artificial heart valves

Abstract

This document provides devices and methods for treating cardiac disease. For example, this document provides prosthetic heart valves and transcatheter heart valve replacement methods. The prosthetic heart valve can be configured with a low-profile configuration for fitting within a small-diameter delivery sheath. The prosthetic heart valve may include a valve member attached to a stent frame. In some embodiments, the valve member is a shaped biomaterial with novel shapes and resulting performance characteristics. A topical protective cover member may be attached to the stent frame to prevent the valve member from contacting the stent frame as the valve member cycles between open and closed configurations.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION This disclosure relates to devices and methods for the treatment of cardiac disease. For example, this disclosure relates to prosthetic heart valves and methods for transcatheter heart valve implantation. [Background technology]

[0002] Heart valve stenosis is a condition in which the heart valves become narrowed (stenotic). In valvular stenosis, the tissue that makes up the valve leaflets stiffens, narrowing the valve opening and reducing the amount of blood that can flow through the opening. When the stenosis is mild, overall cardiac output remains normal. However, when the valve becomes severely narrowed, cardiac output decreases and cardiac function can be impaired.

[0003] Aortic stenosis affects approximately 5% of all people over the age of 75. Aortic stenosis occurs when the aortic valve in the heart narrows. When the aortic valve is blocked in this way, the heart has to work harder to pump blood to the body. Ultimately, this extra work limits the amount of blood the heart can pump and can weaken the heart muscle. The left atrium can enlarge as pressure increases, and blood and fluid can then collect in the lung tissue (pulmonary edema), making breathing difficult. Medication can alleviate the symptoms of mild to moderate aortic stenosis. However, the only way to treat severe aortic stenosis is through surgery to replace the valve.

[0004] Treatments for repairing or replacing the aortic valve include balloon valvuloplasty (valvotomy), surgical aortic valve replacement, and transcatheter aortic valve replacement (TAVR). TAVR involves replacing the aortic valve with a prosthetic valve delivered, for example, via the femoral artery (transfemoral) or the left ventricular apex of the heart (transapical). TAVR is sometimes referred to as transcatheter aortic valve implantation (TAVI). Summary of the Invention

[0005] This specification describes devices and methods for the treatment of cardiac disease. For example, this specification describes prosthetic heart valves and transcatheter heart valve replacement methods. In some embodiments, the prosthetic heart valve includes a valve member made of a biomaterial that is molded into a specific three-dimensional ("3D") shape. The shape of the molded valve member is specifically designed to provide enhanced performance characteristics, such as, but not limited to, low mean pressure gradients, low leaflet stresses, large valve open area, high coaptation surface, and long duration in the open state, to name a few, as described herein.

[0006] In some embodiments, the prosthetic heart valve includes an expandable metal stent frame surrounding a valve member. A localized protective cover member may be attached to portions of the stent frame to prevent direct contact between the valve member and the stent frame when the valve member is in an open state. Such a protective cover member can extend the useful life of the valve member by protecting the valve member from direct contact with the metal stent frame. Additionally, a skirt may be attached to the stent frame to cover other portions of the stent frame to prevent the valve member from contacting those portions. In some embodiments, the combination of the skirt and the localized protective cover member prevents the valve member from directly contacting any portions of the stent frame that are not covered.

[0007] In one aspect, the present disclosure relates to a prosthetic heart valve. Such a prosthetic heart valve may include a stent frame reconfigurable between a low-profile delivery configuration and an expanded, operable configuration, and a valve member attached to the stent frame. The valve member may include three leaflets. Each leaflet has a free edge and a three-dimensional shape. The three-dimensional shape of the leaflet includes: (i) a first planar region including a first free edge that terminates at a central location of the leaflet's free edge; (ii) a second planar region including a second free edge that terminates at a central location of the leaflet's free edge; and (iii) a concave region disposed between the first and second planar regions and having an apex at the central location of the leaflet's free edge.

[0008] Such a prosthetic heart valve may optionally include one or more of the following features. In some embodiments, the valve member is configured to allow blood flow through the prosthetic heart valve from the inflow end of the prosthetic heart valve to the outflow end of the prosthetic heart valve and prevent blood flow through the prosthetic heart valve from the outflow end to the inflow end. In some embodiments, the valve member extends to an edge of the stent frame at the inflow end. The concave region may join with the first planar region along a first curved path, and the concave region may join with the second planar region along a second curved path. The first free edge may be straight, and the second free edge may be straight. In some embodiments, the first free edge and the second free edge are non-parallel to one another. An angle may be defined between the first free edge and the second free edge. The angle may be between 80° and 120°. In some embodiments, the first and second planar regions are not coplanar. The valve member may comprise a biomaterial. In some embodiments, the biomaterial is shaped to create a three-dimensional shape.

[0009] In another aspect, the present disclosure is directed to a prosthetic heart valve including a valve member with three flexible leaflets and a stent including a metal framework reconfigurable between a low-profile delivery configuration and an expanded, operable configuration. The metal framework includes (i) three commissure posts to which the valve member is attached and (ii) three frame portions, each of which is positioned between two of the commissure posts. The prosthetic heart valve also includes three separate protective cover members attached to the three frame portions and covering the local valve-facing surfaces of each of the three frame portions.

[0010] Such a prosthetic heart valve may optionally include one or more of the following features: The three separate protective cover members may comprise bovine pericardium sutured to the three frame portions. The prosthetic heart valve may also include a skirt attached to the inside and outside of the inflow end of the stent. In some embodiments, the skirt abuts the protective cover members. The valve member may be configured to allow blood flow through the prosthetic heart valve from the inflow end of the prosthetic heart valve to the outflow end of the prosthetic heart valve and to prevent blood flow through the prosthetic heart valve from the outflow end to the inflow end. The valve member may include three free edges. Each of the three free edges may extend between two of the commissure posts. The valve member may be reconfigurable between a fully closed configuration in which the three free edges contact each other and a fully open configuration in which the three free edges are spaced apart from each other. In the fully open configuration, a medial portion of each of the three free edges may be located closer to the inflow end than the outflow edges of each of the three separate protective cover members. In the fully closed configuration, all portions of each of the three free edges may be located closer to the outflow end than the outflow edges of each of the three separate protective cover members. In some embodiments, each of the three frame portions is located equidistant between two of the commissure posts.

[0011] Certain embodiments of the invention described herein can be implemented to achieve one or more of the following advantages: In some embodiments, cardiac diseases such as valvular stenosis can be treated using the devices and methods provided herein. Some patients who are too high-risk for traditional surgical valve replacement can be treated using the prosthetic valve devices and transcatheter heart valve replacement methods provided herein. In some embodiments, the valve members of the prosthetic heart valve are shaped in specific ways that improve various valve performance characteristics. Additionally, some embodiments include localized protective cover members attached to certain portions of the stent frame to prevent direct contact between the valve members and the stent frame when the valve members are in an open state. The protection provided by the cover members enhances the performance and durability of the valve leaflets.

[0012] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.Although methods and materials similar or similar to those described herein can be used to implement the present invention, suitable methods and materials are described herein.All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.In case of conflict, the present specification, including definitions, will prevail.In addition, materials, methods, and examples are merely illustrative and are not intended to be limiting.

[0013] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

[0014] Like numbers refer to corresponding parts throughout. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a side view of an exemplary prosthetic heart valve, according to some embodiments. [Figure 2] FIG. 2 is a top view of the prosthetic heart valve of FIG. 1, with the valve in a fully closed configuration. [Figure 3] FIG. 2 is a top view of the prosthetic heart valve of FIG. 1, with the valve in a fully open configuration. [Figure 4] 2 is a perspective view of an exemplary stent or metal framework of the prosthetic heart valve of FIG. 1. [Figure 5] 2 is a plan view of an exemplary leaflet portion of a valve member of the prosthetic heart valve of FIG. 1. [Figure 6] 2 shows a mold for the prosthetic heart valve of FIG. 1 and the resulting molded valve member. [Figure 7] 7 shows the valve member of FIG. 6 in a fully closed state. [Figure 8] 7 shows the valve member of FIG. 6 in a fully open state. DETAILED DESCRIPTION OF THE INVENTION

[0016] This specification describes devices and methods for the treatment of cardiac disease. For example, this specification describes prosthetic heart valves and transcatheter heart valve replacement methods. 1-3, an exemplary prosthetic heart valve 100 can be used to replace a patient's native heart valve. The prosthetic heart valve 100 is particularly well suited for use in the location of the native aortic valve, but may also be utilized in the location of other native heart valves, such as, but not limited to, the mitral valve, pulmonary valve, and tricuspid valve.

[0017] In some cases, the prosthetic heart valve 100 may be deployed using minimally invasive transcatheter techniques. Thus, the prosthetic heart valve 100 can be radially compressed (e.g., crushed) into a low-profile delivery system configuration for passage through a delivery sheath and into the patient's vasculature. The delivery system may be percutaneously inserted into the patient's blood vessel (e.g., the femoral artery, femoral vein, radial artery, etc.) and then navigated to the target location using imaging techniques such as fluoroscopy, MRI, or ultrasound. In some situations, a guidewire may be placed first. Radiopaque and / or echogenic markers may be included at one or more locations on the prosthetic heart valve 100 to enhance imaging. At the target location, the prosthetic heart valve 100 is deployed from the delivery system and then allowed to expand in situ to position it at the target location. The prosthetic heart valve 100 may be self-expanding or expandable by mechanical means, such as a balloon. Other access techniques, such as a transapical approach, are also contemplated.

[0018] Figures 1-3 show the prosthetic heart valve 100 in an expanded configuration after deployment from a delivery system. Figure 2 shows the prosthetic heart valve 100 in a closed state. Figure 3 shows the prosthetic heart valve 100 in an open state.

[0019] The prosthetic heart valve 100 operates as a one-way valve. That is, the prosthetic heart valve 100 functions to allow blood to flow through the prosthetic heart valve 100 in a direction from the inflow end 102 (FIG. 1) to the outflow end 104. Conversely, the prosthetic heart valve 100 functions to prevent blood from flowing in the opposite direction through the prosthetic heart valve 100, i.e., from the outflow end 104 to the inflow end 102. For clarity, FIGS. 2 and 3 are views of the outflow end 104. The prosthetic heart valve 100 also defines a central longitudinal axis 101.

[0020] The prosthetic heart valve 100 includes a stent frame 110, a skirt 140, a valve member 160, and a protective cover member 180. The skirt 140 is attached to the stent frame 110 so as to cover inner and outer portions of the stent frame 110. In the illustrated embodiment, the skirt 140 is attached to the stent frame 110 by sutures that are used to sew the skirt 140 to itself (while capturing a portion of the stent frame 110). As described further below, in some embodiments, the skirt 140 is a single, integral piece of covering material. Alternatively, in some embodiments, the skirt 140 is made from two or more separate pieces of covering material.

[0021] Valve member 160 is disposed within stent frame 110 and is attached to stent frame 110 at three commissure posts 112. Protective cover members 180 are also attached to stent frame 110. In particular, in the illustrated embodiment, protective cover members 180 are attached to stent frame 110 at three locations on stent frame 110, each bisecting the location of a commissure post 112. In some embodiments, stent frame 110 may include additional portions between commissure posts 112, and additional protective cover members 180 may be attached to the additional portions.

[0022] The stent frame 110 is comprised of elongated members arranged in a generally cylindrical shape and three commissure posts 112. In the illustrated embodiment of the stent frame 110, the elongated members are arranged in a cellular fashion; that is, the elongated members define a plurality of open cells. The stent frame 110 may be comprised of stainless steel, a shape memory alloy, a plastically deformable alloy, or a combination thereof. Examples of such alloy materials include, but are not limited to, nickel-titanium alloys such as Nitinol® alloys, cobalt-chromium alloys such as Elgiloy® alloys, platinum-tungsten alloys, tantalum alloys, and the like. Other alloys that may be used in fabricating the stent frame 110 include, but are not limited to, other cobalt-chromium alloys, titanium-cobalt-chromium-molybdenum alloys, and the like. In addition to these materials, the stent frame 110 may also be comprised of a polymer, a biomaterial, or a combination thereof. In some embodiments, the stent frame 110 may initially be a tube (e.g., Nitinol® or Elgiloy® tubing) that is laser cut, expanded to the desired open cylindrical configuration, and then heat-set to convert the cylinder into its original elongated member configuration.

[0023] In some embodiments, the elongated members of the stent frame 110 are wires that are wound, woven, and / or attached together (e.g., welded or glued) to create a cylindrical configuration.

[0024] In some embodiments, the stent frame 110 may have a coating on at least a portion of either the exterior or interior surface. The coating may include a polymer, including, but not limited to, polytetrafluoroethylene (PTFE), silicone, biopolymers, and other suitable polymers. In other embodiments, the coating may include a radiopaque material. In some embodiments, the coating may include a drug-eluting material.

[0025] The prosthetic heart valve 100 also includes a skirt 140. The skirt 140 covers all or a portion of the stent frame 110. In the illustrated embodiment, the skirt 140 is a single, integral piece of covering material that is wrapped around the inflow end 102 of the stent frame 110 to cover an inner portion of the stent frame 110 and an outer portion of the stent frame 110. Alternatively, in some embodiments, the skirt 140 is made from two or more separate portions of covering material. For example, in some embodiments, a first portion of the skirt 140 may be used to cover at least a portion of the inner side of the stent frame 110, and a second separate portion of the skirt 140 may be used to cover at least a portion of the outer side of the stent frame 110. In some such embodiments, the inner portion of the skirt 140 may be made from a different type of material than the type of material used for the outer portion of the skirt 140. In certain embodiments, skirt 140 may be made from materials including, but not limited to, Dacron, polyester fabric (e.g., PVL), polyethylene terephthalate (PET), Teflon®-based materials, polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyurethane, silicone, BiO-A®, copolymers, film or foil materials, or combinations of the foregoing and / or similar materials. In some embodiments, skirt 140 has a material composition and configuration that inhibits or prevents tissue ingrowth into skirt 140. In some embodiments, skirt 140, or portions thereof, has a microporous structure that provides a tissue ingrowth scaffold for durable sealing and supplemental fixation strength of prosthetic heart valve 100.

[0026] The skirt 140 may be attached to the stent frame 110 in a variety of suitable ways. For example, in some embodiments, the skirt 140 is sewn to the elongated members of the stent frame 110. In some embodiments, the skirt 140 is glued to the stent frame 110. In some embodiments, a portion of the stent frame 110 is sandwiched between two layers of the skirt 140 that are sewn together. In some embodiments, a combination of such attachment methods is used. These and all other variations in frame member types, material compositions, material processing, configurations, manufacturing techniques, and methods for attaching the skirt 140 to the stent frame 110 are contemplated within the scope of the disclosure provided herein.

[0027] The prosthetic heart valve 100 also includes a valve member 160. The valve member 160 may comprise a tissue material. In some embodiments, the tissue material may be a biomaterial. In some embodiments, the tissue material may be a cross-linked collagen-based biomaterial comprising acellular or cellular tissue selected from the group consisting of cardiovascular tissue, cardiac tissue, heart valves, aortic root, aortic wall, aortic valve cusps, pericardial tissue, connective tissue, dura mater, dermal tissue, vascular tissue, cartilage, pericardium, ligaments, tendons, blood vessels, umbilical cord tissue, bone tissue, fascia, and submucosa and skin. In some embodiments, the tissue material is an implantable biomaterial, such as the biomaterial described in the disclosure of U.S. Pat. No. 9,205,172, filed December 21, 2005, entitled "Implantable Biomaterial and Method of Producing Same," which is incorporated herein by reference in its entirety. In some embodiments, the cross-linked collagen-based biomaterial is treated with the Adapt® treatment process. This is an anti-calcification treatment process for biomaterials that leaves no residual DNA and has over 10 years of clinical data showing no calcification when used in cardiac surgery. In some embodiments, the tissue material may be an artificial tissue. In some embodiments, the artificial tissue may comprise a single-piece molded or formed polymer. In some embodiments, the artificial tissue may comprise polytetrafluoroethylene, isotropic silicone, polyethylene terephthalate, other polymers, and other polymer coatings.

[0028] As described further below, in some embodiments, valve member 160 may comprise a shaped tissue material. More specifically, at least some or all of the leaflets of valve member 160 may comprise a shaped tissue material (e.g., using a mold and the Adapt® treatment process). In some embodiments, valve member 160 is a single-piece three-dimensional valve constructed from a single piece of tissue material, as described further below.

[0029] The valve member 160 is bonded to itself such that it captures the three commissure posts 112, thereby attaching the valve member 160 to the stent frame 110 at the three commissure posts 112. In some embodiments, the valve member 160 has slits into which the three commissure posts 112 are received. This is described, for example, in PCT / US2021 / 040596, filed July 7, 2021, and incorporated herein by reference in its entirety. Such bonding techniques allow for a larger diameter open state (as depicted in FIG. 3) and also reduce leaflet stress at the juncture points. The valve member 160 may be attached to itself and / or the three commissure posts 112 by means such as suturing, using mechanical clips, sewing, using hooks or barbs, using adhesives, bonding, mechanical channels, and combinations thereof.

[0030] The prosthetic heart valve 100 also includes protective cover members 180. In the illustrated embodiment, three protective cover members 180 are included. Some embodiments may include fewer or more than three protective cover members 180. The protective cover members 180 are localized covering materials attached to specific locations on the stent frame 110. The primary purpose of the protective cover members 180 is to block or prevent the valve member 160 from contacting the stent frame 110 when the valve member 160 reconfigures to its open state (e.g., as shown in FIG. 3 ). Protecting the valve member 160 in this manner can extend the useful life of the valve member 160.

[0031] In fact, in the illustrated embodiment, no portion of the valve member 160 (other than where the valve member 160 is attached to the stent frame at the three commissure posts 112) directly contacts the stent frame 110. The skirt 140 and protective cover member 180 are contacted by the valve member 160, and the skirt 140 and protective cover member 180 thereby serve to prevent the valve member 160 from directly contacting the stent frame 110. In the illustrated embodiment, as best seen in FIG. 1 , the upper edges of the skirt 140 abut the respective lower edges of the protective cover members 180. Thus, the inner surface of the stent frame 110 is completely covered in those areas.

[0032] In some embodiments, protective covering member 180 is a patch made of bovine pericardium sutured to stent frame 110. In some embodiments, protective covering member 180 is made of any other suitable biomaterial or synthetic material, such as those materials described above for skirt 140 or valve member 160, and / or combinations of such materials. For example, in some embodiments, protective covering member 180 comprises bovine pericardium on the inside of stent frame 110 and PET on the outside of stent frame 110.

[0033] 4, an isolated view of the stent frame 110 (without the skirt 140 and valve member 160) and protective cover member 180 is provided. The protective cover member 180 is shown in a specific location inside the stent frame 110. It can be seen that the protective cover members 180 are located on three portions of the stent frame 110, each equidistantly positioned between two commissure posts 112. Three separate protective cover members 180 are attached to the three frame portions of the stent frame 110 to cover the local valve-facing surfaces of each of the three frame portions.

[0034] Valve member 160 includes three free edges that extend between the three commissure posts 112 and abut (contact) one another when valve member 160 is in a closed configuration (e.g., as shown in FIG. 2 ) and spread apart when valve member 160 is in an open configuration (e.g., as shown in the fully open configuration of FIG. 3 ). Protective cover member 180 serves to protect valve member 160 (particularly including the intermediate portions of the free edges of valve member 160) from direct contact with stent frame 110 when valve member 160 is in the fully open configuration.

[0035] In the fully open configuration, the central portion of each of the three free edges of valve member 160 is located closer to the inflow end 102 than the edge of each of the three separate protective cover members 180 that is closest to the outflow end 104. In other words, when valve member 160 is in its open configuration, the central portion of each of the three free edges of valve member 160 is below (closer to the inflow end 102) than the upper edge (or "outflow edge," since it is closer to the outflow end 104) of protective cover member 180. This arrangement helps ensure that protective cover member 180 prevents the free edges of valve member 160 from directly contacting stent frame 110 when valve member 160 is in the fully open configuration.

[0036] As best seen in FIG. 4 , in the illustrated embodiment, protective cover member 180 is attached to a portion of stent frame 110 that is directly connected to adjacent commissure posts 112 by two elongated members 114 that extend in opposite directions like an arch. That is, two elongated members 114 extend from each portion of stent frame 110 to which protective cover member 180 is attached. One of the two elongated members 114 extends directly to a first commissure post 112, and the other of the two elongated members 114 extends directly to a second commissure post 112. Protective cover member 180 bisects both the first and second commissure posts 112. Because the elongated members 114 extend directly between the commissure posts 112 and the portion of the stent frame 110 to which the protective cover members 180 are attached, large open cells are defined by the stent frame 110 between the protective cover members 180 and the commissure posts 112.

[0037] Referring also to Figure 5, valve member 160 is comprised of three leaflets 162. Figure 5 shows an example of a single leaflet 162 so that its particular shape can be clearly envisioned. Leaflet 162 constitutes the portion of valve member 160 that extends between commissure posts 112 of stent frame 110. Leaflet 162 is the portion of valve member 160 that performs most or all of the reconfiguration movement as valve member 160 cycles between closed and fully open configurations (e.g., as shown in Figures 2 and 3).

[0038] Although the leaflet 162 shown in FIG. 5 is shown two-dimensionally, the natural shape of the leaflet 162 (in its unstressed state) is actually three-dimensional. That is, the leaflet 162 includes a first planar region 163, a second planar region 164, and a concave region 165. The first planar region 163 and the second planar region 164 are each planar (but not within the plane of FIG. 5 ). The concave region 165 may be concave, curved, dish-shaped, etc. The concave region 165 is disposed between the first planar region 163 and the second planar region 164. The first planar region 163 and the second planar region 164 are non-coplanar with respect to one another. That is, the first planar region 163 defines a first plane, and the second planar region 164 defines a second plane that is different from the first plane. The extension planes defined by the first planar region 163 and the second planar region 164 intersect with each other.

[0039] The first planar region 163 and the second planar region 164 comprise the free edges of the leaflet 162. The first planar region 163 comprises a first free edge 163e, and the second planar region 164 comprises a second free edge 164e. The first free edge 163e and the second free edge 164e together constitute the free edge of the leaflet 162.

[0040] The first free edge 163e contacts the second free edge 164e at a center position 166 of the free edge of the leaflet 162. While the first free edge 163e and the second free edge 164e are each straight in the illustrated embodiment, they are not collinear with each other. The first free edge 163e and the second free edge 164e are not parallel to each other. Rather, an angle "α" is defined between the first free edge 163e and the second free edge 164e. In some embodiments, the angle α is within the range of, but not limited to, 80° to 120°, 70° to 130°, 90° to 110°, or 100° to 140°.

[0041] The concave region 165 is disposed between the first planar region 163 and the second planar region 164. The concave region 165 joins the first planar region 163 along a first curved path 163i. The concave region 165 joins the second planar region 164 along a second curved path 164i. The first curved path 163i extends to a center position 166 of the free edge of the valve leaflet 162. The second curved path 164i also extends to the center position 166 of the free edge of the valve leaflet 162. The first curved path 163i intersects with the second curved path 164i at the center position 166 of the free edge of the valve leaflet 162. Therefore, the concave region 165 can be said to include an apex located at the center position 166 of the free edge of the valve leaflet 162.

[0042] FIG. 6 illustrates one method by which a valve member 160 having three leaflets 162 can be manufactured. In this example, the material of the valve member 160 is formed using a mold 170 to have the three-dimensional shape of the leaflets 162 as described above. Here, half of the mold 170 is shown, with the other half of the mold 170 not shown for simplicity. Such a mold 170 can be used to form the material of the valve member 160 to have three leaflets 162 with a first flat region 163, a second flat region 164, and a concave region 165. In some embodiments, the mold 170 may include openings, channels, ports, or be made of a porous material to allow fluid to pass through the mold 170 and reach the tissue material during the tissue molding process.

[0043] In addition to the leaflets 162, the valve member 160 may optionally include a base portion 167. In the illustrated embodiment, there is a boundary line 168 between the base portion 167 and the portion of the valve member 160 that includes the leaflets 162. Alternatively, in some embodiments, the base portion 167 is simply a direct extension of the portion of the valve member 160 that includes the leaflets 162 (without a distinct boundary line 168). In some embodiments, the valve member 160 is attached to the stent frame 110 such that the base portion 167 extends all the way to the edge of the stent frame 110 at the inflow end 102 of the prosthetic heart valve 100.

[0044] After forming the three-dimensional shape of the valve member 160 as shown in FIG. 6, the valve member 160 may be formed into a generally cylindrical shape within the stent framework 110. 7 and 8 show the valve member 160 in a closed and fully open configuration, respectively, where the stent frame 110 and other portions of the prosthetic heart valve 100 are not shown so that the geometric features of the valve member 160 can be more easily visualized.

[0045] The geometric features of the valve member 160 (e.g., the leaflets 162, including the first planar region 163, the second planar region 164, and the concave region 165) and how they are arranged on the valve member 160, as described particularly with reference to Figure 5, are designed and selected by the inventors to achieve certain advantageous performance characteristics for the prosthetic heart valve 100. For example, the geometric features of the valve member 160 enhance the performance characteristics of the prosthetic heart valve 100, such as, but not limited to, a high leaflet coaptation area, a low mean pressure gradient, a large valve open area, low leaflet stress, and a long duration of the valve 160 in its open state.

[0046] While the specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of a particular invention. Certain features that are described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described herein as acting in a certain combination, and even initially claimed as such, one or more features from a claimed combination may in some cases be deleted from the combination, and a claimed combination may be directed to a subcombination or a variation of a subcombination.

[0047] Specific embodiments of the present invention have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims may be performed in a different order and still achieve desirable results. As an example, the processes depicted in the accompanying figures do not necessarily require the particular order shown or sequential order to achieve desirable results. In some implementations, multitasking may be advantageous.

Claims

1. 1. A prosthetic heart valve, comprising: a stent frame that is reconfigurable between a low-profile delivery configuration and an expanded, operable configuration; a valve member having a single piece of collagen-based biomaterial attached to the stent frame and having a plurality of leaflets, each leaflet having a free edge and shaped and crosslinked to retain a three-dimensional shape comprising a concave region; the prosthetic heart valve includes an inflow end and an outflow end, the valve member being configured to (i) open to allow blood flow from the inflow end to the outflow end, and (ii) close to prevent blood flow from the outflow end to the inflow end; The prosthetic heart valve wherein the concave region of each leaflet is spaced from an edge of the stent frame at the inflow end by a portion of the collagen-based biomaterial that is shaped to be non-planar.

2. 2. The prosthetic heart valve of claim 1, wherein the concave region of each leaflet has an apex at a central location of the free edge of the leaflet.

3. Each valve leaflet is a first planar region including a first free edge terminating at a central location of the free edge of the leaflet; a second planar region including a second free edge terminating at the center of the free edge of the leaflet; The prosthetic heart valve of claim 1 , wherein the concave region is disposed between the first planar region and the second planar region.

4. 4. The prosthetic heart valve of claim 3, wherein the first free edge is straight and the second free edge is straight.

5. The prosthetic heart valve of claim 4 , wherein the first free edge and the second free edge are non-parallel to one another.

6. 5. The prosthetic heart valve of claim 4, wherein the angle defined between the first free edge and the second free edge is between 80° and 120°.

7. The prosthetic heart valve of claim 3 , wherein the first planar region and the second planar region are non-coplanar.

8. 1. A prosthetic heart valve, comprising: a valve member including flexible leaflets; a metal framework comprising: (i) a plurality of cells; (ii) a plurality of commissure posts to which the valve member is attached; and (iii) a plurality of frame portions defining one or more openings smaller than the plurality of cells; a skirt attached to the inlet end of the metal framework; a plurality of protective cover members attached to and covering local valve-facing surfaces of the frame portion, the protective cover members being separate from the skirt.

9. 9. The prosthetic heart valve of claim 8, wherein each of the frame portions is directly connected to two adjacent commissure posts by two respective elongated members of the metal framework that extend in opposite directions like an arch.

10. 9. The prosthetic heart valve of claim 8, wherein the skirt defines a cylinder, and the commissure posts and the frame portions all extend from the cylinder toward the outflow end of the metal framework.

11. 11. The prosthetic heart valve of claim 10, wherein the plurality of cells comprises a plurality of smaller cells and a plurality of larger cells, the skirt is attached to the plurality of smaller cells to define the cylinder, and each of the frame portions is located between two of the commissure posts, thereby defining two larger cells of the plurality of larger cells.

12. The prosthetic heart valve of claim 10 , wherein the plurality of larger cells are not covered by the skirt.

13. 9. The prosthetic heart valve of claim 8, wherein the protective covering members include three separate protective covering members including bovine pericardium sutured to the frame portions.

14. The prosthetic heart valve of claim 8 , wherein the skirt abuts the protective cover member.

15. The skirt is a first skirt material attached to the interior of the metal framework; a second skirt material attached to the exterior of the metal frame; The prosthetic heart valve of claim 8 , wherein the first and second skirt materials are different types of materials.

16. 9. The prosthetic heart valve of claim 8, wherein the valve member comprises three leaflets, each leaflet including a free edge, each of the free edges extending between two of the commissure posts.

17. 17. The prosthetic heart valve of claim 16, wherein the valve members are reconfigurable between a fully closed configuration in which the free edges contact one another and a fully open configuration in which the free edges are separated from one another.

18. 18. The prosthetic heart valve of claim 17, wherein in the fully open configuration, an intermediate portion of each of the free edges is located closer to the inflow end than an outflow edge of each of the protective cover members.

19. 19. The prosthetic heart valve of claim 18, wherein in the fully closed configuration, all portions of each of the free edges are located closer to the outflow end than the outflow-side edges of each of the protective cover members.

20. The prosthetic heart valve of claim 8 , wherein each of the frame portions is located equidistant between two of the commissure posts.

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