Prosthetic valve with laminated skirt assembly having reduced overall thickness and improved stretchability

Abstract

An implantable prosthetic valve including a plurality of cusp valves and an annular frame radially expandable from a radially compressed state to a radially expanded state. The prosthetic valve also includes a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the skirt assembly being formed from a thin elastomeric material. The reinforcing layer includes a first set of yarns and a second set of yarns interwoven in a leno weave pattern, the first set of yarns and the second set of yarns being non-perpendicular and non-parallel to a longitudinal axis of the frame when the valve is in the radially expanded state. The first and second encapsulation layers may be fused or bonded along designated regions to form one or more pockets that allow portions of the reinforcing layer disposed therein to move freely.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 267,535, filed February 3, 2022, which is incorporated by reference in its entirety.

[0002] The present disclosure relates to prosthetic heart valves, and in particular to encapsulated skirts (e.g., inner and outer skirts) having an overall reduced thickness and enhanced elasticity that allows the skirts to transition to an axially extended configuration when the prosthetic valve is placed in a compressed radially compressed state. [Background technology]

[0003] The human heart can suffer from a variety of valvular diseases that can cause serious cardiac dysfunction, ultimately requiring repair of the native valve or replacement of the native valve with an artificial valve (prosthetic valve). Numerous repair devices (e.g., stents) and prosthetic valves are known, as are numerous methods for implanting the devices and prosthetic valves in humans. Percutaneous and minimally invasive surgical approaches are used in a variety of procedures to deliver prosthetic medical devices to locations that are not easily accessible by surgery, or to locations in the body where access without surgery is desirable. In one embodiment, the prosthetic heart valve can be loaded onto the end of a delivery device in a compressed configuration or state and advanced through the patient's vascular system to reach the prosthetic valve at the implantation site in the heart. The prosthetic valve is then radially expanded to its functional size, for example, by inflating a balloon to which the prosthetic valve is attached, or by actuating a mechanical actuator that applies an expansive force to the prosthetic valve, or by deploying the prosthetic valve from a sheath of a delivery device, allowing the prosthetic valve to self-expand to its functional size.

[0004] Such an expandable transcatheter prosthetic heart valve may include an annular metal frame, a multi-cusp valve structure supported within the frame, an inner skirt coupled to an inner portion of the metal frame, and an outer skirt coupled to an outer portion of the metal frame. The inner skirt may perform multiple functions. For example, the inner skirt may function as a seal to prevent (or reduce) paravalvular leakage, to anchor the cusps to the frame, and to protect the cusps from damage due to contact with the frame during compression of the prosthesis and during operating cycles. The outer skirt may cooperate with the inner skirt to further reduce or avoid paravalvular leakage after implantation of the prosthesis. The inner skirt may be constructed of a tough, tear-resistant material such as polyethylene terephthalate (PET), although various other synthetic or natural materials may be used.

[0005] The inner and outer skirts are often constructed of semi-porous materials, such as woven polyethylene terephthalate (PET). The porosity of the skirt material is designed to promote cellular ingrowth from the surrounding native tissue or from the surrounding overgrowth device. Such tissue ingrowth into the skirt may integrate the implanted heart valve into the patient's native anatomy and may further reduce paravalvular leakage (PVL). However, such ingrowth may propagate from the porous skirt onto the cusps of the implanted prosthetic heart valve. Indeed, tissue and pannus growth has been observed on the cusps of the implanted prosthetic valve, which may act as a substrate for subsequent thrombus deposition onto the upper surface.

[0006] Additionally, the inner and outer skirts are often secured to the frame by sewing or stitching the fabric of the respective skirt to the frame. The sewing of the inner skirt to the frame can expose the leaflets to the sutures. Repeated contact between the leaflets and the exposed sutures and between the leaflets and the skirt fabric material during valve operation cycles can cause wear of the leaflets. To address such issues, the inner and / or outer skirts can be encapsulated. However, encapsulation of the skirts can have undesirable effects.

[0007] Therefore, there is a need for improved skirts in prosthetic valves. Summary of the Invention [Means for solving the problem]

[0008] Described herein are prosthetic heart valves and methods for assembling the same. The disclosed prosthetic heart valves and methods can, for example, allow an encapsulated outer skirt on the prosthetic valve to have a reduced thickness and volume when in an axially stretched state (corresponding to the compressed state of the prosthetic valve), thereby reducing the overall compression profile of the prosthetic valve. In another example, the encapsulated outer skirt configuration as disclosed herein can allow for increased flexibility and / or stretchability of the encapsulated outer skirt as the prosthetic valve transitions between a compressed state and a radially expanded state. Thus, the devices and methods disclosed herein can overcome one or more deficiencies associated with, among other things, typical prosthetic heart valves and the delivery and implantation of those typical prosthetic heart valves.

[0009] The prosthetic heart valve may include a frame and a valvular structure (e.g., a multi-cusp valve) coupled to the frame. In addition to these components, the prosthetic heart valve may further include one or more components disclosed herein.

[0010] In some examples, the prosthetic heart valve can include a radially expandable and compressible frame.

[0011] In some examples, the prosthetic heart valve can include a skirt assembly.

[0012] In some examples, a skirt assembly for a prosthetic heart valve can include a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a fabric including a first set of yarns and a second set of yarns interwoven with the first set of yarns, the skirt assembly having a first thickness at a plurality of relatively thin regions between adjacent yarns and a second thickness at the yarns, the first thickness being less than the second thickness.

[0013] In some examples, the reinforcing layer of the skirt assembly comprises a fabric, the fabric including a first set of yarns and a second set of yarns that are non-perpendicular and non-parallel to the longitudinal axis of the prosthetic heart valve when the frame of the prosthetic heart valve is in a radially expanded state.

[0014] In some examples, the reinforcing layer of the skirt assembly includes a fabric, the fabric including a first set of yarns and a second set of yarns, and the spacing between adjacent yarns in the first set of yarns is in the range of about 0.5 mm to about 2.0 mm.

[0015] In some examples, the yarns within the first set of yarns in the fabric for the reinforcing layer of the skirt assembly have a thickness or diameter in the range of about 8 μm to about 16 μm.

[0016] In some examples, the yarns within the second set of yarns in the fabric for the reinforcing layer of the skirt assembly have a thickness or diameter in the range of about 8 μm to about 16 μm.

[0017] In some examples, the reinforcing layer of the skirt assembly includes a woven fabric having a weave density of less than 150 ppi.

[0018] In some examples, the first encapsulating layer of the skirt assembly includes an elastomer and has a thickness in a range from about 5 μm to about 15 μm.

[0019] In some examples, the second encapsulation layer of the skirt assembly includes an elastomer and has a thickness in a range from about 5 μm to about 15 μm.

[0020] In some examples, the skirt assembly has a first thickness at a plurality of relatively thin regions between adjacent yarns and a second thickness at the yarns, the first thickness being less than the second thickness, the first thickness being in a range from about 10 μm to about 30 μm.

[0021] In some examples, a skirt assembly for a prosthetic heart valve can include a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the first encapsulation layer and the second encapsulation layer being adhered to one another along one or more adhesive regions, and one or more pockets being formed in the region between the one or more adhesive regions, thereby enabling a portion of the reinforcing layer in the one or more pockets to be unadhered to either the first encapsulation layer or the second encapsulation layer.

[0022] In some examples, the reinforcement layer can move relative to the first encapsulation layer and relative to the second encapsulation layer within one or more pockets.

[0023] In some examples, the first encapsulation layer and the second encapsulation layer are fused to one another at one or more adhesive regions.

[0024] In some examples, the one or more bonded regions include a first bonded region along a first circumferential edge of the skirt assembly and a second bonded region along a second circumferential edge of the skirt assembly.

[0025] In some instances, the one or more adhesive regions are shaped to correspond to a cusp edge portion of a leaflet valve that is sutured to the skirt assembly along the adhesive region.

[0026] In some examples, the prosthetic heart valve includes one or more of the components described in Examples 1-94.

[0027] In some examples, the prosthetic valve includes an annular frame radially expandable from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, a plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the annular frame, and a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven with the first set of yarns. In some examples, the skirt assembly has a first thickness at the plurality of relatively thin regions between adjacent yarns and a second thickness at the yarns, the first thickness being less than the second thickness.

[0028] In some examples, the prosthetic valve includes an annular frame radially expandable from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, a plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the annular frame, and a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven in a leno weave pattern with the first set of yarns, the first set of yarns and the second set of yarns being non-perpendicular and non-parallel to the longitudinal axis, respectively, when the annular frame is in the radially expanded state. In examples, each of the first encapsulation layer and the second encapsulation layer is formed from an elastomer and has a thickness in the range of about 5 μm to about 15 μm.

[0029] In some examples, the prosthetic valve includes an annular frame configured to radially expand from a radially compressed state to a radially expanded state, the annular frame having an inflow end and an outflow end, a plurality of cusp valves configured to control blood flow therethrough, and a skirt assembly including a reinforcement layer interposed between a first encapsulation layer and a second encapsulation layer. In examples, the skirt assembly is configured such that the first encapsulation layer and the second encapsulation layer are fused along one or more bonded regions and one or more pockets are formed in the region between the one or more bonded regions, allowing portions of the reinforcement layer in the one or more pockets to be unbonded to either the first encapsulation layer or the second encapsulation layer.

[0030] In some examples, a skirt assembly for a prosthetic valve is configured to be attached to a surface of an annular frame and to the prosthetic valve and is configured to be movable between a relaxed state and an axially extended state. The skirt assembly includes first and second encapsulation layers, each of which comprises an elastomeric material, and a reinforcing layer disposed between the first and second encapsulation layers, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven with the first set of yarns, each of the first and second sets of yarns being non-perpendicular and non-parallel to a top edge and a bottom edge of the skirt assembly when the skirt assembly is in the relaxed state. In an example, the skirt assembly is configured such that the first encapsulation layer and the second encapsulation layer are fused along one or more adhesive regions to form one or more pocket regions between the first encapsulation layer and the second encapsulation layer, and the first encapsulation layer and the second encapsulation layer are not fused to each other within the pocket regions.

[0031] In some examples, a method for assembling a prosthetic valve includes mounting a plurality of cusp valves to an annular frame radially expandable from a radially compressed state to a radially expanded state, the frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, the plurality of cusp valves being configured to control blood flow from the inflow end to the outflow end of the frame; forming a skirt assembly including a woven reinforcement layer interposed between a first encapsulation layer and a second encapsulation layer, the forming including fusing the first encapsulation layer and the second encapsulation layer along one or more fused regions, the one or more fused regions including a first region along a top edge of the skirt assembly and a second region along a bottom edge of the skirt assembly; and mounting the skirt assembly to the annular frame.

[0032] The various innovations in the present disclosure can be used in combination or separately. This Summary is provided to introduce in a simplified form a selection of various concepts that are further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The above and other objects, features, and advantages of the present disclosure will become more apparent from the Detailed Description below, from the claims, and from the accompanying drawings. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 shows a side view of an exemplary implantable prosthetic valve.

[0034] [Diagram 2] FIG. 2 shows a top perspective view of the prosthetic valve of FIG.

[0035] [Diagram 3] FIG. 3 shows a top perspective view of an exemplary frame of the prosthetic valve of FIG.

[0036] [Figure 4] FIG. 4 shows a flattened view of the frame shown in FIG.

[0037] [Diagram 5] FIG. 5 shows a cross-sectional view of the prosthetic valve of FIG. 1 taken along line 5-5 in FIG.

[0038] [Figure 6] FIG. 6 illustrates the formation of a first encapsulation layer onto a mandrel according to an exemplary process for manufacturing the inner skirt of the prosthetic valve of FIG.

[0039] [Figure 7]FIG. 7 illustrates the placement of a reinforcing layer onto the first encapsulation layer shown in FIG. 6 according to an exemplary process for manufacturing the inner skirt.

[0040] [Figure 8] FIG. 8 illustrates the placement of multiple masks onto the reinforcing layer shown in FIG. 7 according to an exemplary process for manufacturing the inner skirt.

[0041] [Figure 9] FIG. 9 illustrates the formation of a second encapsulation layer over the reinforcing layer with the mask shown in FIG. 8 according to an exemplary process for manufacturing the inner skirt.

[0042] [Figure 10] FIG. 10 illustrates removal of the mask after forming the second encapsulation layer shown in FIG. 9 according to an exemplary process for manufacturing the inner skirt.

[0043] [Figure 11] FIG. 11 is a cross-sectional view of a portion of an inner skirt having a window on one side thereof that exposes the underlying woven fabric of the reinforcing layer.

[0044] [Figure 12] FIG. 12 is a cross-sectional view showing threading of a suture through the woven fabric forming the reinforcing layer at the window shown in FIG.

[0045] [Figure 13] FIG. 13 is a cross-sectional view illustrating suturing the inner skirt shown in FIG. 11 to adjacent struts of the frame of the prosthetic valve.

[0046] [Figure 14] FIG. 14 is a perspective view of an artificial valve according to another example.

[0047] [Figure 15]15 is a cross-sectional view of the prosthetic valve of FIG. 14 taken along line 15-15 in FIG.

[0048] [Figure 16A] FIG. 16A shows a portion of two interwoven yarns in the skirt when the skirt is in a relaxed state (corresponding to the radially expanded state of the prosthetic valve) and an axially stretched state (corresponding to the radially compressed state of the prosthetic valve). [Figure 16B] FIG. 16B shows a portion of two interwoven yarns in the skirt when the skirt is in a relaxed state (corresponding to the radially expanded state of the prosthetic valve) and an axially stretched state (corresponding to the radially compressed state of the prosthetic valve).

[0049] [Figure 17] FIG. 17 illustrates a portion of a braided layer for the outer skirt of the prosthetic valve of FIGS. 14-15, according to one example.

[0050] [Figure 18] FIG. 18 illustrates a portion of a plain weave layer for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example.

[0051] [Figure 19A] FIG. 19A illustrates, in accordance with another example, various leno weaving layers and related leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15. [Figure 19B] FIG. 19B illustrates some of the various leno weaving layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19C] FIG. 19C illustrates various leno weave layers and related leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19D]FIG. 19D illustrates some of the various leno weaving layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19E] FIG. 19E illustrates some of the various leno weaving layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19F] FIG. 19F illustrates various leno weave layers and related leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19G] FIG. 19G illustrates some of the various leno weaving layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19H] FIG. 19H illustrates various leno weave layers and related leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19I] FIG. 19I illustrates some of the various leno weaving layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example. [Figure 19J] FIG. 19J illustrates various leno layers and associated leno weaving techniques for the outer skirt of the prosthetic valve of FIGS. 14-15, according to another example.

[0052] [Figure 20A] FIG. 20A is a schematic illustration of a portion of an encapsulated skirt according to another example.

[0053] [Figure 20B] FIG. 20B is a cross-sectional view of a portion of the exemplary encapsulated skirt shown in FIG. 20A.

[0054] [Figure 21] FIG. 21 is a schematic illustration of a plan view of a portion of an encapsulated skirt having a pocket formed therein, according to another example.

[0055] [Figure 22] FIG. 22 is a schematic illustration of an assembly for forming a skirt assembly for a prosthetic valve, according to one example.

[0056] [Figure 23] FIG. 23 is a plan view of a pressure plate that may be used in the assembly of FIG. 22 to form a skirt assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] As discussed above, encapsulation of the inner and / or outer skirt of a prosthetic valve can have undesirable effects. For example, encapsulation can cause the skirt to become overly stiff, which can inhibit the transition of the skirt between a relaxed state and an axially elongated state as the prosthetic valve transitions between a radially expanded state and a compressed state. In other instances, encapsulation of the inner and / or outer skirt can increase the volume of the skirt material, which can undesirably increase the profile of the prosthetic valve in the compressed state, which can make, for example, transcatheter delivery and manipulation of the prosthetic valve more difficult.

[0058] The encapsulated skirt as disclosed herein addresses the above problems. For example, the skirt configuration disclosed herein can allow for a reduction in the thickness and volume of the encapsulated outer skirt when placed in an axially stretched state (corresponding to the crimped state of the prosthetic valve). In another example, the skirt configuration disclosed herein can allow for improved flexibility and / or stretchability of the encapsulated outer skirt.

[0059] General Considerations All features described herein are independent of each other and may be used in combination with any other feature described herein unless structurally impossible. For example, the exemplary prosthetic valve shown in Figures 1 and 2 may include any exemplary inner and outer skirts disclosed herein. In another example, the exemplary inner and outer skirts shown in Figures 1, 2, 5-15, and 20A-21 may include a reinforcing layer having any exemplary weave pattern as disclosed herein and / or as illustrated in Figures 17-19J. In yet another example, the exemplary inner and outer skirts 1, 2, 5-15, 20A-21 may be manufactured via any technique disclosed herein, such as via the technique illustrated in Figures 6-10.

[0060] For purposes of this specification, certain aspects, advantages, and novel features of the examples of the disclosure are described herein. The disclosed methods, devices, and systems should not be construed as limiting in any way. Instead, the disclosure is directed to all novel and non-obvious features and aspects of the various disclosed examples, alone, in various combinations with each other, and in various subcombinations with each other. The methods, devices, and systems are not limited to any particular aspects, features, or combinations thereof, and the disclosed examples do not require any one or more particular advantages to be present or problems to be solved. Technology from any example can be combined with technology described in any one or more other examples.

[0061] Although operations in some disclosed examples are described in a particular sequential order for convenience of presentation, it will be understood that aspects of the description encompass permutations unless a particular order is required by specific language set forth below. For example, operations described sequentially may in some cases be permuted or performed simultaneously. Moreover, for simplicity, the accompanying drawings may not show various ways in which the disclosed methods may be used in combination with other methods. Additionally, the description sometimes uses terms such as "provide" or "achieve" or "enable" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by those skilled in the art.

[0062] Although operations in some disclosed examples are described in a particular sequential order for convenience of presentation, it will be understood that aspects of the description encompass permutations unless a particular order is required by specific language set forth below. For example, operations described sequentially may in some cases be permuted or performed simultaneously. Moreover, for simplicity, the accompanying drawings may not show various aspects in which the disclosed methods may be used in combination with other methods. Additionally, the description sometimes uses terms such as "provide" or "achieve" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by those skilled in the art.

[0063] As used herein with respect to prosthetic heart valve assemblies and with respect to their implantation and construction, "proximal" refers to a location, orientation, or portion of a component that is closer to the user and to a handle of a delivery system or device that is located external to the patient, and "distal" refers to a location, orientation, or portion of a component that is farther from the user and from the handle and closer to the implantation site. The terms "longitudinal" and "axial" refer to an axis extending in a proximal-distal direction, unless expressly defined otherwise.

[0064] The terms "axial," "radial," and "circumferential," as used herein, are used to describe the placement and assembly of components relative to the geometry of the frame of the prosthetic heart valve. Such terms are used merely for convenience of description and are not intended to strictly limit the disclosed examples. In particular, when a component or action is described with respect to a particular direction, directions parallel to the specified direction as well as slight deviations therefrom are included. Thus, a description of components extending along the axis of the frame does not require that the components be aligned or overlapped with respect to the center of the frame, but rather, the components can extend substantially along a direction parallel to the central axis of the frame.

[0065] As used herein, the terms "unitarily molded" and "unitarily constructed" refer to structures that do not include any welding, attachments, or other means for fastening separately formed pieces of material together.

[0066] As used herein, actions that occur "concurrently" or "concurrently" occur generally at the same time as one another, but delays in the occurrence of actions relative to one another, such as those due to spacing between components, are expressly within the scope of the term unless expressly stated to the contrary.

[0067] As used in this application and the claims, the singular forms "a," "an," and "the" include the plural unless the context clearly dictates otherwise. Additionally, the term "comprises" means "comprises." Furthermore, the term "couple" generally means to physically, mechanically, chemically, magnetically, and / or electrically couple or connect, and does not exclude the presence of intermediate elements between coupled or associated members, unless specifically stated to the contrary. As used herein, "and / or" means "and" or "or," and also means "and" and "or."

[0068] Directions and other relative references may be used herein to facilitate illustration and explanation of the principles, but are not intended to be limiting. For example, certain terms may be used, such as "inside," "outside," "upper," "lower," "internal," "external," "top," "bottom," "inside," "outer," "left," "right," and the like. Such terms are used where applicable to provide some clarity in dealing with relative relationships, particularly with respect to the illustrated examples. However, such terms are not intended to imply absolute relationships, positions, or orientations. For example, an "upper" part of an object may become a "lower" part simply by flipping it over. It is still the same part, and the object remains the same.

[0069] Exemplary Prosthetic Valves The prosthetic valves disclosed herein can be radially compressible and radially expandable between a radially compressed state and a radially expanded state. Thus, the prosthetic valve can be compressed onto or held by an implant delivery device during delivery in a radially compressed state, and then expanded to a radially expanded state after the prosthetic valve reaches the implantation site. It will be understood that the prosthetic valves disclosed herein can be used with a variety of implant delivery devices and implanted via a variety of delivery procedures, examples of which will be described in more detail below.

[0070] 1 and 2 show two different views of a prosthetic valve 10 according to one example. The valve shown is configured to be implanted into the native aortic annulus, but in other examples may be configured to be implanted into other native annulus of the heart. The valve 10 may have several main components: a stent or frame 12, a valvular structure 14, and a skirt assembly 15. The skirt assembly 15 may include an inner skirt 16 and, optionally, an outer skirt 18.

[0071] The valvular structure 14 (or leaflet structure) may include three leaflets 40 (although more or fewer leaflets may be used) that collectively form the leaflet structure, which may be configured to collapse in a tricuspid arrangement. The valvular structure 14 is configured to permit blood to flow through the prosthetic valve 10 in a direction from the inlet end 48 of the prosthetic valve to the outlet end 50 of the prosthetic valve, and is configured to prevent blood from flowing through the prosthetic valve from the outlet end 50 to the inlet end 48.

[0072] Each leaflet 40 may have a curved, generally U-shaped inlet or apical edge 52. In this manner, the inlet edge of the valvular structure 14 has an undulating, curved, scalloped shape. Forming the leaflets in this scalloped shape can reduce stress on the leaflets, thus improving the durability of the valve. Additionally, the scalloped shape can eliminate or at least minimize folds and corrugations in the abdomen (central region of each leaflet) of each leaflet that can lead to premature calcification in these regions. The scalloped shape also allows for a smaller and more uniform compression shape at the inflow end of the valve, reducing the amount of tissue material used to form the leaflet structure. The leaflets 40 can be formed from pericardial tissue (e.g., bovine pericardial tissue), from biocompatible synthetic materials, or from a variety of other suitable natural or synthetic materials, as known in the art and as described in U.S. Pat. No. 6,730,118, which is incorporated herein by reference.

[0073] The bare frame 12 (with the other components of the prosthetic valve removed) is shown in Figure 3. In the illustrated example, the frame 12 has an annular shape defining an inlet end 54 and an outlet end 56 and includes a plurality of struts (or frame members). The frame 12 may be formed with a plurality of circumferentially spaced slots or commissure windows 20 (three in the illustrated example) configured to attach the commissures 58 of the valvular structure 14 to the frame, as described in more detail in U.S. Patent No. 9,393,311, which is incorporated herein by reference.

[0074] The frame 12 can be formed from any of a variety of suitable plastically expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., Nitinol) as known in the art. When constructed from an expandable material (e.g., a plastically expandable material), the frame 12 (and thus the valve 10) can be compressed into a radially compressed state on a delivery catheter and then expanded inside the patient by an inflatable balloon or another suitable expansion mechanism. When constructed from a self-expandable material, the frame 12 (and thus the valve 10) can be compressed into a radially compressed state and restrained in the compressed state by insertion into a sheath or equivalent mechanism of the delivery catheter. After introduction into the body, the valve can be driven forward from the delivery sheath, which allows the valve to expand to its functional size. Examples of prosthetic valves in a compressed or radially compressed state are shown and described in U.S. Pat. No. 11,013,600, which is incorporated herein by reference.

[0075] Suitable plastically expandable materials that may be used to form the frame 12 include, but are not limited to, stainless steel, nickel-based alloys (e.g., cobalt-chromium alloys or nickel-cobalt-chromium alloys), polymers, or combinations thereof. In a particular example, the frame 12 includes a nickel-cobalt-chromium-molybdenum alloy, such as MP35N® (a trademark of SPS Technologies), which is equivalent to UNS R30035 (covered by ASTM F562-02). MP35N® / UNS R30035 includes 35% nickel, 35% cobalt, 20% chromium, and 10% molybdenum by weight. It has been found that the use of MP35N to form the frame 12 may provide better structural results compared to stainless steel. In particular, when MP35N is used as the frame material, the same or better performance in terms of radial crush force resistance, fatigue resistance, and corrosion resistance can be achieved with less material. Moreover, the less material required and the potentially reduced compressed profile of the frame can provide a less bulky valve assembly for percutaneous delivery to a treatment location within the body.

[0076] 3 and 4, the frame 12 in the illustrated example includes a first lower row I of circumferentially extending angled struts 22 disposed across the inflow end of the frame, a second row II of circumferentially extending angled struts 24, a third row III of circumferentially extending angled struts 26, a fourth row IV of circumferentially extending angled struts 28, and a fifth row V of circumferentially extending angled struts 32 at the outflow end 56 of the frame. A plurality of substantially straight axially extending struts 34 may be used to interconnect the struts 22 of the first row I and the struts 24 of the second row II. The fifth row V of angled struts 32 is connected to the fourth row IV of angled struts 28 by a plurality of axially extending window frame portions 30 (defining the commissure windows 20) and a plurality of axially extending struts 31. Each axial strut 31 and each frame portion 30 extends from a position defined by the convergence of the lower ends of two angled struts 32 to another position defined by the convergence of the upper ends of two angled struts 28.

[0077] Each commissure window frame portion 30 can attach to a corresponding commissure 58 of the leaflet structure 14. Each frame portion 30 is fixed at its upper and lower ends to adjacent strut rows, providing a robust configuration that enhances fatigue resistance under cyclic loading of the valve as compared to known cantilever struts for supporting the commissures of the leaflet structure. This configuration allows for a reduced frame wall thickness, resulting in a smaller compressed diameter of the prosthetic valve. In a particular example, the thickness T (FIG. 3) of the frame 12, as measured between the inner and outer diameters, is about 0.48 mm or less.

[0078] The struts and frame portions of the frame collectively define a plurality of open cells of the frame. At the inflow end of frame 12, struts 22, 24, and 34 define a lower row of cells that define opening 36. The second row of struts 24, the third row of struts 26, and the fourth row of struts 28 define two middle rows of cells that define opening 38. The fourth row of struts 28 and the fifth row of struts 32, together with frame portion 30 and struts 31, define an upper row of cells that defines opening 60. Opening 60 is relatively large and may be sized to allow a portion of leaflet structure 14 to protrude or bulge into and / or through opening 60 when frame 12 is compressed, thereby minimizing the compressed profile of the prosthetic valve.

[0079] As shown in FIG. 4, the lower end of strut 31 is connected to two struts 28 at nodes or junctions 44, and the upper end of strut 31 is connected to two struts 32 at nodes or junctions 46. Strut 31 can have a thickness less than the thickness of junctions 44, 46. Junctions 44, 46, together with junctions 64 connecting adjacent struts 32, prevent complete closure of aperture 60 when frame 12 is compressed. Thus, the configuration of strut 31 and junctions 44, 46, 64 helps provide sufficient space within compressed aperture 60 to allow a portion of the valve to protrude outward (i.e., bulge) through the aperture. This allows the valve to be compressed to a relatively smaller diameter than if all of the leaflet material were constrained within the compressed frame.

[0080] The frame 12 can be configured to prevent or at least minimize the possibility of over-expansion of the valve at a given balloon pressure, particularly at the outflow end portion of the frame supporting the leaflet structure 14. In appearance, the frame can be configured such that the angles 42a, 42b, 42c, 42d, 42e between the struts are relatively large. The larger such angles, the greater the force required to open (expand) the frame. Thus, the angles between the struts of the frame can be selected to limit radial expansion of the frame at a given opening pressure (e.g., balloon inflation pressure). In certain instances, such angles are at least 110 degrees or greater when the frame is expanded to its functional size, and more particularly, such angles are at least 120 degrees or greater when the frame is expanded to its functional size. U.S. Pat. No. 9,393,110 (incorporated herein above) further describes the frame 12, as well as other configurations of frames that may be incorporated into prosthetic heart valves, such as the prosthetic valves 10, 200 described herein.

[0081] 1, 2, and 5, the skirt assembly 15 can include an encapsulated inner skirt 16 located inside the frame 12 and an outer skirt 18 located outside the frame 12. The outer skirt 18 can include a plurality of circumferentially spaced apart protruding portions or projections 66 formed along the outflow edge (the top edge in the illustrated example) of the outer skirt and recesses 68 located between adjacent projections. In other examples, the outer skirt 18 can have a straight outflow edge without any projections or recesses (e.g., similar to outer skirt 202 in FIG. 14).

[0082] The inflow (lower) and outflow (upper) edges of the outer skirt 18 may be secured to the frame 12 and / or to the inner skirt 16, for example, by thermal bonding, adhesive, and / or suturing. As shown in the illustrated example, the projections 66 along the outflow edge of the outer skirt 18 may be secured to the struts of the frame by sutures 70, while the recesses 68 located between adjacent projections may remain unsecured to the frame 12 and to the encapsulated inner skirt 16. The outer skirt 18 may function as a sealing member for the prosthesis 10 by sealing against the native annulus tissue, thereby helping to reduce paravalvular leakage past the prosthesis 10.

[0083] In some examples, as shown in Figures 1 and 2, the outer skirt 18 can be configured to extend radially outward from the frame 12 when the prosthetic valve 10 is in the radially expanded configuration. Alternatively, the outer skirt 18 can be configured to form a tight fit with the frame 12 (e.g., similar to the outer skirt 202 in Figure 14), such that the outer skirt 18 lies against the outer surface of the frame 12 when the prosthetic valve 10 is in the radially expanded configuration. The outer skirt 18 can be formed from any of a variety of synthetic materials or natural tissues (e.g., pericardial tissue). Suitable synthetic materials include any of a variety of biocompatible fabrics (e.g., PET fabrics) or non-fabric films, including any of the materials disclosed below for the reinforcing layer 88 of the inner skirt 16. Further details regarding the outer skirt 18 are disclosed in U.S. Patent No. 9,393,110, incorporated herein by reference above.

[0084] As further shown in Figures 1 and 2, the encapsulated inner skirt 16 in the illustrated example extends from the inlet end 54 of the frame to the fourth row IV of angled struts 28. In other examples, the encapsulated inner skirt 16 can extend from the inlet end 54 of the frame to a position that is less than the fourth row IV of struts (e.g., to the second row II or third row III of struts), or the encapsulated inner skirt can extend the entire height of the frame 12 (e.g., from the inlet end 54 to the outlet end 56). In alternative examples, the encapsulated inner skirt 16 can be positioned and / or sized to extend onto a different portion of the frame 12 than the configuration shown in Figures 1 and 2. In some examples, the inlet end of the encapsulated inner skirt 16 can be axially spaced from the inlet end 54 of the frame 12.

[0085] Although the shape of the encapsulated inner skirt 16 is typically tubular or cylindrical (forming a complete circle as a cross-sectional shape in a plane perpendicular to the longitudinal axis of the valve), the inner skirt 16 need not extend 360 degrees circumferentially around the inner surface of the frame 12. In other words, the encapsulated inner skirt 16 can have a cross-sectional shape that is not a complete circle (in a plane perpendicular to the axis of the valve lumen). The encapsulated inner skirt 16 can be initially formed as a flat strip and then formed into an annular shape by joining opposing edge portions together, for example, by sewing, by heat bonding, and / or by adhesive. Alternatively, the encapsulated inner skirt 16 can be directly formed into an annular shape, such as by constructing the encapsulated skirt inner layer 16 on a cylindrical mandrel, as described below.

[0086] Referring to FIG. 5, the encapsulated inner skirt 16 has a first side 72 formed by a first encapsulation layer 84 and defining the inner surface of the inner skirt, and a second side 74 formed by a second encapsulation layer 86 and defining the outer surface of the inner skirt 16. As will be described in more detail below, the frame-facing surface 74 of the inner skirt 16 may have one or more windows or openings through which the otherwise encapsulated skirt fabric layer is exposed. Sutures may be passed through the fabric layers of the inner skirt 16 at the windows to secure the inner skirt 16 to the frame 12. The outer skirt 18 has been omitted from FIG. 5 for ease of illustration.

[0087] When the encapsulated inner skirt 16 is attached to the frame 12, a first side 72 of the inner skirt 16 faces inwardly, toward the leaflet structure 14 located within the prosthetic valve 10, and a second side 74 of the inner skirt 16 faces outwardly, abutting against the inner surface of the frame 12. In certain examples, the encapsulated inner skirt 16 can include a reinforcing layer 88 interposed between a first encapsulating layer 84 and a second encapsulating layer 86. In an exemplary example, the reinforcing layer 88 can be a fabric layer. The first encapsulating layer 84 and the second encapsulating layer 86 form the inner and outer layers, respectively, of the illustrated inner skirt 16. In a particular example, the inner surface of the reinforcement layer 88 can be completely covered by a first encapsulation layer 84 on the first side 72, and the outer surface of the reinforcement layer 88 can be partially covered by a second encapsulation layer 86 on the second side 74, with the second encapsulation layer 86 defining one or more windows or openings 90 (see FIG. 10 ) exposing the reinforcement layer 88 on the second side 74.

[0088] The reinforcing layer 88 reinforces the inner skirt 16 and can improve tear resistance. The reinforcing layer can also function as an anchoring layer for suturing the inner skirt 16 to the frame 12 and for supporting the apical edge portions of the leaflets 40, as described in more detail below. Additionally, the reinforcing layer 88, in cooperation with the encapsulation layers 84, 86, can help reduce (or prevent) paravalvular leakage through the prosthetic valve 10 when in the expanded configuration.

[0089] In examples, the reinforcing layer 88 can include a fabric woven from various types of natural or synthetic fibers (or filaments, or yarns, or strands), including, but not limited to, gauze, PET fibers (e.g., Dacron), polyester fibers, polyamide fibers, ultra-high molecular weight polyethylene (UHMWPE) fibers, etc. In examples, the reinforcing layer 88 can have a woven, braided, or knitted pattern or structure similar to one or more structures described below with reference to Figures 17-19J (or in another configuration). Additionally, the reinforcing layer 88 can be a woven, braided, or knitted structure formed from metal filaments or wires (e.g., filaments or wires made of Nitinol, stainless steel, or titanium), glass filaments or wires, carbon filaments or wires, or ceramic (e.g., alumina oxide) filaments or wires.

[0090] Alternatively, the reinforcing layer 88 can include filaments, fibers, yarns, or wires, such as those made of any of the materials described above, where the filaments, fibers, yarns, or wires are not necessarily woven, braided, or braided together. For example, the reinforcing layer 88 can include a layer of parallel filaments, fibers, yarns, or wires, or can include multiple layers of filaments, fibers, yarns, or wires, stacked on top of each other. In a particular example, the reinforcing layer 88 can include any of a variety of nonwoven fabrics, such as felt. The thickness of the reinforcing layer 88 can vary, but can be less than 6 mils, desirably less than 4 mils, and more desirably about 2 mils.

[0091] Additionally or alternatively, the reinforcing layer 88 may include one or more layers or films formed from any of a variety of semi-crystalline polymeric materials or thermoplastics having aligned or partially aligned (e.g., parallel) molecular chains. Such materials may exhibit anisotropic mechanical properties, such as increased mechanical strength along the length of the molecular chains. Suitable semi-crystalline polymeric materials may include, for example, PTFE, PET, polypropylene, polyamide, polyetheretherketone (PEEK), etc., and these layers or films may be positioned between and encapsulated by the encapsulating layers 84, 86 to reinforce the inner skirt 16. Unless otherwise noted, the following description will refer to fabric layers as exemplary reinforcing layers for ease of explanation, although it will be understood that non-fabric layers having sufficiently high tensile strength may also be used as reinforcing layers.

[0092] The encapsulation layers 84, 86 may be formed from any suitable biocompatible material. Desirably, the encapsulation layers 84, 86 include a material that is relatively less abrasive than the fabric layers to reduce wear on the leaflets 40. The encapsulation layers 84, 86 may include, for example, a membrane or film formed from a nonwoven fiber or non-fibrous material. The biocompatible material used to form the layers 84, 86 may be a non-absorbable polymeric material (i.e., a material that does not dissolve after being implanted in the body), and such a material may be an elastomer.

[0093] In an example, either of the encapsulation layers 84, 86 can have a porous microstructure that promotes the ingrowth of surrounding tissue to help secure the prosthetic valve 10 within the body cavity. In an alternative example, the encapsulation layers 84, 86 can be sealing layers to prevent or at least reduce or limit the ingrowth of native tissue. As used herein, a "sealing layer" refers to a layer that is constructed such that when implanted into a patient, cellular ingrowth into the layer is prevented or at least inhibited or limited. In some examples, such sealing layers are substantially non-porous or have pores therein that are small enough in size to prevent cellular tissue ingrowth. The size and characteristics of the pores (e.g., porosity, tortuosity) in the sealing layer can be configured to prevent cellular ingrowth, which may also depend on the location of the implant (e.g., pressure gradient, blood flow conditions), the desired implant life, the thickness of the sealing layer, and / or other factors. In some examples, the size of each hole in the sealing layer can be, for example, 20 μm or less, 10 μm or less, or 5 μm or less. In some implementations, the sealing layer can have a variety of hole sizes, and the distribution of hole sizes can be such that at least 90% of the holes have a size of 8 μm or less. Alternatively or additionally, in some implementations, the distribution of hole sizes in the sealing layer can be such that at least 90% of the holes have a size of 20 μm or less, 10 μm or less, or 5 μm or less. Sealing layers that can be utilized with the encapsulated skirts disclosed herein are further described in U.S. Provisional Patent Application Nos. 63 / 112,080 and 63 / 240,766, each of which is incorporated herein by reference.

[0094] Examples of encapsulation layer materials include, but are not limited to, ePTFE, non-expanded porous PTFE, polyester or expanded PTFE yarns, PTFE, ultra-high molecular weight polyethylene (UHMWPE), other polyolefins, composites such as ePTFE with PTFE fibers or UHMWPE films with embedded UHMWPE fibers, polyimides, silicones, polyurethanes (PU), thermoplastic PU (TPU), other thermoplastic materials, hydrogels, fluoroethyl polypropylene (FEP), polypropyl fluoroamine (PFA), other related fluorinated polymers, or various combinations of the above materials. In certain examples, the encapsulation layers 84, 86 can be formed from respective tubes formed from suitable polymeric materials (e.g., ePTFE or UHMWPE tubes) that can be bonded together when subjected to a heat treatment. In some examples, the encapsulation layers 84, 86 can be formed from the same type of material, although different materials can be used to form the encapsulation layers depending on the particular application.

[0095] Microporous ePTFE tubes can be manufactured by a number of well-known methods. Expanded PTFE is often manufactured by mixing particulate dry polytetrafluoroethylene resin with a liquid lubricant to form a viscous slurry. The mixture can be forced into a die, typically cylindrical, and compressed to form a cylindrical billet. The billet can then be ram extruded through an extrusion die to produce a tubular or sheet-like structure known in the art as an extrudate. The extrudate comprises a mixture of extruded PTFE and lubricant, referred to as "wet PTFE." Wet PTFE has a microstructure consisting of agglomerated, cohesive PTFE resin particles that are highly crystalline. After extrusion, the wet PTFE can be heated to a temperature below the flash point of the lubricant to volatilize most of the lubricant from the PTFE extrudate. The resulting PTFE extrudate is largely free of lubricant and is known in the art as dry PTFE. The dried PTFE can then be stretched uniaxially, biaxially, or radially using suitable mechanical equipment known in the art. Stretching is typically performed at elevated temperatures, for example, above room temperature and below the crystalline melting point of PTFE, 327°C. By stretching the dried PTFE uniaxially, biaxially, or radially, the aggregated cohesive PTFE resin forms fibrils that emanate from the nodes (areas of aggregated PTFE) and are oriented parallel to the axis of expansion. After stretching, the dried PTFE is referred to as expanded PTFE ("ePTFE") or microporous PTFE.

[0096] UHMWPE is composed of very long polyethylene chains with a molecular weight in the millions, typically between 2 and 6 million. UHMWPE has great resistance to aggressive chemicals, extremely low moisture absorption, and a very low coefficient of friction. UHMWPE is self-lubricating and has excellent wear resistance. UHMWPE is processed using compression molding, ram extrusion, gel spinning, and sintering. UHMWPE is commercially available as a powder, in sheets or rods, and as fibers.

[0097] The encapsulation layers 84, 86 can be formed by a number of means. For example, the encapsulation layers 84, 86 can be formed using an electrospinning process, which uses electrical forces to draw electrically charged threads of a polymer solution or melt to fiber diameters on the order of hundreds of nanometers. In another example, the encapsulation layers 84, 86 can be formed using a centrifugal spinning technique. In centrifugal spinning, a spinning fluid is introduced into a rotating spinning head. When the rotation speed reaches a critical value, centrifugal forces overcome the surface tension of the spinning fluid, causing a liquid jet to emerge from the nozzle tip of the spinning head. The jet then undergoes a drawing process, which ultimately deposits it onto a collector to form solidified nanofibers. In yet another example, the encapsulation layers 84, 86 can be formed using an atmospheric plasma spray (APS) technique, which is a special variation of a thermal spray process. APS uses an electric arc to ionize the flowing process gas and controls the hot gas flow to melt a wide variety of powder feedstocks, thereby providing high quality coatings on the target object. In yet other examples, the encapsulation layers 84, 86 can be formed using any other suitable method, including dip coating, spray coating, melt spinning, and the like. For example, either of the encapsulation layers 84, 86 can be formed by dipping the fabric layer 88 into a liquefied polymeric material and then curing the liquefied polymeric material.

[0098] 6-10 illustrate one exemplary process for forming the inner skirt 16 (and / or other encapsulated skirts described herein). Although the use of an electrospinning process is described below, this is merely exemplary in nature and is not intended to be limiting. It will be understood that other processes for depositing the polymer layer, such as centrifugal spinning, APS, dip coating, or others, may also be used.

[0099] First, as shown in FIG. 6, a first encapsulation layer 84 including a first coating material can be deposited circumferentially around the exterior surface of a cylindrically shaped mandrel 100 by electrospinning means (or using other techniques). As known in the art, an electrospinning system can include a spinneret that is used to extrude a polymer solution or melt to form a fiber. To deposit the first encapsulation layer 84 onto the mandrel 100, the electrospinning system can be configured to rotate the fiber extrusion spinneret in a circular motion around the mandrel 100. Alternatively, the fiber extrusion spinneret can be configured to remain stationary while the mandrel 100, located in front of the spinneret, rotates about its longitudinal axis.

[0100] Second, as shown in Figure 7, a fabric layer 88 can be disposed over the first encapsulating layer 84. The fabric layer 88 can be in the form of a sheet of fabric material tightly wrapped around the first encapsulating layer 84. For example, as discussed above, the fabric layer 88 can have a woven structure (such as shown in and described below with reference to Figures 17-19J) that includes warp and weft fibers that run perpendicular to one another.

[0101] In an alternative example, the fabric layer 88 may also be deposited onto the first encapsulating layer 84. It will be appreciated that this construction method is not limited to examples in which the reinforcing layer is a plain woven fabric, and that this method may be used to form a skirt in which the reinforcing layer may take any of the forms disclosed herein. For example, the reinforcing layer 88 may be a preformed woven or leno material that is wrapped around the first encapsulating layer 84. In yet another example, the layer 88 may be formed by weaving or leno weaving one or more yarns or filaments around the first encapsulating layer 84 to form a woven or leno layer around the first encapsulating layer.

[0102] Third, as shown in Figure 8, one or more masks 92 can be placed onto the fabric layer 88 at selected regions 94 of the fabric. Fourth, as shown in Figure 9, a second encapsulation layer 86 including a second coating material can be deposited by electrospinning (or using other techniques) onto the masked fabric layer 88. The mask 92 is then removed after depositing the second encapsulation layer 86, as shown in Figure 10. Thus, one or more windows 90 corresponding to the selected regions 94 are formed, where the windows 90 expose the fabric layer 88 located directly underneath the windows 90.

[0103] 8-9 , the mask 92 can temporarily cover selected regions 94 of the fabric layer 88 to prevent those selected regions 94 from being deposited with the second coating material of the second encapsulation layer 86. Alternatively, the selected regions 94 can be functionally masked without the need to apply a physical mask 94. For example, the associated movement and operation (e.g., activation and / or deactivation) of the fiber extrusion spinneret relative to the mandrel 100 can be programmed such that the second coating material of the second encapsulation layer 86 can be deposited only on portions of the fabric layer 88 located outside of the selected regions 94.

[0104] In the illustrated example of FIGS. 8-9, three annular bands of masks 92 are shown corresponding to three selected regions 94 along the perimeter of the fabric layer 88. As a result, three annular windows 90 are formed after removal of the masks 92, as shown in FIG. 10. In other examples, any of the masks 92 can have a non-annular shape such that the corresponding selected regions 94, and the resulting windows 90, do not completely surround the fabric layer 88. For example, any of the masks 92 can have a customized shape at a customized location to form a customized window 90. Additionally, although three windows 90 are shown in the illustrated example, the inner skirt can be formed with fewer or more windows, and the windows can be located anywhere along the skirt. In an example, the inner skirt can be formed with one or more circumferentially extending rows of windows, where each row includes a plurality of circumferentially spaced windows. In examples, one or more windows may be formed along the entrance edge and / or along the exit edge of the inner skirt.

[0105] Although not shown, it will be understood that anchoring mechanisms may be provided at each of the steps described above to temporarily secure the position of each layer. As a non-limiting example, layers of PTFE tape may be wrapped around one or both ends of second encapsulation layer 86 to help secure the position of second encapsulation layer 86 relative to underlying layers of the assembly and relative to mandrel 100 during subsequent processing.

[0106] In a representative example, the fabric layer 88 has a plurality of openings through which the first encapsulation layer 84 and the second encapsulation layer 86 can be fused to one another. In an example, the openings in the fabric layer 88 may be formed by weaving, knitting, or braiding fibers or yarns to form a fabric layer having a predetermined pattern (e.g., such as those shown in and described below with reference to FIGS. 17-19J, or others). In another example, the fabric layer 88 may have a nonwoven porous structure that has openings. In another example, if a nonwoven fabric (e.g., felt) is used to form the fabric layer, the openings in the fabric layer 88 may be formed by cutting (e.g., laser cutting) openings in the fabric layer.

[0107] In an example, the first encapsulation layer 84 and the second encapsulation layer 86 can be fused through the openings in the fabric layer 88 simultaneously during the process of depositing the second encapsulation layer 86 onto the masked fabric layer 88. As the second coating material extruded from the spinneret is deposited onto the fabric layer 88 to form the second encapsulation layer 86, some of the second coating material may penetrate through the openings in the fabric layer 88 and fuse to the fibers in the first encapsulation layer 84.

[0108] In other examples, the fusion of the first encapsulation layer 84 and the second encapsulation layer 86 may occur after depositing the second encapsulation layer 86 onto the masked fabric layer 88. For example, the assembly shown in FIG. 10 may be subjected to an encapsulation process in which the first encapsulation layer 84 and the second encapsulation layer 86 are bonded to one another through openings in the fabric layer 88 by applying heat and / or pressure to the assembly. Additionally, the fabric layer 88 may have a shorter axial length than the first encapsulation layer 84 and the second encapsulation layer 86 to facilitate bonding the first encapsulation layer 84 and the second encapsulation layer 86 at their respective ends to encapsulate the fabric layer 88 between the encapsulation layers. Similar encapsulation processes are described in U.S. Pat. Nos. 10,045,846 and 10,232,564, each of which is incorporated herein by reference.

[0109] In an example, ePTFE can be used as the first coating material for depositing the first encapsulation layer 84 and / or the second coating material for depositing the second encapsulation layer 86. Alternatively, other materials can be used, such as UHMWPE, polyurethane composites, or any other non-absorbable polymeric materials as described above. The inner skirt 16 can desirably have a laminate structure in which the fabric layer 88 is sandwiched between two fused layers (i.e., between the fused first encapsulation layer 84 and second encapsulation layer 86). In some examples, the same material can be used to deposit the first encapsulation layer 84 and the second encapsulation layer 86. Based on the fusion or adhesion between the layers, the first encapsulation layer 84 and the second encapsulation layer 86 can be integrated with each other, thereby effectively forming a unitary structure (i.e., no physical interlayer boundary) in which the fabric layer 88 is encapsulated. The density of the first encapsulation layer 84 can be the same as or different from the density of the second encapsulation layer 86. In other examples, the first coating material used to deposit the first encapsulation layer 84 can be different from the second coating material used to deposit the second encapsulation layer 86.

[0110] After the first encapsulation layer 84 and the second encapsulation layer 86 are intimately fused together to encapsulate the fabric layer 88, the inner skirt 16 may be removed from the mandrel 100. One or both end portions of the inner skirt 16 may be trimmed to a desired height. The inner skirt 16 may then be attached to the frame 12.

[0111] 6-10 and the above description illustrate a process for forming the annular shaped inner skirt 16, it will be appreciated that the same process may be used to form the outer skirt 18. Additionally, as discussed above, the inner skirt 16 may be initially formed as a flat strip and then formed into an annular shape by bonding two opposing edges together. Instead of using a cylindrically shaped mandrel 100 to form a flat strip, the first encapsulation layer 84 and the second encapsulation layer 86, as well as the fabric layer 88, may be constructed on a flat substrate (e.g., by forming on a flat metal plate having a compressible coating and pressing with a second flat metal plate, as described below).

[0112] Although the process described above uses masking to form the windows 90 on the second encapsulation layer 86 of the inner skirt 16, it will be understood that other methods may be used to form these windows 90. For example, the second encapsulation layer 86 may initially be deposited over the entire surface of the fabric layer 88. Selected regions 94 on the second encapsulation layer 86 may then be located and removed, for example, by laser cutting, chemical attack, or other means. As a result, windows 90 may be formed at the selected regions 94 on the second encapsulation layer 86, thereby exposing the fabric layer 88 located directly below in the windows. In another example, the second encapsulation layer 86 may be prefabricated such that the selected regions 94 are free of the second coating material. The prefabricated second encapsulation layer 86 may then be wrapped around the fabric layer 88. As a result, the fabric layer 88 may be exposed through the windows 90 formed at the selected regions 94. The assembly (first encapsulation layer 84, fabric layer 88, and second encapsulation layer 86) can then be subjected to a heat-based and / or pressure-based encapsulation process as described above, which results in the first encapsulation layer 84 and the second encapsulation layer 86 being bonded to one another.

[0113] The inner skirt 16 may be sewn to the frame 12 at the locations of the windows 90. For example, the inner skirt 16 may be disposed within the frame 12. The locations of the windows 90 may be disposed to generally correspond with the first row of struts 22, the third row of struts 26, and the fourth row of struts 28, although other configurations may be used. The inner skirt 16 may also be secured to the first, third, and fourth rows of struts using a suture that extends around the struts and through the fabric layer 88 at the locations of the windows 90, as described further below in connection with FIGS. 11-13. Because the windows in the illustrated example extend continuously around the entire circumference of the inner skirt, a continuous circumferentially extending whipstitch may be formed along each row of struts and along the fabric layer 88 at each window 90.

[0114] As discussed above, the windows 90 may be formed at selected locations and may have any of a variety of shapes, allowing the inner skirt to be sewn to the frame at a variety of locations. For example, as noted above, the inner skirt may be formed as a row of circumferentially spaced windows, allowing for the placement of individual sutures or stitches that do not extend continuously along the entire row of struts, such as in selected portions of the inner skirt that are subject to tension or stress.

[0115] 11-13 illustrate an exemplary method for sewing the inner skirt 16 to the frame 12. FIG. 11 illustrates a cross-sectional view of a portion of the inner skirt 16 having a first side 72 and a second side 74. As discussed above, the inner skirt 16 has an encapsulated fabric layer 88 interposed between a first encapsulation layer 84 on the first side 72 and a second encapsulation layer 86 on the second side 74. FIG. 11 also illustrates a window 90 on the second encapsulation layer 86 of the inner skirt 16, exposing the underlying fabric layer 88. An interlayer boundary (as shown by the dashed line) may not be present when the same material is used to form the encapsulation layers 84, 86, which may be fused or bonded together to form a single, integral structure that encapsulates the fabric. In the illustrated example, fabric layer 88 is shown as having a woven construction including interwoven filaments, fibers, or yarns 96. Interwoven filaments 96 desirably have sufficient strength to act as anchors to hold sutures 98, as described below.

[0116] 12 illustrates generally how a suture 98 may be threaded through the window 90 between the fabric layer 88 and the first encapsulation layer 84. In the illustrated example, the suture 98 is attached to a needle 102. The tip 108 of the needle 102 may be blunted so as not to penetrate the first encapsulation layer 84. By sliding the needle 102 through the window 90 from the second side 74 while applying a light force to the needle tip 108, the first encapsulation layer 84 may be pushed slightly away from the fabric layer 88, thereby creating a space for the needle 102 to be inserted between the first encapsulation layer 84 and the fabric layer 88. As shown, the needle 102 and attached suture 98 may slide into the fabric layer 88 from a first end 104 of the window 90, pass behind one or more filaments 96 (e.g., 96a and 96b) exposed by the window 90, and then be slidingly guided out of the fabric layer 88 at the second end 106 of the window 80. In this manner, the suture 98 does not extend through the entire thickness of the inner skirt 16. In some instances, the first encapsulation layer 84 is not separated from the fabric layer 88 by the insertion of the needle 102 (as shown in FIG. 12), in which case the needle 102 and attached suture 98 may be passed partially through the thickness of the first encapsulation layer 84, but not through the entire thickness of the inner skirt.

[0117] 13 illustrates diagrammatically the suturing of the fabric layer 88 of the inner skirt 16 to the adjacent struts 22 of the frame 12. Desirably, the first side 72 of the inner skirt 16 faces inwardly toward the leaflet structure 14 located within the prosthetic valve 10, and the second side 74 of the inner skirt 16 faces outwardly in contact with the frame 12. By passing a needle 102 and attached suture 98 through the window 90 and between the fabric layer 88 and the first encapsulation layer 84, the woven filaments 96 (e.g., 96a and 96b) located between the first end 104 and the second end 106 of the window 80 can collectively function as anchors to hold the suture 98. The suture 98 can then be wrapped around the adjacent struts 22, thereby securing the woven filaments (e.g., 96a and 96b) to the adjacent struts 22. Thus, the inner skirt 16 may be fixedly attached to the frame 12. Figure 13 illustrates strut 22 for illustrative purposes. It will be understood that the inner skirt 16 may be sewn to the other struts (e.g., 26, 28, 32) of the frame in a similar manner.

[0118] As mentioned above, the fabric layer 88 may also have a non-woven structure without distinct woven threads. In such a case, the suture 98 may be attached to a needle having a sharp tip. The needle may be used to puncture the fabric layer 88 and pass the suture 98 through the fabric layer. In this manner, the portion of the fabric layer 88 located between the first end 104 and the second end 106 of the window 90 may function as an anchor to hold the suture 98, which anchors the portion of the fabric to the adjacent struts 22. Thus, the inner skirt 16 may be fixedly attached to the frame 12.

[0119] The sutures 98 are routed between the first encapsulation layer 84 and the fabric layer 88 and are therefore not exposed on the first side 72 of the inner skirt 16. In other words, the sutures 98 are covered by the first encapsulation layer 84. The inner surface of the fabric layer is also covered by the first encapsulation layer. Thus, wear of the leaflets 40 due to repeated contact between the leaflets 40 and the inner skirt 16 and between the leaflets 40 and the sutures 98 during the operation cycle of the prosthetic valve 10 can be avoided. Desirably, the inner skirt 16 is sutured to the frame 12 only at one or more windows 90 on the second encapsulation layer 86, thereby avoiding contact between the moving parts of the leaflets 40 and the sutures 98. Additionally, the first encapsulation layer 84 desirably covers the entire extent of the inner surface of the fabric layer, or at least covers the portions of the fabric layer that would otherwise come into contact with the moving parts of the leaflets during the operation cycle of the prosthetic valve. In some instances, the suture 98 may pass through the entire thickness of the inner skirt, such as at a location on the inner skirt that does not contact the moving portions of the leaflets.

[0120] As noted above, the leaflets 40 may be secured to one another at adjacent sides to form commissures 58. Each commissure 58 may be secured to a corresponding commissure window 20 of the frame 12 as described in U.S. Patent Publication No. 2012 / 0123529. The inflow or apical edge 52 of the leaflet 40 may be sutured to the inner skirt 16 along a suture line that follows the curvature of the scalloped inflow edge of the leaflet structure. The fabric layer 88 may provide the necessary strength to hold the sutures. Any suitable suture, such as Ethibond sutures, may be used to secure the leaflets 40 to the fabric layer 88 of the inner skirt.

[0121] In some instances, the inflow edge 52 of the leaflet 40 is secured to the inner skirt 16 prior to attaching the inner skirt 16 to the frame. After securing the leaflet 40 to the inner skirt 16, the inner skirt is secured to the frame as described above, and the commissures 58 of the leaflet are attached to the frame. In other instances, the inner skirt 16 can be attached to the frame without the leaflets, and then the inflow edge 52 of the leaflet is secured to the inner skirt.

[0122] In a particular example, the inflow edge 52 of the leaflet 40 can be secured to the inner skirt via a thin PET reinforcement strip (not shown) as disclosed in U.S. Pat. No. 7,993,394, which is incorporated herein by reference. As described in U.S. Pat. No. 7,993,394, the reinforcement strip can be sutured to the inflow edge of the valve. The reinforcement strip and the bottom edge of the leaflet can then be sutured to the inner skirt 16. The reinforcement strip is desirably secured to the inner surface of the leaflet 40 such that the inflow edge 52 of the leaflet is interposed between the reinforcement strip and the inner skirt when the leaflet and reinforcement strip are secured to the inner skirt. The reinforcement strip allows for secure suturing to protect the pericardial tissue that forms the leaflet structure from tearing.

[0123] In an example, the outer skirt 18 can be constructed in a manner similar to the inner skirt 16. That is, the outer skirt 18 can also have a reinforcing layer encapsulated by an inner encapsulation layer and an outer encapsulation layer (such as a structure similar to the fabric layer 88 sandwiched between the encapsulation layers 84, 86). A window (similar to the window 90) can be formed on one of the encapsulation layers of the outer skirt 18. Because the outer skirt 18 is attached to the outside of the frame 12, the outer layer 18 is desirably positioned with the side of the outer skirt 18 having the window facing the frame 12. In such an arrangement, the outer skirt 18 can be attached to the frame 12 by sewing the encapsulated fabric layer to the frame 12 through the window facing the frame.

[0124] The reinforcing layer in the outer skirt can be a fabric including one or more of the materials described above with reference to reinforcing layer 88. Additionally, the reinforcing layer in the outer skirt can have a woven, braided or knitted pattern or construction such as those described below with reference to Figures 17-19J (or of another configuration). Additionally, the encapsulating layer for the outer skirt 18 can be manufactured via the methods described above with reference to the encapsulating inner skirt 16 and / or can include the materials described above with reference to the encapsulating layers 84, 86.

[0125] In another example, the outer skirt 18 can include a fabric layer coated with only one encapsulation layer. When attaching the outer skirt 18 to the frame 12, the outer skirt 18 can be positioned so that the uncoated (unencapsulated) side of the fabric layer faces inwardly toward the frame 12, such that the outer skirt 18 can be attached to the frame 12 by sewing the exposed fabric layer to the frame 12. Alternatively, the uncoated side of the fabric layer can face outwardly away from the frame 12.

[0126] In another example, the outer skirt 18 can include only a fabric layer without any encapsulation layer. In this manner, the outer skirt 18 can be sewn directly to the frame 12. Because the sutures on the outer skirt 18 are not subjected to repeated contact by the moving leaflets 40, leaflet wear due to the sutures on the outer skirt 18 is of less concern compared to the sutures on the inner skirt 16. By eliminating one or both encapsulation layers, the outer layer 18 can have a relatively thin construction, which can reduce the overall profile of the prosthetic valve 10 when compressed into a radially compressed state.

[0127] Figure 14 illustrates another example prosthetic valve 200. The prosthetic valve 200 may have similar structure and components as the prosthetic valve 10 of Figures 1 and 2, except that the prosthetic valve 200 includes an encapsulated outer skirt 202. Common components in Figures 1, 2, and 14 are labeled with the same reference numbers and will not be described further.

[0128] As seen in FIGS. 14 and 15, the encapsulated outer skirt 202 can be of a similar structure to the encapsulated inner skirt 16. Specifically, the outer skirt 202 includes an inner (first) encapsulation layer 204, an outer (second) encapsulation layer 206, and a reinforcing layer 208 disposed between the encapsulation layers 204, 206. The outer skirt is attached to the outside of the frame 12. In examples, the skirt 202 can be formed and attached to the frame 12 using one or more techniques described above in connection with the encapsulated skirt 16, and can include materials in the reinforcing layer and / or materials in the encapsulation layer as described above with reference to the encapsulated skirt 16. Additionally, in examples, the reinforcing layers 88 and / or 208 can have a woven, braided, or knitted pattern or configuration similar to one or more patterns or configurations described below with reference to FIGS. 17-19J (or in alternative patterns or configurations).

[0129] 15 shows, for purposes of illustration, a cross-sectional view of the frame 12 and outer skirt 202, with other components of the prosthetic valve removed. The outer skirt 202 can be configured to form a close fit with the frame 12, such that the outer skirt 202 lies against the outer surface of the frame 12 when the prosthetic valve 200 is in the radially expanded configuration (shown in FIGS. 14-15).

[0130] It will be appreciated that the prosthetic valve 200 may optionally include an encapsulated inner skirt similar to the inner skirt 16, or may include a non-encapsulated inner skirt. In alternative examples, the prosthetic valve 200 (and / or the prosthetic valve 10) may include other configurations for the inner and outer skirts. For example, the inner and outer skirts may be continuous layers extending over a portion or the entirety of the inner and / or outer surfaces of the frame. Such configurations are shown and described in U.S. Provisional Patent Application Nos. 63 / 112,080 and 63 / 240,766, both of which are incorporated herein by reference above.

[0131] It will be further appreciated that when the prosthetic valve 10, 200 is compressed (e.g., on a balloon of a delivery device or, in the case of a self-expanding valve, within a sheath delivery device) to a radially compressed state for delivery into a patient's body, the frame 12 elongates in the direction of the frame's longitudinal axis L. When the prosthetic valve is radially expanded from the radially compressed state to a radially expanded state, the frame 12 shortens axially along axis L. Thus, it is desirable for the encapsulated skirts (e.g., encapsulated inner skirt 16 and encapsulated outer skirt 202, etc.) to exhibit sufficient axial stretch or elasticity so as not to inhibit expansion of the frame 12 during compression of the prosthetic valve.

[0132] To such end, in certain examples, the reinforcing layers 88, 208 may include yarns, filaments, fibers, or wires (woven, braided, or woven structures or patterns) that are non-parallel and non-perpendicular to the top and bottom edges of the skirts. In examples, the reinforcing layers 88, 208 may include yarns, filaments, fibers, and / or wires that are non-parallel and non-perpendicular to the top and bottom edges of the inner skirt 16 and the outer skirt 202, respectively. Stated another way, the yarns, filaments, fibers, or wires extend at an angle greater than 0 degrees and less than 90 degrees (e.g., 45 degrees) relative to the longitudinal axis L of the frame 12.

[0133] 16A and 16B, the reinforcement layer 208 can include a fabric having a first set of interwoven yarns 210 and a second set of interwoven yarns 212, where the yarns 210, 212 are non-parallel and non-perpendicular to the top and bottom edges 214, 216 of the encapsulated outer skirt 202. Stated another way, the yarns 210, 212 extend at an angle greater than 0 degrees and less than 90 degrees relative to the longitudinal axis L of the frame 12.

[0134] In some examples, in the relaxed state of the skirt, the yarns 210, 212 extend at an angle ranging from 20 degrees to 70 degrees relative to the top and bottom edges 214, 216, or at a narrower angle ranging from 30 degrees to 60 degrees relative to the top and bottom edges 214, 216, or at an even narrower angle ranging from 40 degrees to 50 degrees relative to the top and bottom edges 214, 216. In one embodiment, the yarns 210, 212 extend at 45 degrees relative to the top and bottom edges 214, 216 and to the longitudinal axis L of the prosthetic valve 200.

[0135] In some examples, the yarns 210, 212 can be generally parallel to some struts connected to the outer skirt of the frame when the prosthetic valve is in the expanded state. In a particular example, the skirt 202 is sutured to one or more of the angled struts 22, 24, 26, 28 (see FIG. 4). The frame struts connected to the outer skirt can be referred to as "skirt support struts." Typically, although not required, the skirt support struts are oriented at an angle of 45 degrees relative to the longitudinal axis L when the frame is in the radially expanded state. However, in other examples, the skirt support struts and yarns 210, 212 can be at an angle of more than 45 degrees or less than 45 degrees relative to the longitudinal axis L, depending on the particular frame configuration.

[0136] The reinforcing layer 208 can be formed by weaving yarns at a selected angle (e.g., 45 degrees) relative to the top and bottom edges of the fabric. Alternatively, the reinforcing layer 208 can be cut diagonally from a vertically woven fabric (with the yarns running perpendicular to the edges of the material) such that the fibers run at a selected angle (e.g., 45 degrees) relative to the cut top and bottom edges of the fabric. The yarns 210, 212 can include multifilament yarns (yarns containing multiple fibers or filaments) or can include monofilament yarns (yarns containing a single fiber or filament).

[0137] In an example, the frame 12 can be partially compressed during assembly of the prosthetic valve. The encapsulated outer skirt 202 can then be attached to the frame in a partially compressed state, such as via any technique described herein, such that the skirt support struts are generally parallel to the yarns 210, 212 in a partially compressed state. In another example, the outer skirt 202 can be formed on or attached to the frame 12 in a radially expanded state, in which case the outer skirt 202 and frame 12 can be compressed together or simultaneously.

[0138] Due to the orientation of the yarns relative to the top and bottom edges, the fabric layer can undergo greater stretch in the axial direction (i.e., parallel to axis L, from top edge 214 to bottom edge 216). Thus, when the metal frame 12 is compressed, the skirt 202 can stretch axially with the frame, thus providing a more uniform and predictable compression profile. Each cell of the metal frame in the illustrated example includes at least four angled struts (e.g., struts 22, 24, 26) that can be driven to axial alignment (i.e., so that the angled struts are more aligned relative to the length of the frame). The angled struts of each cell act as a mechanism to drive the yarns 210, 212 of the reinforcement layer 208 in the same manner and / or in the direction of the struts, allowing the skirt 202 to stretch along the length of the struts. This allows for greater stretching of the skirt and avoids undesirable deformation of the struts when the prosthetic valve is compressed. As mentioned above, the encapsulation layers 204, 206 can be formed from any of a variety of elastomers that can stretch axially when the prosthetic valve is compressed and the frame is stretched, such as, for example, silicone or polyurethane or a thermoplastic, as described above in connection with layers 84, 86.

[0139] The movement of the yarns 210, 212 during compression is illustrated in Figures 16A and 16B. Figure 16A shows a portion of the two interwoven yarns 210, 212 when the outer skirt 202 is in a relaxed state corresponding to the radially expanded state of the prosthetic valve 200. Figure 16B shows the yarns 210, 212 when the outer skirt 202 is in an axially stretched or axially elongated state, which corresponds to the radially compressed state of the prosthetic valve after compression. As shown, the yarns 210, 212 move from an orientation at a 45 degree angle relative to the longitudinal axis L toward an orientation in which the yarns are closer to being parallel to the longitudinal axis L.

[0140] In examples, the spacing between the woven (or knitted or braided) yarns can be increased to facilitate axial stretching of the encapsulated outer skirt 202. For example, in certain examples, the reinforcement layer 208 can have a weave density of less than 150 ppi (picks per inch), less than 100 ppi, less than 70 ppi, or 50 ppi or less. In certain examples, the reinforcement layer 208 can have a weave density of about 30 ppi to about 50 ppi, as compared to known fabric skirts having weave densities of about 150 ppi to 160 ppi. This construction allows the skirt 202 to stretch or lengthen axially to at least 40% of its initial length D when the prosthetic valve is radially compressed (the initial length D being the distance between the top edge 214 and the bottom edge 216 of the skirt when the prosthetic valve is in a radially expanded state). This low weave density can cause the interwoven yarns (e.g., woven, braided, or braided structures) to become unstable and prone to fraying. Advantageously, the encapsulation layers 204, 206 encapsulate the yarns and act as a support mechanism to prevent fraying even in a relatively loose weave. Moreover, during the assembly process described above in connection with FIGS. 6-10, the first encapsulation layer (layer 84 in FIGS. 6-10) can be attached to the woven fabric reinforcement layer (layer 88), which helps stabilize the fabric and prevents fraying until the second encapsulation layer (layer 86) is formed or placed on the woven fabric reinforcement layer. In addition, as noted above, the woven fabric reinforcement layer in some examples can be braided around the first encapsulation layer supported on the mandrel 100, which further helps stabilize the reinforcement layer 208.

[0141] In a particular example, the yarns 210, 212 can have about 10 to about 50 filaments per yarn, with 20 filaments per yarn being a specific example. The filaments of the yarns 210, 212 can have a thickness ranging from about 8 μm to about 20 μm, with 10 μm being a specific example. The filaments of the yarns 210, 212 can be formed from TPU, PET, or UHMWPE, although it will be understood that the filaments can be formed from any of the materials described above in connection with the reinforcement layer 88.

[0142] In certain examples, the yarns 210, 212 can be textured to increase the elasticity of the skirt in the axial direction. For example, the yarns can be bulked, e.g., twisted or coiled, heat set, and untwisted or uncoiled, so that the yarns retain their deformed (e.g., twisted or coiled) shape in a relaxed or unstretched configuration. When the prosthetic valve is radially compressed and the skirt 202 is axially stretched, the yarns 210, 212 can straighten from their deformed (e.g., twisted or coiled) state, increasing the elasticity and length of the skirt. Woven fabrics including textured yarns are further disclosed in U.S. Publication No. 2018 / 0206982, which is incorporated herein by reference. Because the yarns 210, 212 are embedded within the elastomeric encapsulation layers 204, 206, the encapsulation layers can stretch axially to accommodate the straightening of the yarns 210, 212. Utilizing textured yarns 210, 212 in this manner allows the skirt 202 to stretch axially greater than 40% of its initial length D when the prosthetic valve is radially compressed.

[0143] It will be understood that the examples described above in relation to the reinforcing layer 208 of the encapsulated outer skirt 202 and shown in Figures 16A and 16B may be applied to the reinforcing layer 88 of the encapsulated inner skirt 16, or to other skirt configurations, such as those described in U.S. Provisional Patent Application No. 63 / 112,080 and U.S. Provisional Patent Application No. 63 / 240,766, both of which are incorporated herein by reference.

[0144] Exemplary Reinforcement Layer Weave Patterns FIG. 17 shows an exemplary portion of a braided layer 300 that may be used as a reinforcing layer, such as reinforcing layer 88, 208, in an encapsulated skirt. In FIG. 17, the x-axis represents the circumferential direction of the encapsulated skirt, and the y-axis represents the axial direction of the encapsulated skirt. The braided layer 300 is composed of a first set of yarns 302 and a second set of yarns 304 that are interwoven, as in biaxial braiding. FIG. 17 shows the braided layer 300 when the prosthetic valve is radially expanded. The illustrated example may be in a relaxed state of the braided layer, meaning that the braided layer is not axially stretched or elongated. As shown, the yarns 302, 304 may be oriented at an angle of about 45 degrees relative to the longitudinal axis L of the prosthetic valve, forming a braid angle 306 of 90 degrees. In some examples, the yarns 302, 304 can extend parallel to the struts of the frame 12 when the frame is in a radially expanded state.

[0145] To help stabilize the braid and / or increase the tensile strength of the braid, layer 300 can include a third set of axially extending yarns 308 that are woven together with yarns 302, 304 to form a triaxial braid. Yarns 308 can be formed from an elastomer (e.g., PU or TPU) that can stretch axially when the prosthetic valve is radially compressed. Alternatively or in addition to forming yarns 308 from an elastomer, yarns 308 can be textured as described above to increase the elasticity of the skirt in the axial direction. Yarns 302, 304 can be formed from the same material as yarns 308, or can be formed from different materials.

[0146] Additionally, the braided layer 300 can be a hybrid fabric (e.g., a woven, knitted, or braided structure) incorporating yarns or filaments of different materials with different material properties. For example, one or more yarns of the fabric can be more inelastic, i.e., less elastic, than one or more other yarns of the fabric. In one implementation, for example, one or more low modulus yarns can be made of PET and one or more high modulus yarns can be made of PU, TPU, or other elastomers. The low modulus yarns can be selectively placed (according to a predefined pattern) within the fabric to strengthen it, while the high modulus yarns can be selectively placed (according to a predefined pattern) to increase its elasticity in a given direction (e.g., axial direction). Specifically, in FIG. 17, yarns 302, 304 can be made of PET and yarn 308 can be made of PU or TPU.

[0147] In another example, the reinforcing layer (reinforcing layer 88, 208, etc.) can be constructed from a fabric layer 400 having a woven structure (e.g., plain weave, including variations). A plain weave (also called a tabby weave) is a weave in which all the weft threads pass over and under the warp threads to form a crisscross pattern. The warp threads are parallel to each other across the warp threads. FIG. 18 illustrates a plain weave with a weft thread 402 crossed over a warp thread 404. A plain weave has the highest number of crossovers per unit space compared to other weave patterns, resulting in a strong and durable fabric. Variations of the plain weave include a rib weave, in which either the warp or weft threads are heavy, and a basket weave, in which two or more weft threads pass over and under two or more warp threads. The high number of crossovers also allows the fabric to be relatively thin while still maintaining strength, allowing the outer skirt 202 to be sewn to the frame 12 and compressing the prosthetic heart valve without tearing the reinforcing layer 208.

[0148] As discussed above, the weft yarns 402 and warp yarns 404 can be disposed in a non-parallel and non-perpendicular orientation relative to the top and bottom edges 214, 216 of the skirt 202, respectively. In an example, the weft yarns 402 and warp yarns 404 can be moved from an angular orientation of about 45 degrees relative to the longitudinal axis L (corresponding to a radially expanded state of the prosthetic valve 200 when the outer skirt 202 is in a relaxed state) toward a more parallel orientation of the yarns 402, 404 relative to the longitudinal axis L (corresponding to a radially compressed state of the prosthetic valve when the outer skirt 202 is in an axially stretched or axially elongated state, e.g., post-compression). Additionally, the weft yarns 402 and warp yarns 404 can have material compositions similar to those discussed above.

[0149] In other examples, the reinforcing layer (such as reinforcing layer 88, 208) may be a fabric that includes one or more Leno yarns woven into the fabric to increase the stability of the fabric and to allow for a looser weave, i.e., less dense weave. Various leno weave patterns may be used to weave the Leno yarns into the reinforcing layer 88, 208. Examples of half leno weaves, full leno weaves, and related weaving techniques that may be utilized to manufacture the reinforcing layers are illustrated in Figures 19A-19J.

[0150] Specifically, Figure 19A is a cross-sectional view illustrating a shed (e.g., temporary separation of warp strands / warp yarns to form upper and lower warp strands / warp yarns) where a leno yarn, "leno end," or "cross end" 1060 forms the top shed on the left side of the figure above a weft strand / weft yarn 1064, and a standard warp strand / warp yarn 1062 forms the bottom shed. Figure 19B illustrates a continuous shed where a leno strand / leno yarn 1060 forms the top shed on the right side of a standard warp strand / warp yarn 1062. In Figures 19A and 19B, the leno strand / leno yarn 1060 can cross under a standard strand / yarn 1062 in a pattern known as bottom doping. Alternatively, the leno strand / yarn 1060 can cross over the top of the standard strand / yarn 1062, known as top doping, as in Figures 19H and 19I.

[0151] FIG. 19C illustrates an exemplary leno weave interwoven pattern 500 that is produced when one warp beam is used on a loom and the strain or tension of the leno strands / leno yarns 1060 and standard strands / yarns 1062 are made equal such that both the strands / yarns 1060 and the strands / yarns 1062 are curved around the weft strands / weft yarns 1064. FIG. 19D illustrates another exemplary leno weave pattern 502 created when multiple warp beams are used and the leno strands / leno yarns 1060 are under less tension than the standard strands / yarns 1062 such that the standard strands / yarns 1062 remain relatively straight within the weave and perpendicular to the weft strands / weft yarns 1064, while the leno strands / leno yarns 1060 curve around the standard strands / yarns 1062.

[0152] Figure 19E illustrates a leno weave interweave pattern 504 that is similar to pattern 500 in Figure 19C, except that the alternating leno strands / yarns 1060 are point drafted (e.g., a technique in which the leno strands / yarns are pulled through a heddle) so that the weave directions of adjacent leno strands / yarns 1060 are reversed. Figure 19F illustrates a leno weave interweave pattern 506 that is similar to pattern 502 in Figure 19D, except that the alternating leno strands / yarns 1060 are point drafted so that the weave directions of adjacent leno strands / yarns are reversed.

[0153] FIG. 19G is a cross-sectional view taken across the weft strand / weft yarn 1064 for a leno weave structure, which can be either leno weave pattern 500 or 504.

[0154] FIG. 19J illustrates a representative portion of the leno weave pattern 500 of FIG. 19C as viewed from the back of the fabric.

[0155] Further details regarding fabric skirts, including leno weaves, that may be utilized with the skirts described herein are disclosed in U.S. Pat. No. 11,013,600 and U.S. Patent Publication No. 2019 / 0374337, each of which is incorporated herein by reference.

[0156] Features related to improved stretch / flexibility and features related to reduced compression profile As discussed above, it is desirable for the encapsulated skirts (e.g., encapsulated inner skirt 16 and encapsulated outer skirt 202, etc.) to exhibit sufficient stretch or elasticity (flexibility) in the axial direction so as not to inhibit expansion of the frame during compression of the prosthetic valve. Additionally, it is desirable to reduce the overall compression profile of the prosthetic valve to allow for improved transcatheter delivery of the prosthetic valve. However, encapsulation of the skirt fabric layer (i.e., reinforcing layer) may reduce the skirt's flexibility and / or elasticity and increase its thickness, thereby increasing the overall compression profile of the prosthetic valve when attached to the prosthetic valve. Moreover, reduced flexibility of the encapsulated skirt may adversely affect the functionality of the prosthetic valve after implantation. For example, as discussed above, the inner skirt and / or outer skirt may function as a sealing member and reduce or avoid paravalvular leakage. Thus, an encapsulating skirt material that is too stiff can reduce the ability of the skirt (eg, the outer skirt) to conform to the patient's anatomy and form an adequate seal.

[0157] Thus, the encapsulated skirts disclosed herein may form and include features to address one or more of the above problems. For example, the encapsulated skirts disclosed herein may have increased flexibility or stretchability and / or reduced thickness compared to prior art encapsulated skirts, and may improve the extension of the skirt when the prosthetic valve is placed in a compressed state. Additionally, in examples, the encapsulated skirts disclosed herein may have a reduced volume when compressed, thereby reducing the compression profile of the prosthetic valve. Still further, the increased flexibility of the encapsulated skirts disclosed herein may improve the formation of non-deployable surfaces or complex curved shapes after implantation and radial expansion of the prosthetic valve, for example, allowing the skirt to conform to the native anatomy and allowing an adequate seal to be formed between the prosthetic valve and the native anatomy.

[0158] For example, each encapsulation layer (e.g., a TPU or other thermoplastic encapsulation layer) can be provided with or formed to have a reduced thickness. Further, in examples, the yarns or filaments can include a leno weave pattern that allows the yarns or filaments to have a greater degree of spacing (i.e., greater spacing between the yarns or between the filaments).

[0159] FIG. 20A illustrates an exemplary portion of an encapsulated skirt 600 (which may be, for example, an outer skirt or an inner skirt). In the example, the top edge 602 of the skirt 600 is oriented toward the outflow end of the prosthetic valve (e.g., prosthetic valve 10 or 200, etc.), and the bottom edge 604 is oriented toward the inflow end of the prosthetic valve. The exemplary skirt 600 includes a reinforcing layer 606 including a first plurality of yarns 608 (which may be filaments, yarns, or threads) and a second plurality of yarns 610 (which may be filaments, yarns, or threads of the same type as compared to the yarns 608 or a different type, such as one with a lower modulus than the yarns 608), where the first plurality of yarns 608 are interwoven and perpendicular to the second plurality of yarns 610. A plurality of joints 612 are formed where the yarns 608, 610 cross and weave together. Similar to the example described above with reference to Figures 16A and 16B, the yarns 608, 610 can be arranged at a non-perpendicular and non-parallel angle to the longitudinal axis L of the artificial valve when the skirt 600 is in a relaxed state (corresponding to the radially expanded state of the artificial valve) (e.g., both yarns are arranged in an orientation at an angle of approximately 45 degrees to the longitudinal axis L), and can be movable to an axially extended position in which both yarns are more nearly parallel to the longitudinal axis L when the skirt 600 is in an axially extended or elongated state (corresponding to the radially compressed state of the artificial valve, such as after compression).

[0160] As discussed above, a plain weave patterned fabric or reinforcing layer typically has a minimum weave density of about 160 ppi to maintain the structural integrity of the fabric. To increase flexibility and reduce thickness of the skirt 600, including the illustrated portion, the yarns 608, 610 in the reinforcing layer 606 can include a leno weave pattern, such as one or more of the leno weave patterns described above with reference to Figures 19A-19J. For example, each yarn 608 can represent a yarn 1064 (e.g., a weft yarn) and each yarn 610 can represent a pair of yarns 1062, 1064 (e.g., a pair of weft yarns 608 and warp yarns woven around the weft yarns 608 to form a joint 612). Thus, in an example, the reinforcing layer 606 can have a weave density of about 10 ppi to about 60 ppi. Further, in examples, the spacing S1 between adjacent yarns 608 and the spacing S2 between adjacent yarns 610 can be at least 0.5 mm, at least 0.6 mm, at least 0.7 mm, at least 0.8 mm, at least 0.9 mm, or at least 1.0 mm. In particular examples, the spacings S1, S2 can range from about 0.5 mm to about 2.0 mm, and more specifically, can range from about 1.0 mm to about 2.0 mm. Moreover, the leno weave pattern can provide fixed positioning of the yarns 608, 610 at the joints 612 to maintain the spacing and position of the yarns within the weave pattern when transitioning between an axially stretched or elongated state and a relaxed state.

[0161] The reduced weave density may increase the flexibility or stretchability of the skirt 600 (compared to prior art skirts) and may additionally reduce the overall bulk or volume of the skirt (compared to prior art skirts), thereby reducing the overall compression profile of the prosthetic valve to which the skirt is attached.

[0162] Additionally or alternatively, the skirt 600 can be provided with or formed with relatively thin encapsulation layers 614, 616 (e.g., TPU or other thermoplastic encapsulation layers) disposed on the inner and outer surfaces of the reinforcement layer 606. In an example, one or more of the encapsulation layers 614, 616 can have a thickness ranging from about 5 μm to about 15 μm, which may be similar to the thickness of the reinforcement layer yarns 608, 610. For example, as discussed above, the yarn thickness can range from about 8 μm to about 20 μm, with 10 μm being one specific example. In an alternative example, the yarns 608, 610 can be thicker (e.g., up to 30 μm) or thinner (e.g., as low as 5 μm) compared to the encapsulation layers 614, 616. At junctures 612, skirt 600 may have an increased thickness as compared to other areas of the skirt because yarns 608, 610 overlap or interweave via a leno weave pattern at each juncture. For example, junctures 612 may have a thickness ranging from about 30 μm to about 150 μm, depending on, for example, the diameter of yarns 608, 610, the thickness of each of encapsulation layers 614, 616, and / or the particular weave pattern of reinforcement layer 606.

[0163] FIG. 20B illustrates an exemplary cross-section of skirt 600 taken along line BB shown in FIG. 20A. As seen in FIG. 20B, the regions 618 between adjacent yarns 608 in skirt 600 (formed by bonded encapsulation layers 614, 616) have a thickness T1 (e.g., in the range of about 10 μm to about 30 μm, with 20 μm being one example). Each yarn 608 has a diameter D (e.g., in the range of about 8 μm to about 20 μm), and the thickness of skirt 600 at yarns 608 is increased due to encapsulation layers 614, 616 disposed thereon. Thus, at each yarn 608, skirt 600 has a total thickness T2 (e.g., in the range of about 18 μm to about 46 μm). Total thickness T2 may vary depending on the thickness of layers 614, 616 and depending on the thickness of yarns 608, 610.

[0164] The relatively thin regions 618 between the yarns can further increase the flexibility or stretchability of the skirt 600 (compared to prior art skirts) and can additionally reduce the overall bulk or volume of the skirt (compared to prior art skirts), thereby reducing the overall compression profile of the prosthetic valve to which the skirt is attached.

[0165] Additionally or alternatively, the flexibility or stretchability of the skirt 600 can be increased by decreasing the degree or total area of ​​bonding between the yarns 608, 610 of the reinforcing layer 606 and between the encapsulating layers 614, 616. In an example, the encapsulating layers 614, 616 can be attached or bonded at selected areas or strips to allow the reinforcing layer 606 to move freely between the encapsulating layers 614, 616 in the unattached or unbonded areas. In other words, one or more pockets can be formed between the encapsulating layers 614, 616 where the reinforcing layer 606 is not bonded and can move unrestrained between axially stretched and relaxed states.

[0166] One embodiment is illustrated in Figure 21, where a skirt 600 includes a first encapsulation region 620 extending along a top edge 602 of the skirt and a second encapsulation region 622 extending along a bottom edge 604 of the skirt. Within the first encapsulation region 620 and the second encapsulation region 620, 622, respectively, the encapsulation layers 614, 616 are adhered to each other and to the surfaces of the portions of the yarns 608, 610 that lie within the regions 620, 622. Encapsulation at the bottom 604 and top 602 edges of the skirt 600 may seal the reinforcing layer 606 within the encapsulating layers 614, 616 and may prevent or limit lateral and / or axial sliding or displacement of the reinforcing layer between the encapsulating layers 614, 616, and may further prevent fraying of the yarns 608, 610 at opposing edges of the skirt.

[0167] The skirt 600 can optionally include one or more additional encapsulation regions. For example, the skirt 600 can include a third encapsulation region including one or more U-shaped regions 624 extending along a region of the skirt corresponding to a scallop line of the valvular structure (e.g., the U-shaped inlet or apical edge 52 of the valvular structure 14 shown in FIG. 2). Each U-shaped region 624 has a size and shape corresponding to an apical edge portion of a leaflet 40. Thus, there can be a U-shaped region 624 for each leaflet 40 (e.g., three leaflets 40, and three U-shaped regions). The apical edge portions of the leaflets 40 can optionally be secured to the skirt along the U-shaped regions 624 (e.g., by sutures). For example, if the skirt 600 is an inner skirt of a prosthetic valve, the apical edge portions of the leaflets are typically sutured to the skirt along the U-shaped regions 624.

[0168] Thus, pockets 626, 628 can be formed between the layers 614, 616 in the regions or areas where the layers 614, 616 are not bonded to one another. Each pocket 626 can be surrounded by a U-shaped region 624 and by a portion of the first encapsulation region 620. Each pocket 628 can be surrounded by two adjacent U-shaped regions 624 and by a portion of the second encapsulation region 622. The encapsulation regions 620, 622, 624 can be referred to as bonded regions of the skirt assembly. The pockets 626, 628 can be referred to as unbonded regions of the skirt assembly. The reinforcement layer 606 can be retained within the pockets 626, 628 and, because it is not attached to the encapsulation layers 614, 616, can be free to move within the pockets between a relaxed state and an axially stretched state as the prosthetic valve transitions between a radially expanded state and a radially compressed state. Additionally, the bonded regions are less stretchable than the non-bonded regions. Advantageously, when the cusp edge portions of the leaflets are secured (e.g., sutured) to the skirt along the U-shaped region 624, they can prevent or minimize axial stretching of the leaflets 40 when the prosthetic valve is radially compressed.

[0169] 22, a method for forming the skirt 600 can include utilizing a press plate assembly including a flat first plate 702 and a second plate 706, the flat first plate 702 can have a slightly compressible surface layer 704 disposed on an inner surface of the first plate (e.g., a silicone layer disposed on the surface of the flat metal plate). The three layers of the skirt (i.e., a first encapsulation layer 614, a second encapsulation layer 616, and a reinforcing layer 606 disposed therebetween) can be disposed between the first and second plates. Compressing all tree layers between the first and second plates 702 and 706 under a predetermined pressure and / or elevated temperature causes both encapsulation layers to adhere to each other and to the reinforcing layer, thereby encapsulating each filament or yarn of the skirt. The second plate can optionally include a slightly compressible layer (e.g., a silicone layer) that contacts an adjacent surface of the skirt assembly during the encapsulation process. The process of applying pressure and / or heat via plates can cause the material forming layers 614, 616 to flow, forming thinned areas 618 between yarns 608, 610 at a desired thickness.

[0170] 23, to form the skirt 600 having pockets 626, 628, a second plate 706 includes one or more recesses 708, 710 formed on an inner surface of the plate 706. The recess 708 corresponds in size and shape to the pocket 626, and the recess 710 corresponds in size and shape to the pocket 628. Thus, the inner surface of the plate 706 includes protruding or raised areas 712 surrounding the recesses 708, 710, which correspond to the bond areas 620, 622, 624 of the skirt. Thus, when the first plate 702 and the second plate 706 are pressed against the three layers of the skirt (i.e., the first encapsulation layer, the second encapsulation layer, and the reinforcing layer disposed therebetween), the raised areas 712 of the second plate press against each layer of the skirt and bond the layers 614, 616 to one another along designated areas (e.g., areas 620, 622, 624), while the recessed areas 708, 710 prevent the plates 702, 706 from applying pressure and / or heat to the remainder of the skirt, thereby forming pockets 620, 622, 624 in which the layers 614, 616 are not bonded but which nonetheless retain the reinforcing layer 606.

[0171] delivery technology To implant the prosthetic valve into the native aortic valve via a transfemoral delivery approach, the prosthetic valve is mounted in radial compression along the distal end portion of the delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral artery and driven forward into and through the descending aorta, around the aortic arch, and through the ascending aorta. The prosthetic valve is positioned inside the native aortic valve and radially expanded (e.g., by inflating a balloon, by driving one or more actuators of the delivery device, or by deploying the prosthetic valve from a sheath to allow the prosthetic valve to self-expand). Alternatively, the prosthetic valve can be implanted inside the native aortic valve in a transapical procedure, in which the prosthetic valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the prosthetic valve is positioned inside the native aortic valve. Alternatively, in a transaortic procedure, the prosthetic valve (on the distal end portion of the delivery device) is introduced into the aorta through a surgical incision in the ascending aorta, such as by a partial J sternotomy or a right parasternal minithoracotomy, and then driven forward through the ascending aorta toward the native aortic valve.

[0172] To implant the prosthetic valve inside the native mitral valve via a transseptal delivery approach, the prosthetic valve is mounted in radial compression along the distal end portion of the delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral vein and driven forward into the inferior vena cava and through the inferior aorta, into the right atrium, across the atrial septum (through a puncture made in the atrial septum), into the left atrium, and toward the native mitral valve. Alternatively, the prosthetic valve can be implanted inside the native mitral valve in a transapical procedure, in which the prosthetic valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the prosthetic valve is positioned inside the native mitral valve.

[0173] To implant the prosthetic valve inside the native tricuspid valve, the prosthetic valve is mounted in radial compression along the distal end portion of the delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral vein and driven forward into and through the inferior vena cava into the right atrium, where the prosthetic valve is positioned inside the native tricuspid valve. A similar approach can be used to implant the prosthetic valve inside the native pulmonary valve or pulmonary artery, except that the prosthetic valve is driven forward through the native tricuspid valve into the right ventricle and toward the pulmonary valve / artery.

[0174] Another delivery approach is the transatrial approach, where the prosthetic valve (on the distal end portion of the delivery device) is inserted through an incision in the chest and an incision is made through the atrial wall (the atrial wall of the right or left atrium) to access either of the native heart valves. Atrial delivery can also be performed intravascularly, such as from a pulmonary vein. Yet another delivery approach is the transventricular approach, where the prosthetic valve (on the distal end portion of the delivery device) is inserted through an incision in the chest and an incision is made through the wall of the right ventricle (typically at or near the base of the heart) to implant the prosthetic valve inside the native tricuspid valve or inside the native pulmonary valve or inside the pulmonary artery.

[0175] In all delivery approaches, the delivery device can be driven forward over a guidewire previously inserted into the patient's vasculature. Moreover, the disclosed delivery approaches are not intended to be limiting. Any of the prosthetic valves disclosed herein can be implanted using any of a variety of delivery procedures and any of a variety of delivery devices known in the art.

[0176] Any of the systems, devices, apparatus, etc. herein may be sterilized (e.g., using heat / heat, pressure, steam, radiation, and / or chemicals, etc.) to ensure safe use on patients, and any of the methods herein may include sterilizing the associated system, device, apparatus, etc. as one of the method steps. Examples of heat / heat sterilization include steam sterilization and autoclave sterilization. Examples of radiation used for sterilization include, but are not limited to, gamma radiation, ultraviolet light, and electron beam. Examples of chemicals used for sterilization include, but are not limited to, ethylene oxide, hydrogen peroxide, peracetic acid, formaldehyde, and glutaraldehyde. Hydrogen peroxide sterilization may be performed, for example, using hydrogen peroxide plasma.

[0177] Additional Examples of the Disclosed Technology In view of the above examples of the disclosed subject matter, the present application discloses additional embodiments, as listed below. It should be noted that a feature in an embodiment individually, or two or more features in combination in that embodiment, and optionally in combination with one or more features in one or more additional embodiments, are also further embodiments falling within the disclosure of the present application.

[0178] Example 1. 1. A prosthetic valve comprising: an annular frame radially expandable from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end; a plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the annular frame; and a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven with the first set of yarns, the skirt assembly having a first thickness at a plurality of relatively thin regions between adjacent yarns and a second thickness at the yarns, the first thickness being less than the second thickness.

[0179] Example 2. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiment 1, wherein the yarns in each of the first set of yarns and the second set of yarns are non-perpendicular and non-parallel to the longitudinal axis when the annular frame is in a radially expanded state.

[0180] Example 3. The prosthetic heart valve of any of the embodiments herein, particularly embodiments 1 or 2, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle ranging from about 20 degrees to about 70 degrees relative to a longitudinal axis of the annular frame.

[0181] Example 4. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-3, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at a 45 degree angle relative to the longitudinal axis of the frame.

[0182] Example 5. The prosthetic heart valve as described in any embodiment herein, particularly as described in any of embodiments 1-4, wherein each of the first encapsulation layer and the second encapsulation layer is formed from an elastomer.

[0183] Example 6. The prosthetic heart valve as described in any of the Examples herein, particularly any of Examples 1-5, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness in the range of about 5 μm to about 15 μm.

[0184] Example 7. 13. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-6, wherein the yarns of the first set are interwoven with the yarns of the second set in a leno weave pattern.

[0185] Example 8. The prosthetic heart valve according to any of the embodiments herein, particularly according to any of the embodiments 1-7, wherein the woven fabric has a weave density of less than 150 ppi.

[0186] Example 9. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiment 8, wherein the woven layer has a weave density of 60 ppi or less.

[0187] Example 10. The prosthetic heart valve as described in any of the Examples herein, particularly Example 9, wherein the woven layer has a weave density of about 10 ppi to about 60 ppi.

[0188] Example 11. 13. The prosthetic heart valve according to any embodiment herein, in particular any of embodiments 1-10, wherein the spacing between adjacent yarns in the first set of yarns is at least 0.5 mm.

[0189] Example 12. The prosthetic heart valve as described in any of the Examples herein, particularly Example 11, wherein the spacing between adjacent yarns in the first set of yarns is in the range of about 0.5 mm to about 2.0 mm.

[0190] Example 13. The prosthetic heart valve as described in any embodiment herein, in particular any of embodiments 1-12, wherein the spacing between adjacent yarns in the second set of yarns is at least 0.5 mm.

[0191] Example 14. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 13, wherein the spacing between adjacent yarns in the second set of yarns is in the range of about 0.5 mm to about 2.0 mm.

[0192] Example 15. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-14, wherein the yarns in the first set of yarns have a thickness or diameter in the range of about 8 μm to about 16 μm.

[0193] Example 16. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-15, wherein the yarns in the second set of yarns have a thickness or diameter in the range of about 8 μm to about 16 μm.

[0194] Example 17. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-16, wherein the first encapsulation layer is adhered to the second encapsulation layer at a plurality of relatively thin regions.

[0195] Example 18. The prosthetic heart valve according to any of the Examples herein, particularly any of Examples 1-17, wherein the first thickness is in the range of about 10 μm to about 30 μm.

[0196] Example 19. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 1-18, wherein the skirt assembly is configured such that the first encapsulation layer and the second encapsulation layer are adhered to one another along one or more adhesive regions and such that one or more pockets are formed in an area between the one or more adhesive regions, and the first encapsulation layer and the second encapsulation layer are not adhered to one another within the pockets.

[0197] Example 20. A prosthetic heart valve as described in any embodiment herein, particularly embodiment 19, wherein the reinforcing layer is fixed to the first encapsulation layer and to the second encapsulation layer within one or more adhesive regions, and the portion of the reinforcing layer within the pocket is disposed between the first encapsulation layer and the second encapsulation layer but is not adhered to either the first encapsulation layer or the second encapsulation layer.

[0198] Example 21. A prosthetic heart valve as described in any embodiment herein, particularly embodiments 19 and 20, wherein one or more pockets are configured such that portions of the reinforcing layer within the pocket are movable relative to the first encapsulation layer and relative to the second encapsulation layer within the respective corresponding pocket.

[0199] Example 22. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 19-21, wherein the one or more adhesive regions include a first adhesive region along a first circumferential edge of the skirt assembly and a second adhesive region along a second circumferential edge of the skirt assembly, the first edge being located opposite the second edge.

[0200] Example 23. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 19-22, wherein the one or more adhesive regions include one or more U-shaped adhesive regions corresponding to at least a portion of a scallop line in a plurality of valve leaflets.

[0201] Example 24. An artificial heart valve as described in any embodiment herein, particularly any of embodiments 1-23, wherein the skirt assembly is configured such that, when the annular frame is in a radially compressed state, the skirt assembly is axially elongated to at least 40% of its initial length when the annular frame is in a radially expanded state.

[0202] Example 25. 1. An artificial valve comprising: an annular frame radially expandable from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end; a plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the annular frame; and a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven in a leno weave pattern with the first set of yarns, the first set of yarns and the second set of yarns being non-perpendicular and non-parallel to the longitudinal axis when the annular frame is in the radially expanded state; and

[0203] Example 26. The prosthetic heart valve as described in any example herein, particularly as described in Example 25, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness in the range of about 5 μm to about 10 μm.

[0204] Example 27. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiments 25 and 26, wherein the woven fabric has a weave density of less than 150 ppi.

[0205] Example 28. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiment 27, wherein the fabric has a weave density of 60 ppi or less.

[0206] Example 29. The prosthetic heart valve as described in any of the examples herein, particularly as described in Example 28, wherein the woven fabric has a weave density of about 10 ppi to about 60 ppi.

[0207] Example 30. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 25-29, wherein the spacing between adjacent yarns in the first set of yarns is at least 0.5 mm.

[0208] Example 31. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 30, wherein the spacing between adjacent yarns in the first set of yarns is in the range of about 1.0 mm to about 2.0 mm.

[0209] Example 32. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 25-31, wherein the spacing between adjacent yarns in the second set of yarns is at least 0.5 mm.

[0210] Example 33. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 32, wherein the spacing between adjacent yarns in the second set of yarns is in the range of about 1.0 mm to about 2.0 mm.

[0211] Example 34. The prosthetic heart valve as described in any embodiment herein, particularly any one of embodiments 25-33, wherein each yarn in the first set of yarns has a thickness or diameter in the range of about 8 μm to about 16 μm.

[0212] Example 35. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 25-34, wherein each yarn in the second set of yarns has a thickness or diameter in the range of about 8 μm to about 16 μm.

[0213] Example 36. The prosthetic heart valve of any of the embodiments herein, particularly any of embodiments 25-35, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle in the range of about 20 degrees to about 70 degrees relative to the longitudinal axis of the annular frame.

[0214] Example 37. A prosthetic heart valve as described in any embodiment herein, particularly embodiment 36, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at a 45 degree angle relative to the longitudinal axis of the annular frame.

[0215] Example 38. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 25-37, wherein the skirt assembly further comprises a plurality of thinner regions between adjacent yarns where the first encapsulation layer is directly adhered to the second encapsulation layer.

[0216] Example 39. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 38, wherein each of the plurality of thinner regions has a thickness ranging from about 10 μm to about 30 μm.

[0217] Example 40. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 39, wherein each of the plurality of thinner regions has a thickness ranging from about 10 μm to about 20 μm.

[0218] Example 41. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 25-37, wherein the skirt assembly is configured such that the first encapsulation layer and the second encapsulation layer are adhered to one another along one or more adhesive regions and such that one or more pockets are formed in the region between the one or more adhesive regions, and the first encapsulation layer and the second encapsulation layer are not adhered to one another within the pockets.

[0219] Example 42. A prosthetic heart valve as described in any embodiment herein, particularly embodiment 41, wherein the reinforcing layer is fixed to the first encapsulation layer and to the second encapsulation layer within one or more adhesive regions, and the portion of the reinforcing layer within the pocket is disposed between the first encapsulation layer and the second encapsulation layer but is not adhered to either the first encapsulation layer or the second encapsulation layer.

[0220] Example 43. A prosthetic heart valve as described in any embodiment herein, particularly embodiments 41 and 42, wherein one or more pockets are configured such that portions of the reinforcing layer within the pocket are movable relative to the first encapsulation layer and relative to the second encapsulation layer within the respective corresponding pocket.

[0221] Example 44. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 41-43, wherein the one or more adhesive regions include a first adhesive region along a first circumferential edge of the skirt assembly and a second adhesive region along a second circumferential edge of the skirt assembly, the first edge being located opposite the second edge.

[0222] Example 45. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 41-44, wherein the one or more adhesive regions include one or more U-shaped adhesive regions corresponding to at least a portion of a scallop line in a plurality of valve leaflets.

[0223] Example 46. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 41-45, wherein the skirt assembly includes an outer skirt attached onto the outer surface of the annular frame, the outer skirt being configured to form a tight fit with the annular frame such that the outer skirt lies in abutment against the outer surface when the annular frame is in a radially expanded state.

[0224] Example 47. An artificial heart valve as described in any embodiment of the present specification, particularly any of embodiments 25-46, wherein the skirt assembly is configured such that, when the annular frame is in a radially compressed state, the skirt assembly is axially elongated to at least 40% of its initial length when the annular frame is in a radially expanded state.

[0225] Example 48. 1. An artificial valve comprising: an annular frame configured to radially expand from a radially compressed state to a radially expanded state, the annular frame having an inflow end and an outflow end; a plurality of cusp valves configured to control blood flow therethrough; and a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the skirt assembly being configured such that the first encapsulation layer and the second encapsulation layer are fused along one or more adhesive regions and such that one or more pockets are formed in an area between the one or more adhesive regions, thereby allowing a portion of the reinforcing layer in the one or more pockets to be unbonded to either the first encapsulation layer or the second encapsulation layer.

[0226] Example 49. A prosthetic heart valve as described in any embodiment herein, particularly embodiment 48, wherein the skirt assembly includes an outer skirt attached onto the outer surface of the annular frame, the outer skirt being configured to form a tight fit with the annular frame such that the outer skirt lies in abutment against the outer surface when the annular frame is in a radially expanded state.

[0227] Example 50. The prosthetic heart valve as described in any embodiment herein, particularly embodiments 48 and 49, wherein the reinforcing layer comprises a fabric, the fabric comprising a first set of yarns and a second set of yarns interwoven with the first set of yarns in a weave pattern, the first set of yarns and the second set of yarns being non-perpendicular and non-parallel to the longitudinal axis of the frame, respectively.

[0228] Example 51. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiment 50, wherein the weave pattern is a leno weave pattern.

[0229] Example 52. The prosthetic heart valve as described in any embodiment herein, particularly embodiments 50 and 51, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle ranging from about 20 degrees to about 70 degrees relative to a longitudinal axis of the annular frame.

[0230] Example 53. A prosthetic heart valve as described in any embodiment herein, particularly embodiment 52, wherein the skirt assembly is configured such that when the annular frame is in a radially expanded state, the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle of approximately 45 degrees relative to the longitudinal axis of the annular frame.

[0231] Example 54. The prosthetic heart valve according to any of the embodiments herein, particularly any of embodiments 50-53, wherein the woven fabric has a weave density of less than 150 ppi.

[0232] Example 55. The prosthetic heart valve as described in any embodiment herein, particularly as described in embodiment 54, wherein the fabric has a weave density of 60 ppi or less.

[0233] Example 56. The prosthetic heart valve as described in any example herein, particularly as described in example 55, wherein the woven fabric has a weave density of about 10 ppi to about 60 ppi.

[0234] Example 57. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 50-56, wherein the spacing between adjacent yarns in the first set of yarns is at least 0.5 mm.

[0235] Example 58. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 57, wherein the spacing between adjacent yarns in the first set of yarns is in the range of about 1.0 mm to about 2.0 mm.

[0236] Example 59. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 50-58, wherein the spacing between adjacent yarns in the second set of yarns is at least 0.5 mm.

[0237] Example 60. The prosthetic heart valve as described in any embodiment herein, particularly embodiment 59, wherein the spacing between adjacent yarns in the second set of yarns is in the range of about 1.0 mm to about 2.0 mm.

[0238] Example 61. The prosthetic heart valve as described in any example herein, particularly any of Examples 48-60, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness in the range of about 5 μm to about 15 μm.

[0239] Example 62. The prosthetic heart valve as described in any example herein, particularly as described in example 61, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness in the range of about 5 μm to about 10 μm.

[0240] Example 63. The prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 48-62, wherein the reinforcing layer is attached to the first encapsulation layer and to the second encapsulation layer within one or more adhesive regions.

[0241] Example 64. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 48-63, wherein the one or more pockets are configured such that portions of the reinforcing layer within the pockets are movable relative to the first encapsulation layer and relative to the second encapsulation layer.

[0242] Example 65. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 48 to 64, wherein the one or more adhesive regions include a first adhesive strip along a first circumferential edge of the skirt assembly and a second adhesive strip along a second circumferential edge of the skirt assembly, the first edge being located opposite the second edge.

[0243] Example 66. A prosthetic heart valve as described in any embodiment herein, particularly any of embodiments 48-65, wherein the one or more adhesive regions include one or more U-shaped adhesive strips corresponding to at least a portion of the scalloped lines in the plurality of valve leaflets.

[0244] Example 67. A skirt assembly for a prosthetic valve, the prosthetic valve including an annular frame configured to radially expand from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, and a plurality of leaflets configured to control blood flow from the inflow end to the outflow end of the annular frame, the skirt assembly being configured to be attached to a face of the annular frame and configured to be movable between a relaxed state and an axially extended state, the skirt assembly including a first encapsulation layer and a second encapsulation layer, each comprising an elastomeric material, and a plurality of leaflets disposed between the first encapsulation layer and the second encapsulation layer. a reinforcing layer interwoven with the yarns of the first set, the reinforcing layer comprising a woven fabric, the woven fabric comprising a first set of yarns and a second set of yarns interwoven with the yarns of the first set, each of the yarns of the first set and the second set being non-perpendicular and non-parallel to a top edge and a bottom edge of the skirt assembly when the skirt assembly is in a relaxed state, the skirt assembly being configured such that the first encapsulation layer and the second encapsulation layer are fused along one or more adhesive regions to form one or more pocket regions between the first encapsulation layer and the second encapsulation layer, the first encapsulation layer and the second encapsulation layer not fused to each other within the pocket regions.

[0245] Example 68. The skirt assembly as described in any example herein, particularly example 67, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness ranging from about 5 μm to about 15 μm.

[0246] Example 69. The skirt assembly as described in any embodiment herein, particularly as described in embodiments 67 and 68, wherein the first set of yarns and the second set of yarns are interwoven in a leno weave pattern.

[0247] Example 70. The skirt assembly of any embodiment herein, particularly any of embodiments 67-69, wherein the spacing between adjacent yarns in the first set of yarns is at least 0.5 mm.

[0248] Example 71. The skirt assembly as described in any example herein, particularly example 70, wherein the spacing between adjacent yarns in the first set of yarns is in the range of about 0.5 mm to about 2.0 mm.

[0249] Example 72. The skirt assembly of any embodiment herein, particularly any of embodiments 67-71, wherein the spacing between adjacent yarns in the second set of yarns is in the range of about 0.5 mm to about 2.0 mm.

[0250] Example 73. The skirt assembly as described in any embodiment herein, particularly any of embodiments 67-72, wherein the skirt assembly is configured such that when the skirt assembly is in a relaxed state, the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle of about 45 degrees relative to the top edge and the bottom edge of the skirt assembly.

[0251] Example 74. A skirt assembly as described in any embodiment herein, particularly any of embodiments 67-73, wherein the one or more pocket regions are configured such that a portion of the reinforcement layer outside of the one or more adhesive regions is disposed between the first encapsulation layer and the second encapsulation layer, but is not attached to either the first encapsulation layer or the second encapsulation layer.

[0252] Example 75. A skirt assembly as described in any embodiment herein, particularly any of embodiments 67-74, wherein the one or more adhesive areas include a first adhesive area along a top edge of the skirt assembly and a second adhesive area along a bottom edge of the skirt assembly.

[0253] Example 76. The skirt assembly as described in any embodiment herein, particularly embodiment 75, wherein the reinforcing layer is sealed within the first encapsulation layer and the second encapsulation layer via the first adhesive region and the second adhesive region.

[0254] Example 77. A skirt assembly as described in any embodiment herein, particularly embodiments 75 and 76, wherein the first and second adhesive regions limit lateral and axial movement of the reinforcing layer within the first encapsulation layer and within the second encapsulation layer.

[0255] Example 78. A skirt assembly as described in any embodiment herein, particularly any of embodiments 67-77, wherein the one or more adhesive regions include one or more U-shaped adhesive regions corresponding to at least a portion of the scallop lines in the multiple leaflets.

[0256] Example 79. A skirt assembly as described in any embodiment herein, particularly any of embodiments 67 to 78, wherein the skirt assembly is an outer skirt configured to be attached onto the outer surface of the annular frame.

[0257] Example 80. A skirt assembly as described in any embodiment of the present specification, particularly any of embodiments 67-79, wherein the skirt assembly is configured such that when the annular frame is in a radially compressed state, the skirt assembly is axially elongated to at least 40% of its initial length when the annular frame is in a radially expanded state.

[0258] Example 81. 1. A method for assembling a prosthetic valve, comprising: mounting a multi-cusp valve to an annular frame radially expandable from a radially compressed state to a radially expanded state, the frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, the multi-cusp valve being configured to control blood flow from the inflow end to the outflow end of the frame; forming a skirt assembly including a woven reinforcement layer interposed between a first encapsulation layer and a second encapsulation layer, the forming including fusing the first encapsulation layer and the second encapsulation layer along one or more fused regions, the one or more fused regions including a first region along a top edge of the skirt assembly and a second region along a bottom edge of the skirt assembly; and mounting the skirt assembly to the annular frame.

[0259] Example 82. The method of any embodiment herein, particularly embodiment 81, wherein the skirt assembly includes an outer skirt, and attaching the skirt assembly to the annular frame includes attaching the outer skirt onto an outer surface of the annular frame.

[0260] Example 83. The method of any embodiment herein, particularly embodiment 81, wherein the skirt assembly includes an inner skirt, and attaching the skirt assembly to the annular frame includes attaching the inner skirt onto an inner surface of the annular frame.

[0261] Example 84. The method of any embodiment herein, particularly any of embodiments 81-83, wherein the reinforcing layer comprises a woven fabric, the woven fabric comprising a first set of yarns and a second set of yarns interwoven with the first set of yarns in a leno weave pattern, and attaching the skirt assembly to the annular frame comprises attaching the skirt assembly such that when the annular frame is in a radially expanded state, each of the first set of yarns and the second set of yarns are non-perpendicular and non-parallel to the longitudinal axis.

[0262] Example 85. The method of any embodiment herein, particularly embodiment 84, wherein the spacing between adjacent yarns in the first set of yarns is in the range of from about 0.5 mm to about 2.0 mm.

[0263] Example 86. The method as described in any embodiment herein, particularly embodiments 84 and 85, wherein the spacing between adjacent yarns in the second set of yarns is in the range of from about 0.5 mm to about 2.0 mm.

[0264] Example 87. The method of any embodiment herein, particularly any of embodiments 84-86, wherein forming the skirt assembly includes positioning the reinforcing layer such that the yarns in each of the first set of yarns and the second set of yarns are oriented at an angle of about 45 degrees relative to the top and bottom edges of the skirt assembly.

[0265] Example 88. The method of any embodiment herein, particularly any of embodiments 81-87, wherein each of the first encapsulation layer and the second encapsulation layer has a thickness in the range of about 5 μm to about 15 μm.

[0266] Example 89. The method of any of the embodiments herein, particularly any of embodiments 81-88, wherein the one or more fused regions further comprise one or more U-shaped regions, the one or more U-shaped regions corresponding to at least a portion of a scallop line in the plurality of leaflets.

[0267] Example 90. The method of any embodiment herein, particularly any of embodiments 81-89, wherein forming the skirt assembly comprises pressing the skirt assembly between the first plate and the second plate.

[0268] Example 91. The method of any embodiment herein, particularly embodiment 90, further comprising applying heat to the skirt assembly while pressing the skirt assembly between the first plate and the second plate.

[0269] Example 92. The method as described in any embodiment herein, particularly as described in embodiments 90 and 91, wherein the first plate comprises a flat plate having a compressible coating.

[0270] Example 93. The method of any embodiment herein, particularly any of embodiments 99-92, wherein the second plate includes one or more recesses and one or more raised regions that form one or more fused regions when the skirt assembly is pressed between the first plate and the second plate.

[0271] Example 94. A prosthetic heart valve or skirt assembly for such a prosthetic heart valve, as described in any embodiment herein, in particular any one of embodiments 1 to 93, wherein the prosthetic heart valve or skirt assembly is sterile.

[0272] Various features described herein with respect to any embodiment may be combined with other features described in any one or more of the other embodiments, unless otherwise stated. For example, any one or more features in one outer skirt or inner skirt may be combined with any one or more features in another outer skirt or inner skirt.

[0273] In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it will be recognized that the illustrated embodiments are merely preferred embodiments of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. Accordingly, all that comes within the scope and spirit of the claims is claimed as the invention.

Claims

1. An artificial valve, an annular frame radially expandable from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end; a plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the annular frame; a skirt assembly including a reinforcing layer interposed between a first encapsulation layer and a second encapsulation layer, the reinforcing layer including a woven fabric, the woven fabric including a first set of yarns and a second set of yarns interwoven with the first set of yarns; the skirt assembly having a first thickness at a plurality of relatively thin regions between adjacent yarns and a second thickness at the yarns, the first thickness being less than the second thickness.

2. 2. The prosthetic valve of claim 1, wherein the yarns in each of the first set of yarns and the second set of yarns are non-perpendicular and non-parallel to the longitudinal axis when the annular frame is in the radially expanded state.

3. 3. The prosthetic valve of claim 1, wherein the skirt assembly is configured such that, when the annular frame is in the radially expanded state, yarns in each of the first and second sets of yarns are oriented at an angle in the range of about 20 degrees to about 70 degrees relative to the longitudinal axis of the annular frame.

4. 4. The prosthetic valve of claim 1, wherein the skirt assembly is configured such that, when the annular frame is in the radially expanded state, yarns in each of the first and second sets of yarns are oriented at a 45 degree angle relative to the longitudinal axis of the frame.

5. The prosthetic valve of any one of claims 1 to 4, wherein each of the first encapsulation layer and the second encapsulation layer is composed of an elastomer and has a thickness in the range of about 5 μm to about 15 μm.

6. The prosthetic valve of any one of claims 1 to 5, wherein the woven fabric has a weave density of less than 150 ppi.

7. The prosthetic valve of claim 6 , wherein the woven layer has a weave density of 60 ppi or less.

8. The prosthetic valve of claim 7 , wherein the woven layer has a weave density of about 10 ppi to about 60 ppi.

9. 9. The prosthetic valve of claim 1, wherein the spacing between adjacent yarns in the first set of yarns is in the range of about 0.5 mm to about 2.0 mm.

10. 10. The prosthetic valve of claim 1, wherein the spacing between adjacent yarns in the second set of yarns is in the range of about 0.5 mm to about 2.0 mm.

11. The prosthetic valve of any one of claims 1 to 10, wherein the yarns in the first set of yarns have a thickness or diameter in the range of about 8 μm to about 16 μm.

12. The prosthetic valve of any one of claims 1 to 11, wherein the yarns in the second set of yarns have a thickness or diameter in the range of about 8 μm to about 16 μm.

13. The prosthetic valve of any one of claims 1 to 12, wherein the first encapsulation layer is adhered to the second encapsulation layer at the plurality of relatively thin regions.

14. The artificial valve according to any one of claims 1 to 13, wherein the first thickness is in the range of about 10 μm to about 30 μm.

15. 15. The prosthetic valve of any one of claims 1 to 14, wherein the skirt assembly is configured such that the first encapsulation layer and the second encapsulation layer are adhered to one another along one or more adhesive regions and one or more pockets are formed in areas between the one or more adhesive regions, and the first encapsulation layer and the second encapsulation layer are not adhered to one another within the pockets.

16. 16. The prosthetic valve of claim 15, wherein the reinforcing layer is fixed to the first encapsulation layer and to the second encapsulation layer within the one or more adhesive regions, and the portion of the reinforcing layer within the pocket is disposed between the first encapsulation layer and the second encapsulation layer but is not adhered to either the first encapsulation layer or the second encapsulation layer.

17. 17. The prosthetic valve of claim 15 or 16, wherein the one or more pockets are configured such that portions of the reinforcement layer within the pocket are movable relative to the first encapsulation layer and relative to the second encapsulation layer within a respective pocket.

18. 18. The prosthetic valve of claim 15, wherein the one or more adhesive regions include a first adhesive region along a first circumferential edge of the skirt assembly and a second adhesive region along a second circumferential edge of the skirt assembly, the first edge being opposite the second edge.

19. The artificial valve of any one of claims 15 to 18, wherein the one or more adhesive regions include one or more U-shaped adhesive regions corresponding to at least a portion of a scallop line in a plurality of leaflets.

20. 20. The prosthetic valve of claim 1, wherein the skirt assembly is configured such that, when the annular frame is in the radially compressed state, the skirt assembly is axially lengthened to at least 40% of its initial length when the annular frame is in the radially expanded state.

21. 1. A skirt assembly for a prosthetic valve, the prosthetic valve including an annular frame configured to radially expand from a radially compressed state to a radially expanded state, the annular frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, and a plurality of leaflets configured to control blood flow from the inflow end to the outflow end of the annular frame, the skirt assembly configured to be attached to a face of the annular frame and configured to be movable between a relaxed state and an axially extended state, the skirt assembly comprising: a first encapsulation layer and a second encapsulation layer, each of which comprises an elastomeric material; and a reinforcing layer disposed between the first encapsulating layer and the second encapsulating layer, the reinforcing layer comprising a woven fabric, the woven fabric comprising a first set of yarns and a second set of yarns interwoven with the first set of yarns, each of the first set of yarns and the second set of yarns being non-perpendicular and non-parallel to a top edge and a bottom edge of the skirt assembly when the skirt assembly is in the relaxed state; A skirt assembly for an artificial valve, wherein the first encapsulation layer and the second encapsulation layer are configured to be fused along one or more adhesive regions to form one or more pocket regions between the first encapsulation layer and the second encapsulation layer, and the first encapsulation layer and the second encapsulation layer are not fused to each other within the pocket regions.

22. The skirt assembly of claim 21, wherein the first encapsulation layer and the second encapsulation layer each have a thickness in the range of about 5 μm to about 15 μm.

23. The skirt assembly of claim 21 or 22, wherein the spacing between adjacent yarns in the first set of yarns ranges from about 0.5 mm to about 2.0 mm.

24. 24. The skirt assembly of any one of claims 21 to 23, wherein the skirt assembly is configured such that when the skirt assembly is in the relaxed state, yarns in each of the first and second sets of yarns are oriented at an angle of approximately 45 degrees relative to the top and bottom edges of the skirt assembly.

25. The skirt assembly of any one of claims 21 to 24, wherein the one or more pocket regions are configured such that a portion of the reinforcement layer outside of the one or more adhesive regions is disposed between the first encapsulation layer and the second encapsulation layer, but is not attached to either the first encapsulation layer or the second encapsulation layer.

26. The skirt assembly of any one of claims 21 to 25, wherein the one or more adhesive regions include a first adhesive region along the top edge of the skirt assembly and a second adhesive region along the bottom edge of the skirt assembly.

27. 27. The skirt assembly of claim 26, wherein the reinforcement layer is sealed within the first encapsulation layer and the second encapsulation layer via the first and second adhesive regions.

28. 28. The skirt assembly of claim 26 or 27, wherein the first and second adhesive regions limit lateral and axial movement of the reinforcement layer within the first encapsulation layer and within the second encapsulation layer.

29. The skirt assembly of any one of claims 21 to 28, wherein the one or more adhesive regions include one or more U-shaped adhesive regions corresponding to at least a portion of a scallop line in the plurality of leaflets.

30. 1. A method for assembling a prosthetic valve, comprising: mounting a plurality of cusp valves to an annular frame radially expandable from a radially compressed state to a radially expanded state, the frame having an inflow end, an outflow end, and a longitudinal axis extending from the inflow end to the outflow end, the plurality of cusp valves configured to control blood flow from the inflow end to the outflow end of the frame; forming a skirt assembly including a woven fabric reinforcement layer interposed between a first encapsulation layer and a second encapsulation layer, said forming including fusing the first encapsulation layer and the second encapsulation layer along one or more fused regions, said one or more fused regions including a first region along a top edge of the skirt assembly and a second region along a bottom edge of the skirt assembly; and attaching the skirt assembly to the annular frame.

31. 31. The method of claim 30, wherein forming the skirt assembly includes positioning the reinforcing layer such that the yarns in each of the first and second sets of yarns are oriented at an angle of approximately 45 degrees relative to the top and bottom edges of the skirt assembly.

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