandable sheath of any one of examples herein, particularly examples 1-72, wherein the medical device is a prosthetic heart valve.
EXAMPLE 74: An expandable sheath for deploying a medical device having a proximal end and a distal end, an inner surface and an outer surface and comprising: an inner liner comprising one or more polymer layers; wherein the inner liner has a first surface and an opposite second surface, wherein the first surface of the inner liner defines the inner surface of the sheath; a first polymeric layer surrounding radially outward of the inner liner, such that it positioned at the second surface of the inner liner and wherein the first polymeric layer comprises one or more sublayers; a braided layer disposed radially outward of the first polymeric layer; a second polymeric layer surrounding radially outward of the braided layer, wherein the second polymeric layer comprises one or more sublayers; an outer liner comprising one or more polymer layers; wherein the outer liner has a first surface and an opposite second surface, wherein the first surface of the outer liner overlies the second polymeric layer, and wherein the second surface of the liner layer defines the outer surface of the sheath; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; wherein the inner liner, the first polymeric layer, the second polymeric layer and the outer liner form a laminate structure; and wherein when a medical device is passed through the sheath, the diameter of the sheath locally expands from a first unexpended diameter around the medical device to a second expanded diameter, while the first and second polymeric layers resist axial elongation of the sheath such that a length of the sheath remains substantially constant; and wherein the sheath resiliently returns to a third diameter after the passage of the medical device.
EXAMPLE 75: A method of making an expandable sheath, the method comprising: forming an inner liner; wherein the inner liner comprises one or more polymer layers and wherein the inner liner has a first surface and an opposite second surface; forming a first polymeric layer, wherein the first polymeric layer is positioned radially outward of the inner liner; wherein the first polymeric layer comprises one or more sublayers; and wherein the first polymeric layer overlies the second surface of the inner liner; positioning a braided layer radially outward of a first polymeric layer; forming a second polymeric layer such that it is positioned radially outward of the braided layer; wherein the second polymeric layer comprises one or more sublayers; forming an outer liner radially outward of the second polymeric layer; wherein the outer liner comprises one or more polymer layers; and wherein the outer liner has a first surface and an opposite second surface and wherein the first surface of the outer liner is in contact with at least a portion of the second polymeric layer; heating the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, and the outer liner to form a laminate structure; and crimping the laminate structure to form a plurality of longitudinally-extending pleats, wherein the plurality of longitudinally-extending pleats are configured to expand upon passage of a medical device through the sheath.
EXAMPLE 76: The method of any one of examples herein, particularly example 75, wherein the step of forming the inner liner comprises wrapping a first material around an initial mandrel.
EXAMPLE 77: The method of any one of examples herein, particularly example 75 or 76, wherein the first material comprises an ultra-high-molecular-weight polyethylene (UHMWP) polymer film.
EXAMPLE 78: The method of any one of examples herein, particularly example 76 or 77, wherein the step of wrapping of the first material comprises forming two or more polymer layers of the inner liner.
EXAMPLE 79: The method of any one of examples herein, particularly example 77 or 78, wherein the UHMWP polymer film is porous.
EXAMPLE 80: The method of any one of examples herein, particularly examples 75-79, wherein the step of forming the first polymeric layer comprises wrapping a second material radially outward of the second surface of the inner liner.
EXAMPLE 81: The method of any one of examples herein, particularly example 80, wherein the step of wrapping of the second material comprises forming two or more polymer sublayers of the first polymeric layer.
EXAMPLE 82: The method of any one of examples herein, particularly examples 75-81, wherein the step of forming the first polymeric layer comprises coating of the second surface of the inner liner with one or more layers of a second material to form the one or more sublayers of the first polymeric layer.
EXAMPLE 83: The method of any one of examples herein, particularly example 82, wherein the coating comprises dipping, spray-coating, brush-coating, doctor blade coating, or any combination thereof.
EXAMPLE 84: The method of any one of examples herein, particularly examples 75-83, wherein the step of forming the second polymeric layer comprises wrapping a third material outward of the braided layer.
EXAMPLE 85: The method of any one of examples herein, particularly example 84, wherein the step of wrapping of the third material comprises forming two or more polymer sublayers of the second polymeric material.
EXAMPLE 86: The method of any one of examples herein, particularly examples 75-83, wherein the step of forming the second polymeric layer comprises coating the braided layer with one or more layers of a third material to form the one or more sublayers of the first polymeric layer.
EXAMPLE 87: The method of any one of examples herein, particularly example 86, wherein the coating comprises dipping, spray-coating, brush-coating, doctor blade coating, or any combination thereof.
EXAMPLE 88: The method of any one of examples herein, particularly examples 81-87, wherein the second material and the third material are the same or different.
EXAMPLE 89: The method of any one of examples herein, particularly examples 81-88, wherein the second material and/or the third material comprise a polyolefin or a polyurethane.
EXAMPLE 90: The method of any one of examples herein, particularly example 89, wherein the polyolefin comprises polyethylene, polypropylene, or a combination thereof.
EXAMPLE 91: The method of any one of examples herein, particularly example 90, wherein the polypropylene comprises a bi-oriented polypropylene, a cast polypropylene, or a combination thereof.
EXAMPLE 92: The method of any one of examples herein, particularly example 91, wherein the polyethylene comprises a low-density polyethylene (LDPE), a high density polyethylene (HDPE), or a combination thereof.
EXAMPLE 93: The method of any one of examples herein, particularly example 92, wherein the polyolefin comprises a bi-oriented polypropylene, a cast polypropylene, a low-density polyethylene (LDPE), a high density polyethylene (HDPE), or a combination thereof.
EXAMPLE 94: The method of any one of examples herein, particularly example 89, the second material and/or the third material comprise a thermoplastic polyurethane.
EXAMPLE 95: The method of any one of examples herein, particularly examples 75-94, wherein the step of forming the outer liner comprises wrapping a fourth material radially outward of the second surface of the second polymeric layer.
EXAMPLE 96: The method of any one of examples herein, particularly example 95, wherein the step of wrapping the fourth material comprises forming two or more polymer layers of the outer layer.
EXAMPLE 97: The method of any one of examples herein, particularly example 95 or 96, wherein the fourth material and the first material are the same or different.
EXAMPLE 98: The method of any one of examples herein, particularly examples 95-97, wherein the fourth material comprises an ultra-high-molecular-weight polyethylene (UHMWP) polymer film.
EXAMPLE 99: The method of any one of examples herein, particularly example 98, wherein the UHMWP polymer film is porous.
EXAMPLE 100: The method of any one of examples herein, particularly examples 75-99, wherein after forming the laminate structure, the method further comprises forming a third polymeric layer at at least a portion of the proximal end of the sheath.
EXAMPLE 101: The method of any one of examples herein, particularly example 100, the step of forming the third polymeric layer comprises wrapping a fifth material radially outward of an outer surface of the outer liner, forming one or more polymer layers of the third polymeric layer.
EXAMPLE 102: The method of any one of examples herein, particularly example 101, wherein the fifth material comprises an ultra-high-molecular-weight polyethylene (UHMWP) polymer film.
EXAMPLE 103: The method of any one of examples herein, particularly example 102, wherein the UHMWP polymer film is porous.
EXAMPLE 104: The method of any one of examples herein, particularly examples 100-103, wherein the sheath is heated to a temperature from about 120° C. to about 150° C. to laminate the third polymeric layer to at least a portion of the outer liner.
EXAMPLE 105: The method of any one of examples herein, particularly examples 100-104, wherein an outer surface of the third polymeric layer is substantially smoother than an outer surface of the outer liner.
EXAMPLE 106: The method of any one of examples herein, particularly examples 100-105, wherein an outer surface of the third polymeric layer has a roughness substantially smaller than an outer surface of the outer liner.
EXAMPLE 107: The method of any one of examples herein, particularly examples 100-106, wherein the third polymeric layer has a porosity substantially larger than a porosity of the outer liner.
EXAMPLE 108: The method of any one of examples herein, particularly examples 100-107, wherein the third polymeric layer is not bonded to the braided layer.
EXAMPLE 109: The method of any one of examples herein, particularly examples 100-108, wherein the portion of the proximal end is from about 10 mm to about 150 mm from a proximal edge of the sheath.
EXAMPLE 110: The method of any one of examples herein, particularly examples 100-109, wherein the third polymeric layer comprises from about 2 to about 10 layers.
EXAMPLE 111: The method of any one of examples herein, particularly examples 100-110, wherein the third polymeric layer forms a substantial seal with a patient's natural anatomy upon insertion into a patient's body.
EXAMPLE 112: The method of any one of examples herein, particularly examples 75-111, wherein the tensile strength of the first polymeric layer and/or the second polymeric layer is substantially the same or different as the tensile strength of the inner liner and/or outer liner.
EXAMPLE 113: The method of any one of examples herein, particularly examples 75-112, wherein the tensile strength of the first polymeric layer and/or the second polymeric layer is larger than the tensile strength of the inner liner and/or outer liner.
EXAMPLE 114: The method of any one of examples herein, particularly examples 75-112, wherein the tensile strength of the first polymeric layer and/or the second polymeric is smaller than the tensile strength of the inner liner and/or outer liner.
EXAMPLE 115: The method of any one of examples herein, particularly examples 75-114, wherein prior to the step of forming the laminate structure, the method further comprises positioning a first heat shrink tube radially outward of the second surface of the outer liner.
EXAMPLE 116: The method of any one of examples herein, particularly example 115, wherein the step of heating comprises applying heat to the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, the outer liner, and the heat shrink tube.
EXAMPLE 117: The method of any one of examples herein, particularly example 116, further comprises removing the first heat shrink tube after forming the laminate structure.
EXAMPLE 118: The method of any one of examples herein, particularly examples 75-117, wherein after the step of heating, the method comprises removing the laminate structure from the initial mandrel prior.
EXAMPLE 119: The method of any one of examples herein, particularly examples 75-118 wherein the step of crimping comprises positioning the laminate structure on a second mandrel, wherein the second mandrel is the same or different from the first mandrel and crimping the laminate structure to form the plurality of longitudinally-extending pleats.
EXAMPLE 120: The method of any one of examples herein, particularly example 119, further comprising positioning a second heat shrink tube radially outward of the plurality of longitudinally-extending pleats and heating the laminate structure having the plurality of longitudinally-extending pleats and the second heat shrink tube to cause the plurality of longitudinally-extending pleats to at least partially bond to each other.
EXAMPLE 121: The method of any one of examples herein, particularly example 120, further comprising removing the second heat shrink tube.
EXAMPLE 122: The method of any one of examples herein, particularly examples 75-121, wherein the step of heating comprises at least partially bonding the inner liner, the first polymeric layer, the second polymer layer, and the outer liner together.
EXAMPLE 123: The method of any one of examples herein, particularly examples 75-122, wherein the step of heating comprises at least partially encapsulating the braided layer within the inner liner, the first polymeric layer, the second polymer layer, and the outer liner.
EXAMPLE 124: The method of any one of examples herein, particularly examples 80-123, wherein the step of heating comprises the second material at least partially penetrating the porous first material.
EXAMPLE 125: The method of any one of examples herein, particularly examples 84-124, wherein the step of heating comprises the third material at least partially penetrating the porous fourth material.
EXAMPLE 126: The method of any one of examples herein, particularly examples 75-125, further comprising positioning one or more inner sacrificial layers prior to forming the inner liner and removing the one or more inner sacrificial layers prior to creating the plurality of longitudinally-extending pleats.
EXAMPLE 127: The method of any one of examples herein, particularly examples 75-126, further comprising positioning one or more outer sacrificial layers radially outward of the outer liner after forming the outer liner and removing the one or more outer sacrificial layers prior to creating the plurality of longitudinally-extending pleats.
EXAMPLE 128: The method of any one of examples herein, particularly examples 75-127, further comprising positioning a cushioning layer adjacent to the braided layer and removing it in a later processing step.
EXAMPLE 129: The method of any one of examples herein, particularly example 128, further comprising applying a sealing layer to the cushioning layer.
EXAMPLE 130: The method of any one of examples herein, particularly examples 75-129, wherein the braided layer comprises a plurality of helical multifilar filaments braided together.
EXAMPLE 131: The method of any one of examples herein, particularly example 130, wherein the plurality of helical multifilar filaments comprise nitinol.
EXAMPLE 132: The method of any one of examples herein, particularly example 130 or 131, wherein the method comprises applying an elastic coating to a portion of the plurality of helical multifilar filaments
EXAMPLE 133: The method of any one of examples herein, particularly examples 75-132, further comprising setting the braided layer to a contracted diameter prior to placing the braided layer radially outward of the first polymeric layer.
EXAMPLE 134: The method of any one of examples herein, particularly examples 75-133, wherein when a medical device is passed through the formed sheath, the diameter of the sheath locally expands from a first unexpended diameter around the medical device to a second expanded diameter, while the first and second polymeric layers resist axial elongation of the sheath such that a length of the sheath remains substantially constant; and wherein the sheath resiliently returns to a third diameter after the passage of the medical device.
EXAMPLE 135: A method of making an expandable sheath, the method comprising: forming an inner liner; wherein the inner liner comprises one or more polymer layers and wherein the inner liner has a first surface and an opposite second surface; forming a first polymeric layer, wherein the first polymeric layer is positioned radially outward of the inner liner; wherein the first polymeric layer comprises one or more sublayers; and wherein the first polymeric layer overlies the second surface of the inner liner; positioning a braided layer radially outward of a first polymeric layer; forming a second polymeric layer such that it is positioned radially outward of the braided layer; wherein the second polymeric layer comprises one or more sublayers; forming an outer liner radially outward of the second polymeric layer; wherein the outer liner comprises one or more polymer layers, and wherein the outer liner has a first surface and an opposite second surface, and wherein the first surface of the outer liner is in contact with at least a portion of the second polymeric layer; heating the inner liner, the first polymeric layer, the braided layer, the second polymeric layer, and the outer liner to form a laminate structure; and crimping the laminate structure to form a plurality of longitudinally-extending pleats, wherein the plurality of longitudinally-extending pleats are configured to expand upon passage of a medical device through the sheath; and then forming a third polymeric layer radially outward of at least a portion of the outer liner; wherein the third polymeric layer comprises one or more polymer layers.
EXAMPLE 136: A method of delivering a prosthetic device to a procedure site, the method comprising: inserting an expandable sheath at least partially into the vasculature of the patient, the expandable sheath comprising a plurality of radially arranged layers including an inner liner, a first polymeric layer radially outward of the inner liner, a braided layer radially outward of the first polymeric layer, a second polymeric layer radially outward of the braided layer, and an outer liner, and wherein the sheath comprises a plurality of longitudinally-extending pleats; advancing a medical device through an inner lumen defined by a first surface of the inner liner of the sheath, the medical device applying an outward radial force on the inner liner of the sheath; locally expanding the sheath from an unexpanded state to a locally expanded state; at least partially unfolding the plurality of longitudinally-extending pleats during a local expansion of the sheath, wherein each of the plurality of longitudinally-extending pleats incorporates at least a portion of the plurality of radially arranged layers; locally collapsing the sheath from the locally expanded state at least partially back to the unexpanded state after passage of the medical device.
EXAMPLE 137 A method of delivering a prosthetic device to a procedure site, the method comprising: inserting an expandable sheath at least partially into the vasculature of the patient, the expandable sheath comprising a plurality of radially arranged layers including an inner liner, a first polymeric layer radially outward of the inner liner, a braided layer radially outward of the first polymeric layer, a second polymeric layer radially outward of the braided layer, an outer liner, and a third polymer layer disposed radially outward of at least a portion of the outer liner, and wherein the sheath comprises a plurality of longitudinally-extending pleats; advancing a medical device through an inner lumen defined by a first surface of the inner liner of the sheath, the medical device applying an outward radial force on the inner liner of the sheath; locally expanding the sheath from an unexpanded state to a locally expanded state; at least partially unfolding the plurality of longitudinally-extending pleats during a local expansion of the sheath, wherein each of the plurality of longitudinally-extending pleats incorporates at least a portion of the plurality of radially arranged layers; and locally collapsing the sheath from the locally expanded state at least partially back to the unexpanded state after passage of the medical device.
EXAMPLE 138: The method of delivering a prosthetic device of any one of examples herein, particularly example 136 or 137, wherein locally expanding the sheath from the unexpanded state to the locally expanded state comprises at least partially straightening a plurality of filaments of the braided layer.
EXAMPLE 139: The method of delivering a prosthetic device of any one of examples herein, particularly examples 136-138, wherein locally expanding the sheath comprises at least partially smoothing the plurality of longitudinally-extending pleats.
EXAMPLE 140: The method of delivering a prosthetic device of any one of examples herein, particularly examples 136-139, wherein locally collapsing the sheath comprises directing an inward radial force on the plurality of radially arranged layers.
EXAMPLE 141: The method of delivering a prosthetic device of any one of examples herein, particularly example 140, wherein directing an inward radial force comprises compressing the plurality of radially arranged layers with a tubular outer elastic layer.
EXAMPLE 142: The method of delivering a prosthetic device of any one of examples herein, particularly example 140 or 141, wherein directing an inward radial force on the plurality of radially arranged layers comprises coupling movement of the inner liner, the first polymeric layer, the second polymeric layer, and the outer liner with movement of the braided layer, wherein the braided layer comprises a self-contracting material.
EXAMPLE 143: The method of delivering a prosthetic device of any one of examples herein, particularly examples 136-142, wherein the step of locally collapsing the sheath comprises buckling a plurality of filaments of the braided layer.
EXAMPLE 144: The method of delivering a prosthetic device of any one of examples herein, particularly examples 136-143, wherein advancing the medical device comprises advancing a prosthetic heart valve through an inner lumen defined by a first innermost surface of the inner liner of the sheath.
EXAMPLE 145: The method of delivering a prosthetic device of any one of examples herein, particularly example 144, further comprising introducing the prosthetic heart valve to the procedure site and expanding the prosthetic heart valve within the procedure site.
Throughout this application, various publications and patent applications are referenced. The disclosures of these publications in their entirety are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this disclosure pertains. However, it should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
This application is a continuation of PCT patent application No. PCT/US2022/038481, filed on Jul. 27, 2022, that claims the benefit of U.S. Provisional Application No. 63/230,631, filed Aug. 6, 2021, and U.S. Provisional Application No. 63/324,436, filed Mar. 28, 2022, the contents of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63324436 | Mar 2022 | US | |
| 63230631 | Aug 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2022/038481 | Jul 2022 | WO |
| Child | 18411286 | US |
