Patent Application
20230110800
This application is a national phase application of PCT Application No. PCT/US2020/066171, internationally filed on Dec. 18, 2020, which claims the benefit of Provisional Application No. 62/951,292, filed Dec. 20, 2019, which are incorporated herein by reference in their entireties for all purposes.
Implantable medical devices including prosthetic valves, and associated support structures.
Various types of support structures are implemented in association with implantable medical devices. Self-expanding nitinol frames are often used as a support structure for replacement heart valves. These devices can be deployed into a calcified aortic annulus for treatment. In various circumstances, such support structures either have insufficient flat plate stiffness to perform effectively or exert undesirable, chronic radial forces on surrounding tissue.
Various examples relate to support structures (e.g., prosthetic valve structures) that incorporate a frame that, upon transitioning to a deployed configuration, include a proximal section has increased stiffness, or resistance to deformation in a transverse plane to a longitudinal axis of a device, including resistance to a change in shape, size, or both. Such an increase in transverse deformation resistance may be measured as an increase in radial compressive resistance or an increase in flat plate stiffness, for example, or both. Such increases in transverse deformation resistance may be realized through a reduction in length of the increased stiffness region of the support structure, such as through longitudinal compression of the region following an initial radial expansion of the region.
According to an example (“Example 1”) a support structure for an implantable device includes a tubular body having a longitudinal axis, the tubular body including a first region that is annular shape and is characterized by a first transverse deformation resistance (e.g., a first radial compressive resistance and/or first flat plate stiffness); and a second region that is annular in shape and is characterized by a second transverse deformation resistance (e.g., a second radial compressive resistance and/or second flat plate stiffness). The second region may include a plurality of frame elements that define the annular shape of the second region. The plurality of frame elements may have a shape / geometry (e.g., curvature) and / or cross-section (e.g., regions of relatively reduced cross-section) such that the second region exhibits a relatively higher degree of compressibility in the longitudinal direction than in the radial or transverse direction.
In some examples, at least a portion of each of the plurality of frame elements has a region of reduced cross section including a width in a radial direction transverse to the longitudinal axis of the tubular body and a thickness in a longitudinal direction parallel to the longitudinal axis of the tubular body, the width in the region of reduced cross section being greater than the thickness (e.g., at least two times, four times, six times or some other multiple the thickness) such that the second region exhibits a relatively higher degree of compressibility in the longitudinal direction than in the radial direction.
According to another example (“Example 2”), further to Example 1, the second transverse deformation resistance (e.g., radial and/or flat plate stiffness) is greater than the first transverse deformation resistance (e.g., radial and/or flat plate stiffness).
According to another example (“Example 3”), further to Example 1, the first region includes a plurality of frame elements defining the annular shape of the first region, and further wherein at least a portion of each of the plurality of frame elements of the first region has a width in the radial direction transverse to the longitudinal axis of the tubular body and a thickness in the longitudinal direction parallel to the longitudinal axis of the tubular body, the width of each of the plurality of frame elements of the first region being less than 4 times of the thickness of each of the plurality of frame elements of the first region.
According to another example (“Example 4”), further to Example 1, the support structure includes one or more leaflets coupled to the first region.
According to another example (“Example 5”), further to Example 4, the one or more leaflets are formed of a natural material.
According to another example (“Example 6”), further to Example 4, the one or more leaflets are formed of a synthetic material.
According to another example (“Example 7”), a support structure for an implantable device includes a tubular body having a longitudinal axis, the implantable device being transitionable between a delivery configuration and a deployed configuration, and the tubular body includes a first region that is annular shape and is characterized by a first transverse deformation resistance; and a second region that is annular in shape and is characterized by a second transverse deformation resistance, the second region including a plurality of frame elements defining the annular shape of the second region, the plurality of frame elements intersecting with one another to form a plurality of cells, each of the plurality of cells defining a longitudinal apex facing a longitudinal direction along the longitudinal axis of the support structure and a lateral apex transverse to the longitudinal apex and facing along a circumference of the support structure, and further wherein in the deployed configuration the longitudinal apex defines an obtuse angle and the circumferential apex defines an acute angle.
According to another example (“Example 8”), further to Example 7, each of the plurality of cells defines a pair of longitudinal apices facing the longitudinal direction and a pair of lateral apices facing along the circumferential direction, and further wherein in the deployed configuration each of the longitudinal apices defines an obtuse angle and each of the lateral apices defines an acute angle.
According to another example (“Example 9”), further to Example 8, each pair of lateral apices of the plurality of cells defines a circumferential centerline of the plurality of cells that extends between the pair of lateral apices of each of the plurality of cells, and further wherein at least a portion of each of the intersecting frame members define the pair of longitudinal apices of each of the plurality of cells intersecting the circumferential centerline of each of the plurality of cells.
According to another example (“Example 10”), further to Example 9, the obtuse angle defined by each longitudinal apex in the deployed configuration is greater than 100 degrees, 130 degrees, 150 degrees, or 170 degrees, or any value or range between the foregoing values.
According to another example (“Example 11”), further to Example 9, the obtuse angle defined by each longitudinal axis is between 100 degrees and 170 degrees.
According to another example (“Example 12”), further to Example 9, the second transverse deformation resistance is greater than the first transverse deformation resistance.
According to another example (“Example 13”), a method of implanting a prosthetic valve includes advancing the prosthetic valve to a target region within a patient's anatomy in a delivery configuration in which the prosthetic valve is at a first, compressed delivery diameter, the prosthetic valve including a support structure comprising a first region having an annular shape and characterized by a first transverse deformation resistance, and a second region having an annular shape and characterized by a second transverse deformation resistance, wherein the second region includes a plurality of frame elements intersecting with one another to form a plurality of cells, each of the plurality of cells defining a longitudinal apex facing a longitudinal direction along the longitudinal axis of the support structure and a lateral apex transverse to the longitudinal apex and facing along a circumference of the support structure, wherein when the prosthetic valve is in the delivery configuration the longitudinal apex defines an acute angle and the circumferential apex defines an obtuse angle; and deploying the prosthetic valve such that the longitudinal apex defines an obtuse angle and the circumferential apex defines an acute angle. In some implementations, deploying the prosthetic valve further includes axially, or longitudinally compressing the second region and locking the second region in an axially compressed configuration.
According to another example (“Example 14”), further to Example 13, the obtuse angle of the longitudinal apex is at least one hundred eighty (180) degrees.
According to another example (“Example 15”), further to Example 13, wherein the obtuse angle of the longitudinal apex exceeds one hundred eighty (180) degrees.
According to another example (“Example 16”), a method of forming a support structure for a prosthetic valve includes cutting a pattern of closed cells from a tube to form the support structure having a first diameter and a first length, each closed cell being defined by a plurality of fame members, expanding the first diameter of the support structure from the first diameter to a second diameter, axially compressing a portion of less than all of the length of the support structure to form a first region and a second region, the first region including a first plurality of cells and the second region including a second plurality of cells, wherein a shape of the cells in the second plurality of cells differs from a shape of the cells in the first plurality of cells, heat setting the support structure at a geometry having the first and second regions such that the first region is characterized by a first transverse deformation resistance, and such that the second region is characterized by a second transverse deformation resistance different from the first transverse deformation resistance.
According to another example (“Example 17”), further to Example 16, the cells of the support structure each have the same shape (e.g., each being generally diamond-shaped) prior to axially compressing the portion of less than all of the length of the support structure to form the first region and the second region. In various implementations, the cells of the second region have a relatively more elongate shape in the longitudinal direction than the transverse direction in an initial, delivery configuration.
According to another example (“Example 18”), a support structure of an implantable device includes a framework having a first region configured to support one or more leaflets and a second region configured to provide enhanced transverse deformation resistance, the second region defining a plurality cells each having a first height and width when the second region is at a delivery configuration, a second height and width when the second is expanded from the delivery configuration to an initial, expanded configuration, and a third height and width when the second region is longitudinally compressed from the initial, expanded configuration to a final, deployed configuration having enhanced transverse deformation resistance relative to the initial, expanded configuration, the support structure including at least one locking mechanism configured to lock one or more of the plurality of cells at the third height and width.
The locking mechanism optionally includes a first lock component projecting within a corresponding cell, the first lock component including a first sliding surface and a first projection and defining a first receiver; and a second lock component projecting toward the first lock component, the second lock component including a second sliding surface and a second projection and defining a second receiver.
In some exam ples, the first and second lock com ponents are configured such that the first and second sliding surfaces slide against each during collapse of the corresponding cell to facilitate receipt of the first projection in the second receiver and the second projection in the first receiver to lock the locking mechanism and retain the corresponding cell in a collapsed configuration.
According to another example (“Example 19”), further to Example 18, the support structure is included as part of a prosthetic valve.
According to another example (“Example 20”), further to Example 18, the support structure is a stent structure.
According to another example (“Example 21”), further to any one of Examples 18 to 20, the optional first and second sliding surfaces cause the first and second locking components to elastically deflect during collapse of the corresponding cell.
According to another example (“Example 22”), further to any one of Examples 18to 21, the optional first and second locking components are symmetric in shape.
According to another example (“Example 23”), further to any one of Examples 18 to 22, the optional first and second locking components are integrally formed with the support structure.
According to another example (“Example 24”), a support structure of an implantable device, the support structure defining a longitudinally compressible portion having a distal end and a locking mechanism associated with the support structure, the locking mechanism includes a body having a first end and a second end, a securing portion positioned at the second end of the body, the securing portion operable to selectively engage the distal end of the longitudinally compressible portion of the support structure.
According to another example (“Example 25”), further to Example 24, wherein the locking mechanism further comprises a compressing member retainer configured to retain a compressing member.
According to another example (“Example 26”), further to Example 25, wherein the compressing member retainer is configured to release the compressing member when the securing portion is engages with the distal end of the longitudinally compressible portion of the support structure.
According to another example (“Example 27”), further to any one of Examples 24-26, wherein the securing portion is positioned at an acute angle relative to the body of the locking mechanism.
According to another example (“Example 28”), further to any one of Examples 24-27, wherein the locking mechanism further comprises a coupling portion positioned at the first end of the body of the locking mechanism.
According to another example (“Example 29”), further to any one of Examples 24-28, wherein the coupling portion is configured to couple to the support structure.
The foregoing Examples are just that, and should not be read to limit or otherwise narrow the scope of any of the inventive concepts otherwise provided by the instant disclosure. While multiple examples are disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature rather than restrictive in nature.
The accompanying drawings are included to provide a further understanding of inventive embodiments of the disclosure and are incorporated in and constitute a part of this specification, illustrate examples, and together with the description serve to explain various inventive principles.
This disclosure is not meant to be read in a restrictive manner. For example, the terminology used in the application should be read broadly in the context of the meaning those in the field would attribute such terminology.
With respect to terminology of inexactitude, the terms “about” and “approximately” may be used, interchangeably, to refer to a measurement that includes the stated measurement and that also includes any measurements that are reasonably close to the stated measurement. Measurements that are reasonably close to the stated measurement deviate from the stated measurement by a reasonably small amount as understood and readily ascertained by individuals having ordinary skill in the relevant arts. Such deviations may be attributable to measurement error, differences in measurement and/or manufacturing equipment calibration, human error in reading and/or setting measurements, minor adjustments made to optimize performance and/or structural parameters in view of differences in measurements associated with other components, particular implementation scenarios, imprecise adjustment and/or manipulation of objects by a person or machine, and/or the like, for example. In the event it is determined that individuals having ordinary skill in the relevant arts would not readily ascertain values for such reasonably small differences, the terms “about” and “approximately” can be understood to mean plus or minus 10% of the stated value.
Certain terminology is used herein for convenience only. For example, words such as “proximal,” “distal,” “top”, “bottom”, “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” describe the relative configuration shown in the figures or the orientation of a part in the installed position. The referenced components may be oriented in any of a variety of orientations. Similarly, throughout this disclosure, where a process or method is shown or described, the method may be performed in any order or simultaneously, unless it is clear from the context that the method depends on certain actions being performed first.
The term “transverse deformation resistance” as used herein refers to resistance to deformation in a substantially transverse plane to a longitudinal axis of a support structure. Examples of measures of transverse compressive resistance include radial compressive resistance and flat plate stiffness, for example.
Persons skilled in the art will readily appreciate that the various embodiments of the inventive concepts provided in the present disclosure can be realized by any number of methods and apparatuses configured to perform the intended functions. It should also be noted that the accompanying figures referred to herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the drawing figures should not be construed as limiting.
Various examples address expandable support structures with one or more regions of enhanced transverse deformation resistance (e.g., enhanced flat plate stiffness and/or radial compressive resistance). Various examples include configurations that help minimize the disadvantages associated with high degrees of chronic outward radial force. Support structures having enhanced transverse deformation resistance can be advantageous for promoting and/or maintaining the reshaping of the tissue structures into which they are implanted. For example, where an expandable support structure consistent with various examples discussed herein is employed in a prosthetic valve implanted in a valve orifice, it may be desirable for the prosthetic valve to stent open the valve orifice and re-circularize the annulus so that performance of the leaflets of the prosthetic valve is not hindered, thus providing a support structure that helps maximize the capability of the leaflets to operate at their kinematically-optimal deployed shape.
In various examples, the enhanced transverse deformation resistance regions are fully radially expanded by longitudinally compressing them. The enhanced transverse deformation resistance regions can be first expanded to an intermediate deployed diameter, and then longitudinally compressed to a fully deployed diameter at which the regions exhibit their desired transverse deformation resistance. Such expansion techniques and associated support structure configurations facilitate expansion to a known/pre-selected diameter which can help reduce wrinkles/deformations in leaflet shape following deployment that would otherwise lead to suboptimal leaflet kinematics. Such expansion mechanisms and enhanced transverse deformation resistance can also help ensure uniform cell expansion/configuration and more consistent performance (e.g., fatigue resistance, deployed shape, stiffness, and the like) following deployment.
The transverse deformation resistance (e.g., radial compressive resistance and/or flat plate stiffness) of many conventional self-expanding prosthetic support structure designs may not be sufficiently high to overcome the stiffness/resistance of surrounding tissue (e.g., tissue of a calcified valve annulus) to reshape or to otherwise maintain a desired shape of the surrounding tissue. Comparatively, expandable prosthetic support structure designs (e.g., expandable or self-expanding) that have a high outward radial force to overcompensate for relatively lower transverse deformation resistance (e.g., oversized self-expanding structures), may exert chronic outward forces on surrounding tissue that may give rise to other issues, including conduction system disturbance issues (e.g., bundle branch block, complete heart block, and the need for pacemaker implantation).
As shown in
As described above, in various embodiments, one or more leaflets 3000 are coupled to the first region 2100, which can also be described as a leaflet frame, to provide a one-way valve structure. Any of a variety of mechanical valve, biological leaflet, and synthetic leaflet designs may be employed as desired. In general terms, the leaflets 3000 are coupled to the first region 2100 such that they are operable to open to allow flow from the inflow region to pass through the leaflet frame subcomponent outflow region, also referred to as the forward flow direction, and are operable to close to restrict flow from flowing from the outflow region through the inflow region, also referred to as the retrograde flow direction. The one or more leaflets 3000 can be coupled to the inner surface and/or outer surface of the support structure 2000, to a film that associated with the support structure 2000, and/or may be wrapped about one or more portions of the support structure 2000, for example, and a variety of suitable attachment mechanisms, including mechanical fasteners are also contemplated.
In some embodiments, the prosthetic valve 1000 has a central longitudinal axis Xv. Likewise, a central longitudinal axis Xf of the support structure 2000 is coaxial with the central axis Xv of the prosthetic valve 1000, as shown in
The prosthetic valve 1000, and thus the support structure 2000 along with the one or more leaflets 3000 and graft material 4000, is optionally collapsible to a reduced profile, delivery configuration and then expandable (e.g., self-expanding or expanded by the application of an internal force, such as by balloon expansion or other expansion mechanism discussed herein) in situ. As shown in
Although the support structure 2000 generally defines a circular transverse cross-section in an unloaded state (e.g., when not under a transverse load), it should be understood that any variety of cross-sections (e.g., oval- or rectangular-shaped) are also contemplated. The support structure 2000 has an inner side 2008 and an outer side 2010 opposite the inner side 2008. The inner side 2008 faces toward the central longitudinal axis Xf, and the outer side 2010 faces outwardly, or away from the central longitudinal axis Xf. The support structure 2000 generally extends from the distal end 2002 (also described as an outflow end) to the proximal end 2004 (also described as an inflow end). As shown in
In some examples, the transverse deformation resistance of the second region 2200 is enhanced relative to the transverse deformation resistance of the first region 2100 by way of one or more material properties of the various structural components of the second region 2200 (e.g., via selective strain hardening). In some examples, the transverse deformation resistance of the second region 2200 is additionally or alternatively enhanced relative to the transverse deformation resistance of the first region 2100 by why of the orientation and/or configuration of the various structural elements of the second region 2200.
For instance, as shown in
In some embodiments, the plurality of strut elements 2102 define a collapsible (e.g., elastically) and expandable (e.g., self-expanding, or expandable via balloon or other suitable mechanism as discussed herein) framework, and also serve to support one or more leaflets, as mentioned above. As shown in
In various examples, the apex angles 2114 of each of the distal-facing apices 2110 may have a value that is approximately the same in more than one of the plurality of rows (e.g., 2106 and 2108) of closed cells 2118, or values that vary as desired. In some embodiments, each of the apex angles 2114 of the distal-facing apices 2110 that are defined in rows 2106 and 2108 is within 10% of a common apex angle defined by those distal-facing apices 2110. In particular, it may be advantageous for the distal-facing apices 2110 that fall in the region where the leaflet(s) are attached to the support structure 2000 to approach a common apex angle. For example, the distal-facing apices 2110 including the leaflet attachment struts 2103 may approach a common apex angle, or otherwise be within a desired range of a common apex angle. Although a 10% range is given, in other embodiments, each of those apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle described above is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those vales).
In various examples, the apex angles 2116 of each of the proximal-facing apices 2112 may have a value that is approximately the same in more than one of the plurality of rows (e.g., 2108 and 2109) of closed cells 2118, or values that vary as desired. In some embodiments, each of the apex angles 2116 of the proximal-facing apices 2112 that are defined in rows 2108 and 2109 is within 10% of a common apex angle defined by those proximal-facing apices 2112. In particular, it may be advantageous for the proximal-facing apices 2112 that fall in the region where the leaflet(s) are attached to the support structure 2000 to approach a common apex angle. For example, the proximal-facing apices 2112 including the leaflet attachment struts 2103 may approach a common apex angle, or otherwise be within a desired range of a common apex angle. Although a 10% range is given, in other embodiments, each of those apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle described above is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those vales).
In some examples, the apex angles 2114 and/or the apex angles 2116 of one or more columns of closed cells 2118 defined by the plurality of closed cells 2118 are approximately the same as another one of the columns of closed cells 2118. For example, the apex angles of one or more columns is optionally within 10% of a common apex angle defined by the one or more columns of closed cells 2118 of proximal-facing apices 2112 and/or distal-facing apices 2110. In particular, it may be advantageous for the apices that fall in the region where the leaflet(s) are attached to the support structure 2000 to approach a common apex angle. For example, the apices including the leaflet attachment struts may approach a common apex angle, or otherwise be within a desired range of a common apex angle. Although a 10% range is given, in other embodiments, each of the apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those values).
The closed cells 2118 of the first region 2100 of the support structure 2000 generally intersect with one another at intersection locations Pd. As shown in the example of
In a similar manner to the apex angles 2114 and the apex angles 2116, in various examples, one or more of the apex angles 2128 and/or apex angles 2130 has approximately the same value between one or more of the plurality of closed cells 2118 (e.g., within 10% of a common apex angle, although other values such as values within 5%, 15%, 20%, or some other value of a common apex angle are contemplated). In particular, and as mentioned above, it may be advantageous for the apices that fall in the region where the leaflet(s) are attached to the support structure 2000 to approach a common apex angle. For example, the apices including the leaflet attachment struts may approach a common apex angle, or otherwise be within a desired range of a common apex angle. In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those values).
In various examples, the cell heights 2120 of the closed cells 2118 may be the same or different for different rows and/or columns of closed cells 2118 of the first region 2100 of the support structure 2000. Similarly, the cell widths 2122 of the closed cells 2118 may be the same or different for different rows and/or columns of closed cells 2118 of the first region 2100 of the support structure 2000.
The In various of examples, varying the apex angles of the proximal and distal-facing apices 2112, 2110 and/or the first and second lateral-facing apices 2124, 2126 of the closed cells helps control compaction forces (e.g., the force needed for diametrically compacting the prosthetic valve 1000 to a compact delivery configuration) as well as the transverse deformation resistance of the particular region of the support structure 2000 upon deployment. It should also be understood that other factors, including material selection, strut geometry (cross-section and curvature), and other characteristics may be selected to vary transverse deformation resistance of the first region 2100. Thus, in various examples, the support structure 2000 can be configured such that the transverse deformation resistance of the first region 2100 is different from the transverse deformation resistance of the second region 2200.
For example, with reference now to
In some embodiments, the plurality of strut elements 2202 define a collapsible (e.g., elastically) and expandable (e.g., self-expanding, or expandable via balloon or other suitable mechanism as discussed herein) framework, and also serve to support one or more leaflets, as mentioned above. As shown, the plurality of strut elements 2202 define a plurality of rows of closed cells 2218 (e.g., row 2206 and row 2208) defining an undulating, alternating pattern of proximal-facing apices 2212 pointing in a proximal direction and distal-facing apices 2210 pointing in a distal direction. As shown in
In various examples, each of the apex angles 2214 of each of the distal-facing apices 2210 has a value that is approximately the same in more than one of the plurality of rows (e.g., 2206 and 2208) of closed cells 2218. For example, in some embodiments, each the apex angles 2214 is within 10% of a common apex angle defined by the plurality of rows of distal-facing apices 2210. In other embodiments, each of the apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those vales).
In various examples, each of the apex angles 2216 of each of the proximal-facing apices 2212 has a value that is approximately the same in more than one of the plurality of rows (e.g., 2206 and 2208) of closed cells 2218. For example, in some embodiments, each the apex angles 2216 is within 10% of a common apex angle defined by the plurality of rows of proximal-facing apices 2212. In other embodiments, each of the apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those vales).
In some examples, the apex angles 2214 and/or the apex angles 2216 of one or more columns of closed cells 2218 defined by the plurality of closed cells 2218 are approximately the same as another one of the columns of closed cells 2218. For example, the apex angles of one or more columns is optionally within 10% of a common apex angle defined by the one or more columns of closed cells 2218 of proximal-facing apices 2212 and/or distal-facing apices 2210. In other embodiments, each of the apex angles is within 5%, 15%, 20%, or some other value of a common apex angle. In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those values).
The closed cells 2218 of the second region 2200 of the support structure 2000 generally intersect with one another at intersection locations Pp. As shown in the example of
In a similar manner to the apex angles 2214 and the apex angles 2216, in various examples, each of the apex angles 2228 and/or apex angles 2230 of has approximately the same value between one or more of the plurality of closed cells 2218 (e.g., within 10% of a common apex angle, although other values such as values within 5%, 15%, 20%, or some other value of a common apex angle are contemplated). In some examples, the common apex angle is 30 degrees, although any of a variety of common apex angles is contemplated (e.g., 10, 15, 20, 30, 40, 45, 50, 60, 90 degrees and ranges between any of those values).
In various examples, the cell heights 2220 of the closed cells 2218 may be the same or different for different rows and/or columns of closed cells 2218 of the second region 2200 of the support structure 2000. Similarly, the cell widths 2222 of the closed cells 2218 may be the same or different for different rows and/or columns of closed cells 2218 of the second region 2200 of the support structure 2000.
In some embodiments, varying the apex angles of the proximal and distal-facing apices 2210, 2212 and the lateral-facing apices 2224, 2226 of the closed cells helps control compaction forces (e.g., the force needed for diametrically compacting the prosthetic valve 1000 to a compact delivery configuration) as well as the transverse deformation resistance of the particular region of the support structure 2000 upon deployment. Thus, in various examples, the support structure 2000 can be configured such that the transverse deformation resistance of the second region 2200 is different from the transverse deformation resistance of the second region 2200.
During longitudinal compression, the strut elements 2202 are deformed, which includes modifying the various apex angles of the second region 2200.
As shown in
As shown in
Increasing the apex angles 2214, 2216 of the proximal and distal-facing apices 2210, 2212 (e.g., increasing the angle between adjacent strut elements 2202), operates to increase the transverse deformation resistance of the row 2206 of closed cells 2218, thereby increasing the transverse deformation resistance of the region of the support structure 2000 where the row 2206 of closed cells 2218 is located (e.g., in this case, the second region 2200). It should also be understood that other factors, including material selection, strut geometry (cross-section and curvature), and other characteristics may be selected to vary transverse deformation resistance of the second region 2200.
In various examples, the intersection points (e.g., Pd and Pp) defines a hinge region for the various strut elements (e.g., 2102 and 2202) intersecting or otherwise interfacing with one another at the intersection points (e.g., Pd and Pp). In some examples, the strut elements (e.g., 2102 and/or 2202) of the support structure 2000 may include one or more sections thereof that are configured to deform to facilitate or accommodate the change in apex angles discussed above. These deformations of the one or more sections of the strut elements may include elastic deformation, plastic deformation, or combinations thereof. For instance, as shown in
Referring back now to
In various examples, decreasing the cell height 2220 of the closed cells 2218 the second region 2200 may be accomplished by drawing together the proximal and distal end regions 2236, 2238 of the second region 2200 of the support structure 2000. For instance, in a delivery configuration, the proximal and distal end regions 2236, 2238 may be a first distance apart from one another (see
In some examples, like that shown in
In some examples, drawing together the proximal and distal end regions 2236, 2238 of the second region 2200 of the support structure 2000 during or following deployment to an enlarged diameter has the further effect of increasing the radial dimension of the second region from a first diameter to a second larger diameter. For example, the diameter of the second region 2200 shown in
In some examples, the deformation sections (e.g., 2232 and 2234) of the strut elements (e.g., 2102 and 2202) act as live hinges in that these deformation regions permit the strut elements to pivot or change angle relative to the intersections regions (e.g., Pd and Pp) as well as permitting the strut elements to change angle relative to one another. In some examples, one or more of the first and second regions 2100, 2200 of the support structure 2000 are formed by laser cutting a tube, such as a nitinol tube. In various examples, the second region 2200 (and optionally the first region 2100) are shape set at the intermediate state, such that the second region 2200 is configured to self-expand toward the intermediate state at the intermediate diameter, or profile. According to one example, support structure 2000 is cut from a 6 mm outer diameter nitinol tube and shape set to a 24 mm outer diameter. The support structure 2000 is crushed from 24 mm to a 6 mm delivery diameter. The final deployment diameter of the support structure 2000 may be 29 mm or more. These dimensions are meant as examples only, and a variety of shapes and sizes are contemplated.
In some examples, one or more of the first and second regions 2100, 2200 of the support structure 2000 may be formed such that the intersection points (e.g., Pd and Pp) define an intersection hub to which the strut elements are coupled. For instance, in some examples, one or more of the strut elements forming a respective one of the first and second regions 2100, 2200 of the support structure 2000 are coupled to the hub at a reduced cross-section region (e.g., the end sections) in order to reduce strain on the strut elements, as the strut elements are operable to pivot about the hubs without requiring substantial deformation of the more central sections of the strut elements. This feature may be particularly helpful during longitudinal compression, and such features may also help to minimize or reduce elastic recoil back from the longitudinally compressed configuration due to energy stored in the strut elements due longitudinal compression of the second region 2200.
It is also to be appreciated that the support structure 2000 may be initially shape set to any of the configurations discussed herein, including the delivery configuration, the deployed configuration, or any configuration therebetween (e.g., a partially deployed configuration). For instance, in some examples, the support structure 2000 may be shape set to a partially deployed configuration wherein the prosthetic valve 1000 is crushed down to a delivery configuration (e.g., stored potential energy), and wherein the fully deployed configuration requires mechanically expanding the prosthetic valve 1000 to beyond the shape set configuration. In some examples, mechanically expanding the prosthetic valve 1000 to beyond the shape set configuration requires one or more of radially expanding the first region 2100 and radially expanding and axially compressing the second regions 2200. In some examples, radially expanding and axially compressing the second regions 2200 requires mechanical intervention, such as one or more axial tensioning screws that engage with one or more portions of the prosthetic valve to draw the proximal and distal end regions 2236, 2238 of the support structure 2000 closer together that they are in the delivery configuration. Additionally, or alternatively, mechanical intervention may include utilizing one or more suturing elements or tethers to draw together the proximal and distal end regions 2236, 2238 of the support structure 2000. In some examples, the mechanical intervention means discussed above may remain in place to lock the support structure 2000 (and thus the prosthetic valve 1000) in the fully deployed configuration).
In various examples, the prosthetic valve 1000 includes a locking mechanism for securing the second region 2200 in an axially, or longitudinally compressed state. The locking mechanism may include components secured to the second region 2200 of the support structure 2000 (e.g., integrally formed therewith) that interact with one another during collapse of the cells formed by the second region 2200 of the support structure 2000. The locking mechanism associated with a cell or set of cells can then lock and retain the corresponding cell(s) in a collapsed configuration. Additional example locking mechanisms are contemplated. In some designs, locking mechanism is configured to engage with the first region 2100, the second region 2200, or both the first region 2100 and the second region 2200. Various systems and methods for locking or maintaining at least portions of the prosthetic valve 1000 in a longitudinally compressed state are contemplated herein.
As shown, the first and second lock components 7010, 7020 form a first receiver 7014 and a second receiver 7024, respectively. And, as shown, the first and second lock components 7010, 7020 include a first projection 7016 and a second projection 7026, respectively. Once the first and second lock components 7010, 7020 have slid far enough, the first and second projections 7016, 7026 slide past one another such that the first and second lock components 7010, 7020 are able to move back toward one another, with the first projection 7016 sliding into the first receiver 7014 and the second projection 7026 sliding into the second receiver 7024, thereby locking the first and second lock components 7010, 7020 together and the associated cell in a longitudinally compressed state. As previously referenced, any number of locking mechanisms 7000 may be incorporated into the second region 2200 to facilitate locking the various rows of closed cells in a more closed, or longitudinally compressed state.
As seen in
In some embodiments, the aperture 7112 may have a shape that is complementary to a cross-sectional shape of the strut elements 2202. For example, the aperture 7112 may have a shape that is substantially rectangular or square. It should be clear, however, that the aperture may take a variety of shapes suitable for facilitating coupling with the support structure 2000. In some embodiments the coupling portion 7108 and, in some embodiments the aperture 7112, can be a hook like shown with reference to the securing portion 7110 or any other operable shape.
With further reference to
In some embodiments, the securing arm 7113 includes a compressing member retainer 7116. The compressing member retainer 7116 is operable to retain, or couple to, a portion of the support structure 2000 (not shown) for compressing the second region 2200 of the prosthetic valve 1000. The compressing member retainer 7116 may include a hook, an eyelet, a groove, or a wall for engaging the compressing member 7500 which in turn engages the support structure 2000 during compression. As seen in
Referring now to
As the distal end of the compressing member 7500 is advanced away from the prosthetic valve 1000, the portion of the compressing member 7500 contacting the proximal end 2004 of the second region 2200 of the prosthetic valve 1000 causes the second region 2200 to longitudinally compress. As can be seen in
As can also be seen in
Referring now to
As previously discussed, the first region 2100 and the second region 2200 are coupled together. Thus, as the second region 2200 is longitudinally compressed and consequently radially expands, the first region 2100 also adjusts. In some embodiments, this may result in the first region 2100 including a tapered shape where the first diameter of the first region 2100 at a position where the first and second regions 2100, 2200 are couple is greater than the second diameter of the first region 2100 of the outflow end 1002 of the prosthetic valve 1000, as can be seen in
It will be understood that the locking mechanism 7000 may be formed of any suitable material including but not limited to nitinol, metal alloys, polymers, etc. It will also be understood that the compressing member 7500 may work in combination with or separate from the locking mechanism 7000 to maintain the second region 2200 in a longitudinally compressed state when the compressing member is locked to the prosthetic valve 1000 in order to maintain the second region 2200 in a longitudinally com pressed position.
Although the locking mechanism 7000 is shown and described in association with a prosthetic valve, it should be understood that the locking mechanism can be applied to any of a variety of expanding and expandable support structures, including any expandable (e.g., self-expanding) tubular framework defining a pattern of cells.
In various examples, the leaflet or leaflet construct is formed of a biocompatible, synthetic material (e.g., including ePTFE and ePTFE composites, or other materials as desired). In other examples, the leaflet construct 104 is formed of a natural material, such as repurposed tissue, including bovine tissue, porcine tissue, or the like.
As used herein, the term “elastomer” refers to a polymer or a mixture of polymers that has the ability to be stretched to at least 1.3 times its original length and to retract rapidly to approximately its original length when released. The term “elastomeric material” refers to a polymer or a mixture of polymers that displays stretch and recovery properties similar to an elastomer, although not necessarily to the same degree of stretch and/or recovery. The term “non-elastomeric material” refers to a polymer or a mixture of polymers that displays stretch and recovery properties not similar to either an elastomer or elastomeric material, that is, considered not an elastomer or elastomeric material.
In accordance with some embodiments herein, the leaflet comprises a composite material having at least one porous synthetic polymer membrane layer having a plurality of pores and/or spaces and an elastomer and/or an elastomeric material filling the pores and/or spaces of the at least one synthetic polymer membrane layer. In accordance with other examples, the leaflet further comprises a layer of an elastomer and/or an elastomeric material and/or a non-elastomeric material on the composite material. In accordance with examples, the composite material comprises porous synthetic polym er m em brane by weight in a range of about 10% to 90%.
An example of a porous synthetic polymer membrane includes expanded fluoropolymer membrane having a node and fibril structure defining the pores and/or spaces. In some examples, the expanded fluoropolymer membrane is expanded polytetrafluoroethylene (ePTFE) membrane. Another example of porous synthetic polymer membrane includes microporous polyethylene membrane.
Examples of an elastomer and/or an elastomeric material and/or a non-elastomeric material include, but are not limited to, copolymers of tetrafluoroethylene and perfluoromethyl vinyl ether (TFE/PMVE copolymer), (per)fluoroalkylvinylethers (PAVE), urethanes, silicones (organopolysiloxanes), copolymers of silicon-urethane, styrene/isobutylene copolymers, polyisobutylene, polyethylene-co-poly(vinyl acetate), polyester copolymers, nylon copolymers, fluorinated hydrocarbon polymers and copolymers or mixtures of each of the foregoing. In some examples, the TFE/PMVE copolymer is an elastomer comprising essentially of between 60 and 20 weight percent tetrafluoroethylene and respectively between 40 and 80 weight percent perfluoromethyl vinyl ether. In some examples, the TFE/PMVE copolymer is an elastomeric material comprising essentially of between 67 and 61 weight percent tetrafluoroethylene and respectively between 33 and 39 weight percent perfluoromethyl vinyl ether. In some examples, the TFE/PMVE copolymer is a non-elastomeric material comprising essentially of between 73 and 68 weight percent tetrafluoroethylene and respectively between 27 and 32 weight percent perfluoromethyl vinyl ether. The TFE and PMVE components of the TFE-PMVE copolymer are presented in wt%. For reference, the wt% of PMVE of 40, 33-39, and 27-32 corresponds to a mol% of 29, 23-28, and 18-22, respectively.
In some examples, the TFE-PMVE copolymer exhibits elastomer, elastomeric, and/or non-elastomeric properties.
In some examples, the composite material further comprises a layer or coating of TFE-PMVE copolymer comprising from about 73 to about 68 weight percent tetrafluoroethylene and respectively from about 27 to about 32 weight percent perfluoromethyl vinyl ether.
In some examples, the leaflet is an expanded polytetrafluoroethylene (ePTFE) membrane having been imbibed with TFE-PMVE copolymer comprising from about 60 to about 20 weight percent tetrafluoroethylene and respectively from about 40 to about 80 weight percent perfluoromethyl vinyl ether, the leaflet further including a coating of TFE-PMVE copolymer comprising from about 73 to about 68 weight percent tetrafluoroethylene and respectively about 27 to about 32 weight percent perfluoromethyl vinyl ether on the blood-contacting surfaces.
As discussed above, the elastomer and/or an elastomeric material may be combined with the expanded fluoropolymer membrane such that the elastomer and/or the elastomeric material occupies substantially all of the void space or pores within the expanded fluoropolymer membrane.
The frames can be etched, cut, laser cut, stamped, three-dimensional printed or wire wound, among other suitable processes. The frames can be self-expanding or balloon expandable (e.g., when configured for transcatheter implantation) or non-expandable (e.g., when configured for surgical implantation). The various frames can comprise materials, such as, but not limited to, any metallic or polymeric material, such as an elastically (e.g., nitinol) or plastically (e.g., stainless steel) deformable metallic or polymeric material that is generally biocompatible. Other materials suitable for any of the frames described herein include, but are not limited to, other titanium alloys, stainless steel, cobalt-nickel alloy, polypropylene, acetyl homopolymer, acetyl copolymer, a drawn filled tube (e.g., nitinol wire with a platinum core), other alloys or polymers, or any other material that is generally biocompatible having adequate physical and mechanical properties to function as a frame as described herein.
While the embodiments and examples illustrated and described above are generally described in association with transcatheter approaches, it should be appreciated that a variety of additional well-known delivery procedures can be utilized without departing from the spirit or scope of the present application, including surgical and laparoscopic approaches. Non-limiting delivery procedures include transseptal, transapical, left atriotomy, and transaortic approaches, among others.
Moreover, the inventive concepts hereby addressed have been described above both generically and with regard to specific examples. It will be apparent to those skilled in the art that various modifications and variations can be made in the examples without departing from the scope of the disclosure. Likewise, the various components discussed in the examples are combinable. Thus, it is intended that the examples be viewed collectively, as a whole, as also intimating various modifications and variations of those specific examples.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/066171 | 12/18/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62951292 | Dec 2019 | US |
