Multi-layer covering for prosthetic heart valve

Abstract

To improve a prosthetic heart valve covering.SOLUTION: A prosthetic heart valve including a frame, leaflet structure, and sealing member disposed around an outer surface of the frame is disclosed. As one example, the sealing member includes an inner layer and a plush outer layer comprising a plush outer surface. The inner layer is arranged against the outer surface of the frame and the outer layer is arranged against and attached to the inner layer. The inner layer is folded over at inflow and outflow ends, in an axial direction relative to a central longitudinal axis of the frame, to overlap respective ends of the outer layer and form tapered folds at opposite ends of the sealing member, each tapered fold including a narrower, first portion where the inner layer folds over and contacts itself and a wider, second portion where the inner layer overlaps an outer surface of an end portion of the outer layer.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 005,020, filed April 3, 2020, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to prosthetic heart valves, and in particular to prosthetic heart valves with covering or sealing members. [Background technology]

[0003] The human heart can suffer from a variety of valvular heart diseases. These valvular heart diseases can result in significant cardiac dysfunction, ultimately requiring repair of the native valve or replacement of the native valve with a prosthetic valve. There are numerous known repair devices (e.g., stents) and prosthetic valves, as well as numerous known methods for implanting these devices and prosthetic valves in humans. Percutaneous, minimally invasive surgical approaches are utilized in various procedures to deliver prosthetic medical devices to internal locations not readily accessible by surgery or where non-surgical access is desirable. In one specific example, a prosthetic heart valve may be crimped onto the distal end of a delivery device and advanced through the patient's vasculature (e.g., through the femoral artery and aorta) until the prosthetic valve reaches the implantation site within the heart. The prosthetic valve is then expanded to its functional size, for example, by inflating a balloon on which the prosthetic valve is mounted, activating a mechanical actuator that applies an expansion force to the prosthetic valve, or deploying the prosthetic valve from a sheath in the delivery device so that the prosthetic valve can self-expand to its functional size.

[0004] Prosthetic valves that rely on a mechanical actuator for expansion can be referred to as "mechanically expandable" prosthetic heart valves. The actuator typically takes the form of a pull cable, suture, wire, and / or shaft configured to transmit an expansion force from the handle of the delivery device to the prosthetic valve.

[0005] Most expandable transcatheter heart valves include a cylindrical metal frame or stent with prosthetic valve leaflets mounted within the frame. These valves may further include one or more coverings (e.g., sealing members or skirts) on the inner or outer surface of the frame that extend around the periphery of the frame. These coverings may be configured to establish a seal with native tissue when the prosthetic valve is placed at the implantation site (and thus may be referred to as sealing members). In some embodiments, a single-layer woven skirt may not be able to establish a sufficient seal against the heart's native annulus by itself. In other embodiments, the valve may include both an inner skirt (located on the inner surface of the frame) and an outer skirt (located on the outer surface of the frame). However, such a skirt configuration may result in a bulkier valve with a larger crimp profile. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 6,730,118 [Patent Document 2] International Publication No. 2018 / 222799 Brochure [Patent Document 3] US Patent Publication No. 2012 / 0239142 [Patent Document 4] U.S. Patent Publication No. 2018 / 0028310 [Patent Document 5] U.S. Patent No. 9,339,384 [Patent Document 6] U.S. Provisional Patent Application No. 63 / 069,567 [Patent Document 7] U.S. Provisional Patent Application No. 63 / 138,890 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there is a need for improved prosthetic heart valve coverings. [Means for solving the problem]

[0008] Described herein are embodiments of coverings for prosthetic heart valves and methods of making and using such coverings. The prosthetic heart valve may include a frame and a leaflet assembly disposed on the inner surface of the frame. The prosthetic heart valve may include a covering in the form of a sealing member disposed around the periphery of the frame and on the outer surface of the frame. The sealing member may include a woven inner layer and a knitted outer layer, the knitted outer layer configured to promote tissue growth and seal to native tissue when the valve is implanted, and the woven inner layer configured to inhibit tissue growth and protect the leaflets of the leaflet assembly from ablation by the inner layer. As such, end portions of the inner layer may overlap end portions of the outer layer to form tapered folds at each end of the sealing member.

[0009] In one exemplary embodiment, a prosthetic heart valve includes a frame including a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end, a leaflet structure at least partially disposed within the frame, and a sealing member disposed over an outer surface of the frame. The sealing member includes an inner layer made of a woven fabric and an outer layer made of a knitted fabric. The knitted fabric includes a base layer having a plurality of courses formed by co-knitting first and second base yarns and a plurality of wales formed from warp yarns, each loop of the warp yarns being knitted with the first and second base yarns of two adjacent courses. The inner layer is disposed against the outer surface of the frame, and the outer layer is disposed against and attached to the inner layer, the inner layer being folded back at each end in an axial direction relative to a central longitudinal axis of the frame to form folds that overlap each end of the outer layer.

[0010] In another exemplary embodiment, a prosthetic heart valve includes a frame including a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end, a leaflet structure at least partially disposed within the frame, and a sealing member disposed across an outer surface of the frame, the sealing member extending axially relative to a central longitudinal axis of the frame from the inflow end to a midpoint of the frame located between the inflow end and the outflow end. The sealing member includes an inner layer made of a woven fabric and an outer layer made of a knitted fabric. The knitted fabric includes a base layer formed by knitting together first and second base yarns, and a plush outer surface formed by knitting a plurality of pile yarns into loops and extending outward from the base layer. The inner layer is disposed against the outer surface of the frame, and the outer layer is disposed against and attached to the inner layer, and the inner layer is folded over at opposite axial ends of the sealing member to form folds that overlap each end of the outer layer.

[0011] In yet another exemplary embodiment, a prosthetic heart valve includes a frame including a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end, a leaflet structure at least partially disposed within the frame, and a sealing member disposed across an outer surface of the frame, the sealing member extending axially relative to a central longitudinal axis of the frame from the inflow end to a midpoint of the frame located between the inflow end and the outflow end. The sealing member includes an inner layer of woven fabric and an outer layer of knit fabric. The knit fabric includes a base layer including a plurality of courses formed by co-knitting first and second base yarns and a plurality of wales formed from warp yarns, each loop of the warp yarns being knitted with the first and second base yarns of two adjacent courses, and a plush outer surface formed by knitting a plurality of pile yarns into loops extending outward from the base layer. The inner layer is positioned against the outer surface of the frame, the outer layer is positioned against and attached to the inner layer, and the inner layer is folded back at each end of the sealing member to form tapered folds, each tapered fold overlapping each end of the outer layer at a wider portion of the tapered fold.

[0012] The foregoing and other objects, features, and advantages of the techniques of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a prosthetic heart valve according to one embodiment. [Figure 2A] FIG. 1 is a perspective view of a prosthetic heart valve according to another embodiment. [Figure 2B] FIG. 2B is a perspective view of the prosthetic valve of FIG. 2A, with components on the exterior of the frame shown in phantom for illustrative purposes. [Figure 3] FIG. 1 is a cross-sectional side view of a multi-layer skirt disposed along the periphery of the outer surface of the frame of an example prosthetic heart valve. [Figure 4]4 is a side view of a multi-layer skirt disposed along the periphery of the outer surface of the frame of the example prosthetic heart valve of FIG. 3. [Figure 5] 4 is a detailed view of a portion of the inner surface of the frame and multi-layer skirt of the example prosthetic heart valve of FIG. 3. [Figure 6] FIG. 6 is an exploded perspective view of the multi-layer skirt of FIGS. 3-5 before the layers of the multi-layer skirt are secured together. [Figure 7] FIG. 1 is a schematic diagram of the outer layer of an example multi-layer skirt showing the various yarn components knitted together to form the outer layer. [Figure 8] 1 is a micrograph of the loop surface of the outer layer of an example multi-layer skirt. [Figure 9] 1 is a micrograph of the mesh surface or base layer of the outer layer of the aforementioned example multi-layer skirt. [Figure 10] 1 is a micrograph of the inner layer of an example multi-layer skirt. [Figure 11] FIG. 11 is a detailed view of a portion of the micrograph of FIG. 10 showing the woven structure of the inner layer. [Figure 12] 5 is a side view of the prosthetic heart valve with multi-layer skirt of FIG. 4 in a first expanded state in which the valve is expanded to a target diameter. [Figure 13] 13 is a side view of the prosthetic heart valve with multi-layer skirt of FIG. 4 in a second expanded state in which the valve is not fully deployed to the configuration of FIG. 12. [Figure 14] 13 is a side view of the prosthetic heart valve with the multi-layer skirt of FIG. 4 in a third expanded state in which the valve has expanded to the configuration of FIG. 12 to an over-deployed state. [Figure 15] 5 is a side view of the prosthetic heart valve with the multi-layer skirt of FIG. 4 crimped onto a delivery device. [Figure 16] FIG. 1 is a side view of one embodiment of a delivery device configured to deliver and implant a radially expandable prosthetic heart valve at an implantation site. DETAILED DESCRIPTION OF THE INVENTION

[0014] For purposes of description, certain aspects, advantages, and novel features of embodiments of the present disclosure are described herein. These described methods, systems, and devices should not be construed as limiting in any respect. Rather, the present disclosure is directed to all novel and unobvious features and aspects of the various disclosed embodiments, alone and in various combinations and subcombinations. The methods, systems, and devices of the present disclosure are not limited to any particular aspect or feature thereof or combination thereof, nor do the methods, systems, and devices of the present disclosure require that any one or more particular advantages be present or problems be solved.

[0015] A feature, integer, property, compound, chemical moiety, or group described in combination with a particular aspect, embodiment, or example of the present disclosure should be understood to be applicable to any other aspect, embodiment, or example described herein, unless a contradiction occurs. Any feature disclosed in this application (including the accompanying claims, abstract, and drawings), and / or any step of any similarly disclosed method or process, may be combined in any combination, except for combinations in which at least some of such features and / or steps are mutually exclusive. The present disclosure is not limited to the details of any of the foregoing embodiments. The scope of the present disclosure extends to every novel one or every novel combination of features disclosed in this application (including the accompanying claims, abstract, and drawings), or every novel one or every novel combination of steps of any similarly disclosed method or process.

[0016] Although some operations in the methods of the present disclosure are described in a particular sequential order for convenience of presentation, it should be understood that this description encompasses reordering unless a particular order is required by specific language set forth below. For example, a series of operations described sequentially may in some cases be reordered or performed simultaneously. Moreover, for reasons of simplicity, the accompanying figures may not show the various ways in which the methods, systems, and devices of the present disclosure can be utilized in combination with other systems, methods, and devices.

[0017] As used herein, the terms "a" and "at least one" include one or more of the specified elements. That is, if there are two of a specified element, then one of those elements is also present, and thus there is "one" element. The term "plurality" means two or more of the specified elements.

[0018] As used herein, the term "and / or" used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase "A, B, and / or C" means "A," "B," "C," "A and B," "A and C," "B and C," or "A, B, and C."

[0019] As used herein, the term "coupled" generally means physically joined or linked and does not exclude the presence of intermediate elements between the coupled items unless specifically stated to the contrary.

[0020] Directions and other relative references (e.g., inside, outside, upper, lower, etc.) may be used to facilitate explanation of the figures and principles herein, but are not intended as limitations. For example, terms such as "inner," "outer," "top," "bottom," "internal," and "external" may be used. Such terms are used, where applicable, to bring some clarity to the description, particularly when addressing relative relationships with respect to the illustrated embodiments. However, such terms are not intended to represent absolute relationships, positions, and / or orientations. For example, with respect to an object, an "upper" portion can become a "lower" portion simply by flipping the object. However, the portions are still the same portion, and the object remains the same object. As used herein, "and / or" means "and" or "or" and "and" and "or."

[0021] As used herein, with respect to prosthetic heart valves and delivery devices, "proximal" refers to a location, direction, or portion of a component that is closer to the handle of the delivery device, which is located external to the user and / or patient, and "distal" refers to a location, direction, or portion of a component that is farther from the user and / or handle of the delivery device and closer to the implantation site. The terms "longitudinal" and "axial," unless expressly defined otherwise, refer to axes extending proximally and distally. Additionally, the term "radial" refers to directions oriented perpendicular to an axis and points along a radius from the center of an object (such as the longitudinal axis of a prosthetic valve) about which the axis is centered.

[0022] Examples of the techniques of the present disclosure Described herein are prosthetic heart valves, covering or sealing members for prosthetic heart valves, and methods of making covering or sealing members for prosthetic heart valves. These prosthetic heart valves may include a frame, a leaflet assembly including a plurality of leaflets disposed on and attached to an inner surface of the frame, and a sealing member disposed on and around an outer surface of the frame.

[0023] In some embodiments, the sealing member may comprise a woven inner layer and a knitted outer layer. The sealing member may comprise an upper fold (or outflow fold) and a lower fold (or inflow fold), the upper fold being formed by an upper end portion (outflow end portion) of the inner layer folded over itself and extending inward to overlap the upper end portion (outflow end portion) of the outer layer, and the lower fold being formed by a lower end portion (inflow end portion) of the inner layer folded over itself and extending inward to overlap the lower end portion (inflow end portion) of the outer layer. The upper fold may be located at a midpoint of the frame, and the lower fold may be located at the inflow end of the frame. The upper and lower folds (which may also be referred to herein as first and second folds) form tapered sections at each end of the sealing member, which reduces the overall crimp profile of the valve and reduces pushing forces during delivery of the valve crimped onto the delivery device through the guiding sheath and to the target implantation site.

[0024] The outer layer can be configured to promote tissue growth and seal to the native tissue of the heart valve annulus (e.g., after implantation of the valve), and the inner layer can be configured to inhibit tissue growth and prevent the leaflets from contacting the inner or back surface of the outer layer, thereby reducing the likelihood of the leaflets undergoing ablation.

[0025] Embodiments of the presently disclosed technology, including the disclosed sealing member or skirt, may be used in combination with a variety of prosthetic heart valves configured to be implanted at various locations within the heart.

[0026] 1 illustrates a prosthetic heart valve 10 according to one embodiment. While all of the prosthetic valves disclosed herein are adapted for implantation within the native aortic valve annulus, in other embodiments, they may be adapted for implantation within other native valve annulus of the heart (e.g., the pulmonary, mitral, and tricuspid valves). Additionally, the disclosed prosthetic valves may be implanted within vessels in communication with the heart, including the pulmonary valve (to replace the function of a diseased pulmonary valve) or the superior or inferior vena cava (to replace the function of a diseased tricuspid valve).

[0027] The prosthetic valve 10 can have four main components: a stent or frame 12, a valve structure 14, an inner skirt 16, and a perivalvular outer sealing member or outer skirt 18. The prosthetic valve 10 can have an inflow end portion 15, a middle portion 17, and an outflow end portion 19. The inner skirt 16 can be disposed over and / or bonded to the inner surface of the frame 12, while the outer skirt 18 can be disposed over and / or bonded to the outer surface of the frame 12.

[0028] The valve structure 14 can have three leaflets 40, which collectively form the valve leaflet structure. The leaflets 40 can be configured to collapse in a tricuspid configuration, although other embodiments can have more or fewer leaflets (e.g., one or more leaflets 40). The leaflets 40 can be secured to each other at adjacent sides to form the commissures 22 of the valve leaflet structure 14. The lower edge of the valve structure 14 can have a wavy, curved, fan-shaped portion and can be secured to the inner skirt 16 with sutures (not shown). In some implementations, the leaflets 40 can be formed from pericardial tissue (such as bovine pericardial tissue), a biocompatible synthetic material, or various other suitable natural or synthetic materials as known in the art and as described in U.S. Patent No. 6,273,999, which is incorporated herein by reference.

[0029] The frame 12 can be formed with a plurality of circumferentially spaced slots or commissure windows 20 configured to attach the commissures 22 of the valve structure 14 to the frame. The frame 12 can be made from any of a variety of suitable plastically expandable materials (e.g., stainless steel) or expandable materials (e.g., nickel-titanium alloys (NiTi) such as Nitinol) as known in the art. In some embodiments, when fabricated from a plastically expandable material, the frame 12 (and thus the prosthetic valve 10) can be crimped onto a delivery catheter into a radially contracted configuration and then expanded inside the patient by an inflatable balloon or equivalent expansion mechanism. When fabricated from a self-expanding material, the frame 12 (and thus the prosthetic valve 10) can be crimped into a radially contracted configuration and held in this contracted configuration by insertion into a delivery catheter sheath or equivalent mechanism. Once inside the body, the prosthetic valve can be advanced from the delivery sheath, allowing the prosthetic valve to expand to its functional size.

[0030] Suitable plastically expandable materials that can be used to form the frame 12 include, but are not limited to, stainless steel, biocompatible high-strength alloys (e.g., cobalt-chromium alloys or nickel-cobalt-chromium alloys), polymers, or combinations thereof. In certain embodiments, the frame 12 is made from a nickel-cobalt-chromium-molybdenum alloy, such as MP35N® alloy (SPS Technologies, Jenkintown, Pennsylvania), which is equivalent to UNS R30035 alloy (covered by ASTM F562-02). MP35N® alloy / UNS R30035 alloy contains 35% nickel, 35% cobalt, 20% chromium, and 10% molybdenum by weight. Further details regarding the prosthetic valve 10 and its various components are described in U.S. Patent Application Publication No. 2009 / 0129994, which is incorporated herein by reference.

[0031] Figure 2A is a perspective view of another embodiment of a prosthetic heart valve 50. Valve 50 can have three main components: a stent or frame 52, a valve structure 54, and a sealing member 56. Figure 2B is a perspective view of prosthetic valve 50, with the components on the exterior of frame 52 (including sealing member 56) shown in phantom for illustrative purposes.

[0032] Similar to the valve structure 14 of FIG. 1 , the valve structure 54 can have three leaflets 60, which collectively form a valve leaflet structure. The leaflets 60 can be configured to collapse in a tricuspid configuration. Each leaflet 60 can be coupled to the frame 52 along its inflow edge 62 (the lower edge in the drawing, also referred to as the "leaflet edge") and at a commissure 64 of the valve structure 54, where adjacent portions of the two leaflets are interconnected. Reinforcing elements (not shown), such as fabric strips, can be coupled directly to the leaflet edges of the leaflets and to the struts of the frame to couple the leaflet edges to the frame.

[0033] 1, frame 52 may be made from any of a variety of suitable plastically expandable or self-expanding materials as known in the art and as described above. In the illustrated embodiment, frame 52 comprises a plurality of circumferentially extending rows of angled struts 72 that define a plurality of rows of cells or openings 74 in the frame. Frame 52 may have a cylindrical or substantially cylindrical shape having a constant diameter from the inflow end 66 to the outflow end 68 of the frame, as shown, or the frame may have a varying diameter along its height as disclosed in U.S. Patent Publication No. 2005 / 0129994, which is incorporated herein by reference.

[0034] The sealing member 56 in the illustrated embodiment is attached to the outer surface of the frame 52 and functions to prevent or at least minimize paravalvular leakage by forming a seal against surrounding tissue (e.g., the native valve leaflets and / or the native valve annulus). The sealing member 56 may include an inner layer 76 (which may be in contact with the outer surface of the frame 52) and an outer layer 78. The sealing member 56 may be coupled to the frame 52 using any suitable technique or mechanism. For example, the sealing member 56 may be sewn to the frame 52 with sutures that may extend around the struts 72 and through the inner layer 76. In an alternative embodiment, the inner layer 76 may be attached to the inner surface of the frame 52, while the outer layer 78 is located on the outer surface of the frame 52.

[0035] The outer layer 78 may be configured or shaped to extend radially outward from the inner layer 76 and the frame 52 when the prosthetic valve 50 is deployed. When the prosthetic valve is fully expanded outside the patient's body, the outer layer 78 may expand away from the inner layer 76 to form a space between the two layers, thereby allowing the outer layer 78 to expand into contact with surrounding tissue, such as the native valve annulus, when implanted in the body.

[0036] Further details regarding the prosthetic valve 50 and its various components are described in US Patent Publication No. 2005 / 0129994, which is incorporated herein by reference.

[0037] 16 illustrates a delivery device 400 according to one embodiment, which may be used to implant an expandable prosthetic heart valve (such as the prosthetic heart valve 10 of FIG. 1, the prosthetic heart valve 50 of FIGS. 2A-2B, or any of the other prosthetic heart valves described herein). In some embodiments, the delivery device 400 is specifically adapted for use in introducing a prosthetic valve into the heart.

[0038] 16 is a balloon catheter that includes a handle 402 and a steerable outer shaft 404 extending distally from the handle 402. The delivery device 400 can further include a mid-shaft 406 (also referred to as a balloon shaft) that extends proximally and distally from the handle 402, the portion that extends distally from the handle 402 also extending coaxially through the outer shaft 404. The delivery device 400 can further include an inner shaft 408 that extends coaxially through the mid-shaft 406 and the outer shaft 404 distally from the handle 402 and coaxially through the mid-shaft 406 proximally from the handle 402.

[0039] The outer shaft 404 and the intermediate shaft 406 are configured to translate (e.g., move) longitudinally relative to one another along a central longitudinal axis 420 of the delivery device 400, which may facilitate delivery and positioning of the prosthetic valve at an implantation site within a patient's body.

[0040] The midshaft 406 may include a proximal end portion 410 that extends proximally from the proximal end of the handle 402 to an adapter 412. A rotatable knob 414 may be mounted on the proximal end portion 410 and configured to rotate the midshaft 406 about a central longitudinal axis 420 and relative to the outer shaft 404.

[0041] The adapter 412 may include a first port 438 configured to receive a guidewire therethrough and a second port 440 configured to receive fluid (e.g., inflation fluid) from a fluid source. The second port 440 may be fluidly coupled to the inner lumen of the midshaft 406.

[0042] The midshaft 406 may further include a distal end portion that extends distally beyond the distal end of the outer shaft 404 when the distal end of the outer shaft 404 is positioned away from the inflatable balloon 418 of the delivery device 400. The distal end portion of the inner shaft 408 may extend distally beyond the distal end portion of the midshaft 406.

[0043] The balloon 418 may be coupled to the distal end portion of the midshaft 406 .

[0044] In some embodiments, the distal end of the balloon 418 may be coupled to the distal end of the delivery device 400, such as to a nosecone 422 (as shown in FIG. 16 ) or to an alternative component (e.g., a distal shoulder) located at the distal end of the delivery device 400. An intermediate portion of the balloon 418 may overlap a valve mounting portion 424 of the distal end portion of the delivery device 400, and the distal end portion of the balloon 418 may overlap a distal shoulder 426 of the delivery device 400. The valve mounting portion 424 and the intermediate portion of the balloon 418 may be configured to receive a prosthetic heart valve in a radially compressed state. For example, as shown schematically in FIG. 16 , a prosthetic heart valve 450 (which may be one of the prosthetic valves described herein) may be mounted around the balloon 418 at the valve mounting portion 424 of the delivery device 400.

[0045] A balloon shoulder assembly comprising distal shoulder 426 is configured to hold prosthetic heart valve 450 (or other medical device) in a fixed position on balloon 418 during delivery through the patient's vasculature.

[0046] The outer shaft 404 may include a distal tip portion 428 mounted on its distal end. The outer shaft 404 and the intermediate shaft 406 may translate axially relative to one another to position the distal tip portion 428 adjacent the proximal end of the valve mounting portion 424 when the prosthetic valve 450 is mounted in radial compression on the valve mounting portion 424 (as shown in FIG. 16 ) and during delivery of the prosthetic valve to the target implantation site. As such, the distal tip portion 428 may be configured to prevent axial movement of the prosthetic valve 450 in the proximal direction relative to the balloon 418 when the distal tip portion 428 is positioned proximal to the valve mounting portion 424.

[0047] An annular space may be defined between the outer surface of the inner shaft 408 and the inner surface of the midshaft 406 and configured to receive fluid from a fluid source via the second port 440 of the adapter 412. The annular space may be fluidly coupled to a fluid passageway formed between the outer surface of the distal end portion of the inner shaft 408 and the inner surface of the balloon 418. Fluid from the fluid source may then flow from the annular space into the fluid passageway, thereby inflating the balloon 418 and radially expanding and deploying the prosthetic valve 450.

[0048] The inner lumen of the inner shaft may be configured to receive a guidewire therethrough for guiding the distal end portion of the delivery device 400 to a target implantation site.

[0049] The handle 402 may include a steering mechanism configured to adjust the curvature of the distal end portion of the delivery device 400. In the illustrated embodiment, for example, the handle 402 includes an adjustment member, such as a rotatable knob 460 as shown, which is further operatively coupled to the proximal end portion of a pull wire. The pull wire can extend distally from the handle 402 through the outer shaft 404 and have a distal end portion secured to the outer shaft 404 at or near its distal end. Rotating the knob 460 increases or decreases tension in the pull wire, thereby adjusting the curvature of the distal end portion of the delivery device 400. Further details regarding steering or bending mechanisms for delivery devices can be found in U.S. Patent Application Publication No. 2009 / 0129994, which is incorporated herein by reference.

[0050] The handle 402 can further include an adjustment mechanism 461 that includes an adjustment member, such as the illustrated rotatable knob 462, and an associated locking mechanism that includes another adjustment member configured as a rotatable knob 478. The adjustment mechanism 461 is configured to adjust the axial position of the intermediate shaft 406 relative to the outer shaft 404 (e.g., for fine-tuning positioning at the implantation site). Further details regarding the delivery device 400 can be found in U.S. Patent Nos. 6,273,999 and 6,329,747, which provisional patent applications are incorporated herein by reference.

[0051] In some embodiments, a prosthetic heart valve may include a single-layer sealing member or a single-layer outer skirt made of a woven material. However, this type of skirt is expensive to manufacture and may not adequately seal against the tissue of the heart's native annulus. In some embodiments, a two-layer sealing member or a two-layer outer skirt made of different materials or structural materials (e.g., the same material with different textile or fiber structures) may be effective in addressing some of these challenges, such as improving the seal against the native tissue while reducing costs. However, a two-layer skirt can be bulky and increase the pushing force through the introducer of a valve delivery system, thereby increasing the difficulty of delivering a compressed valve to a target implantation site within the heart. Furthermore, the outer layer of a two-layer skirt may cause ablation of the valve leaflets, which may reduce their durability.

[0052] FIGS. 3-15 illustrate one embodiment of a bilayer skirt (e.g., a sealing member or covering) 102 for a prosthetic heart valve. The bilayer skirt is configured to promote tissue in-growth, improve sealing against the tissue of the heart's native annulus, and further protect the leaflets of the prosthetic heart valve and reduce pressure forces applied during delivery of the valve to a target implantation site within the heart. For example, FIG. 3 illustrates a side cross-sectional view of the skirt 102 on an example prosthetic heart valve. FIGS. 4 and 5 illustrate exterior and interior views, respectively, of the skirt 102 on this example prosthetic heart valve. FIGS. 6-11 illustrate various views and portions of the skirt 102, focusing on the particular fabric structure of the two layers of the skirt 102. FIGS. 12-14 illustrate the skirt 102 on this example prosthetic heart valve at different stages of deployment (e.g., during implantation at a target implantation site), and FIG. 15 illustrates the skirt 102 on this example prosthetic heart valve when the valve is in a crimped state on a delivery device.

[0053] It should be noted that although the skirt 102 is shown in Figures 3-5 and 12-15 as being positioned on the valve 100 including the frame 52 and the valve structure 54, in alternative embodiments, the skirt 102 may be disposed on the outer surface of different types of frames of different prosthetic heart valves, as will be described further below. For example, in some embodiments, the skirt 102 may replace the outer skirt 18 of the prosthetic heart valve 10 of Figure 1.

[0054] Referring first to Figure 3, a side view of a prosthetic heart valve 100 is shown in accordance with one embodiment. Valve 100 comprises the frame 52 and valve structure 54 of valve 50 shown in Figures 2A and 2B. However, valve 100 comprises an outer sealing member (also referred to herein as an "outer covering" or "skirt") 102 that differs from that of valve 50. Skirt 102 is shown in cross section in Figure 3 to show its various layers.

[0055] The skirt 102 is disposed on an outer surface 104 of the frame 52, opposite an inner surface 106 of the frame 52, the inner and outer surfaces being radially aligned with respect to a central longitudinal axis 108 of the valve 100. As shown in FIG. 3, the commissures 64 are attached to the inner surface 106, and the outer skirt 102 is disposed on the outer surface around the entire periphery of the frame 52 (e.g., as shown in FIG. 4, as further described below).

[0056] As discussed above and shown in FIG. 3 , the skirt 102 is a two-layer skirt 102 including an outer layer 110 and an inner layer 112 bonded together. In some embodiments, the outer layer 110 can be made of a knitted, woven, braided, or nonwoven material, which may result in a softer, plusher (e.g., brushed) surface in appearance and / or texture. In some embodiments, the inner layer 112 can be made of a woven material. The outer layer 110 can be configured to promote tissue growth to seal the valve 100 against native tissue (when implanted), while the inner layer can be configured to inhibit tissue growth and protect the leaflets of the valvular structure 54 from ablation by the outer layer 110. Further details regarding the material construction of the outer and inner layers 110, 112 of the skirt 102 are discussed below with reference to FIGS. 4-11 .

[0057] 3, the inner surface (e.g., radially inwardly facing surface) of the inner layer 112 is disposed adjacent to and positioned against the outer surfaces 104 of the struts of the frame 52 along and across the entire periphery of the frame 52 (e.g., as shown in FIG. 4). Further, the outer layer 110 is disposed on (e.g., positioned against) the inner layer 112. More specifically, the inner surface (e.g., radially inwardly facing surface) of the outer layer 110 is in flush contact with the outer surface (e.g., radially outwardly facing surface) of the inner layer 112.

[0058] In some embodiments, as shown in FIG. 3 , the skirt 102 extends axially relative to the central longitudinal axis 108 from the inflow tip 114 of the frame 52 (e.g., a tip located at the inflow end 66) to approximately midway between the outflow end 68 and the inflow end 66 of the frame 52 (e.g., approximately midway of the frame). In some embodiments, the skirt 102 may extend axially to a midpoint of the frame that is equidistant between the outflow end 68 and the inflow end 66. In other embodiments, the skirt 102 may extend axially to a midpoint of the frame that is located between the outflow end 68 and the inflow end 66 but closer to the inflow end 66 than the outflow end 68. In still other embodiments, the skirt 102 may extend axially to a midpoint of the frame that is located between the outflow end 68 and the inflow end 66 but closer to the outflow end 68 than the inflow end 66. In other embodiments, the skirt 102 may extend the entire height of the frame from the inflow end 66 to the outflow end 68, or substantially the entire height of the frame. In other embodiments, the skirt 102 may extend from the outlet end 68 to a position downstream of the inlet end 66 that is offset from the inlet end 66. In yet other embodiments, the skirt 102 may be offset upstream from the outlet end 68 and offset downstream from the inlet end 66.

[0059] 3 , the inner layer 112 can have a length 116 (in the axial direction) that is shorter than the length 118 of the frame 52 and longer than the length 120 of the outer layer 110. The inner layer 112 can extend from the inflow tip 114 to a midpoint of the frame 52, while the outer layer 110 can extend from a first point located a distance away from the inflow tip 114 (e.g., axially inward) to a second point located a distance away from the midpoint of the frame 52 (e.g., short of the midpoint of the frame 52). In some embodiments, the first point can be located at or proximal to the first rung 140 of the frame 52.

[0060] By having the inner and outer layers 112, 110 of the skirt have different lengths as described above, the overall crimp profile of the valve 100 may be reduced (e.g., as shown in FIG. 15 ). Furthermore, by not having the outer layer 110 extend the entire length to the inflow end 66 of the frame (e.g., to the inflow tip), the crimp profile at the bulkier inflow end 66 of the valve 100 may be reduced. While the length 120 of the outer layer 110 is reduced relative to the length 116 of the inner layer 112, the length 120 of the outer layer 110 may still be selected to maximize the surface area available for contact with natural tissue after implantation.

[0061] In some embodiments, the length 116 of the inner layer 112 can be in the range of 13-17 mm, and the length 120 of the outer layer 110 can be in the range of 7.0-15 mm. In other embodiments, the length 116 of the inner layer 112 can be in the range of 13-17 mm, and the length 120 of the outer layer 110 can be in the range of 7-13 mm.

[0062] The length 116 of the inner layer 112 may be the effective folded length of the inner layer 112 when assembled on the frame (as shown on the valve in FIG. 3). However, the unfolded manufactured length of the inner layer (length 117 shown in FIG. 6) is longer to account for the folds over the ends of the outer layer 110. For example, as shown in FIG. 3, the skirt 102 includes an upper, first fold portion 122 located at the end of the skirt 102 nearest the outflow end 68 of the frame 52 and a lower, second fold portion 124 located at the end of the skirt 102 nearest the inflow end 66 of the frame 52. In other words, the second fold portion 124 is located at (e.g., proximal to) the inflow tip 114 of the frame 52, and the first fold portion 122 is located farther from (than) the inflow tip 114.

[0063] The first and second turn-up portions 122, 124 are each formed by another end (an end located on an opposite side) of the inner layer 112. For example, the first turn-up portion 122 is formed by folding back an upper or outflow first end portion 128 of the outer layer 110 (e.g., an end located closer to the outflow end 68) at a location axially outward from the upper or outflow first end portion 128 of the outer layer 110, over the axially extending main portion 126 of the inner layer 112 and over the first end portion 128 of the outer layer 110. As a result, the first end portion 130 of the inner layer 112 overlaps the outer surface of the first end portion 128 of the outer layer 110.

[0064] Similarly, the second fold 124 is formed by folding the lower or inflow second end portion 132 of the inner layer 112 over the axially extending main portion 126 of the inner layer 112 and over the second end portion 132 of the outer layer 110 at a location axially outward from the lower or inflow second end portion 132 of the outer layer 110 (e.g., the end portion closer to the inflow end 66). As a result, the second end portion 134 of the inner layer 112 overlaps the outer surface of the second end portion 132 of the outer layer 110.

[0065] 3 , the first fold portion 122 and the second fold portion 124 each form a tapered portion (e.g., narrower portion) at each end of the skirt 102. For example, each axial end of the skirt 102 has a wider portion 136 formed by overlapping layers of the inner layer 112 and the outer layer 110 (e.g., three overlapping layers total) and a narrower portion 138 formed by two overlapping layers of the inner layer 112. The narrower portion 138 is located axially outward from the wider portion 136. As a result, each end of the skirt 102 tapers (e.g., narrows) from each end of the outer layer 110 to each end of the skirt 102.

[0066] The first fold 122 may be effective in covering the leaflets and thus protecting them from the brushed or plush edges of the outer layer 110, thereby reducing ablation to the leaflets. The second fold 124 may be effective in reducing the pushing force when a prosthetic heart valve crimped onto a delivery device (e.g., as shown in FIG. 15 ) is inserted into and through a guiding sheath as the valve is advanced to a target implantation site.

[0067] For example, as shown in FIG. 15 , a valve 100 including a frame 52 and a skirt 102 can be crimped onto a delivery device 300. In some embodiments, as shown in FIG. 15 , the valve 100 can be crimped onto the delivery device 300 inside (proximal to) the nosecone 302 and between the proximal shoulder (disposed within the proximal section 304 of the inflatable balloon of the delivery device 300) and the distal shoulder (disposed within the distal section 306 of the inflatable balloon) of the delivery device 300. As shown in FIG. 15 , the overall crimp profile of the valve 100 can be reduced (e.g., when compared to other valves having multi-layer skirts) due to the structure of the inner and outer layers of the skirt 102 as described herein (e.g., the crimped diameter of the skirt portion 310 of a valve 100 including a skirt 102 can be only slightly larger than the crimped diameter of the frame portion 312 of a valve 100 without a skirt 102). Additionally, the tapering of the lower fold 124 at the distal end 314 of the skirt, which is the end closest to the nosecone 302 (e.g., the inflow end of the valve 100), can be effective in reducing pushing forces when advancing the valve 100 on the delivery device 300 into and through an introducer coupled to an introducer sheath inserted into the patient's vasculature.

[0068] Figure 4 shows an exterior view (a view from outside the valve 100) of the skirt 102 attached to and extending around the periphery of the outer surface 104 of the valve 100. As described above with reference to Figure 3 and as further shown in Figure 4, the skirt 102 extends axially from the inlet end 66 of the valve 100 to a midpoint 142 of the valve 100.

[0069] 4, the exposed outer surface 144 of the outer layer 110 is shown, with the upper first fold portion 122 and the lower second fold portion 124 extending above and below this exposed outer surface, respectively. In some embodiments, as shown in FIG. 4, the lower second fold portion 124 may be axially longer than the upper first fold portion 122. As explained above, this configuration may be effective in reducing the crimp profile and overall bulk of the valve 100 at the inlet end 66.

[0070] 4, the inner and outer layers 112, 110 of the skirt 102 are coupled (e.g., bonded) together at the overlapping fold areas (e.g., proximal to the folds 122 and 124) by a plurality of overlock stitches 146. More specifically, the overlock stitches 146 may be applied at the tapered portions of each of the folds 122 and 124 to allow for stretching of the valve between the crimped and expanded configurations (e.g., as shown in FIGS. 12-14, as described further below). For example, a first line of overlock stitches 146 is disposed at the first fold 122 around the periphery of the frame 52, and a second line of overlock stitches 146 is disposed at the second fold 124 around the periphery of the frame 52.

[0071] As an example, FIGS. 12-14 illustrate the valve 100 in three expanded configurations (e.g., expanded relative to a compressed or crimped configuration as shown in FIG. 15). These three expanded configurations include a first expanded configuration 200 ( FIG. 12 ), a second expanded configuration 202 ( FIG. 13 ), and a third expanded configuration 204 ( FIG. 14 ). The first expanded configuration 200, shown in FIG. 12 , illustrates the valve 100 in an example deployed expanded size (e.g., expanded to a target diameter). The second expanded configuration 202, shown in FIG. 13 , illustrates the valve 100 in an incompletely deployed state (e.g., expanded to a diameter smaller than the deployed or target diameter). In contrast, the third expanded configuration 204, shown in FIG. 14 , illustrates the valve 100 in an over-deployed state (e.g., expanded to a diameter larger than the deployed or target diameter).

[0072] 12-14 each illustrate varying degrees of fanning (e.g., wavy or undulating) toward the leading edge 206 of the skirt 102. The fanning or wavy portion of the leading edge 206 may be formed by the leading edge 206 being positioned on and / or attached to each leading tip 114 of the frame 52 and then waving inwardly away from the leading end 66 of the frame 52 and toward the leading outflow end 68 of the frame 52 to form inner crests (e.g., peaks) in the fanned leading edge 206 between adjacent leading tips 114.

[0073] For example, in the second expanded configuration (e.g., under-deployed configuration) 202 shown in FIG. 13 , the inward crest 208 of the fan-shaped inflow edge 206 becomes more pronounced (e.g., the amplitude of the wavy inflow edge 206 is greater than in the other configurations shown in FIGS. 12 and 14 ). As the frame 52 is further expanded, the inflow edge 206 straightens, thereby reducing the amplitude of the crest 208. For example, in the third expanded configuration (e.g., over-deployed configuration) 204 shown in FIG. 14 , the inflow edge 206 becomes almost completely straight, and the crest 208 nearly disappears compared to the remainder of the inflow edge 206. In this manner, the skirt overlock stitches 146 allow for elongation of the skirt 102 between the various expanded configurations of the valve. This may provide greater flexibility in the final expanded diameter of the valve 100.

[0074] Returning to FIG. 4, in some embodiments, the overlock stitches 146 may be angled in the same direction around the periphery of the frame 52 (and valve 100).

[0075] 4 and 5, both the inner layer 112 and the outer layer 110 of the skirt 102 are disposed on the outer surface 104 of the frame 52. In some embodiments, as shown in FIGS. 3-5, the valve 100 does not have an additional inner skirt disposed on the inner surface 106 of the frame 52.

[0076] 5, the skirt 102 is positioned against and along the outer surface 104 of the frame 52, and the leaflets 60 are positioned against and attached to the inner surface 106 of the frame 52. For example, the leaflet edge portions of the leaflets 60 may be sewn to struts 72 that generally follow the contours of the leaflet edge portions of the leaflets. In some embodiments, the skirt 102 is attached to the struts 72 of the frame 52 with one or more fasteners (e.g., sutures) 148.

[0077] In some embodiments, as shown in FIG. 5 , a lower portion of the inner layer 112 may be secured to struts 72 attached at their lower tips 114 by one or more fasteners 148 (e.g., sutures). For example, as shown in FIG. 5 , one or more fasteners 148 are coupled to at least the inner layer 112 and form loops around the struts 72 at and / or around the tips 114. In some embodiments, an upper portion (e.g., outflow portion) of the inner layer 112 may be further secured to struts 72 located proximal to the midpoints 142. In some embodiments, additional portions of the inner layer 112 and / or outer layer 110 may be secured to struts 72 of the frame 52. In some embodiments, more or fewer sutures than those shown in FIG. 5 may be used to secure the lower portion of the inner layer 112 to the struts 72.

[0078] 6 is an exploded perspective view of the skirt 102 before the outer layer 110 and the inner layer 112 are secured together. The inner layer 112 may be referred to as a woven layer and may be made of a woven material. In some embodiments, the woven material may be a plain weave fabric made from, for example, polyethylene terephthalate (PET) fibers (e.g., Dacron). In other embodiments, the woven material of the inner layer 112 may be other types of woven fabrics made from implantable polymers such as ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), polypropylene, thermoplastic polyurethane (TPU), and polyetheretherketone (PEEK). In other embodiments, the woven material of the inner layer 112 may be other types of woven constructions, such as satin, twill, leno, or other derivatives of plain weave. In some embodiments, the woven material of the inner layer 112 can be a fabric that is post-treated by calendaring to reduce fabric thickness, which can favor further profile reduction, and surface modification, which can reduce cell attachment and tissue ingrowth and overgrowth. In some embodiments, the woven material of the inner layer 112 can be a fabric that is post-treated by applying a thin film coating of a polymer, such as thermoplastic polyurethane (TPU), on the inner surface for surface modification to actively inhibit tissue ingrowth and overgrowth.

[0079] In some embodiments, the inner layer 112 can also be comprised of a film including any of a variety of crystalline or semi-crystalline polymeric materials, such as, for example, polytetrafluoroethylene (PTFE), PET, polypropylene, polyamide, polyetheretherketone (PEEK), TPU, etc. In this manner, the inner layer 112 can be relatively thin yet strong enough to allow the skirt 102 to be sewn to the frame and the prosthetic heart valve to be crimped without tearing. Further details regarding the fiber structure of the inner layer 112 are discussed below with reference to FIGS. 10 and 11. In some embodiments, the inner layer 112 can also be comprised of an electrospun membrane including any of a variety of crystalline or semi-crystalline polymeric materials, such as, for example, polytetrafluoroethylene (PTFE), PET, UHMWPE, etc.

[0080] In some embodiments, the outer layer 110 may be referred to as a knit layer and may be made of a knitted material (e.g., a knitted fabric). In some embodiments, the knitted material of the outer layer 110 may be made of a PET knitted fabric. In other embodiments, the knitted material may be made of a different type of fiber or yarn (excluding a PET fabric), such as nylon, ePTFE, or TPU. In some embodiments, the outer layer 110 may be made of a woven or nonwoven fabric made from PET or the like. As further described below with reference to FIGS. 7-9, the outer layer 110 may be knitted, woven, or nonwoven to comprise an outer soft plush (e.g., brushed) surface 150 and a base surface or layer 152.

[0081] For example, the plush surface 150 can be a plush nap or plush pile of the fibers of the outer layer 110. Examples of fibers having pile include velour, velvet, velveteen, corduroy, terry, fleece, etc. As further described below with reference to FIGS. 7-9, the base layer 152 can be comprised of warp yarns and base yarns (e.g., strands) organized into a mesh-like structure. As shown in FIG. 6, the pile of the plush surface 150 can be comprised of pile strands or pile yarns 154 organized into loops extending from the base layer 152. These looped yarns are effective in expanding the surface area of ​​the skirt's outer layer 110, thereby enabling faster sealing against the native tissue after implantation. In some embodiments, the pile yarns (e.g., loop yarns) 154 can be individual strands / yarns incorporated into the base layer 152, as further described below with reference to FIGS. 7-9.

[0082] The outer layer 110 may be attached to the inner layer 112 by a plurality of overlock stitches 146 (e.g., by sutures, thread, etc.), as described above with reference to FIG. 4 . More specifically, the inner surface 160 of the outer layer 110 may be positioned against the outer surface 162 of the inner layer 112 between dashed lines 156. For example, in FIG. 6 , the location of the ends of the outer layer 110 (e.g., the ends of end portions 128 and 132) when the outer layer 110 is attached to the inner layer 112 is represented as dashed line 156 on the inner layer 112. Dashed line 158 corresponds to the location where the outermost axial end of the inner layer 112, positioned against the outer surface of the frame 52, begins to fold back toward and onto the outer plush surface 150 of the outer layer 110. In other words, dashed line 158 corresponds to the location where the bends of the folds 122 and 124 are formed on the inner layer 112.

[0083] Once the outer layer 110 and the inner layer 112 are positioned in flush contact with each other as described above, the outer layer 110 and the inner layer 112 may be attached together by a line of overlock stitches 146 as shown in Figure 4. In some embodiments, the line of overlock stitches 146 may extend between the outer layer 110 and the inner layer 112 along their length (e.g., the length shown in Figure 6) within the area of ​​the dashed line 156 (e.g., at or inward of the dashed line 156).

[0084] As shown in Figure 6, the upper edge of the inner layer 112 and the upper edge of the outer layer 110 are offset from each other by a distance d1 to form a tapered upper first fold 122 (on the frame 52), and the lower edge of the inner layer 112 and the lower edge of the outer layer 110 are offset from each other by a distance d2 to form a tapered lower second fold 124 (on the frame 52). In some embodiments, the distances d1 and d2 may be the same. In other embodiments, the distance d2 may be greater than the distance d1, thereby creating a longer tapered region at the inflow end of the valve, as shown in Figure 3.

[0085] In some embodiments, once the outer layer 110 is secured to the inner layer 112, the resulting skirt piece is folded and sewn into a cylindrical shape. The resulting skirt 102 can then be secured to the frame 52 by an attachment means, such as by being sewn, clipped, glued, etc. to the struts 72.

[0086] 7-9 illustrate in more detail the fabric structure of the outer layer 110 according to one embodiment. Specifically, FIG. 7 schematically illustrates various yarn components knitted together to form the plush surface 150 and base layer 152 of the outer layer 110. As will be further explained below, this particular knit structure of the outer layer 110 results in the plush surface 150 disposed on one side (e.g., the loop side) of the outer layer 110 and a mesh-like surface (base layer 152) disposed on the other, opposite side (e.g., the mesh side) of the outer layer 110. Micrographs of example outer layer fibers constructed according to the schematic diagram of FIG. 7 are illustrated in FIG. 8 (showing the plush or loop side) and FIG. 9 (showing the base or mesh side).

[0087] In some embodiments, the outer layer 110 can be configured as a crocheted fabric, which can be referred to as a crocheted velour fabric or fabric due to the yarn and knitting techniques utilized to create it, as described further below.

[0088] Because the outer layer 110 is a knitted fabric, the outer layer 110 comprises a series of courses, each extending in a course direction 170, and a series of wales, each extending in a wale direction 172. These course directions 170 and wale directions 172 are shown in Figures 7-9 for reference. For example, Figure 7 shows a portion of the outer layer 110 in one orientation as it is knitted (e.g., as it is fabricated), while Figures 8 and 9 show a portion of the outer layer 110 in an orientation in which it will be placed on a prosthetic heart valve (e.g., as shown in Figure 4). For further reference, in Figures 8 and 9, the course direction is substantially parallel to the central longitudinal axis 108 of the valve (as shown in Figure 4).

[0089] The outer layer 110 can be knitted (e.g., in the course direction 170) to a desired width. As a result, the edges of the outer layer 110 do not require laser cutting.

[0090] 7, the outer layer 110 is composed of a plurality of different yarns. In some embodiments, these various yarns may have different deniers, different filament counts, and / or different textures. However, in some embodiments, the various yarns of the outer layer 110 may be composed of the same material (e.g., PET).

[0091] In Figure 7, these various yarns of the outer layer 110 consist of first base yarns 164, second base yarns 166, and warp yarns 168, all of which are knitted together to form the base layer 152, or mesh surface, of the outer layer 110 (as shown in more detail in Figure 9). For example, as shown in Figure 7, the first base yarns 164 and the second base yarns 166 are knitted together and extend along the course direction, thereby forming courses 174.

[0092] Each course 174 is connected to an adjacent course 174 by one warp loop 176 in a series of spaced warp loops in the course 174, and each warp loop 176 in a course 174 is part of an individual wale 178. In Figure 9, the longitudinal configuration (relative to the central longitudinal axis of the valve frame) of the series of consecutive courses 174 is illustrated. In addition, Figure 9 shows the horizontal configuration (circumferential configuration when placed on the valve frame) of the series of spaced wales 178 (e.g., spaced apart by a section of each course). In this manner, the base layer 152, or mesh surface, of the outer layer 110 is formed as a mesh-like structure.

[0093] In some embodiments, as shown in FIG. 7, the first base yarn 164 can be comprised of one or more strands / yarns (e.g., one, two, or three, etc.) that extend through a central portion of each course 174, and the second base yarn 166 can be comprised of one or more strands / yarns (e.g., three, four, or six, etc.) that extend around or on the outer surface of the strands / yarns of the first base yarn 164.

[0094] In some embodiments, the strands / yarns of first base yarn 164 can be twisted strands / yarns having a denier of about 1D to about 100D, about 10D to about 30D, or about 15D to about 25D, and a filament count of about 8 to about 100 filaments per strand / yarn, about 8 to about 28 filaments per strand / yarn, or about 13 to about 23 filaments per strand / yarn. In other embodiments, the strands / yarns of first base yarn 164 can be twisted strands / yarns having a denier of about 20D and a filament count of about 18 filaments per strand / yarn.

[0095] In some embodiments, the strands / yarns of the second base yarn 166 can be textured strands / yarns having a denier of about 10D to about 100D, about 30D to about 50D, or about 35D to about 45D and a filament count of about 10 to about 200 filaments per strand / yarn, about 17 to about 37 filaments per strand / yarn, or about 22 to about 32 filaments per strand / yarn. In other embodiments, the strands / yarns of the second base yarn 166 can be textured strands / yarns having a denier of about 40D and a filament count of about 27 filaments per strand / yarn. For example, the filaments of the strands / yarns of the second base yarn 166 can be twisted, heat set, and detwisted to maintain a deformed twisted shape in a relaxed, unstretched configuration, thereby texturing the filaments. In other embodiments, the filaments may be textured by false twist texturing or pin texturing, crimping, coiling, or the like.

[0096] In some embodiments, the warp yarns 168 strands / yarns can be fully drawn (FDY) or twisted yarns ranging from 2 turns per inch to 6 turns per inch, with a denier of about 1D to about 50D, about 10D to about 30D, or about 15D to about 25D, and a filament count of about 1 to about 50 filaments per strand / yarn, about 7 to about 37 filaments per strand / yarn, or about 13 to about 23 filaments per strand / yarn. In other embodiments, the warp yarns 168 strands / yarns can be FDYs with a denier of about 20D and a filament count of about 18 filaments per strand / yarn.

[0097] Additionally, in some embodiments, the first and second base yarns 164, 166 and warp yarns 168 may be knitted at a density of about 17 wales per inch and about 61 courses per inch. In some embodiments, the first and second base yarns 164, 166 and warp yarns 168 may be knitted at a density within the range of about 14 to about 28 wales per inch and about 40 to about 75 courses per inch.

[0098] As discussed above, in some embodiments, the first and second base yarns 164, 166 and the warp yarns 168 strands / yarns may be made from, for example, a biocompatible thermoplastic polymer such as PET, UHMWPE, polypropylene, nylon, ePTFE, PTFE, polyvinylidene fluoride (PVDF), or PEEK, or other suitable natural or synthetic fibers, or soft monolithic materials.

[0099] As shown in Figure 7, the various yarns of the outer layer 110 further include pile yarns 154 that are embedded in the base layer 152. For example, the pile yarns 154 are formed as one or more loops extending from first base yarns 164 and second base yarns 166 of the base layer 152. The "loop face" of the outer layer 110 formed from the overlapping loops of pile yarns 154 is shown in Figure 8.

[0100] As shown in FIG. 8 , the upper edge 180 of the outer layer 110 (e.g., the edge located closer to the midpoint of the valve when the skirt is placed over the valve as shown in FIG. 4 ) (and the lower edge, not shown in FIG. 8 ) does not have the looped pile yarns 154, but instead comprises only the second base yarns 166. This can be effective in providing tapered ends in the skirt turnups 122 and 124. In some embodiments, as shown in FIGS. 7 and 8 , the edges of the base layer 152, including the upper edge 180 (which can also be referred to as the outflow edge), comprise twice the amount of strands / yarns of the second base yarns 166 to strengthen these edges and improve assembly integrity and fabric durability. In an alternative embodiment, the upper edge 180 can comprise the first base yarns 164 and the second base yarns 166, but no pile yarns 154.

[0101] In some configurations, the pile yarn 154 is a textured strand / yarn having a denier of about 10D to about 150D or about 19D to about 21D and a filament count of about 10 to about 300 filaments per strand / yarn or about 17 to about 19 filaments per strand / yarn. In other embodiments, the pile yarn 154 strand / yarn may be textured with a denier of about 20D and a filament count of about 18 filaments per strand / yarn.

[0102] In some embodiments, the loops of pile yarn 154 on the plush surface 150 may have a particular pattern, such as not being knitted on each wale 178, but alternating in a 1:1 (1 loop wale and 1 empty wale), 1:2 (1 loop wale and 2 empty wales), or 2:1 ratio, so that the loop density on the plush surface 150 is adjusted based on the size and filament count of the pile yarn 154 used. In some embodiments, the loops of pile yarn 154 on the plush surface 150 may have a particular pattern, such as not being knitted on each course, thereby achieving various loop densities.

[0103] In some embodiments, the pile yarns 154 have an enhanced surface area, such as with a wave or wavy structure (as shown in FIG. 7). In configurations such as the looped pile of FIGS. 7 and 8, the loop structure and enhanced surface area provided by the textured strands or yarns of the pile yarns 154 may allow the loops to act as a scaffold for tissue growth into or around the pile loops. Facilitating tissue growth into the plush surface 150 may improve valve retention at the implant site and contribute to the long-term stability of the valve.

[0104] The construction of the outer layer 110 as described herein may also contribute to improved compressibility and shape memory properties of the skirt 102 compared to known valve coverings and skirts. For example, the pile yarns 154 may be flexible such that the plush surface 150 compresses under load (e.g., when in contact with tissue, an implant, etc.) and returns to its original size and shape when the load is released. This may be effective in improving the seal between the plush layer 150 and, for example, the walls of the native annulus. The compressibility provided by the plush surface 150 of the outer layer 110 may also be advantageous in reducing the crimp profile of the prosthetic valve.

[0105] In some embodiments, the compressed thickness of outer layer 110 is about 0.8 mm and the uncompressed thickness of outer layer 110 is about 1.2 mm. In other embodiments, the compressed thickness of outer layer 110 is in the range of about 0.6 mm to about 1.0 mm and the uncompressed thickness of outer layer 110 is in the range of about 1.0 mm to about 1.4 mm.

[0106] Figures 10 and 11 show in more detail the fabric construction of the inner layer 112. Specifically, Figure 10 shows a micrograph of an example of the inner layer 112, and Figure 11 shows an enlarged detail portion of the micrograph of Figure 10. As explained above, the inner layer 112 is a woven fabric.

[0107] 10 and 11, the inner layer 112 may include a plurality of first strands 182 (e.g., yarns, etc.) oriented generally along the x-axis and a plurality of second yarns 184 oriented generally along the y-axis. In some configurations, the second strands / yarns 184 are warp strands / yarns, i.e., the second strands / yarns 184 are held by the loom during the weaving process, while the first strands / yarns 182 are weft strands / yarns and are interwoven with the warp strands / yarns by a moving shuttle or weft-carrying mechanism during the weaving process. However, in some embodiments, it is possible for the first strands / yarns 182 to be warp strands / yarns and the second strands / yarns 184 to be weft strands / yarns.

[0108] First strand / yarn 182 and second strand / yarn 184 may each comprise multiple constituent filaments that are spun, wound, twisted, commingled, interwoven, etc. together to form each strand / yarn.

[0109] In some embodiments, the first strand / yarn 182 has a denier of about 1D to about 100D, about 10D to about 50D, about 10D to about 30D, or about 15D to about 25D. In some embodiments, the first strand / yarn 182 has a filament count of about 1 to about 300 filaments per strand / yarn, about 10 to about 100 filaments per strand / yarn, about 10 to about 50 filaments per strand / yarn, about 10 to about 30 filaments per strand / yarn, or about 10 to about 28 filaments per strand / yarn. In some embodiments, the first strand / yarn 182 has a denier of about 20D and a filament count of about 18 filaments per strand / yarn. In some embodiments, the first strand / yarn 182 can be a flat strand / flat yarn (non-twisted strand / yarn). However, in alternative embodiments, the first strand / yarn 182 may be comprised of twisted and / or textured filaments.

[0110] The second strand / yarn 184 can be a twisted strand / yarn comprised of multiple twisted filaments. In alternative embodiments, the second strand / yarn can be comprised of flat (untwisted) filaments or textured filaments. In some embodiments, the second strand / yarn 184 has a denier of about 1D to about 100D, about 10D to about 50D, about 10D to about 30D, or about 15D to about 25D. In some embodiments, the second strand / yarn 184 has a filament count of about 1 to about 100 filaments per strand / yarn, about 10 to about 100 filaments per strand / yarn, about 10 to about 50 filaments per strand / yarn, about 10 to about 30 filaments per strand / yarn, or about 10 to about 28 filaments per strand / yarn. In some embodiments, the second strand / yarn 184 has a denier of about 20D and a filament count of about 18 filaments per strand / yarn.

[0111] The first strands / yarns 182 and the second strands / yarns 184 can be woven together to form the inner layer 112. For example, the first strands / yarns 182 and the second strands / yarns 184 can be woven together in a plain weave pattern, which is a repeating pattern in which a first strand / yarn 182 (e.g., a weft strand / yarn) passes over a second strand / yarn 184 (e.g., a warp strand) and then passes under an adjacent second strand / yarn 184. This weave pattern is shown in detail in FIG.

[0112] In some embodiments, the density of the first strands / threads 182 is from about 10 strands / threads per inch to about 500 strands / threads per inch, from about 50 strands / threads per inch to about 200 strands / threads per inch, or from about 100 strands / threads per inch to about 200 strands / threads per inch. In some embodiments, the density of the first strands / threads 182 is about 160 strands / threads per inch.

[0113] In some embodiments, the density of the second strands / threads 184 is from about 10 strands / threads per inch to about 500 strands / threads per inch, from about 50 strands / threads per inch to about 200 strands / threads per inch, or from about 100 strands / threads per inch to about 200 strands / threads per inch. In some embodiments, the density of the second strands / threads 184 is about 170 strands / threads per inch.

[0114] In alternative embodiments, other weave patterns (e.g., other than a plain weave pattern) may be used, such as over 2 under 2, over 2 under 1, etc. The first woven portion may also be woven in a plain weave derivative pattern, such as twill, satin, or any combination thereof.

[0115] In some embodiments, the first strand / thread 182 and the second strand / thread 184 can be made from any of a variety of biocompatible thermoplastic polymers, such as PET, nylon, ePTFE, UHMWPE, or other suitable natural or synthetic fibers. For example, in some embodiments, the first strand / thread 182 and the second strand / thread 184 can be made from a PET strand / thread.

[0116] In some embodiments, the inner layer 112 can be woven on a machine and then heat treated or heat set to achieve the desired size and configuration. For example, depending on the material selected, heat setting can shrink the inner layer 112. In some embodiments, heat setting can also create a textured effect or increase the amount of texture in the strands / yarns.

[0117] In some embodiments, the resulting thickness of the inner layer 112 can be about 10 to about 150 μm, about 20 to about 100 μm, or about 40 to about 80 μm, hi some embodiments, the resulting thickness of the inner layer 112 can be about 60 μm.

[0118] In some embodiments, the resulting fabric of the inner layer 112 may be calendered. Calendering the inner layer 112 may include pressing the fabric with a pair of heated rollers to reduce the thickness of the fabric. Calendering the inner layer 112 may result in a lower overall crimp profile for the prosthetic heart valve including the skirt 102. In these embodiments, the resulting thickness of the inner layer 112 may be in the range of about 1 to about 30 μm or about 5 to about 15 μm. In some embodiments, the thickness of the calendered inner layer 112 may be about 10 μm.

[0119] The inner layer 112 may then be attached to the outer layer 110 as described above with reference to Figures 3-6.

[0120] The inner layer 112 can protect the leaflets of the prosthetic heart valve from the protruding pile yarns of the outer layer 110. As a result, ablation to the leaflets can be reduced and leaflet durability can be improved. Additionally, the woven inner layer 112 can inhibit or prevent tissue in-growth, further protecting the leaflets and improving leaflet durability.

[0121] In contrast, the plush outer surface of the outer layer 110 promotes tissue ingrowth, increasing the rate at which the valve seals against the heart's natural tissue after implantation.

[0122] Constructing a two-layer skirt as described herein allows the outer layer to be knitted as a narrow ribbon to the desired width, eliminating the need to laser cut the knitted fabric to the desired size. Additionally, the knitted structure described herein may reduce or eliminate the risk of open edges that may be prone to unraveling (and dusting due to laser cutting of molten polymer or cutting of fibers). Thus, the knitted structure of the outer layer of the skirt may dramatically improve the edge quality of the skirt, which may potentially interface with the valve leaflets. As a result, leaflet degradation may be reduced, and leaflet durability and integrity may be improved. Furthermore, using three or more yarns in the base layer of the knitted outer layer may result in a knitted structure of the skirt that is less prone to unraveling or dusting.

[0123] Further examples of the techniques of the present disclosure In view of the above implementations of the subject matter of the present disclosure, the present application discloses the following additional embodiments, where a single feature of an embodiment or a combination of two or more features of an embodiment, optionally in combination with one or more features of one or more other embodiments, constitutes an additional embodiment that is also within the scope of the present disclosure of the present application.

[0124] Example 1. A prosthetic heart valve comprising: a frame having a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; and a sealing member disposed over an outer surface of the frame, the sealing member comprising an inner layer made of a woven fabric and an outer layer made of a knitted fabric, the knitted fabric comprising a base layer having a plurality of courses formed by knitting together first base yarns and second base yarns and a plurality of wales formed from warp yarns, each loop of the warp yarns being knitted together with the first base yarns and second base yarns of two adjacent courses; the inner layer being positioned against the outer surface of the frame; the outer layer being positioned against and attached to the inner layer; the inner layer being folded back at each end in an axial direction relative to a central longitudinal axis of the frame to form folds overlapping each end of the outer layer.

[0125] Example 2. The prosthetic heart valve of any of the examples of this section, particularly Example 1, wherein said outer layer further comprises a plurality of pile yarns, the plurality of pile yarns being knitted into loops and extending outward from said base layer to form a plush outer surface of the outer layer.

[0126] Example 3. A prosthetic heart valve of any of the examples herein, particularly Example 2, wherein the edges of the outer layer extending around the periphery of the frame and located on both ends of the outer layer positioned along the axial direction do not comprise any of the plurality of pile yarns, and the thickness of the outer layer is thinner at these edges than in the remainder of the outer layer comprising these plurality of pile yarns.

[0127] Example 4. The prosthetic heart valve of any of the examples of this section, particularly Example 3, wherein the edges of said outer layer comprise only said second base yarns.

[0128] Example 5. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 3, wherein the folds are formed at both ends of the sealing member located along the axial direction, each fold having a narrower first portion where the inner layer is folded back onto itself and a wider second portion where the inner layer overlaps the outer surface of the end portion of the outer layer, and each fold tapers axially outward from the second portion to the first portion.

[0129] Example 6. The prosthetic heart valve of any of the examples of this section, particularly Example 2, wherein said pile yarn is a textured yarn having a denier in the range of 10D to 150D and a filament count in the range of 10 to 300 filaments per yarn.

[0130] Example 7. The prosthetic heart valve of any of the examples of this chapter, particularly Example 2, wherein said pile yarn is a textured yarn having a denier in the range of 19D to 21D and a filament count in the range of 17 to 19 filaments per yarn.

[0131] Example 8. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 1 to 7, wherein said first base yarn and said second base yarn have one or more of different deniers, different filament counts, and different yarn types, including one of flat yarns, textured yarns, or twisted yarns.

[0132] Example 9. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 1 to 8, wherein said first base yarn has a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per yarn.

[0133] Example 10. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 1 to 9, wherein said second base yarn has a denier in the range of 35D to 45D and a filament count in the range of 22 to 32 filaments per yarn.

[0134] Example 11. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 1 to 10, wherein said first base yarn is twisted and said second base yarn is textured.

[0135] Example 12. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 1 to 11, wherein said warp yarns are fully drawn yarns.

[0136] Example 13. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 1 to 12, wherein said warp threads have a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per thread.

[0137] Example 14. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 1 to 13, wherein the woven fabric of the inner layer and the knitted fabric of the outer layer each comprise polyethylene terephthalate (PET) yarn.

[0138] Example 15. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 1 to 14, wherein said inner layer and said outer layer are attached to one another by a plurality of overlock stitches.

[0139] Example 16. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 15, wherein the plurality of overlock stitches comprises a first line of overlock stitches and a second line of overlock stitches, the first line of overlock stitches securing the inner and outer layers together at an axial position where the inner layer overlaps the outer surface of the inner layer at a first end of the sealing member located at the inflow end of the frame, and the second line of overlock stitches securing the inner and outer layers together at an axial position where the inner layer overlaps the outer surface of the inner layer at a second end of the sealing member located closer to a midpoint of the frame between the inflow end and the outflow end than the inflow end.

[0140] Example 17. A prosthetic heart valve according to any of the embodiments of this chapter, particularly any one of Examples 1 to 16, wherein the length of the outer layer in the axial direction is shorter than the length of the inner layer, and each end of the outer layer is offset from each end of the inner layer.

[0141] Example 18. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 17, wherein the inner layer extends over the frame from the inflow end to a midpoint located between the inflow end and the outflow end.

[0142] Example 19. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 18, wherein the outer layer extends over the inner layer from an axial position spaced from the inflow end to an axial position proximal to but spaced from and not reaching the midpoint.

[0143] Example 20. A prosthetic heart valve of any embodiment of this chapter, particularly Example 17, wherein the folded portions are tapered folded portions arranged on both ends of the sealing member in the axial direction, a first tapered folded portion is formed by folding a first end of the inner layer back onto itself and then extending inward in the axial direction to overlap the first end of the outer layer, and a second tapered folded portion is formed by folding a second end of the inner layer back onto itself and then extending inward to overlap the second end of the outer layer.

[0144] Example 21. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 1 to 20, wherein said first base yarns, said second base yarns, and said warp yarns are knitted together at a density within the ranges of 14 to 28 wales per inch and 40 to 75 courses per inch.

[0145] Example 22. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 1 to 21, wherein said inner layer is comprised of a plurality of warp threads and a plurality of weft threads woven together.

[0146] Example 23. The prosthetic heart valve of any embodiment of this chapter, particularly Example 22, wherein said plurality of warp yarns are twisted yarns and said plurality of weft yarns are flat yarns.

[0147] Example 24. A prosthetic heart valve comprising: a frame having a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; and a sealing member disposed over an outer surface of the frame, the sealing member extending axially from the inflow end to a midpoint of the frame located between the inflow end and the outflow end relative to a central longitudinal axis of the frame; the sealing member comprising an inner layer made of woven fabric and an outer layer made of knitted fabric, the knitted fabric comprising a base layer formed by knitting together first and second base yarns, and a plush outer surface formed by knitting a plurality of pile yarns into loops and extending outward from the base layer; the inner layer being positioned against the outer surface of the frame; the outer layer being positioned against the inner layer and attached to the inner layer; the inner layer being folded over at both ends of the sealing member located on opposite sides of each other in the axial direction to form folds overlapping each end of the outer layer.

[0148] Example 25. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 24, wherein the base layer is further formed from warp yarns knitted together with the first base yarn and the second base yarn to form a plurality of wales of the base layer spaced apart from one another, and these first base yarns and second base yarns form a plurality of courses of the base layer, each course being connected to an adjacent course by a warp loop in each wale.

[0149] Example 26. The prosthetic heart valve of any embodiment of this chapter, particularly Example 25, wherein said warp yarns are fully oriented yarns, said first base yarns are twisted yarns, and said second base yarns are textured yarns.

[0150] Example 27. A prosthetic heart valve according to any of the embodiments of this chapter, particularly any one of Examples 25 and 26, wherein the spaced wales and courses of the base layer form a mesh-like inner surface of the outer layer that is in surface-to-surface contact with the outer surface of the inner layer.

[0151] Example 28. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 25 to 27, wherein said warp threads have a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per thread.

[0152] Example 29. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 25 to 28, wherein said first base yarns, said second base yarns, and said warp yarns are knitted together at a density within the ranges of 14 to 28 wales per inch and 40 to 75 courses per inch.

[0153] Example 30. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 29, wherein said pile yarn has a denier in the range of 10D to 150D and a filament count of 10 to 300 per yarn.

[0154] Example 31 The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 30, wherein said first base yarn and said second base yarn have one or more of different deniers, different filament counts, and different yarn types, including one of textured yarns or twisted yarns.

[0155] Example 32. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 24 to 31, wherein said first base yarn has a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per yarn.

[0156] Example 33. The prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 24 to 32, wherein said second base yarn has a denier in the range of 35D to 45D and a filament count of 22 to 32 filaments per yarn.

[0157] Example 34. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 33, wherein the plurality of pile yarns are flexible, the plush surface is configured to compress under load, and the outer layer has a compressed thickness in the range of 0.6 mm to 1.0 mm, and the outer layer has an uncompressed thickness in the range of 1.0 mm to 1.4 mm.

[0158] Example 35. A prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 34, wherein a first fold of the sealing member is formed at the midpoint, the first fold having a narrower portion formed by two overlapping layers of the inner layer and a wider portion formed by overlapping layers of the outer layer and the inner layer, the inner layer overlapping a first end portion of the outer layer; and a second fold of the sealing member is formed at the inflow end, the second fold having a narrower portion formed by two overlapping layers of the inner layer and a wider portion formed by overlapping layers of the outer layer and the inner layer, the inner layer overlapping a second end portion of the outer layer.

[0159] Example 36. A prosthetic heart valve of any embodiment of this chapter, particularly Example 35, wherein a first end portion of the outer layer is offset in the axial direction from a first end of the sealing member formed by a first folded end of the inner layer at the midpoint, and a second end portion of the outer layer is offset in the axial direction from a second end of the sealing member formed by a second folded end of the inner layer at the inflow end.

[0160] Example 37. A prosthetic heart valve according to any of the embodiments of this chapter, particularly either of Examples 35 and 36, wherein the edges of the outer layer located at the first end portion and the second end portion do not comprise pile yarns among the plurality of pile yarns and have a thickness less than the remainder of the outer layer.

[0161] Example 38. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 37, wherein said inner layer and said outer layer are attached to one another by a plurality of overlock stitches.

[0162] Example 39. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 38, wherein said sealing member is attached to said plurality of struts by a plurality of fasteners.

[0163] Example 40. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 39, wherein said inner layer is comprised of a plurality of warp threads and a plurality of weft threads woven together.

[0164] Example 41. The prosthetic heart valve of any embodiment of this chapter, particularly Example 40, wherein said plurality of warp yarns and said plurality of weft yarns are woven together in a plain weave pattern.

[0165] Example 42. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 24 to 41, wherein the woven fabric of the inner layer and the knitted fabric of the outer layer are made of polyethylene terephthalate (PET) yarn.

[0166] Example 43. A valve valve comprising a frame having a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end, a leaflet structure at least partially disposed within the frame, and a sealing member disposed across an outer surface of the frame, the sealing member extending axially from the inflow end to a midpoint of the frame located between the inflow end and the outflow end relative to a central longitudinal axis of the frame, the sealing member comprising an inner layer of woven fabric and an outer layer of knit fabric, the knit fabric comprising a plurality of base yarns formed by knitting together first and second base yarns. 1. A prosthetic heart valve comprising: a base layer having a plurality of wales formed from courses and warp yarns, each loop of the warp yarns being knitted with a first base yarn and a second base yarn of two adjacent courses; and a plush outer surface formed by a plurality of pile yarns knitted into loops and extending outward from the base layer; an inner layer positioned against the outer surface of the frame; an outer layer positioned against and attached to the inner layer; the inner layer folded back at each end of the sealing member to form tapered folds, each tapered fold overlapping each end of the outer layer at a wider portion of the tapered fold.

[0167] Example 44. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 43, wherein each tapered fold tapers from a wider portion formed by three overlapping layers of the inner layer and the outer layer to a narrower portion formed by two overlapping layers of the inner layer, the narrower portion being configured at one of a first end of the sealing member located at the midpoint and a second end of the sealing member located at the inflow end.

[0168] Example 45. A prosthetic heart valve according to any of the embodiments of this chapter, particularly any of Examples 43 to 44, wherein an end portion of said outer layer is narrower than the remainder of said outer layer and does not include any pile yarns among said plurality of pile yarns.

[0169] Example 46. A prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 43 to 45, wherein the inner layer and the outer layer are attached to each other by a plurality of overlock stitches extending around the periphery of the frame at each end of the sealing member where the inner layer overlaps the outer layer.

[0170] Example 47. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 43 to 46, wherein said first base yarn and said second base yarn have one or more of different deniers, different filament counts, and different yarn types, including one of textured yarns or twisted yarns.

[0171] Example 48. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 43 to 47, wherein the woven fabric of the inner layer and the knitted fabric of the outer layer are made of polyethylene terephthalate (PET) yarn.

[0172] Example 49. A prosthetic heart valve according to any of the embodiments of this chapter, particularly any one of Examples 43 to 48, wherein said inner layer is comprised of a plurality of warp threads and a plurality of weft threads woven together in a plain weave pattern.

[0173] Example 50. A prosthetic heart valve of any of the embodiments of this chapter, particularly any one of embodiments 43 to 49, wherein the length of the sealing member is shorter than the length of the frame, and the length of the outer layer of the sealing member is shorter than the length of the sealing member, both of these lengths being in the axial direction.

[0174] Example 51. A prosthetic heart valve of any of the embodiments of this chapter, particularly any one of Examples 43 to 50, wherein the leaflets of the leaflet structure are positioned on the inner surface of the frame and face the inner surface of the inner layer of the sealing member.

[0175] Example 52. A prosthetic heart valve comprising: a frame having a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; and a sealing member disposed over an outer surface of the frame, the sealing member comprising an inner layer and a plush outer layer having a plush outer surface, the inner layer being disposed against the outer surface of the frame, the outer layer being disposed against the inner layer and attached to the inner layer, the inner layer being folded back at the outflow end and inflow end of the inner layer in an axial direction relative to a central longitudinal axis of the frame to overlap each end of the outer layer and form tapered folds at both ends of the sealing member, each tapered fold having a narrower first portion where the inner layer is folded back and in contact with itself, and a wider second portion where the inner layer overlaps the outer surface of the end portion of the outer layer.

[0176] Example 53. A prosthetic heart valve of any of the examples of this chapter, particularly Example 52, wherein the outer layer is made of a knitted fabric having the plush outer surface as described above, and the knitted fabric comprises a base layer having a plurality of courses formed by knitting together a first base yarn and a second base yarn and a plurality of wales formed from warp yarns, and each loop of the warp yarn is knitted together with the first base yarn and the second base yarn of two adjacent courses.

[0177] Example 54. A prosthetic heart valve of any of the embodiments of this chapter, particularly Example 53, wherein the outer layer further comprises a plurality of pile yarns that are knitted into loops and extend outward from the base layer to form a plush outer surface of the outer layer.

[0178] Example 55. A prosthetic heart valve according to any of the embodiments of this chapter, particularly Example 54, wherein the edges of the outer layer extending around the periphery of the frame and located on both ends of the outer layer positioned along the axial direction do not comprise any of the pile yarns from the plurality of pile yarns, and the thickness of the outer layer is thinner at these edges than the remaining portion of the outer layer comprising the plurality of pile yarns.

[0179] Example 56. The prosthetic heart valve of any of the embodiments of this chapter, particularly Example 55, wherein said edge of said outer layer comprises only said second base yarn.

[0180] Example 57. The prosthetic heart valve of any embodiment of this chapter, particularly Example 54, wherein said pile yarn is a textured yarn having a denier in the range of 10D to 150D and a filament count in the range of 10 to 300 filaments per yarn.

[0181] Example 58. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 53 to 57, wherein said first base yarn and said second base yarn have one or more of different deniers, different filament counts, and different yarn types, including one of flat yarns, textured yarns, or twisted yarns.

[0182] Example 59. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 53 to 58, wherein said first base yarn has a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per yarn, and said second base yarn has a denier in the range of 35D to 45D and a filament count in the range of 22 to 32 filaments per yarn.

[0183] Example 60. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 53 to 59, wherein said first base yarn is twisted and said second base yarn is textured.

[0184] Example 61. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 53 to 60, wherein said warp threads have a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per thread.

[0185] Example 62. The prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 53 to 61, wherein said first base yarn, said second base yarn, and said warp yarn are knitted together having a density within the range of 14 to 28 wales per inch and 40 to 75 courses per inch, and said inner layer is composed of a plurality of warp yarns and a plurality of weft yarns woven together in a plain weave pattern.

[0186] Example 63. A prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 52 to 62, wherein the inner layer is made of a woven fabric and the outer layer is made of a knitted fabric, and the woven fabric of the inner layer and the knitted fabric of the outer layer are each made of polyethylene terephthalate (PET) yarn.

[0187] Example 64. A prosthetic heart valve of any embodiment of this chapter, particularly any one of Examples 52 to 63, wherein the inner layer and the outer layer are attached to each other by a plurality of overlock stitches, the plurality of overlock stitches comprising a first line of overlock stitches and a second line of overlock stitches, the first line of overlock stitches securing the inner and outer layers together at an axial position where the inner layer overlaps the outer surface of the inner layer at a first end of the sealing member located at the inflow end of the frame, and the second line of overlock stitches securing the inner and outer layers together at an axial position where the inner layer overlaps the outer surface of the inner layer at a second end of the sealing member located closer to a midpoint of the frame between the inflow end and the outflow end than the inflow end.

[0188] Example 65. A prosthetic heart valve of any embodiment of this chapter, particularly any one of embodiments 52 to 64, wherein the length of the outer layer in the axial direction is shorter than the length of the inner layer, each end of the outer layer is offset from each end of the inner layer, and each tapered fold portion tapers axially outward from the second portion to the first portion.

[0189] In view of the numerous possible embodiments to which the principles of the disclosed technology may be applied, it should be understood that these illustrative embodiments are merely preferred examples of the disclosed technology and should not be construed as limiting the scope of the claimed subject matter, which is further defined by the appended claims and their equivalents. [Explanation of symbols]

[0190] 10. Artificial Heart Valves 12 frames 14 Valve structure, valve leaflet structure 15 Inlet end part 16 Inner skirt 17 Middle part 18 Perivalvular outer sealing member, perivalvular outer skirt 19 Outflow end part 20 Commissural window 22 Commissures 40 leaflets 50 Artificial Heart Valves 52 frames 54 Valve structure 56 Sealing member 60 leaflets 62 incoming edges 64 Commissure 66 Inlet end 68 Outflow end 72 Strut 74 cells, opening 76 Inner layer 78 Outer layer 100 Artificial Heart Valves 102 sealing member, covering, outer sealing member, outer covering, outer skirt, double-layer skirt 104 Outer surface 106 Inner surface 108 central longitudinal axis 110 Outer layer 112 Inner layer 114 Inflow tip, lower tip 116 length 117 length 118 length 120 length 122 First fold 124 Second fold 126 Main part 128 first end portion 130 first end portion 132 second end portion 134 second end portion 136 Wider part 138 Narrower part 140 First Lang 142 Midpoint 144 Outer surface 146 Overlock Stitch 148 Sutures and fasteners 150 outer soft plush (e.g., brushed) surface, outer plush surface, plush surface, plush layer 152 base surface, base layer 154 Pile strands, pile yarns, loop yarns 156 dashed line 158 dashed line 160 inner surface 162 Outer surface 164 First Base Thread 166 Second Base Thread 168 warp threads 170 Course Direction 172 Wale direction 174 courses 176 warp loops 178 Wale 180 upper edge 182 1st Strand / Thread 184 Second Strand / Thread 200 First expansion configuration 202 Second extended configuration, incompletely deployed configuration 204 Third expansion configuration, overexpansion configuration 206 Inflow Edges 208 Inward Crest 300 Delivery Device 302 Nosecone 304 Proximal Section 306 Distal Section 310 Skirt part 312 Frame part 314 Distal end 400 Delivery Device 402 Handle 404 Steerable outer shaft 406 Intermediate shaft 408 Inner Shaft 410 proximal end portion 412 adapter 414 Rotatable Knob 416 Distal end portion 418 Inflatable Balloon 420 central longitudinal axis 422 Nosecone 424 Valve mounting part 426 Distal Shoulder 428 Distal tip 438 First Port 440 Secondary Port 450 Artificial Heart Valves 460 rotatable knob 461 Adjustment mechanism 462 Rotatable Knob 478 Rotatable Knob

Claims

1. a frame comprising a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; a sealing member disposed over an outer surface of the frame; The sealing member comprises: An inner layer; an outer layer having a plush outer surface; Equipped with the inner layer is disposed against the outer surface of the frame, the outer layer is disposed against and attached to the inner layer; the inner layer is folded axially at the inlet and outlet ends of the inner layer relative to the central longitudinal axis of the frame to overlap the ends of the outer layer and form tapered folds at opposite ends of the sealing member; each tapered fold comprises a narrower first portion where the inner layer folds back onto itself and a wider second portion where the inner layer overlaps an outer surface of an end portion of the outer layer.

2. 2. The prosthetic heart valve of claim 1, wherein the outer layer is made of a knitted fabric having the plush outer surface, the knitted fabric comprising a base layer having a plurality of courses formed by co-knitted first and second base yarns and a plurality of wales formed from warp yarns, each loop of the warp yarns being knitted with the first and second base yarns of two adjacent courses.

3. 3. The prosthetic heart valve of claim 2, wherein the outer layer further comprises a plurality of pile yarns, the plurality of pile yarns being woven into loops and extending outward from the base layer to form a plush outer surface of the outer layer.

4. edges of the outer layer extending around the periphery of the frame and located on both ends of the outer layer along the axial direction are free of any pile yarns from the plurality of pile yarns; 4. The prosthetic heart valve of claim 3, wherein the thickness of the outer layer is less at the edge than in the remainder of the outer layer comprising the plurality of pile yarns.

5. 5. The prosthetic heart valve of claim 4, wherein the edge of the outer layer comprises only the second base yarns.

6. 4. The prosthetic heart valve of claim 3, wherein the pile yarn is a textured yarn having a denier in the range of 10D to 150D and a filament count in the range of 10 to 300 filaments per yarn.

7. 7. The prosthetic heart valve of claim 2, wherein the first base yarn and the second base yarn have one or more of different deniers, different filament counts, and different yarn types, including one of flat yarns, textured yarns, or twisted yarns.

8. 8. The prosthetic heart valve according to claim 2, wherein the first base yarns have a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per yarn, and the second base yarns have a denier in the range of 35D to 45D and a filament count in the range of 22 to 32 filaments per yarn.

9. 9. The prosthetic heart valve of claim 2, wherein the first base yarns are twisted and the second base yarns are textured.

10. 10. The prosthetic heart valve according to claim 2, wherein the warp threads have a denier in the range of 15D to 25D and a filament count in the range of 13 to 23 filaments per thread.

11. 11. The prosthetic heart valve of claim 2, wherein the first base yarns, the second base yarns, and the warp yarns are knitted together with a density in the range of 14 to 28 wales per inch and 40 to 75 courses per inch, and the inner layer is comprised of a plurality of warp yarns and a plurality of weft yarns woven together in a plain weave pattern.

12. 12. The prosthetic heart valve of claim 1, wherein the inner layer is made of a woven fabric and the outer layer is made of a knitted fabric, and the woven fabric of the inner layer and the knitted fabric of the outer layer are each made of polyethylene terephthalate (PET) yarn.

13. 13. The prosthetic heart valve of claim 1, wherein the inner layer and the outer layer are attached to each other by a plurality of overlock stitches, the plurality of overlock stitches comprising a first line of overlock stitches and a second line of overlock stitches, the first line of overlock stitches securing the inner layer and the outer layer together at an axial position where the inner layer overlaps the outer surface of the inner layer at a first end of the sealing member located at the inflow end of the frame, and the second line of overlock stitches securing the inner layer and the outer layer together at an axial position where the inner layer overlaps the outer surface of the inner layer at a second end of the sealing member located closer to a midpoint of the frame between the inflow end and the outflow end than the inflow end.

14. 14. The prosthetic heart valve of claim 1, wherein the length of the outer layer in the axial direction is shorter than the length of the inner layer, the ends of the outer layer are offset from the ends of the inner layer, and each tapered fold tapers axially outward from the second portion to the first portion.

15. a frame comprising a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; a sealing member disposed over an outer surface of the frame; Equipped with the sealing member extends axially from the inlet end to a midpoint of the frame located between the inlet end and the outlet end, relative to a central longitudinal axis of the frame; The sealing member is an inner layer made of a woven fabric; an outer layer of knitted fabric, the knitted fabric comprising a base layer formed by first and second base yarns knitted together, and a plush outer surface formed by a plurality of pile yarns knitted into loops and extending outward from the base layer; Equipped with the inner layer is disposed against the outer surface of the frame, the outer layer is disposed against and attached to the inner layer; The inner layer is folded back at both ends of the sealing member that are located on opposite sides along the axial direction to form folded back portions that overlap each end of the outer layer.

16. 16. The prosthetic heart valve of claim 15, wherein the base layer is further formed from warp yarns knitted together with the first base yarn and the second base yarn to form a plurality of spaced-apart wales of the base layer, the first base yarn and the second base yarn forming a plurality of courses of the base layer, each course being connected to an adjacent course by a warp loop in each wale.

17. 17. The prosthetic heart valve of claim 16, wherein the warp yarns are fully oriented yarns, the first base yarns are twisted yarns, and the second base yarns are textured yarns.

18. 18. The prosthetic heart valve of claim 16 or 17, wherein the spaced wales and the courses of the base layer form a mesh-like inner surface of the outer layer that is in flush contact with an outer surface of the inner layer.

19. 19. The prosthetic heart valve of claim 15, wherein the plurality of pile yarns are flexible and the plush surface is configured to compress under load, and the outer layer has a compressed thickness in the range of 0.6 mm to 1.0 mm, and the outer layer has an uncompressed thickness in the range of 1.0 mm to 1.4 mm.

20. 20. The prosthetic heart valve of claim 15, wherein a first fold of the sealing member is formed at the midpoint, the first fold comprising a narrower portion formed by two overlapping layers of the inner layer and a wider portion formed by overlapping layers of the outer layer and the inner layer, the inner layer overlapping a first end portion of the outer layer; a second fold of the sealing member is formed at the inflow end, the second fold comprising a narrower portion formed by two overlapping layers of the inner layer and a wider portion formed by overlapping layers of the outer layer and the inner layer, the inner layer overlapping a second end portion of the outer layer; and edges of the outer layer located at the first end portion and the second end portion do not comprise pile yarns among the plurality of pile yarns and have a thickness less than the remainder of the outer layer.

21. a frame comprising a plurality of struts, the frame being radially contractible and expandable between a contracted configuration and an expanded configuration, the frame having an inflow end and an outflow end; a leaflet structure at least partially disposed within the frame; a sealing member disposed over an outer surface of the frame; the sealing member extends axially from the inlet end to a midpoint of the frame located between the inlet end and the outlet end relative to a central longitudinal axis of the frame, and the sealing member comprises: an inner layer made of a woven fabric; an outer layer made of a knitted fabric; Equipped with The knitted fabric is a base layer comprising a plurality of courses formed by a first base yarn and a second base yarn knitted together, and a plurality of wales formed from warp yarns, wherein each loop of the warp yarns is knitted together with the first base yarn and the second base yarn of two adjacent courses; a plush outer surface formed by a plurality of pile yarns organized into loops and extending outwardly from the base layer; Equipped with the inner layer is disposed against the outer surface of the frame, the outer layer is disposed against and attached to the inner layer; the inner layer is folded back at each end of the sealing member to form tapered folds, each tapered fold overlapping each end of the outer layer at a wider portion of the tapered fold.

22. 22. The prosthetic heart valve of claim 21, wherein each tapered fold tapers from a wider portion formed by three overlapping layers of the inner and outer layers to a narrower portion formed by two overlapping layers of the inner layer, the narrower portion being configured at one of a first end of the sealing member located at the midpoint and a second end of the sealing member located at the inflow end.

23. 23. The prosthetic heart valve of claim 21 or 22, wherein an end portion of the outer layer is narrower than the remainder of the outer layer and does not include any pile yarns from the plurality of pile yarns.

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