Mechanically expandable heart valve

In one embodiment, a prosthetic valve can comprise a radially expandable and compressible frame, which can include a plurality of struts which are pivotally joined together without requiring individual rivets. In some embodiments, the struts are interwoven, and can be joined using integral hinges formed in the struts, such as by performing alternate cuts on the struts, bending the struts to form stopper tabs adjacent to joints and/or drilling holes in the struts to facilitate interconnecting struts at joints, or otherwise forming integral hinges and corresponding holes at junction points between the struts. In another embodiment, the frame comprises a plurality of inner struts and outer struts which are connected by a plurality of chains of interconnected rivets, avoiding the need to provide individual rivets at each junction between struts. In still another embodiment, separate hinges are provided to interconnect the struts. In still another embodiment, separate flanged rivets are provided to connect the struts.

FIELD

The present disclosure relates to implantable, mechanically expandable prosthetic devices, such as prosthetic heart valves, and to methods and assemblies for providing collapsible frames for, and including, such prosthetic devices.

BACKGROUND

Malfunctions within the human heart, such as those resulting from valvular diseases, frequently require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (e.g., stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. In one known technique, a prosthetic device is configured to be implanted in a less invasive procedure by way of catheterization. For example, a collapsible transcatheter prosthetic heart valve can be crimped to a compressed state and percutaneously introduced in the compressed state on a catheter and expanded to a functional size at the desired position by mechanical expansion or using a self-expanding frame or stent. Current frame assembly designs, however, frequently require manufacturing processes requiring handling and assembling many small parts. Improved implant frame designs and methods for assembly are needed. Such frame assemblies would preferably offer one or more of the following advantages over current approaches: minimizing the number of individual parts needed, maintaining flexibility for movement within the patient, collapsing to a low profile to minimize the size of catheter needed during introduction into the patient, and reducing the risk of rivet embolization.

SUMMARY

Embodiments of improved implantable medical devices, such as prosthetic heart valves, are disclosed herein, as well as methods for providing such devices and assemblies.

In one representative embodiment, a method of assembling an implantable medical device comprises providing a plurality of struts, each strut comprising a length and a plurality of apertures spaced apart from each other along the length. The method can further comprise providing a plurality of strut connectors comprising an elongated support member and a plurality of projections spaced apart from each other along the support member. The method can further comprise connecting the struts to each other with the strut connectors to form an annular frame, wherein the projections of each strut connector extend through respective apertures of one of the struts and into respective apertures of one or more other struts to form a plurality of pivot joints between the struts.

In some embodiments, the plurality of struts comprises a first set of inner struts and a second set of outer struts, wherein the inner struts are connected to the outer struts by the strut connectors.

In some embodiments, the strut connectors are placed against respective outer struts and each strut connector comprises at least first and second projections that extend through apertures of the same outer strut and into apertures of different inner struts.

In some embodiments, the strut connectors are placed against respective inner struts and each strut connector comprises at least first and second projections that extend through apertures of the same inner strut and into apertures of different outer struts.

In some embodiments, the method further comprises mounting a valve member comprising a plurality of leaflets inside of the annular frame.

In some embodiments, the strut connectors are formed using electrochemical machining.

In some embodiments, the strut connectors are formed using laser machining.

In another representative embodiment, an implantable medical device comprises a first set of a plurality of first struts extending in a first direction and a second set of a plurality of second struts extending in a second direction, wherein the first struts are interwoven with the second struts to form an annular frame that is radially compressible and expandable. Each first strut can be pivotally connected to at least one second strut.

In some embodiments, each first strut can comprise a plurality of projections spaced apart from each along a length of the first strut and each second strut can comprise a plurality of apertures extending along a length of the second strut, and wherein the projections of the first struts extend into respective apertures of the second struts.

In some embodiments, each first strut has at least one projection that extends radially inwardly and into an aperture of an adjacent second strut and at least one projection extends radially outwardly and into an aperture of an adjacent second strut.

In some embodiments, the projections are integrally formed on the first struts.

In some embodiments, each first strut passes radially outside of at least one second strut and radially inside of at least one second strut.

In some embodiments, the medical device further comprises a valve member which can comprise a plurality of leaflets mounted inside the annular frame.

In another representative embodiment, a method of assembling a frame for an implantable medical device comprises providing a plurality of individual struts comprising a first set of a plurality of first struts and a second set of a plurality of second struts. The method can further comprise interweaving the first struts with the second struts to form an annular frame.

In some embodiments, the individual struts, prior to the act of interweaving, are curved.

In some embodiments, the individual struts, prior to the act of interweaving, have a radius of curvature substantially the same as the radius of curvature of the annular frame formed by the struts.

In some embodiments, the individual struts are laser cut from a metal tube.

In some embodiments, each of the plurality of first struts is formed with a plurality of radially extending projections and each of the plurality of second struts is formed with a plurality of apertures.

In some embodiments the interweaving comprises connecting the first struts to the second struts by extending each of the plurality of projections through a respective one of the plurality of apertures at junctions between a first strut and a second strut.

In some embodiments, the connecting comprises pivotally connecting each of the first struts to a plurality of the second struts.

In some embodiments, the plurality of radially extending projections are formed with a plurality of projections extending radially inwardly, and a plurality of projections extending radially outwardly.

In some embodiments, the method further comprises mounting the first set of the plurality of struts at a first assembly angle, wherein each of the struts in the first set of struts comprises a plurality of the radially extending projections comprising a central protrusion with at least two ears extending outward therefrom in a plane parallel to the strut formed therein. The method can further comprise mounting the second set of the plurality of struts on the first set of struts at a second assembly angle forming a relative assembly angle between the first assembly angle and the second assembly angle. Each of the struts in the second set of struts comprises a plurality of the apertures, wherein each of the apertures comprises a central opening corresponding to the central protrusion and oblong side openings corresponding to the at least two ears. In this embodiment, the mounting forms the frame.

In certain embodiments, the method can further comprise crimping the frame to cause the at least two ears on the first set of struts to rotate away from the corresponding oblong side openings in the second set of struts. The method can further comprise securing a plurality of mechanical lockers to the frame to limit the relative movement of the first set of struts and the second set of struts to a range of relative angles that does not include the relative assembly angle.

In another representative embodiment, an implantable medical device comprises a radially expandable and compressible annular frame comprising a plurality of interconnected struts, the plurality of struts comprising a first set of a plurality of first struts and a second set of a plurality of second struts, wherein the first struts overlap adjacent second struts at junctions, and expansion or compression of the annular frame causes the first struts to pivot relative to the second struts at the junctions. Each of the first struts can comprise a plurality of pairs of radially extending, first stopper tabs spaced apart from each other along a length of the first strut, and each of the second struts can comprise a plurality of pairs of radially extending, second stopper tabs spaced apart from each other along a length of the second strut.

In particular embodiments, the first stopper tabs of each pair of tabs along the first struts extend to opposite sides of an adjacent second strut at a junction and can engage second stopper tabs of the adjacent second strut upon pivoting movement of the first struts relative to the second struts.

In some embodiments, the first stopper tabs extend radially inward and the second stopper tabs extend radially outward.

In another representative embodiment, an implantable medical device comprises a radially expandable and compressible annular frame comprising a plurality of interconnected struts, the plurality of struts comprising a first set of a plurality of first struts and a second set of a plurality of second struts, wherein the first struts overlap adjacent second struts at junctions and expansion or compression of the annular frame causes the first struts to pivot relative to the second struts at the junctions. Each of the first struts can comprise a plurality of apertures spaced apart from each other along a length of the first strut, and each of the second struts can comprise a plurality of apertures spaced apart from each other along a length of the second strut. The device can further comprise a plurality of rivets, each rivet extending through an aperture of a first strut and an aperture of an adjacent second strut at a junction, and each rivet can further comprise a first flange positioned radially outside of a corresponding first strut and a second flange positioned radially inside of a corresponding second strut.

In some embodiments, each rivet comprises a third flange intermediate the first and second flanges and positioned radially between a first strut and a second strut at a junction.

In another representative embodiment, an implantable medical device comprises a radially expandable and compressible annular frame comprising a plurality of interconnected struts, the plurality of struts comprising a first set of a plurality of first struts and a second set of a plurality of second struts, wherein the first struts overlap adjacent second struts at junctions and expansion or compression of the annular frame causes the first struts to pivot relative to the second struts at the junctions, wherein the frame comprises a plurality of hinges at the junctions extending from the first struts through corresponding non-circular apertures of the second struts at the junctions.

In some embodiments, each hinge comprise a cylindrical pivot portion that can rotate in a corresponding aperture of a second strut and a locking member extending from the pivot portion, wherein the locking member is sized and shaped relative to the corresponding aperture of the second strut so as to prevent radial separation of the first and second struts whenever the locking member is rotationally offset from the corresponding aperture upon radial expansion and compression of the frame.

In some embodiments, the second struts are formed with recessed portions surrounding the non-circular apertures and the locking members of the hinges are disposed within the recessed portions.

In some embodiments, the implantable medical device further comprises one or more actuators mounted on the frame and configured to radially expand and compress the frame between a radially compressed state defining a compressed diameter and a radially expanded state defining an expanded diameter. In particular embodiments, each locking member is rotationally offset from corresponding non-circular apertures in the second struts at the compressed diameter, the expanded diameter, and all diameters in between the compressed and expanded diameters.

In some embodiments, the hinges are integrally formed on the first struts.

In some embodiments, the hinges are separate components from the first and second struts. Each of the first struts can comprise a plurality of non-circular apertures, and each hinge extends through an aperture in a first strut and an adjacent aperture in a second strut at a junction.

In some embodiments, each of the hinges further comprises a retaining member configured to be retained within the non-circular apertures on the first struts.

In some embodiments, each of the hinges further comprises a circular base member configured to be retained within a circular recess surrounding one of the non-circular apertures on the first struts.

In some embodiments, the locking members comprise a non-circular shape.

In some embodiments, the locking members comprise a non-circular central protrusion with at least two ears extending outward therefrom in a plane parallel to the strut.

In another representative embodiment, a method of assembling an implantable medical device comprises providing a plurality of first struts and providing a plurality of second struts, each second strut comprising a plurality of non-circular apertures spaced along a length thereof. The method can further comprise connecting the first and second struts to each other to form an annular frame by inserting hinges through the non-circular apertures of the second struts, each hinge having a cylindrical pivot portion disposed in a corresponding non-circular aperture and a locking member extending from one end of the pivot portion, wherein the locking members are rotationally aligned with corresponding non-circular apertures when the hinges are inserted into the non-circular apertures.

In some embodiments, the method can further comprise pivoting the first struts relative to the second struts to cause the locking members to become rotationally offset from their corresponding non-circular apertures, and mounting one or more actuators on the frame, the one or more actuators configured to radially expand and compress the frame within a predetermined range of diameters corresponding to a predetermined range of angles between the first and second struts at which the locking members are at all times rotationally offset from the non-circular apertures.

In some embodiments, each first strut comprises a plurality of non-circular apertures spaced along a length thereof, and connecting the first and second struts further comprises inserting the hinges through the non-circular apertures of the first struts and the second struts.

In some embodiments, the hinges are integral to the first struts.

In some embodiments, the first struts are interwoven with the second struts.

In another representative embodiment, an implantable medical device comprises a radially expandable and compressible annular frame comprising an inner frame sub-assembly and an outer frame sub-assembly. Each of the frame sub-assemblies can comprise a closed annular frame comprising plurality of interconnected struts. The plurality of struts of each frame sub-assembly can comprises a first set of a plurality of first struts and a second set of a plurality of second struts, wherein the first struts overlap adjacent and are rotatably connected to second struts at junctions, and expansion or compression of the annular frame causes the first struts to pivot relative to the second struts at the junctions.

In some embodiments, each of the first struts can comprise either a plurality of projections spaced apart from each other along a length of the first strut or a plurality of apertures spaced apart from each other along a length of the first strut, and each of the second struts can comprise a plurality of apertures and a plurality of projections spaced apart from each other along a length of the second strut. At each of the junctions, either a projection on a first strut may be inserted through an aperture of an adjacent second strut, or a projection on a second strut may be inserted through an aperture of an adjacent first strut to rotatably connect the first strut to the second strut.

In particular embodiments, each of the inner frame sub-assembly and the outer frame comprises at least three inner struts and three outer struts. In particular embodiments, the outer frame assembly comprises six inner struts and six outer struts.

In some embodiments, a prosthetic valve leaflet assembly is positioned within the inner-frame sub-assembly. In particular embodiments, the prosthetic valve leaflet assembly is positioned within and secured to the inner frame sub-assembly without being secured to the outer frame sub-assembly. In more particular embodiments, the prosthetic valve leaflet assembly is positioned so that the prosthetic valve leaflets are prevented from contacting the outer frame sub-assembly when they open during the cardiac cycle, while in other embodiments such contact is minimized.

In some embodiments, a skirt is positioned on the inner frame sub-assembly. In particular embodiments, the skirt is positioned between a first set of inner struts and a second set of outer struts of the inner frame sub-assembly. In another embodiment, the skirt is positioned on the outside of the inner-frame sub-assembly and disposed between the inner frame sub-assembly and the outer frame sub-assembly.

In some embodiments, one or more actuators are positioned on the frame, the one or more actuators being configured to radially expand and compress the frame. In particular embodiments, the actuators may be configured to expand and compress the frame within a predetermined range of diameters corresponding to a predetermined range of angles between the first and second struts.

In another representative embodiment, a method of assembling an implantable medical device comprises assembling an inner frame sub-assembly comprising a plurality of first struts and a plurality of second struts. The method can further comprise connecting the first and second struts to each other to form a first closed annular inner frame sub-assembly by connecting each of the plurality of first struts to at least two of the plurality of second struts. The method can further comprise assembling an outer frame sub-assembly comprising a plurality of third struts and a plurality of fourth struts. The method can further comprise connecting the third and fourth struts to each other to form a second closed annular outer frame sub-assembly by connecting each of the plurality of third struts to at least two of the plurality of fourth struts. The method can further comprise after assembling the inner frame sub-assembly and the outer frame sub-assembly, inserting the inner frame sub-assembly inside the outer frame sub-assembly and interconnecting the two sub-assemblies at a plurality of junctions along the struts forming a single, closed annular frame assembly.

In some embodiments, the method can further comprise assembling a leaflet assembly on the inner frame sub-assembly. In particular embodiments, the leaflet assembly is assembled on the inner frame sub-assembly without contacting the outer frame sub-assembly. In some embodiments, a skirt is positioned on the inner frame sub-assembly. In particular embodiments, the skirt is positioned between a first set of inner struts and a second set of outer struts of the inner frame sub-assembly. In another particular embodiment, the skirt is positioned on the outside of the inner-frame sub-assembly and disposed between the inner frame sub-assembly and the outer frame sub-assembly. In another particular embodiment, the skirt is positioned along with a leaflet assembly on the inside of the inner frame sub-assembly.

In some embodiments, the inner frame sub-assembly and the outer frame-sub-assembly are rotatably interconnected at junctions along the struts via a plurality of hinge members. The hinge members can comprises, for example, rivets, pins, integral projections, or similar mechanisms. In particular embodiments, the hinge members may pass through two or more of the inner frame sub-assembly, the skirt, and the outer frame sub-assembly. In particular embodiments, the rivets or other projections may pass through three or more of the prosthetic valve sub-assembly, inner frame sub-assembly, inner skirt, and outer frame sub-assembly. In particular embodiments an outer skirt may be attached to the outer frame sub-assembly.

DETAILED DESCRIPTION

Described herein are examples of prosthetic implant delivery assemblies and components thereof which can improve a physician's ability to control the size of a mechanically-expandable prosthetic implant, such as prosthetic valves (e.g., prosthetic heart valves or venous valves), stents, or grafts, as well as facilitate separation of the prosthetic implant from the delivery assembly, during the implantation procedure. The present disclosure also provides frames for use with such prosthetic implants. The frames can comprise struts shaped to reduce or eliminate pinching of the soft components of the prosthetic implant (e.g., leaflets of the implant) when the implant is radially compressed to a delivery configuration for delivery into a patient.

FIG. 1shows one example of a prosthetic implant delivery assembly10which may be used with one or more of the embodiments of the present disclosure. The delivery assembly10can include two main components: a prosthetic heart valve14and a delivery apparatus18. The prosthetic valve14can be releasably coupled to the delivery apparatus18, as further described below. It should be understood that the delivery apparatus18and other delivery apparatuses disclosed herein can be used to implant prosthetic devices other than prosthetic valves, such as stents or grafts.

FIG. 2is a side elevational view of the prosthetic valve14shown in its deployed, radially expanded configuration. While only one side of the prosthetic valve14is shown in the drawings, it should be appreciated that the opposite side is similar to the portion shown. The prosthetic valve14can include an annular stent or frame22, and a valve structure24which can be coupled to the frame22. The frame22can have an inflow end portion26, an intermediate portion28, and an outflow end portion30. The prosthetic valve14can define a longitudinal axis extending through the inflow end portion26and the outflow end portion30.

The frame22can be made of any of various suitable materials, such as stainless steel or a nickel titanium alloy (“NiTi”), for example Nitinol, or CoCr alloys, as well. The frame22can include a plurality of interconnected lattice struts32arranged in a lattice-type pattern and forming a plurality of apices34at the outflow end30of the prosthetic valve14. The struts32can also form similar apices at the inflow end of the prosthetic valve (which are covered by a skirt50inFIG. 2). The lattice struts32are shown as positioned diagonally, or offset at an angle relative to, and radially offset from, the longitudinal axis of the prosthetic valve. In other implementations, the lattice struts32can be offset by a different amount than depicted inFIG. 2, or some or all of the lattice struts32can be positioned parallel to the longitudinal axis of the prosthetic valve14. The lattice struts32can comprise a set of inner struts32a(extending from the upper left to the lower right of the frame inFIG. 2) and a set of outer struts32b(extending from the lower left to the upper right of the frame inFIG. 2) connected to the inner struts32a.

The lattice struts32can be pivotably coupled to one another. In the illustrated embodiment, for example, the end portions of the struts32forming the apices34at the outflow end30and at the inflow end26of the frame22can have a respective opening36. The struts32also can be formed with apertures38spaced apart along their lengths between the opposite ends of the struts. Respective hinges can be formed at the apices34and at the locations where struts32overlap each other between the ends of the frame via fasteners40, which can comprise individual rivets or pins that extend through the apertures36,38. The hinges can allow the struts32to pivot relative to one another as the frame22is expanded or contracted, such as during assembly, preparation, or implantation of the prosthetic valve14. For example, the frame22(and thus the prosthetic valve14) can manipulated into a radially compressed or contracted configuration (see, e.g.,FIGS. 6 and 7) and inserted into a patient for implantation. Once inside the body, the prosthetic valve14can be manipulated into an expanded state (e.g.,FIGS. 2 and 4) and then released from the delivery apparatus18(e.g.,FIG. 1), as further described below.

The frame22can be formed using any suitable technique. Suitable techniques include separately forming individual components (e.g., the struts32and fasteners40) of the frame and then mechanically assembling and connecting the individual components to form the frame22. The struts and fasteners can be formed, for example, by laser cutting those components from sheets or tubes of metal, or by electroforming (electroplating or electrodeposition) or physical vapor deposition, or by electro chemical machining and/or chemical etching.

In some embodiments, electroforming or physical vapor deposition can be used to form subcomponents of the frame22or the entire frame22with pivotable connections between the struts. In one implementation, for example, electroforming or physical vapor deposition can be used to form struts32having integral fasteners40. The individual struts can be assembled together into a frame by inserting the integral fasteners40of each strut through a corresponding aperture of an adjacent strut. In some embodiments, electroforming or physical vapor deposition can be used to form the entire frame in its final, cylindrical, or tubular shape. While in the illustrated embodiments, the frame22is shown as generally cylindrical in shape, other frame shapes may be used, such as, e.g., conical, hour-glass or barrel shaped. In other embodiments, electroforming or physical vapor deposition can be used to form the entire frame in a flattened configuration, after which the ends of the flattened frame are connected to each other to form the final tubular shape of the frame. Frames formed from struts having integral fasteners are further described in detail below.

In other embodiments, the lattice struts32are not coupled to each other with respective hinges (e.g., fasteners40) but are otherwise pivotable or bendable relative to each other to permit radial expansion and contraction of the frame. For example, the frame22can be formed (e.g., via laser cutting, electroforming or physical vapor deposition) from a single piece of material (e.g., a metal tube).

In addition to the lattice struts32, the frame22can include one or more longitudinally extending support struts42. The support struts42can be circumferentially spaced about the frame22and coupled, including being pivotably coupled, to the lattice struts32. The support struts42can be positioned parallel to, and radially spaced apart from, the longitudinal axis of the prosthetic valve. The support struts42can enhance the rigidity to the frame22and help the frame22maintain a uniform shape as it is expanded or contracted. In some implementations, the frame22does not include the support struts42. The support struts42can be connected to the lattice struts32at the hinge joints formed by fasteners40that can extend through respective apertures in the lattice struts and the support struts.

With reference toFIGS. 3A and 3B, a spacer46, such as a washer or bushing, can be disposed in a joint between lattice struts32, or a joint between lattice struts32and support struts42(not shown). When the lattice struts32and/or support struts42are pivotably coupled to one another, the spacers46can assist the lattice struts32, or lattice struts32and support struts42, in moving relative to one another. The spacer46can also act to space the lattice struts32from one another, or from the support struts42. In some implementations, the frame22does not include the spacers46, or the lattice struts32, or lattice struts32and support struts42, are spaced apart in a different manner.

In particular embodiments, the fasteners40do not extend radially outwardly from their respective apertures36,38in the struts and can be contained completely within the apertures. As shown inFIG. 3B, for example, each of the apertures36on the radially outermost struts32can include a counter-bore or enlarged recessed portion37that is sized to receive the head portion41of a respective fastener40(e.g., a rivet). The head portion41can be received entirely within the counter-bore37and does not extend radially outwardly from the counter-bore, for example, the head portion41can be flush with the outer surface of the strut32. Similarly, the apertures38also can be formed with counter-bores to receive the head portions41of the fasteners. In this manner, the fasteners40do not increase or contribute to the overall crimp profile of the prosthetic valve and do not interfere with or place undue stresses on the delivery sheath of the valve (e.g., sheath82inFIG. 1).

Returning toFIG. 2, the prosthetic valve14can include a valvular structure24to regulate the flow of blood through the prosthetic valve. The valvular structure24can comprise, for example, a leaflet assembly48comprising one or more leaflets made of a flexible material. The leaflets can be configured to move between an open position allowing the flow of blood through the valve in a first direction and a closed position blocking the flow of blood through the prosthetic valve in a second direction, opposite the first direction. The leaflets of the leaflet assembly48can be made from in whole or part, biological material (e.g., pericardial tissue, such as bovine or equine pericardium), bio-compatible synthetic materials, or other such materials, such as those described in U.S. Pat. No. 6,730,118, which is incorporated herein by reference.

The prosthetic valve can also include an annular skirt or sealing member50that can be secured to the outer surface of the inflow end portion26of the frame22, for example, with sutures56adjacent the inflow end portion26of the frame22. The inflow end portion of the leaflet assembly48can be secured to the frame22and/or the skirt50, for example using sutures56. The skirt50helps establish a seal with the native tissue at the implantation site to prevent or minimize paravalvular leakage. In alternative embodiments, the prosthetic valve can have a skirt or sealing member mounted on the inside of the frame or a skirt or sealing member mounted on the inside and outside of the frame. The skirt can be formed from natural tissue (e.g., pericardial tissue) or any of various biocompatible synthetic materials, including biocompatible fabrics (e.g., polyethylene terephthalate (PET) fabric).

Further details regarding transcatheter prosthetic heart valves, including the manner in which the valve structure24can be coupled to the frame22of the prosthetic valve14, can be found, for example, in U.S. Pat. Nos. 6,730,118, 7,393,360, 7,510,575, 7,993,394, and 8,652,202, which are incorporated herein by reference in their entireties.

FIG. 4is a side elevational view of a portion of a frame200that can be used with a prosthetic valve in at least certain embodiments of the present disclosure. While only one side of the frame200is depicted inFIG. 4, it should be appreciated that the frame200forms an annular structure having an opposite side that is identical to the portion shown. The frame200is similar to the frame22discussed above but does not include the longitudinal struts42.

The frame200can include a plurality of lattice struts204, including a set of inner struts204aand a set of outer struts204pivotably connected to the inner struts204a. Each of the lattice struts204can include a plurality of apertures208. The apertures208can be used to connect the lattice struts204to one another using fasteners210, such as described above for the lattice struts32(FIG. 2). In other implementations, the apertures208and fasteners210can be omitted. For example, the lattice struts204can be fixedly connected to one another, such as by welding or adhesion, or by laser-cutting the individual struts of the frame from a metal tube. Although not shown inFIG. 4, a spacer may be included between the lattice struts204, such as intermediate the portions of the lattice struts204having the apertures208. In a particular example, the spacers can be configured as described above for the spacer46. Similarly, if desired, the frame200can include support struts (not shown) that can be analogous to the support struts42(FIG. 2).

As best shown in the flattened view of the strut inFIG. 5, in one design that may be used with certain embodiments of this disclosure, each lattice strut204can have an offset, or zig-zag, pattern defined by a plurality of offset linear portions or segments218. The linear segments218in the illustrated embodiment are arranged end-to-end relative to each other with adjacent ends interconnected to each other by intermediate segments220. The strut204can have enlarged end portions224that form the apices at the inflow and outflow end of the frame. Each linear segment218is slightly laterally offset from an adjacent linear segment218in a direction perpendicular to the overall length of the strut204to provide the zig-zag pattern to the strut. Each of the intermediate segments220and end portions224can have a respective aperture208at its geometric center for receiving a fastener210.

The amount of offset of each linear segment218relative to an adjacent linear segment along the length of the strut204can be constant such that an imaginary line214can pass through the aperture208of each intermediate segment220along the entire length of the strut. In alternative embodiments, the amount of offset between two adjacent linear segments218can vary along the length of the strut. For example, the amount of offset between linear segments218adjacent the outflow end of the frame can be greater than the amount of offset between linear segments218adjacent the inflow end of the frame, or vice versa.

The linear segments218can include at least substantially flat or linear opposing longitudinal edges226a,226bextending between curved or rounded edges228of the intermediate segments220. In alternative embodiments, the opposing edges228of the intermediate segments220can be substantially flat or linear edges that extend at an angle between respective ends of the edges226a,226bof the liner segments218.

As best shown inFIG. 5, the width W1of each liner segment218is defined as the distance measured between the opposing edges226a,226bof a segment218. In the illustrated embodiment, the width W1is constant along the length of the strut204. As such, each longitudinal edge226ais laterally offset from an adjacent longitudinal edge226aof an adjacent linear segment218, and each longitudinal edge226bis laterally offset from an adjacent longitudinal edge226bof an adjacent linear segment218. The width W2of each intermediate segment220and end portion224can be greater than the width W1of the linear segments218.

In alternative embodiments, the width W1of each linear segment218can vary along the length of a strut. For example, the width W1of a linear segment218adjacent the inflow end of the frame can be greater than the width W1of a linear segment218adjacent the outflow end of the frame, or vice versa. Further, where the width W1of the linear segments218vary along the length of a strut204, a linear segment can have one longitudinal edge226aor226bthat is collinear with a longitudinal edge of an adjacent linear segment on the same side of the strut, while the other longitudinal edge226a,226bis laterally offset from the longitudinal edge of an adjacent linear strut on the same side of the strut. In other words, the strut204can have an overall zig-zag or offset pattern by virtue of the varying widths W1of the linear segments.

The offset, or zig-zag, pattern of the strut segments218can help space apart the struts204in the circumferential direction when the frame200is in a radially compressed state, as shown inFIGS. 6 and 7. As shown, the open lattice structure of the frame200defining open cells250between the struts204can be preserved even when the frame200is fully compressed or contracted. For example, with reference toFIG. 6, although the width of the cells250along the length of the frame200can vary between adjacent struts, a gap256remains at the middle of a cell250between two adjacent pivot joints254.

When the frame200is incorporated in a prosthetic valve (e.g., the prosthetic valve14), the spaced-apart nature of the struts204, including the gaps256, can assist in protecting the soft components of the prosthetic valve as the frame200is expanded and contracted.FIG. 7, for example, shows a prosthetic valve comprising the frame200, a skirt266mounted on the outside of the frame200and a leaflet assembly264mounted inside of the frame200. An inner skirt (not shown) also can be mounted inside of the frame. The skirt266and leaflet assembly264can be coupled to the frame200, such as with sutures270. The sutures270can extend through the material of the skirt266and/or the leaflet assembly264and radially about the struts204. The gaps256created by the offset configuration of the struts204can protect the leaflets264, the skirt266, and/or the sutures270from being pinched or sheared between adjacent struts204when the prosthetic valve is radially compressed. In this manner, the soft components of the prosthetic valve are protected against damage that can occur from contact with the metal struts of the frame.

The delivery apparatus18ofFIG. 1is particularly suited for implanting the prosthetic valve14or any of the other prosthetic valves disclosed herein. However, it should be noted that any of the prosthetic valves disclosed herein can be implanted using other suitable delivery apparatuses. For example, any of the prosthetic valves disclosed herein can be crimped over an inflatable balloon of a conventional balloon catheter. Once delivered to the implantation site, the balloon can be inflated to expand the prosthetic valve to its fully functional size.

Referring again toFIG. 1, the delivery apparatus18can include a handle70, an elongate shaft72extending distally from the handle70, a plurality of first actuation members76(also referred to as elongate positioning members), such as in the form of positioning tubes, extending through the shaft and distally outwardly from a distal end78of the shaft72, a plurality of release members106(FIG. 9) extending through respective positioning members76, and a plurality of second actuation members86(also referred to as “tethers”) extending through respective release members106. The positioning members76can be at least partially disposed radially within, and extend axially through, one or more lumens of the shaft72. For example, the positioning members76can extend through a central lumen of the shaft72or through separate respective lumens formed in the shaft72.

The shaft72can have a distal end portion82that can function as a sheath for containing or housing the prosthetic valve14in a radially compressed state for delivery through a patient's vasculature. In this regard, the distal end portion82can have a lumen that is sized to receive the prosthetic valve14in a radially compressed state. As shown inFIG. 12, the proximal end portion of the shaft72can extend into an axially extending bore138formed in the distal end portion of the handle70. The proximal end portion of the shaft72can be retained within the axial bore138through pressure or frictional contact with the bore138, using an adhesive, a clamp, a fastener, by thermally bonding the catheter72to the bore138, or by some other technique or mechanism.

The positioning members76have distal end portions that can be releasably connected to the prosthetic valve14via respective release-and-locking units94(as best shown inFIG. 8). As shown inFIG. 12, the positioning members76can extend through the shaft72, and proximally beyond a proximal end140of the shaft, and into a central bore142of the handle70. A lead screw144can be disposed within the central bore142of the handle70. The proximal ends of the positioning members76can be secured to the lead screw144, such as being received within a bore (not shown) of the lead screw144, where they can be secured by pressure or frictional contact with the bore of the lead screw144, using an adhesive, a clamp, a fastener, thermal bonding, or another suitable technique or mechanism.

As shown inFIGS. 8 and 9, each actuation member86can extend through a lumen of a respective positioning member76. The actuation members86can be coupled at their distal end portions to the distal end60of the frame22. For example, the distal end portion of each actuation member86can be connected to an apex34at the distal end60of the frame, such as by welding, an adhesive, or a mechanical fastener. Each actuation member86can also extend through a lumen of a respective locking unit94that can be coupled to the frame22, such as to an apex34at a proximal end62of the frame. The actuation members86can extend proximally into and through the handle70. Proximal end portions88of the actuation members86can be releasably retained by a clamping member182mounted in or on the handle70(FIG. 12).

The actuation members86function to apply a proximally directed pulling force to the distal end60of the frame in cooperation with the positioning members76that apply a distally directed pushing force to the proximal end62of the frame to effect radially expansion of the frame22. In particular embodiments, the actuation members86can comprise a relatively flexible but relatively non-elastic material that can effectively transfer pulling forces generated at the handle70to the distal end of the frame22. For example, the actuation members86can comprise wires, sutures, strings, or similar materials. In other embodiments, the actuation members86can be relatively stiffer component, such as shaft or rod, that can transfer proximally directed pulling forces to the frame as well as distally directed pushing forces to the frame.

The release members106have distal end portions107that extend coaxially through respective locking units94(FIG. 9) and proximal end portions108that extend into the handle70(FIG. 12). The proximal end portions108of the release members106can extend through the lead screw144and can be secured to a release knob168within the handle70.

Referring toFIGS. 1 and 12, a threaded actuator nut148can be disposed about the lead screw144. Internal threads (not shown) of the threaded actuator nut148can engage threads150of the lead screw144. An outer surface152of the threaded actuator nut148can extend through an aperture or window154formed in the outer surface156of the handle70. The outer surface152of the threaded actuator nut148can include a texture, such as ridges158, to aid a user in grasping and rotating the threaded actuator nut148.

Rotation of the threaded actuator nut148in a first direction can cause the lead screw144to translate axially in the distal direction relative to the handle70, thereby causing the positioning members76to translate distally through the lumen of the shaft72. Rotation of the threaded actuator nut148in the opposite direction can cause the lead screw144to translate proximally relative to the handle, thereby causing the positioning members72to retract or translate proximally through the lumen of the shaft72.

In particular implementations, the number and spacing of the threads150of the lead screw144(and thus the mating threads of the threaded actuator nut148), and the axial length of the lead screw144, can be selected to provide a desired degree of travel for the positioning members76and the release members106. For example, the desired degree of travel can be sufficient to allow the frame22(and thus the prosthetic valve14) to be manipulated between a fully expanded state (such as shown inFIGS. 2 and 8) and a fully contracted or compressed state (such as shown inFIGS. 6 and 7), including states in between being fully compressed or contracted and fully expanded, as further described below.

The release-and-locking units94(also referred to as “locking units”) in the illustrated embodiment are configured to releasably connect the positioning members76to the frame22of the prosthetic valve14and to selectively secure the actuation members86to retain the prosthetic valve14in a deployed and expanded state. With reference toFIGS. 8-11, the locking units94can comprise a generally cylindrical body96, which can be secured to the frame22of the prosthetic valve14by a fastener130(e.g., a pin or rivet). The fastener130can extend through an aperture132(FIG. 11) formed in the body96and through one or more corresponding apertures36in the frame struts32forming the apices34of the frame (FIG. 8).

The body94can comprise a locking feature, such as in the form of a clamp98, disposed adjacent a distal end100of the locking unit94for selectively engaging an actuation member86. The clamp98can comprise, for example, a pair of diametrically opposed jaws102that are biased radially inwardly toward each other (as best shown inFIG. 11). A release member106can be disposed within a lumen of each locking unit94to retain the jaws102of the clamp in a non-engaged or non-locking state during delivery of the prosthetic valve14(FIG. 9). Each release member106can extend proximally through a respective positioning member76to the handle70. As discussed above, the proximal end portions108of the release members can be secured to a release knob168in the handle (FIG. 12). Each actuation member86can extend proximally through a lumen of a respective release member106into the handle70.

In particular implementations, the release members106can be made from any suitable biocompatible metallic material or a polymeric material. In at least some examples, the material can be selected to allow the release members106to be easily moveable relative to the jaws102during valve deployment, as further described below. For example, the release members106can be made from a lubricious or low friction material (e.g., PTFE) or can have an outer layer made from a lubricious or low friction material (e.g., PTFE).

When the release members106are disposed within the locking units94extending between the jaws102, the jaws102are held in an unlocked state and are prevented from contacting the actuation members86. In the unlocked state, the actuation members86and the positioning members76can move freely in the axial direction with respect to one another to control radial expansion and compression of the prosthetic valve14. When the prosthetic valve14is to be released from the delivery apparatus18, the release members106can be retracted proximally relative to the locking units94and the positioning members76. As shown inFIGS. 10A and 11, once the release members106are removed from engagement with the jaws102, the jaws102can move to a locked or engaged state engaging the actuation members86, thus securing the actuation members86from further axial movement, thus retaining the frame22of the prosthetic valve14in a desired expanded state.

Referring back toFIGS. 10A and 10B, the locking units94can be releasably coupled to the positioning members76by the release members106. In the illustrated embodiment, for example, a distal end portion110of each positioning member76can include a coupling portion112that can include a tab114and a notch116. Each locking unit94can include a corresponding notch120configured to receive the tab114of the positioning member76. Similarly, each locking unit94can include a tab122to be inserted into, and received by, the notch116of a respective positioning member76. The tabs114,122and notches120,116, along with the release member106, collectively can form a releasable, interlocking joint. The engagement of the tabs114,122with the notches120,116prevent axial separation of the positioning member76from the locking unit94, while the release member106, which extends through the tabs114,122in the locked state, prevents lateral separation of the positioning member76from the locking unit94.

As shown inFIG. 10B, the tab114of the positioning member76can include an axially extending slot128. The slot128can be sized to allow the tab114to be placed around the actuation member86or removed from the actuation member86by passing the actuation through the slot128. However, the slot128desirably is narrower than the diameter of the release member106to prevent lateral separation of the positioning member76from the locking unit94when the release member106is in a position extending through the tabs114,122as depicted inFIG. 9. As noted above, retraction of the release member106from the jaws102of the clamp98allows the jaws to engage the actuation member86. Further retraction of the release member106until the distal end of the release member106is proximal to the tab122and the notch116allows the distal end portion110of the positioning member76to be separated from the locking unit94in a lateral direction (in a direction perpendicular to the length of the locking unit and the positioning member), as depicted inFIG. 10A. As the positioning member76moves in a lateral direction away from the locking unit94, the actuation member86can pass through the slot128in the tab114.

As further shown inFIG. 10A, the tabs114,122can be formed with respective inclined cam surfaces124,126, respectively, to facilitate the separation of the positioning member76from the locking unit94. Each cam surface124,126is inclined relative to the longitudinal axis of the positioning member76at angle less than 90 degrees. As such, applying a proximally directed force to the positioning member76in the direction of arrow134(such as by applying a pulling force to the positioning member at handle70) causes the positioning member76to slide laterally away from the locking unit94in the direction of arrow136.

The locking units94and/or the positioning members76can include a cutting mechanism to cut the portions of the actuation members86that extends proximally beyond the jaws102of the clamps98after the prosthetic valve is expanded and the release members are retracting to actuate the clamps. For example, a blade, or other cutting surface, can be placed across the slot128, such that the actuation members86can be severed when they pass through the slot128during lateral separation of the positioning member76away from the locking unit94.

In another example, the locking units94can include a clamping member that can include cutting jaws (such as sharpened or serrated jaws) positioning proximal to the jaws102. The cutting jaws, like the jaws102, can be retained in an open position away from the actuation member by the release member106. When the release member106is retracted out of engagement with the cutting jaws, the cutting jaws can deflect radially inwardly against the actuation member86, thereby severing it at that location. In further examples, a separate cutting device can be used to sever the actuation members86at a desired location after the positioning members76are released from the prosthetic valve14, and optionally, after the delivery apparatus18is removed from the body.

Referring again toFIGS. 1 and 12, the lead screw144includes an extension portion160that extends proximally from the threaded portion of the lead screw. The extension portion160can comprise two leg portions162defining a U-shaped aperture or slot164between the leg portions162. The release knob168can comprise a slidable member170disposed between the leg portions162and a user-engageable portion172extending radially outwardly from the slidable member170. The proximal end portions108of the release members106can be fixedly secured to the slidable member170, such as with a suitable adhesive, such that axial movement of the slidable member170in the distal and proximal directions causes corresponding movement of the release members.

The release knob168can be configured to be movable with, and also independently of, the lead screw144. As noted above, axial movement of the lead screw144causes corresponding movement of the positioning members76. Thus, when the release knob168is retained relative to the extension portion160of the lead screw144, axial movement of the lead screw144causes the release knob168and the release members106to move with the positioning members76, such as during deployment and expansion of the prosthetic valve. When the release knob168is not retained relative to the extension portion160of the lead screw144, the release knob168can be translated axially relative to the extension portion, thereby effecting axial movement of the release members106relative to the positioning members76to actuate the clamping mechanism98of the locking unit94and release the positioning members76from the frame22of the prosthetic valve.

Various mechanisms can be used to selectively and releasably retain the release knob168axially relative to the extension portion160of the lead screw144. For example, a moveable pin or similar mechanism can be inserted through the slidable member170and one or both leg portions162of the extension portion160to retain the axial position of the slidable member170relative to the lead screw144. Removing the pin from the slidable member170and/or the leg portions162allows axial movement of the release knob168relative to the lead screw.

In another embodiment, the slidable member170can be configured to move between a first position where it is frictionally engaged by the extension portion160and a second position where the slidable member170is no longer frictionally engaged by the extension portion160. In the first position, the axial movement of the lead screw144causes corresponding movement of the release knob168. In the second position, the release knob168can be moved axially independently of the lead screw144in the distal and proximal directions.

The actuation members86can extend proximally beyond the proximal end portions108of the release members106and through an axially extending bore or opening178formed in the proximal end portion180of the handle70. The actuation members86can be selectively secured relative to the handle70using a clamping, or retaining, mechanism182. The retaining mechanism182can comprise a plug member184, a screw member186connected at one end of the plug member184, and knob188connected to the opposite end of the screw member186. The plug member184can be positioned in a radially bore184formed in the proximal end portion180of the handle70. The plug member184can include a triangular or trapezoidal lower surface that can be placed in, and removed from, contact with a corresponding shaped surface192of the radial bore190. In other implementations, the plug member184can have a different shape. The screw member186extends through a captured nut194such that rotation of the knob188causes the plug member184to move toward or away from the surface192of the radial bore190.

When the knob188is fully tightened (such as by rotating the knob188in a first direction), the lower surface of the plug member184can clamp the actuation members86against the surface192, thereby securing the actuation members86against movement relative to the handle70, the shaft72, the locking units94, and the frame22of the prosthetic valve. When the knob190is rotated in the opposite direction, the plug member184can move away from the surface192and the actuation members86, allowing the actuation members to move relative to the handle70, the shaft72, the locking units94, and the frame22of the prosthetic valve.

To use the delivery apparatus18to delivery and implant the prosthetic valve14at a desired location within the heart (e.g., the native aortic valve), the prosthetic valve14is connected to the positioning members76using the locking units94and the release members106, as shown inFIGS. 8 and 9. The release knob168is retained relative to the lead screw144to prevent relative movement between the positioning members76and the release members106. The prosthetic valve14can then be radially compressed or crimped to a compressed state, as shown inFIG. 7. The compressed prosthetic valve14can be loaded into the sheath82of the shaft72.

Conventional techniques and devices can be used to insert and advance the delivery apparatus18and the prosthetic valve14through a patient's vasculature to the desired implantation site. For example, a prosthetic aortic valve can be delivered in a retrograde approach by advancing the delivery apparatus through a femoral artery and the aorta to the native aortic valve. At or adjacent the implantation site, the prosthetic valve14can be deployed from the sheath82by rotating the actuator nut148in a direction to cause the lead screw144to move distally relative to the handle70. This causes the positioning members76and the release members106to move distally relative to the shaft72. The positioning members76push the prosthetic valve14distally relative to the shaft72. The actuator nut148can be rotated until the prosthetic valve is deployed from the distal end of the sheath82. In some implementations, the inherent resiliently of the frame22may cause the prosthetic valve to at least partially expand when advanced from the sheath82.

As the prosthetic valve14is deployed from the sheath82, the retaining mechanism182can be in a release position allowing the actuation members86to move distally with the prosthetic valve. In this manner, the actuation members86do not apply any expansion forces to the prosthetic valve as it is being deployed from the sheath. To apply an expansion force to the prosthetic valve, the retaining mechanism182is tightened to retain the actuation members86relative to the handle70. Continued rotation of the actuator nut148causes the positioning members to continue to apply a distally directed force on the proximal end of the frame22while the actuation members86(which are now restrained by the retaining mechanism182) become taught and apply a proximally directed force on the distal end of the frame22. The application of these forces causes the frame22to foreshorten axially and expand radially.

In some embodiments, the retaining mechanism182can be kept in the locked or engaged position against the actuation members86during valve deployment so long as the actuation members are long enough and contain enough slack to avoid applying any expansion force on the prosthetic valve as it is advanced from the sheath82. For example, the lengths of the actuation members86can be selected to avoid applying any expansion force on the prosthetic valve as it is advanced from the sheath82and after the prosthetic valve is fully deployed from the sheath, the actuation members86become taught and begin to apply an expansion force on the frame opposite the expansion force of the positioning members76to expand the prosthetic valve.

If re-positioning or complete withdrawal of the prosthetic valve from the body is required, the user can rotate the actuator nut148in the opposite direction, which causes the positioning members76to pull the prosthetic valve back into the sheath82. The action of the distal end portions110of the positioning members76being retracted into the sheath82causes the prosthetic valve to compress radially. If desired or needed, the prosthetic valve can be partially compressed without being retracted into the sheath and then re-positioned and re-expanded by rotating the actuator nut148. In some cases, the prosthetic valve can be completely retracted back into the sheath82for re-positioning or complete withdrawal of the prosthetic valve from the body.

Once the prosthetic valve is expanded and positioned at the desired location, the release members106can be retracted from the locking units94. This can be accomplished by releasing the release knob168from the lead screw144and retracting the release knob168proximally, which causes the release members106to retract relative to the locking units94. When the distal ends of the release members106are proximal to the jaws102of the clamping mechanism98, the jaws can engage the actuation members86to retain the prosthetic valve in the expanded state. Further retraction of the release members106past the tabs122of the locking units94allows the positioning members76to be released from the locking units. Retraction of the positioning members76by rotation of the actuator nut148or retracting the handle70causes the distal end portions110of the positioning members to pull free of the locking units94. As discussed above, the portions of the actuation members86proximal to the clamping mechanisms98can be severed and removed from the body. Thereafter, the delivery apparatus can be withdrawn from the body.

The frame designs discussed above in connection withFIGS. 2 and 4include a set of inner struts and a set of outer struts pivotably connected to inner struts by rivets or equivalent fasteners (e.g., inner and outer struts204a,204b, respectively, ofFIG. 4). This may require anywhere from 10 to 50 additional small parts that are secured to the frame by welding or plastic deformation. Individual rivets, for example, may be less than a millimeter (e.g., 0.8 mm) in length and less than a millimeter (e.g., 0.8 mm) in diameter. As can be appreciated, the assembly process for assembling the frame can be time-consuming and can add significant cost to the manufacturing process. And, these additional elements can increase the overall crimp profile of the frame, as well.

Additionally, the outer struts typically are slightly longer than the inner struts to account for the fact that the outer struts are positioned radially outward of the inner struts and have a greater radius of curvature than the inner struts. As such, full pivoting movement between the inner and outer struts may be inhibited when the frame foreshortens upon radial expansion due to the different lengths of the inner and outer struts. To accommodate the different lengths of the inner and outer struts and allow for full movement of the struts, the apertures at the junctions of the inner and outer struts (e.g., apertures208) that receive rivets or other connectors can be slightly elongated and/or enlarged, although this can present challenges for manufacturing and reliability. Additionally, such designs may introduce additional loads such as twisting and bending moments that act on the hinges between the struts.

As shown inFIG. 13, a frame300for a prosthetic heart valve, according to another embodiment, comprises a first set of struts and a second set of struts. The first set of struts comprises a plurality of first struts310(shown in the figure as extending from the lower left to the upper right). The second set of struts comprises a plurality of second struts320(shown in the figure as extending from the upper left to the lower right) interwoven with the first struts310in such a manner that each strut passes over and under struts of the other set. Since in this embodiment, there are no “inner struts” and “outer struts,” but rather two sets of interwoven struts, the struts of both may be of the same length. In some embodiments, then, the same basic part may be used for all struts; in other words, all struts may have of the same size and shape. In some other embodiments, structurally similar struts with differences in manufacturing only in and around the areas of potential junctions with other struts may be used.

Also, in embodiments where the first struts310and the second struts320are of the same length, the frame may reduce or eliminate any “mismatch” in foreshortening (i.e., all struts can foreshorten the same amount and permit full movement of struts during radial expansion) without the need to enlarge or elongate the apertures340at the junctions of the struts.

In some embodiments, the frame300can include separate fasteners (e.g., fasteners40) that extend through respective apertures340at the junctions315,325of the struts. Advantageously, interweaving the struts310and320can reduce the number of hinge connections at the junctions315,325between the struts. For example, in some embodiments, the frame can include fasteners (e.g., fasteners40) only at the junctions325that define the apices at the inflow and outflow ends of the frames. The junctions315located axially between the junctions325at inflow and outflow ends of the frame can be without any fasteners interconnecting a pair of overlapping struts. Instead, due to interweaving of the struts and the inherent elasticity of the struts, the struts can be placed in tension, thereby urging first and second struts together at each junction. The tension imparted on the struts at junctions315, along with the mechanical connections at junctions325, can be sufficient to hold the assembly of struts together.

In alternative embodiments, the frame300can include fasteners at selected junctions315to reinforce the connection between the struts310,320, depending on the overall size and shape of the frame. For example, in one implementation, the frame300can include fasteners only at the junctions315at the middle of the frame (i.e., the junctions315that intersect a plane bisecting the frame halfway between inflow and outflow ends of the frame). For purposes of illustration, each strut310,320is shown having an aperture at each junction325with an overlapping strut. However, in the embodiments described above where there are no fasteners at selected junctions315, the struts310,320need not be formed with any apertures340at the selected junctions. As can be appreciated, reducing the number of fasteners needed to assemble the frame can greatly reduce manufacturing costs.

In other embodiments, rather than employing separately formed fasteners (e.g., rivets) that typically are manually inserted into the apertures at each junction to form a hinge, the frame300can have integral fasteners at strut junctions315, for example as shown in the embodiments inFIGS. 14A-18, as discussed further herein.

FIGS. 14A and 14Billustrate one embodiment frame400for a prosthetic heart valve, wherein the frame has integral fasteners for forming hinges between overlapping struts. In this embodiment, the frame400comprises a first set of struts410interwoven with a second set of struts420. For example, a first strut410aof the first set of struts410can be interwoven with at least a second strut420a, a third strut420band a fourth strut420cof the second set of struts420.

Each first strut410can include a plurality of integral protrusions or projections414spaced apart from each other along the length of the strut. Each second strut420can include a plurality of openings or apertures430spaced apart from each other along the length of the strut, with each aperture receiving a respective projection414to form a hinge between two overlapping first and second struts. As shown, the projections414extend alternately from one side of the strut410and from the other side of the strut from one projection to the next to allow each projection414to extend into a corresponding aperture430of an overlapping strut420in the weave.

As used herein, the terms “integral” or “integrally formed” or “unitary construction” refers to a construction of a component that does not include any seams between different parts of the component. Further, the term “integral” or “integrally formed” or “unitary construction” refer to a construction that does not include any welds, fasteners, adhesives or other means for securing separately formed pieces of material to each other. Thus, an integral projection414(or other feature of a strut) is formed directly on the strut rather than being separately formed and subsequently attached to the strut.

As shown inFIG. 14B, the first strut410can be elastically deformed from weaving the first strut through successive second struts420a,420b,420c. Due to the elasticity of the struts, the struts are placed in tension, urging the first strut against each second strut at each junction (illustrated by force lines432), which helps retain each projection414within an aperture430. In some embodiment, the struts can initially be straight and then can be elastically bent as they are woven together. In other embodiments, first and/or second struts may be pre-formed with curves or bends (such as by heat setting a shape memory material) at the locations of the junctions to facilitate assembly of the frame. The struts can be formed from, for example, super-elastic materials (Nitinol) or non-super-elastic materials (e.g., stainless steel or cobalt chromium alloys), although super-elastic materials are desirable in certain embodiments to maximize the elastic retention forces432at the junctions of the struts.

In the illustrated embodiment, the struts410,420of the frame400are arranged in a basic, or plain weave pattern, where each first strut410extends over then under each successive second strut420. In alternative embodiments, the struts410,420can be arranged in various other weave patterns. The placement of the projections414can be modified from the configuration shown inFIG. 14Bto correspond with the locations of the junctions formed by the particular weave pattern of the struts.

The struts410,420can be manufactured using any of various suitable techniques, as previously described herein. In some embodiments, the struts can, for example, be laser cut from a tube, or laser cut or punched from a flat sheet of metal. Optionally, the struts can undergo an additional rolling process to shape the struts into their final shape prior to assembly. In some embodiments, the struts can be formed with a plurality of spaced apart tab portions that are plastically bent or heat set to form the plurality of projections.

FIGS. 15A and 15Billustrate an alternative embodiment pair of first and second struts500and550, respectively, which can be used to form a frame from a plurality of the first struts500and a plurality of the second struts550. In particular embodiments, each strut500,550can be formed (e.g., laser cut) from a flat sheet of material (e.g., a flat sheet of metal) to form a strut having a radius of curvature that defines the outer curved surface of a frame with other similar struts that are assembled together to form the frame.

FIGS. 15A and 15Bshow the struts as viewed from an axial end of the frame. Thus, the strut500has a radially inwardly facing inner surface502that forms part of the inner surface of the frame and a radially outwardly facing surface504that forms part of the outer surface of the frame. The strut500has a radial thickness T1defined between the surfaces502,504. The strut500also has longitudinally extending, axially facing side surfaces506,508(see alsoFIG. 16A) defining a width W1equal to the thickness of the sheet of material from which the strut is formed.

Similarly, the strut550has a radially inwardly facing inner surface552that forms part of the inner surface of the frame and a radially outwardly facing surface554that forms part of the outer surface of the frame. The strut550has a radial thickness T2defined between the surfaces552,554. The strut550also has longitudinally extending, axially facing side surfaces556,558(see alsoFIG. 16A), which as best shown in the side view ofFIG. 15Cdefine a width W2equal to the thickness of the sheet of material from which the strut is formed.

The struts500,550can be formed with integral features that mate with corresponding features of an overlapping strut to form hinges at the junctions of two struts. In particular, the strut500can be formed with integral projections510at opposite ends of the strut and integral projections520spaced apart along the length of the strut between the end projections510. The strut550can be formed with a plurality of apertures560spaced apart along the length of the strut at locations corresponding to the locations of the projections510,520, as best shown inFIGS. 15B and 15C. Each projection510,520can be received in a corresponding aperture560of an overlapping strut to form a hinge at a junction of two struts500,550. As shown inFIG. 15A, the projections510,520in the illustrated embodiment alternatively extend along the inner surface502and the outer surface504. Thus, some of the projections extend radially inward from a surface502,504and some projections extend radially outward from a surface502,504. In this manner, each first strut500can be interwoven with a plurality of second struts550, similar to struts310,320ofFIG. 13.

A strut500,550having integral features for forming the hinges interconnecting two struts can be formed using any of various suitable techniques, including, without limitation, laser cutting, stamping, machining, electro-etching, electro-forming, three-dimensional printing, or the like. For example, the integral projection510,520can be formed directly on the strut500by forming the entire shape shown inFIG. 15Afrom a single piece of material.

Each projection510at an opposite end of the strut500forms an apex of a frame when inserted into a corresponding aperture560of a strut550. As further shown inFIG. 15A, the projections510can be configured to form a snap-fit connection or engagement with corresponding apertures560. For example, in the illustrated embodiment, each projection510comprises a split projection having a first portion512aand second portion512bseparated by a gap. Each of the first and second portions512a,512bcan have a relatively narrow base514at the inner surface502and tapered, relatively wider end portion516spaced from the inner surface502. The gap allows the first and second portions512a,512bto be displaced toward each other when the wider end portions516are inserted through an aperture560. When the end portions516are passed completely through the aperture560, the first and second portions512a,512bcan return to their non-deflected state (shown inFIG. 15A) under their own resiliency, such that the wider end portions516prevent the projection510from backing out or separating from the aperture.

The projections520do not necessarily need to be fastened or retained inside corresponding apertures560with a snap-fit connection or other fasteners. In particular embodiments, the connections between two struts at the apices of a frame, along with intervening struts as described above, can be sufficient to retain the projections520within corresponding apertures560when the frame is assembled.

In particular embodiments, a frame can be assembled with a plurality of struts500,550without using any other components (e.g., separate rivets and/washers) to form the hinge connections at the junctions of two struts500,550. As can be appreciated, the assembly process is much less time-consuming and costly than frames that require separate component to form the hinge connections.

In alternative embodiments, all of the projections510,520can be formed on a single side of the strut500(side502or side504), in which case the struts500,550are not interwoven with each other. In still other embodiments, the projections may be alternated at other intervals, other than a single interval, so as to correspond to different “weaving” patterns for the struts500,550. For example, a single strut500can extend under two adjacent struts550and then over the next two adjacent struts550.

FIG. 16Ais a side view of a junction formed between a first strut500and a second strut550, according to one embodiment. As shown, the first strut500passes under the second strut550at the point of engagement, or junction, between the struts. At this junction, the projection520of the first strut500extends into an aperture hole560in the second strut550, providing a hinged connection around which the struts can rotate as a frame assembled from multiple struts500,550radially expands or contracts.

FIG. 16Bis a cross-sectional view taken along the line16B-16B ofFIG. 16A. It is understood that at other junctions along the first strut500where it interacts with other second struts550, the first strut may instead pass over the next second strut with the projection520facing radially inwardly towards the second strut550to extend into the corresponding aperture560of that second strut. Additionally, certain junctions between first struts500and second struts550may have neither a projection520nor an aperture560formed in the struts, so long as each of the struts is connected to another strut at an apex of the frame.

In the embodiment ofFIGS. 16A and 16B, the projection520has a square cross-sectional profile in a plane perpendicular to a pivot axis522of the projection. In other embodiments, the projection may have other cross-sectional shapes, such as a circle, triangle, etc.

FIG. 17shows another embodiment of a hinged connection700formed by a first strut710and a second strut720. The first strut710has a projection712that can be formed by flow drilling. As in the embodiment shown inFIG. 15B, the second strut720can include an aperture722cut or drilled therein, within which the projection712may sit, so that the two struts are pivotally engaged and can pivot relative to each other about a pivot axis714. In another embodiment, rather than drilling an aperture722entirely through second strut720, the second strut instead can include a blind hole or recess, such as formed by stamping, etching, or other means, into which projection712can extend to provide pivotal engagement between the struts.

FIGS. 18A-18Cshow another embodiment of a hinge connection800between two struts810,850formed by integral features on the struts. In this embodiment, a first strut810can comprise an enlarged node812at the location of each junction between two struts. The node812is wider than the remainder of the strut and may be circular in shape as shown, although other shapes can be used in other embodiments.

The first strut810includes a radially outwardly facing surface814, a radially inwardly facing surface816, and two longitudinally extending, axially facing surfaces818. Two stopper tabs820are formed on either side of the node812and extend radially inwardly toward the second strut850. One stopper tab820extends radially inwardly from one surface818and the other stopper tab820extends radially inwardly from the other surface818. The first strut810also can have notches822formed in surfaces818adjacent the stopper tabs820.

The second strut850similarly is formed with an enlarged node852at the location of each junction. The second strut850includes a radially outwardly facing surface854, a radially inwardly facing surface856, and two longitudinally extending, axially facing surfaces858. Two stopper tabs860are formed on either side of the node852and extend radially outwardly toward the first strut810. One stopper tab860extends radially outwardly from one surface858and the other stopper tab860extends radially inwardly from the other surface858. The second strut850also can have notches862formed in surfaces858adjacent the stopper tabs860.

As shown inFIGS. 18A and 18B, the struts810,850are placed against each other so that the node812of the first strut overlies the node852of the second strut to form a hinge800. The stopper tabs820of the first strut810extend radially inwardly along opposite sides of the node852of the second strut850, while the stopper tabs860of the second strut850extend radially outwardly along opposite sides of the node812of the first strut810. When the struts810,850are pivoted relative to each other about a pivot axis870, the stopper tabs820of the first strut can engage opposing sides858of the second strut, while the stopper tabs860of the second strut can engage opposing sides818of the first strut. In this manner, the stopper tabs820,860limit the rotational movement of the struts relative to each other. Thus, a frame formed from multiples of the struts810,850can have a maximum expanded diameter and a minimum compressed diameter determined by the range of movement of the struts allowed by the stoppers, can help avoid over-expansion and/or over-compression beyond desired limits.

Further, the engagement of the stopper tabs820against the outer side surface of the node852and the engagement of the stopper tabs860against the outer side surface of the node812can resist separation of the struts at least in the axial direction. In some embodiments, the struts810,850can be interwoven, as shown inFIG. 13, to place the struts in tension against each other to resist separation of the struts in the radial direction. Where the struts are interwoven, pairs of stopper tabs820spaced along the length of the strut can alternately extend from surface814and from surface816. Similarly, pairs of stopper tabs860spaced along the length of the strut can alternately extend from surface854and from surface856.

FIGS. 19A-19Cillustrate a strut connector900(also referred to as a “rivet chain” in some embodiments) that can be used to interconnect struts of a frame of a prosthetic heart valve, according to another embodiment. In the illustrated embodiment, the strut connector900comprises a plurality of rivets or projections910connected by a support member912, which is desirably formed as a unitary part with the projections910integrally formed on the support member912. In one embodiment, the strut connector may900be manufactured using electro chemical machining (ECM), but it can be made using a number of other suitable different technologies, such as electrical discharge machining (EDM), laser machining or computer numerical control (CNC) machining, or molding. Other suitable processes may also be used.

The strut connector900need not be made of the same material as the frame to which it is affixed, since it is a separate part from the frame struts. The strut connector900, including the projections910and the support member912can be formed form any of various biocompatible metals (e.g., stainless steel, nitinol) or polymers (e.g., polyurethane). The strut connector900desirably has sufficient flexibility to conform to the curvature of the outer or inner surface of the strut against which it is placed, as further described below.

FIG. 20is a perspective view of a frame1000, according to one embodiment, that can be assembled using strut connectors900. The frame1000in the illustrated embodiment comprises a plurality of first, outer struts1002connected to a plurality of second, inner struts1004. The frame1000can have a construction similar to the frame200ofFIG. 4, except for hinged connections between the struts. Each strut1002,1004can be formed with a plurality of apertures at the locations where the struts overlap each other, as previously described in connection with the frame200. A strut connector900can be placed along the outer surface of each outer strut1002, with each projection910extending through an aperture in the outer strut1002and into a corresponding aperture of an inner strut1004. The hinged connection is thereby formed at each junction of a first strut1002and a second strut1004.

In alternative embodiments, a strut connector900can be placed against the inner surface of each inner strut1004, with each projection910extending through an aperture in the inner strut1004and into a corresponding aperture of an outer strut1002. In still other embodiments, a strut connector900need not be formed with projections at every junction between the struts1002,1004. For example, in one specific implementation, a strut connector900can be formed with projections910at its opposite ends so as to form hinged connections at the apices along the inflow and outflow ends of the frame and optionally can include projections910at one or more selected locations along the length of the strut connector to form hinged connections between the inflow and outflow ends of the frame.

Further, while the illustrated frame1000includes single strut connector900aligned along each strut1002, in other embodiments, multiple strut connectors900can be placed end-to-end along the length of each strut1002(or each strut1004if placed on the inside of the frame). Moreover, the strut connectors900can be implemented in other frame designs. For example, in one implementation, a frame can be formed from a plurality of interwoven first and second struts, similar toFIG. 13.

As can be appreciated, the use of strut connectors900to assemble the frame can greatly facilitate the manufacturing process by eliminating the step of manually placing individual rivets at each junction between the struts.

FIGS. 21-28illustrate another embodiment of a frame1100for a prosthetic heart valve. As shown inFIG. 21, the frame1100in the illustrated embodiment is formed from a plurality of inner struts1110and a plurality of outer struts1120connected by hinges1115at junctions1105. In alternative embodiments (not shown), the struts may be interwoven, as in the embodiment ofFIG. 13.

The frame1100can include a plurality of actuators1130configured to radially expand and contract the frame and retain an expanded shape when deployed inside a patient's body. Each actuator1130can include an inner member, or piston,1132that extends through an outer member, or cylinder1134. The inner member1132can be connected at one end thereof to a junction1105at one end of the frame, while the outer member1134can be connected to another junction1105of the frame. Longitudinal movement of the inner member1132relative to the outer member1134is effective to radially expand and contract the frame1100, as previously described in connection with the embodiment ofFIGS. 1 and 8-12. The inner members1132can be releasably connected to corresponding actuators of a delivery apparatus. Further details of the actuators1130are disclosed in co-pending co-pending application Ser. No. 15/831,197, filed Dec. 4, 2017, which is incorporated by reference in its entirety herein.

The components forming the hinges1115can be integrated into the construction of the struts. As best shown inFIGS. 22-26, for example, each strut1110comprises a plurality of integral projections1112spaced along the length of the strut at the locations of the junctions1105. Each projection1112can include a cylindrical base1114and a locking member in the form of a plurality of ears1118extending laterally from the end of the base1114. In the illustrated embodiment, each projection includes two ears1118that extend in opposite directions from the end of a base1114, although more than two ears1118may be used in alternative embodiments.

Each strut1120can be formed with a plurality of openings or apertures1122spaced along the length of the strut at the locations of the junctions1105. Each opening1122can include two oblong side portions1124corresponding to the shape of the ears1118. Each opening1122can be formed within a recessed portion1126formed on an outer surface of a strut1120.

In the assembled state of the frame1100, the base1114of each projection1112extends through a corresponding opening1122with the ears1118residing in the recessed portion1126surrounding the opening. The depth of the recessed portion1126desirably is equal to or greater than the height of the ears1118so that the projections do not extend radially beyond the outer surfaces of the outer struts1120. The ears1118and the correspondingly shaped oblong side portions1124allow the ears of the projection1112to be inserted through the side portions1124when the ears1118and the oblong side portions1124are rotationally aligned with each other and then prevent separation of the two struts1110,1120when the ears1118and the side portions1124are rotationally offset or misaligned from each other.

During assembly, the ears1118of a strut1110are aligned with the oblong side portions1124of an opening1122of a strut1120corresponding to a predetermined angle between the struts1110,1120which is greater than the maximum angle between the struts1110,1120allowed by the actuators1130during radial expansion of the frame1100. Thus, once the projections1112of struts1110are inserted through corresponding openings1122of struts1120to form the frame, the struts are then rotated relative to each other, which causes the ears1118to become offset from the oblong side portions1124. The actuators1130can then be mounted on the frame. The actuators1130are configured to radially expand and contract the frame, as noted above, but desirably limit the radial expansion and contraction of the frame within a predetermined range of diameters and a predetermined range of angles between the struts1110,1120at which the ears1118are still rotationally offset from the oblong side portions1124. In this manner, the actuators1130can prevent radial expansion of the frame to a diameter at which the ears1118are rotationally aligned with the oblong side portions1124, thereby preventing separation of the struts1110,1120at any of the junctions1105. Similarly, the actuators1130can prevent radial contraction of the frame to a diameter at which the ears1118are rotationally aligned with the oblong side portions1124, thereby preventing separation of the struts1110,1120at any of the junctions1105when the frame is compressed to a delivery configuration.

In this manner, the hinges1115formed by projections1112and corresponding openings1122can be referred to as “self-locking” hinges in that the mechanical engagement of the ears1118with the adjacent surface of the recessed portion1126locks the struts together at a junction1105and need not rely on placing the struts in tension against each other to retain a connection between the struts. Consequently, the struts need not be formed from super-elastic materials (e.g., Nitinol) to maximize tension on the struts. While the struts can be formed from super-elastic materials or non-super-elastic materials (e.g., stainless steel or cobalt chromium alloys), non-super-elastic materials are desirable in some embodiments because they can provide greater crush resistance and typically are less expensive than super-elastic materials.

The self-locking hinges1115can be formed from the projections1112and openings1122having any of various shapes in addition to those shown in the illustrated embodiment. In general, the projections1112can be formed with a locking member that has a non-circular shape (in a plane perpendicular to the central axis of the projection) and the openings1122can have any non-circular shape that be rotationally aligned with the locking member to permit assembly of the struts and then rotationally offset from the locking member to prevent separation of the struts at the hinge.

In particular embodiments, the frame1100can be assembled as follows. Referring toFIG. 27, the inner struts1110can be mounted on mandrel1150, and then the outer struts1120can be placed over the inner struts1110. The inner and outer struts are placed at a predetermined angle relative to each other to rotationally align the ears1118of the inner struts1110with the oblong openings1124of the outer struts1120, which allows the projections to be inserted through the openings such that the ears1118can reside within the recessed portions1126. Thereafter, the frame may be crimped slightly, causing the ears1118to become rotationally offset from the oblong openings1124, thus locking the struts in place at each junction1105, as depicted inFIG. 27. The actuators1130can then be mounted on the frame1100. As noted above, the actuators1130desirably limit radial expansion of the frame so that the struts do not reach the angle at which the struts were assembled. For example, the actuators1130can be configured to limit radial expansion of the frame to the expanded configuration shown inFIG. 27.FIG. 28shows a radially compressed state of the frame1110, which can be the minimum diameter of the frame allowed by the actuators1130. As shown, in the smallest compressed state allowed by the actuators, the ears1118are still rotationally offset from the oblong openings1124to prevent separation of the struts in the compressed state.

FIGS. 29-33illustrate another embodiment of a hinge assembly1200for a prosthetic heart valve. As shown inFIG. 29, the hinge assembly1200in the illustrated embodiment is formed from an inner strut1220and an outer strut1230connected by a separate hinge member1202at a junction1205. Hinge assembly1200is similar to the hinge shown inFIG. 22, except that inFIG. 22, the connector between the two struts is formed from an integral protrusion from one of the struts, which fits into an opening of the corresponding strut. In the embodiment shown inFIG. 29, the hinge assembly1200is formed using a separate hinge member1202that is not integral to either inner strut1220or outer strut1230, as best shown inFIGS. 30-32B. It is understood that a plurality of such hinge assemblies may be used to form a frame, and that in alternative embodiments (not shown), rather than providing inner struts and outer struts, the struts may be interwoven, as in the embodiment ofFIG. 13. It is further understood that while described as being first inserted through inner strut1220, hinge member1202may be first inserted through outer strut1230.

As best shown inFIGS. 30A-30C, the hinge member1202may include a disc-shaped base1212, from which a cylindrical projection1214extends. At a first end of the cylindrical projection adjacent the base1212are one or more retaining members in the form of a first set of one or more ears1216extending laterally from the cylindrical projection1214. At a second end of the cylindrical projection (opposite the base1212) are one or more locking members in the form of a second set of one or more ears1218. In the illustrated embodiment, each set of ears1216and1218, respectively, comprises two ears that extend in opposite directions from the cylindrical projection1214, although more than two ears may be used in alternative embodiments.

An inner strut1220can be formed with a plurality of inner openings or apertures1222spaced along the length of the strut at the locations of junctions1205with an outer strut1230, similar to the embodiment of frame1100. As best shown inFIG. 31A, each inner opening1222can include two inner oblong side portions1224corresponding to the shape of the two sets of ears,1216and1218. Each inner opening1222can be formed within an inner circular recessed portion1226formed on an inner surface of inner strut1220, within which the disc-shaped base1212of hinge member1202may sit, as best shown inFIG. 32A. The depth of the inner circular recessed portion1226desirably is equal to or greater than the height of the disc-shaped base1212so that the hinge member1202does not extend radially beyond the inner surface of the inner strut1220when hinge frame assembly1200is assembled. As best shown inFIG. 32B, when the cylindrical projection1214and second set of ears1218of the hinge member1202are inserted through the inner opening1222of the inner strut1220, the first set of ears1216are retained within the oblong side portions1224of the inner opening1222, preventing axial and rotational movement of hinge member1202relative to the inner strut1220.

An outer strut1230likewise can be formed with a plurality of outer openings or apertures1232spaced along the length of the strut at the locations of junctions1205with an inner strut1220, similar to the embodiment of frame1100. As best shown inFIG. 31B, each outer opening1232can include two outer oblong side portions1234corresponding to the shape of the second set of ears1218. Each outer opening1232can be formed within an outer circular recessed portion1236formed on an outer surface of outer strut1230, within which the second end of the cylindrical projection1214and the second set of ears1218can be retained, as best shown inFIG. 33, which shows the assembly configuration of the hinge frame assembly1200. The depth of the outer circular recessed portion1236desirably is equal to or greater than the height of the second set of ears1218so that the hinge member1202does not extend radially beyond the outer surface of the outer strut1230when hinge frame assembly1200is assembled.

Once assembled on a frame, the cylindrical projection1214extends through a corresponding opening1232in the outer strut1230, with the second set of ears1218residing in the outer recessed portion1226surrounding the opening. The portion of the outer strut1230surrounding the opening1232within the recessed portion1236resides within a gap1240(FIG. 30C) between the first set of ears1216and the second set of ears1218, allowing the outer strut1230to pivot or rotate relative to the inner strut1220and the hinge member1202. The second set of ears1218and the correspondingly shaped outer oblong side portions1234allow the second set of ears1218to be inserted through the outer oblong side portions1234during assembly when the second set of ears1218and the outer oblong side portions1234are rotationally aligned with each other and then prevent separation of the two struts1220,1230, when the second set of ears1218and the outer oblong side portions1234are rotationally offset or misaligned from each other.

During assembly, in a similar fashion as described above with regard to the embodiment of frame1100, after the second set of ears1218of the hinge member1202are first inserted through an inner strut1220, they are aligned with the outer oblong side portions1234of an opening1232of an outer strut1230corresponding to a predetermined angle between the struts1220,1230which is greater than the maximum angle between the struts1220,1230allowed by, e.g., actuators1130during radial expansion of the frame. Thus, once the second set of ears1218of hinge member1202are inserted through the corresponding openings1224and1234of both sets of struts to form a hinge of the frame, the struts are then rotated relative to each other, which causes the second set of ears1218to become offset from the outer oblong side portions1234, as best shown inFIG. 29.

As with frame1100, after assembling all of the hinges, actuators1130can then be mounted on the frame. The actuators1130are configured to radially expand and contract the frame, as noted above, but desirably limit the radial expansion and contraction of the frame within a predetermined range of diameters and a predetermined range of angles between the struts1220,1230at which the second set of ears1218are still rotationally offset from the outer oblong side portions1234.

For example, a frame diameter in the assembly configuration ofFIG. 33may be 29 mm, while the range of frame diameters between the minimum (crimped) diameter of the frame and the maximum allowable operational diameter of the frame may be between 8 mm and 28 mm, respectively. In this manner, the actuators1130can prevent radial expansion of the frame to a diameter at which the second set of ears1218are rotationally aligned with the outer oblong side portions1234, thereby preventing separation of the struts1210,1230at any of the junctions1205. Similarly, the actuators1130can prevent radial contraction of the frame to a diameter at which the ears1218are rotationally aligned with the oblong side portions1234, thereby preventing separation of the struts1210,1230at any of the junctions1205when the frame is compressed to a delivery configuration. Additionally, once rotationally offset from the outer oblong side portions1234, the second set of ears1218may interact with the outer surface of the outer strut1230to prevent radial movement of the hinge member1202relative to the struts1220,1230.

In this manner, the hinge assembly can be referred to as “self-locking” in that the mechanical engagement of the ears1218with the adjacent surface of the outer recessed portion1236locks the struts together at a junction1105and need not rely on placing the struts in tension against each other to retain a connection between the struts. Consequently, the struts need not be formed from super-elastic materials (e.g., Nitinol) to maximize tension on the struts. While the struts can be formed from super-elastic materials or non-super-elastic materials (e.g., stainless steel or cobalt chromium alloys), non-super-elastic materials are desirable in some embodiments because they can provide greater crush resistance and typically are less expensive than super-elastic materials. Additionally, providing separate hinge members may simplify the manufacturing process for the struts by eliminating the need to specially manufacture a strut having three dimensional hinge protrusions. This may reduce overall manufacturing costs.

The hinge assembly1200can comprise hinge members1202having features corresponding to openings in the struts wherein the features have any of various shapes in addition to those shown in the illustrated embodiment. In general, a hinge member can be formed with a locking member (e.g., ear1218) that has a non-circular shape (in a plane perpendicular to the central axis of the hinge member) and the corresponding opening in the outer strut1232can have any non-circular shape that can be rotationally aligned with the locking member to permit assembly of the struts and then rotationally offset from the locking member to prevent separation of the struts at the hinge.

Similarly, a hinge member can be formed with a retaining member (e.g., ear1216) that has a non-circular shape (in a plane perpendicular to the central axis of the hinge member) and the corresponding opening1222in the inner strut1220can have any non-circular shape that can be rotationally aligned with the retaining member to permit insertion of the hinge member through the opening1222and prevent rotation of the hinge member relative to the inner strut1220. In alternative embodiments, the hinge member can be formed without features (e.g., ears1216) that prevent relative rotation between the hinge member and the inner strut1220.

In particular embodiments (not shown), a frame using a plurality of hinge assemblies1200can be assembled in a similar fashion to the frame1100shown inFIGS. 27 and 28. In such embodiments, the hinge members1202may first be inserted at each of the appropriate openings1222in the inner struts1220, as shown inFIGS. 31A-32Bprior to mounting them on a mandrel1150, as described above. Thereafter, the outer struts1230can be mounted over the inner struts1220and assembly can continue in a manner similar to that described with reference toFIGS. 27 and 28. As noted briefly above, in other embodiments, the hinge members1202can be inserted through the struts1220,1230in the opposite direction, such that the base1212of each hinge member is adjacent an outer surface of an outer strut and the ears1218are adjacent an inner surface of an inner strut.

FIGS. 34-37illustrate a flanged rivet or connector1300that can be used to interconnect struts of a frame of a prosthetic heart valve, according to another embodiment. Referring toFIG. 34, in the illustrated embodiment the rivet1300comprises two elongated cylindrical end portions1302,1304separated by a wide central portion or flange1306. Additionally, a cylindrically shaped, axially extending opening or bore1308can extend completely though the rivet1300.

FIG. 35Ais a perspective view of a frame1400, according to one embodiment, that can be assembled using flanged rivets1300. The frame1400in the illustrated embodiment comprises a plurality of first, inner struts1410connected to a plurality of second, outer struts1420. The frame1400can have a construction similar to the frame200ofFIG. 4, except for the configuration of the hinged connections between the struts. Each strut1410,1420can be formed with a plurality of apertures1402at the locations where the struts overlap each other, as previously described in connection with the frame200. Additionally, as shown in greater detail inFIG. 36, each of the apertures1402can include a counter-bore or enlarged recessed portion1412,1422as previously described inFIG. 3B, that is sized to receive one of the two elongated end portions1302,1304, respectively, both in an initial configuration, and in a second configuration following the deformation of the two elongated end portions1302,1304, as will be further described herein.

As shown inFIGS. 35B and 36, in an initial (non-deformed) configuration, the wide flange1306of the flanged rivet1300is placed between a first inner strut1410and a first outer strut1420at their apertures1402. In this initial configuration, the radially innermost terminal end of the end portion1302can extend beyond the inner surface of the inner strut1410. Similarly, the radially outermost end of the end portion1304can extend beyond the outer surface of the outer strut1420.

As shown inFIG. 37, in a second configuration, the end portions1302,1304are deformed, such as by plastic deformation, so as to form end flanges1312,1314at the opposing ends of the rivet. Each end flange has a diameter that is greater than that of the aperture1402in the adjacent strut1410,1420. Desirably, at least one of the end flanges is not seated tightly against the adjacent surface of the adjacent strut, allowing at least one of the struts to pivot freely relative to the rivet and the other strut.

In particular embodiments, the end flanges can each be received entirely within the enlarged recessed portions1412,1422of the adjacent struts1410,1420. For example, the end flange1312formed by end portion1302can be flush with the inner surface of the inner strut1410and the end flange1314formed by end portion1304can be flush with the outer surface of the outer strut1420. In this manner, the flanged rivets1300do not increase or contribute to the overall crimp profile of the prosthetic valve and do not interfere with or place undue stresses on the delivery sheath of the valve (e.g., sheath82inFIG. 1).

The end portions1302,1304may be deformed simultaneously, or may be deformed separately. For example, the end portions1302,1304can be deformed by applying axially directed compressive forces on the opposite ends of the rivet and/or by applying radially outwardly directed forces within the bore1308(e.g., using a swaging tool) to cause the end portions1302,1304to deform to the shape shown inFIG. 37. In one alternative embodiment (not shown), rather than placing the rivet1300between two struts in an initial configuration, the end portion1302of the rivet1300may be inserted through an aperture1402in a first, inner strut1410and the first end portion1302may be deformed to form the end flange1312, so that the rivet1300is effectively retained by the first, inner strut1410. Subsequently, the first, inner strut1410can be connected to a second, outer strut1420by inserting the second end portion1304of the same rivet1300through the opening in the outer strut and deforming the second end portion1304to form end flange1314. In still another alternative embodiment, a rivet1300may first be connected to an outer strut1420in a similar manner before the outer strut is connected to an inner strut1410.

Providing flanged rivets such as those described in this disclosure may provide benefits to both safety and ease of assembly. Since the rivet is held between struts, this may reduce the risk of separation of the rivet from the struts. Additionally, in embodiments where the rivet is pre-mounted to a strut, this may simplify assembly by holding the rivet in place while it is mounted to the corresponding strut. Additionally, manufacturing the struts separately from the rivets may minimize the cost for manufacturing the struts by allowing them to be manufactured from a flat sheet, while also enabling optimization of the engineering for these separate components (i.e., the rivets and the struts), which serve different functions and may require different mechanical properties.

FIGS. 38A, 38B and 39show another embodiment of a flanged rivet1500formed by drilling or otherwise forming first and second blind holes1508,1510, in first and second end portions1502,1504of the rivet. The rivet1500can have a wide flange or central portion1506intermediate the end portions. The rivet1500can be assembled on two struts1410,1420as previously described by deformed end portions1502,1504.

FIGS. 40A-40Cshow another embodiment of a flanged rivet1600, formed by deforming a simple tube or cylindrical member1602(FIG. 40A) having first and second end portions1604,1606, respectively, and a longitudinal opening or bore1608extending therethrough. Compressive forces can be applied to the opposing ends of the tube1602(indicated by arrows1612), causing the tube to plastically deform and form a central portion or flange1610between the first and second end portions1604,1606. The rivet1600may be assembled on two struts1410,1420as previously described by deforming the end portions1604,1606.

FIGS. 41-44illustrate the assembly of another embodiment of a frame1700for a prosthetic heart valve. As shown inFIG. 43, the frame1700in the illustrated embodiment is formed from at least two separate frame sub-assemblies, including a first, inner frame sub-assembly1710(shown inFIG. 41), and a second, outer frame sub-assembly1720(shown inFIG. 42), as further described herein. The two frame sub-assemblies may be further connected to each other and expanded using a plurality of actuators1730, also described in more detail herein. In other embodiments, the frame1700can include additional frame sub-assemblies positioned radially inward and/or radially outward of frame sub-assemblies1710,1720.

Similar to frame1100shown inFIG. 21, the inner frame sub-assembly1710, best illustrated inFIG. 41, may comprise a plurality of inner struts1712and a plurality of outer struts1714connected by hinge projections1716passing through apertures1718at junctions1715. In alternative embodiments (not shown), the struts may be interwoven, as in the embodiment ofFIG. 13. In other alternative embodiments, rather than using integral projections and apertures, inner struts1712and outer struts1714may be assembled using rivets at apices1711, and/or by using rivets at some or all of the junctions1715. In some embodiments, a separate hinge, such as shown inFIGS. 30A-33, or other separate hinges, such as shown inFIGS. 34-40C, or other suitable separate hinges may be used.

The components forming the hinge projections1716can be integrated into the construction of the struts. As best shown inFIG. 41, for example, three inner struts1712and three outer struts1714each comprises a plurality of integral hinge projections1716spaced along the length of the strut, including at the locations of the junctions1715, which may be similar to the hinge projections1112illustrated inFIG. 25. Additional hinge projections1716may be provided at additional locations along the struts, which may be used to join the inner frame sub-assembly1710to the outer frame sub-assembly1720at junctions1735. Outer struts1714can further each be formed with a plurality of openings or apertures1718spaced along the length of the strut at the locations of the junctions1715, which may be similar to apertures1122, as illustrated inFIG. 24, which may be used to join the inner struts1710to the outer struts1714by a process similar to that described above with regard to frame1100.

Similar to the inner frame sub-assembly1710, the outer frame sub-assembly1720, best illustrated inFIG. 42may comprise a plurality of inner struts1722and a plurality of outer struts1724connected by hinge projections1726of the inner struts1722passing through apertures1728of the outer struts1724at junctions1725. In alternative embodiments (not shown), the struts may be interwoven, as in the embodiment ofFIG. 13. In other alternative embodiments, rather than using integral hinges and apertures, inner struts1722and outer struts1724may be assembled using rivets or the other connection mechanisms described herein and in the incorporated patents and applications at apices1711, and/or at some or all of the junctions1725. In some embodiments, a separate hinge, such as shown inFIGS. 30A-33, or other separate hinges, such as shown inFIGS. 34-40C, or other suitable separate hinges may be used.

The components forming the hinge projections1726can be integrated into the construction of the struts. As best shown inFIG. 42, for example, three inner struts1722and three outer struts1724each comprises a plurality of integral hinge projections1726spaced along the length of the strut, including at the locations of the junctions1725, which may be similar to the hinge projections1112illustrated inFIG. 25. Outer struts1724can further each be formed with a plurality of openings or apertures1728spaced along the length of the strut at the locations of the junctions1725, which may be similar to apertures1122, as illustrated inFIG. 24, which may be used to join the inner struts1722to the outer struts1724by a process similar to that described above with regard to frame1100. Additional apertures1728may be provided at additional locations along the struts, which may be used to join the outer frame sub-assembly1720to the inner frame sub-assembly1710at junctions1735.

The struts of each of the sub-assemblies are arranged to form a plurality of closed cells (each sub-assembly in the illustrated embodiment forms three diamond-shaped cells), which helps retain their pre-assembled annular shape prior to being attached to each other. Once separately assembled as shown inFIGS. 41 and 42, the inner frame sub-assembly1710can be inserted into outer frame sub-assembly1720, such as with the frames rotated by a half cell shift (in this case, 60 degrees), and joined at junctions1735by inserting the hinge projections1716on the struts1712,1714of the inner frame sub-assembly1710through the corresponding apertures1728of the struts1722,1724of the outer frame sub-assembly1720, as illustrated inFIG. 43.FIG. 44shows the assembled frame1700with stippling added to the struts of the inner frame sub-assembly1710for purposes of illustration only. The stippling is added to distinguish the inner frame sub-assembly1710from the outer frame sub-assembly1720and does not represent actual surface ornamentation.

Alternatively, hinge projections on the outer frame assembly may be inserted through apertures on inner frame assembly (in embodiments where hinge projections extend radially inwardly from the struts to which they are connected). Or, separate rivets or other connection mechanisms, such as those described herein and in the incorporated patents and applications, may pass through apertures on both sub-assemblies at the junctions. Or, a combination of suitable connection mechanisms, including those described herein, may be used.

One or more of the struts1712,1714of the inner frame sub-assembly1710and one or more of the struts1722,1724of the outer frame sub-assembly1720can be formed with openings or apertures1740spaced along the length of the struts. The apertures1740can be used to suture leaflets, an inner skirt, and/or an outer skirt to selected struts of the frame, as further described below.

The frame1700can include a plurality of actuators, which may be threaded actuators1730configured to radially expand and contract the frame and retain the frame in an expanded shape when deployed inside a patient's body. Each actuator1730can include an inner member in the form of a screw1732, which may comprise external threads, and which extends through a first outer member, sleeve, or cylinder1734positioned at a junction1725at one end of the outer frame sub-assembly1720, and into a second outer member, sleeve, or cylinder1736that may be positioned at a junction1715on the inner frame sub-assembly1710. One or both of these outer members1734,1736may have internal threads to threadably engage the inner member1732. Also, the outer members1734,1736can be mounted at other locations on the frame1700. For example, the first outer member1734can be mounted on the inner frame sub-assembly1710and the second outer member1736can be mounted on the outer frame sub-assembly1720; or alternatively, both outer members1734,1736can be mounted on the inner frame sub-assembly1710or both outer members1734,1736can be mounted on the outer frame sub-assembly1720.

Rotational movement of the inner member1732relative to the outer members1734,1736is effective to radially expand and compress the frame1700. The actuators1730can be releasably connected to corresponding actuators of a delivery apparatus, for example, each screw1732can be releasably connected to a corresponding drive shaft or drive wire of the delivery apparatus. Further details of the actuators1730are disclosed in co-pending application Ser. No. 15/831,197, filed Dec. 4, 2017, which is incorporated by reference in its entirety herein. In other embodiments, the actuators for radially expanding and compressing the frame1700can be push-pull type actuators as previously described in connection with the embodiments ofFIGS. 1, 8, 12 and 21.

In the assembled state of the frame1700, a plurality of the hinge projections1716,1726extend through corresponding apertures1718,1728. During assembly, the projections are aligned with the apertures, and then the struts are rotated relative to one another, which causes the projections to rotate relative to the apertures, as described above in connection with the method of assembly of frame1100described with reference toFIGS. 27-28, securing the struts of the inner frame sub-assembly and the outer frame sub-assembly together. While in an alternative embodiment, not all junctions between the struts may have hinge projections inserted through apertures, the inner and outer struts of each frame sub-assembly are connected at least at the apices, e.g., apices1711of the inner frame sub-assembly, best illustrated inFIG. 41.

After assembling the frame1700, the actuators1730can then be mounted on the frame. In other embodiments, the outer sleeves1734,1736of the actuators can be mounted on the frame sub-assemblies1720,1710, respectively, prior to assembling the inner and outer frame sub-assemblies, and the screws1732are added after assembling the inner and outer frame sub-assemblies. The actuators1730are configured to radially expand and compress the frame, as noted above, but desirably limit the radial expansion and compression of the frame within a predetermined range of diameters and a predetermined range of angles between the struts of the inner frame sub-assembly1710and the struts of the outer frame sub-assembly1720so as to prevent separation of the two subassemblies at the junctions1735, similar to the process described above with regard to frame1100, making frame1700a “self-locking” frame assembly.

Soft components of the prosthetic valve, such as valve leaflets or an inner skirt may (not shown), can be added to the inner frame sub-assembly1710, while other soft components, such as an outer skirt (not shown) can be added to the outer frame sub-assembly1720. In particular embodiments, the valve leaflets and/or an inner skirt can be mounted or assembled on the inner frame sub-assembly1710and/or an outer skirt can be mounted or assembled on the outer frame sub-assembly1720before the inner frame sub-assembly1710and the outer frame sub-assembly1720are connected to each other to form the fully assembled frame1700. Forming separate inner and outer frame sub-assemblies is advantageous in that is facilitates the assembly of the leaflets and/or the skirt(s) of the prosthetic valve, as further described below. Additional details regarding the assembly of soft components to a frame sub-assembly are described below. In alternative embodiments, the frame1700can be fully assembled prior to assembling the leaflets and the skirt(s) to the frame1700.

FIGS. 45-47illustrate a valve sub-assembly1900, according to another embodiment. As shown inFIG. 45, the valve sub-assembly1900comprises an inner frame sub-assembly1710and a prosthetic valve leaflet assembly1910at least partially mounted on the inner frame-sub assembly1710. An external frame sub-assembly1720can be placed around the inner frame sub-assembly1710as previously described in connection withFIGS. 43-44.

The valve leaflet assembly may comprise three leaflets1912(as in the illustrated embodiment), although it is to be understood that other numbers of leaflets may be used. Each leaflet1912can be formed with commissure tabs1914on opposite sides of the leaflet. Each commissure tab1914can be paired with an adjacent commissure tab1914of an adjacent leaflet to form a commissure1930. The commissures1930can be attached, for example, to struts of an outer frame sub-assembly1720or to components of the actuators1730(e.g., to the sleeves1734). Further details regarding mounting the commissures1930of the leaflets to the frame are disclosed in U.S. Provisional Application Nos. 62/506,430, filed May 15, 2017 and 62/614,299, filed Jan. 5, 2018, and U.S. application Ser. No. 15/978,459, filed May 14, 2018, which are incorporated herein by reference.

The lower or inflow portion of the leaflets may comprise scalloped inflow or cusp edges1920that may be attached, such as by suturing or other suitable techniques, to the lower portions of inner struts1712and outer struts1714. For example, the inflow edges1920can be stitched to the struts1712,1714with sutures passing through the leaflets and openings1740in the struts1712,1714, such as using in-and-out stitching or whip stitching extending along the struts. Alternatively, the sutures can pass through the leaflets and around the struts1712,1714. An inner skirt1940(discussed further below) can be used to reinforce the attachment of the inflow edges1920of the leaflets to the struts1712,1714. One or more narrow reinforcing strips (e.g., a narrow strip of fabric) can be placed along the cusp edge1920of each leaflet and sutured thereto to reinforce the connection of the cusp edge with the struts. For example, the cusp edges1920can be “sandwiched” or disposed between two reinforcing strips that can be sutured to each other and to the cusp edges.

Because the inflow edges1920of the leaflets1912in the illustrated embodiment are attached solely to the inner frame sub-assembly1710, the secured leaflet edges need not pass over a “crossing strut.” In other words, each inflow edge1920of a leaflet is secured along a length of two struts where the two struts do not cross another strut at a junction1715. As best shown inFIG. 45, in the illustrated embodiment, each inflow edge1920is secured to a first strut1712and a second strut1714along the lower halves of the struts between a junction1715aat an apex formed by the intersection of the struts1712,1714and junctions1715b,1715cformed by the intersection of each strut1712,1714with an adjacent crossing strut without passing over the junctions1715b,1715c. Further, when the outer frame1720sub-assembly is attached to the inner frame sub-assembly1710in the manner shown inFIGS. 43-44, the outer frame sub-assembly1720is entirely external to the connection between the inflow edges of the leaflets such that the struts of the outer frame sub-assembly need not be used for attachment of the inflow edges1920of the leaflets.

Avoiding attachment of the inflow edges of the leaflets to any crossing struts provides a more secure leaflet connection, with less stress on the leaflets between the inflow edges1920and the commissure tabs1912. In addition, this manner of connecting the leaflets to the struts provides reduces the risk of leaflet abrasion and a symmetric and smooth attachment line to improve valve performance. Moreover, it is relatively easier to secure the leaflets to the struts1712,1714prior to fully assembling the frame by virtue of the fact that inner frame sub-assembly has less struts than a fully formed frame and therefore there is much greater access to the interior of the frame for the assembler to insert tools and their fingers into the frame during the assembly process. This can greatly simply the process of stitching the leaflets to the struts and/or to any reinforcing strips or skirts.

FIG. 46shows one way of mounting an inner skirt1940to the valve sub-assembly1900. In the illustrated embodiment, the inner skirt1940is “sandwiched” or disposed between the inner struts1712and outer struts1714of the inner frame sub-assembly1710. As such, the connection of the inner struts1712and outer struts1714at junctions1715may be used to help secure the skirt to the inner frame sub-assembly1710, such as by passing the projections1716through corresponding slits or openings in the skirt. The skirt1940can be further secured to the struts1712,1714with sutures that pass through the skirt and through apertures1740of selected struts1712,1714(and/or around selected struts1712,1714). The skirt1940can be formed with an undulating outflow edge1942that is shaped to correspond with the shape a circumferentially extending row of strut segments adjacent the row of strut segments defining the outflow end of the frame assembly.

In another embodiment, as illustrated inFIG. 47, an inner skirt1940is mounted entirely external to the inner frame sub-assembly1710. The skirt1940can be secured to the struts1712,1714of the inner frame sub-assembly1710with sutures extending through apertures1740and/or around selected struts of the inner frame sub-assembly1710.

FIG. 48illustrates another exemplary prosthetic valve2000. The prosthetic valve2000may be formed by first assembling the valve sub-assembly1900ofFIG. 47, with an inner skirt1940provided entirely external to the inner frame sub-assembly1710. An outer frame assembly1720can then be formed and placed around the skirt1940and secured to the inner frame sub-assembly1710as previously described in connection withFIGS. 43-44, except that the connection between the inner frame sub-assembly1710and the outer frame sub-assembly1720at junctions1735may be used to secure the inner skirt1940to the frame1700in lieu of or in addition to sutures that are used to secure the skirt1940to the struts of the frame. In particular, the skirt1940can be retained in place by inserting the projections1716of the inner frame sub-assembly1710that extend through apertures1728of the outer frame sub-assembly1720through slits or openings in the skirt. In this manner, selected projections1716of the inner frame sub-assembly1710extend through respective slits or openings in the skirt1940and through respective openings1728in the outer frame sub-assembly1720.

In alternative embodiments where separate rivets or hinge members are used in lieu of integral projections1716(e.g., such as shown inFIGS. 29-40), one or more rivets or hinge members can extend through an opening in a strut of the inner frame sub-assembly1710, through a slit or opening in the skirt940, and through an opening in a strut of the outer frame sub-assembly1720.

In this way, the inner skirt1940can be sandwiched or held between inner and outer struts of the inner frame sub-assembly1710(FIG. 46) or between the inner frame sub-assembly1710and the outer frame sub-assembly1720(FIG. 48) to provide a strong, durable connection for the inner skirt1940. In still other embodiments, the skirt1940can be disposed between the inner and outer struts of the outer frame sub-assembly1720and held in place with the projections of the inner struts extending though the slits or openings of the skirt.

This form of connecting the skirt to the frame can simplify the assembly process, potentially reducing the amount of stitching by using the projections, rivets, hinges, or other connection mechanisms themselves to connect the skirt to the struts of the frame. In particular, positioning the skirt1940between the inner and outer frame sub-assemblies1710,1720after forming each of the frame sub-assemblies can save considerable time in assembling the entire valve. Additionally, in some embodiments, the entire skirt can be secured to the frame via the projections on the struts (or other hinge mechanisms) without the use of sutures. Additionally, using the relative position of the projections, rivets, hinges, or other connection mechanisms to secure the two frame sub-assemblies at the junctions1735, as well as to connect the inner skirt1940to the frame sub-assemblies, allows these connection mechanisms at junctions1735to serve as self-alignment features for the frame components and soft components, as each projection (or other hinge member) aligns with a pre-formed slit or opening in the soft component (e.g., skirt1940). In other words, the spacing and positioning of the pre-formed slits or openings in the soft components corresponds to the spacing and positioning of the projections on the struts to facilitate proper positioning of the soft component relative to the frame struts during the assembly process.

The prosthetic valve2000can further include an outer skirt (not shown) that can be positioned entirely outside of the outer frame sub-assembly1720. The outer skirt can be secure to the frame using sutures and/or hinge members that secure the inner and outer struts of the outer frame sub-assembly1720.

Still another advantage provided by the prosthetic valve2000is that, with the outer frame sub-assembly1720assembled separately and positioned completely external to the inner frame sub-assembly1710, the struts facing the articulating portions of the leaflets (e.g., the struts located at positions where the leaflets of valve leaflet assembly move toward and away from the frame) are part of the outer frame sub-assembly1720. This creates a gap between the articulating portions of the leaflets (especially the coaptation edges) so as to prevent or minimize contact between the leaflets and the frame during operation of the prosthetic valve, thereby protecting against leaflet abrasion. This can also allow for use of a relatively larger leaflet for improved hemodynamics.

In alternative embodiments, the leaflets1912or portions thereof can be secured to the struts of the frame in a similar manner using one or more hinge members that extend through the leaflets and two overlapping struts in lieu of or in addition to suture attachment of the leaflets. In one implementation, for example, the inflow edges1920of the leaflets can be positioned against the inner surfaces of struts1712,1714a held in place with hinge members (e.g., rivets) that extend through a leaflet, a strut1712,1714and a strut1722,1724of the outer frame. In another implementation, the leaflets1912can be placed between the inner and outer struts1712,1714at junctions1715a,1715b,1715cand retained in place via the projections1716(or other hinge members) that interconnect the struts at those junctions.

FIGS. 49-52illustrate another embodiment of a frame assembly2100for a prosthetic valve. The frame assembly2100may be used when a relatively larger frame is desired. The frame assembly2100can be formed from an inner frame sub-assembly2110(FIG. 49) and an outer frame sub-assembly2120(FIG. 50). As illustrated inFIG. 51, the frame assembly2100is a “9×3” configuration, formed from nine struts positioned in a first direction and nine crossing struts positioned in a second direction, with each strut connected to another strut to form an apex at each of its ends, and to one or more additional struts in between its ends to form junctions, similar to those described above.

FIG. 49shows the inner frame sub-assembly2110apart from the outer frame sub-assembly2120. As best shown inFIG. 49, the inner frame sub-assembly2110may be similar to inner frame sub-assembly1710, with three inner struts2112oriented in a first direction, and three crossing outer struts2114outer struts oriented in a second direction. The inner struts2112and the outer struts2114can be joined to each other at their ends to form apices2111and at junctions2115positioned between the ends of the struts. These junctions may be formed using projections, hinges, rivets, and/or any of the methods and/or mechanisms described herein and in the incorporated patents and applications.

FIG. 50shows the outer frame sub-assembly2120apart from the inner frame sub-assembly2110. As best shown inFIG. 50, the outer frame sub-assembly2120is similar to outer frame sub-assembly1720, except that instead of three inner struts and three crossing outer struts, the outer frame sub-assembly2120comprises six inner struts2212oriented in a first direction, and six crossing outer struts2214outer struts oriented in a second direction. The inner struts2212and the outer struts2214can be joined to each other at their ends to form apices2121and at junctions2125positioned between the ends of the struts. These junctions may be formed using projections hinges, rivets, and/or any of the methods and/or mechanisms described herein and in the incorporated patents and applications.

FIG. 51shows the inner frame sub-assembly2110assembled with the outer frame sub-assembly2120. As illustrated inFIG. 51, once separately assembled, the inner frame sub-assembly2110can be inserted into outer frame sub-assembly2120, and joined at junctions2135using hinges, rivets, and/or any of the methods and/or mechanisms described herein and in the incorporated patents and applications. Stippling has been added to the struts of the inner frame sub-assembly2110for purposes of illustration only. The stippling is added to distinguish the inner frame sub-assembly2110from the outer frame sub-assembly2120and does not represent actual surface ornamentation.

Additionally, as illustrated inFIG. 52, the two sub-assemblies may be further connected to each other via a plurality of actuators2130. The actuators2130in the illustrated embodiment are screw actuators that are similar in construction and function to the screw actuators1730. Similar to actuators1730, each actuator2130in the illustrated embodiment comprises a screw2132that extends through an upper outer member or sleeve2134and a lower outer member or sleeve2136. Rotation of the screw2132is effective to radially expand or compress the frame assembly2100as previously described. In other embodiments, the actuators can be push-pull type actuators as previously described in connection with the embodiments ofFIGS. 1, 8, 12 and 21and/or any of various actuators described in the incorporated patents and/or applications.

Additionally, a pair of commissure attachment members2140can be mounted to the upper end portion of each actuator2130. The commissure attachment members2140of each pair can extend from diametrically opposing sides of an upper sleeve2134of an actuator2130. Each pair of commissure attachment members2140can be used to secure a pair of commissure tabs1914(FIG. 46) of a leaflet assembly. Each commissure tab1914of a leaflet1912can be secured to a respective commissure attachment member2140by placing the commissure tab1914against the commissure attachment member2140and suturing the commissure tab1914in place against the commissure attachment member2140. The sutures can extend through the commissure tab1914and openings2142in the commissure attachment member2140. The inflow edges of the leaflets can be secured to the struts2112,2114of the inner frame sub-assembly, as described above in connection withFIG. 45. A skirt (e.g., a skirt940) can be secured to the frame assembly2100, as previously described in connection with the embodiments ofFIGS. 46-48.

General Considerations

It should be understood that the disclosed embodiments can be adapted for use with prosthetic devices that are implantable in any of the native annuluses of the heart (e.g., the pulmonary, mitral, and tricuspid annuluses), and can be used with any of various delivery approaches (e.g., retrograde, antegrade, transseptal, transventricular, transatrial, etc.). The disclosed embodiments can also be used with prostheses implanted in other lumens of the body.

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. The technologies from any example can be combined with the technologies described in any one or more of the other examples. In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosed technology.

As used herein, the term “proximal” refers to a position, direction, or portion of a device that is closer to the user and further away from the implantation site. As used herein, the term “distal” refers to a position, direction, or portion of a device that is further away from the user and closer to the implantation site. Thus, for example, proximal motion of a device is motion of the device toward the user, while distal motion of the device is motion of the device away from the user. The terms “longitudinal” and “axial” refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

As used herein, operations that occur “simultaneously” or “concurrently” occur generally at the same time as one another, although delays in the occurrence of one operation relative to the other due to, for example, spacing, play or backlash between components in a mechanical linkage such as threads, gears, etc., are expressly within the scope of the above terms, absent specific contrary language.