Embeddable frame

Abstract

An apparatus and method for implanting a frame within a subject's body is provided. An apparatus and method are described in which an implantable frame (20) having struts (98, 99) defining cells (93) is placed within a delivery device (40) to transition the frame (20) from its radially unconstrained configuration to its radially constrained configuration, thereby causing at least a portion of the cells (93) to elongate and curve circumferentially about the longitudinal axis of the frame (20), such that, for each of the portions of the cells (93), the tips (94) of the cells (93) are no longer circumferentially aligned with the bases (96) of the cells (93). Releasing the implantable frame (40) from the delivery device (40) transitions the frame (20) from its radially unconstrained configuration to its radially unconstrained configuration. Other applications are also described.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 405,966 to Karni, entitled "Atrioventricular valve replacement," filed September 13, 2022, and incorporated herein by reference.

[0002] The present invention relates to medical devices and methods, and more particularly to devices and methods for implanting a frame within a subject's body. [Background technology]

[0003] The human heart is a muscular organ that pumps deoxygenated blood through the lungs, oxygenates the blood, and pumps the oxygenated blood to the rest of the body through the contraction of its four chambers.

[0004] After circulating throughout the body, deoxygenated blood enters the right atrium through the vena cava. In healthy individuals, the right atrium contracts, pumping blood through the tricuspid valve into the right ventricle. The right ventricle contracts, pumping blood through the pulmonary semilunar valve into the pulmonary artery, which divides into two branches, one for each lung. As the blood passes through the lungs, it picks up oxygen and re-enters the heart via the left atrium. The left atrium contracts, pumping oxygenated blood into the left ventricle through the mitral valve. The left ventricle contracts, pumping oxygenated blood through the aortic valve into the aorta for distribution to the rest of the body. The tricuspid valve closes during right ventricular contraction, preventing blood from flowing backward into the right atrium. Similarly, the mitral valve closes during left ventricular contraction, preventing blood from flowing backward into the left atrium. The mitral and tricuspid valves are known as atrioventricular valves, and each controls blood flow between the atria and ventricles.

[0005] In the mitral valve, the mitral annulus defines the mitral orifice. Anterior and posterior leaflets extend from the annulus. The leaflets are connected by cords to papillary muscles in the left ventricle.

[0006] During ventricular diastole, in a healthy individual, the left atrium contracts, forcing blood through the mitral valve orifice into the left ventricle. Blood flows through the orifice and, with little resistance, pushes the valve leaflets apart and into the left ventricle. In a healthy individual, the aortic valve leaflets are held closed by blood pressure in the aorta.

[0007] During ventricular systole, the left ventricle contracts, forcing blood through the aortic valve into the aorta, forcing the aortic valve leaflets open. In healthy individuals, the mitral valve annulus contracts, pushing the leaflets inward and reducing the area of ​​the mitral orifice by approximately 20% to 30%. The leaflets coapt to accommodate the extra leaflet surface area, creating a coaptation surface that constitutes a seal. Blood pressure in the left ventricle presses against the ventricular surfaces of the leaflets, forcing them together at their coaptation surfaces to form a tight, leak-tight seal.

[0008] Effective sealing of the mitral valve during ventricular systole depends on adequate coaptation. Inadequate coaptation can be caused by a number of physical abnormalities that allow leaflet prolapse (e.g., elongated or ruptured cords or weak papillary muscles) or prevent coaptation (e.g., short cords or small leaflets). Other pathologies that lead to mitral valve dysfunction include collagen vascular disease, ischemic mitral regurgitation (e.g., resulting from myocardial infarction, chronic heart failure, or failed / unsuccessful surgical or catheter revascularization), myxomatous degeneration of the valve leaflets, and rheumatic heart disease. Mitral regurgitation leads to a number of complications, including arrhythmias, atrial fibrillation, palpitations, chest pain, congestive heart failure, syncope, fatigue, low cardiac output, orthopnea, paroxysmal nocturnal dyspnea, pulmonary edema, shortness of breath, and sudden death.

[0009] The tricuspid valve contains three leaflets: the septal, anterior, and posterior leaflets. Each leaflet is attached to a tricuspid annulus, which defines the tricuspid orifice. The leaflets are connected by chordal tissue to the papillary muscles in the right ventricle. In healthy individuals, the tricuspid valve controls the direction of blood flow from the right atrium to the right ventricle in a manner similar to the control of blood flow in the left side of the heart by the mitral valve. During ventricular diastole, the tricuspid valve opens to allow blood flow from the right atrium to the right ventricle, and during ventricular systole, the tricuspid valve leaflets coapt to prevent backflow of blood from the right ventricle to the right atrium.

[0010] Tricuspid regurgitation occurs when the tricuspid valve does not close properly, which can allow blood to flow backward into the right atrium when the right ventricle contracts. Tricuspid regurgitation is most commonly caused by dilation of the right ventricle, which leads to dilation of the tricuspid annulus, preventing the leaflets from coapting properly. Summary of the Invention

[0011] According to some applications of the present invention, an implantable frame includes struts that define cells. The cells are shaped to define a radially unconstrained configuration, and the frame is configured to be delivered into a subject's body while the frame is held within a delivery device in the radially constrained configuration. When transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame, at least a portion of the cells are configured to elongate and curve circumferentially about the longitudinal axis of the frame, such that, for each of the cell subsets, the cell tips are no longer circumferentially aligned with the cell bases. Typically, in the radially constrained configuration of the frame, each cell belonging to the cell subset is configured to have a shorter axial length than when the cell subset is configured such that the cell tips are circumferentially aligned with the cell bases. This is because, in addition to extending axially, the cells are also curved circumferentially about the axis of the valve frame. This, in turn, typically results in a shorter overall length of the valve frame when the valve frame is in its crimped configuration. In some cases, this is advantageous because the valve frame is relatively stiff when in its crimped configuration, but during delivery, the valve frame typically must negotiate curves, for example, within a blood vessel and / or the left atrium. The relatively short axial length of some of the cells is configured to facilitate navigating curves in anatomical structures, such as curved blood vessels, and / or delivery of the implantable frame within a cardiac chamber, such as the left atrium.

[0012] In some applications of the present invention, an implantable frame includes struts that define cells. At the end of the frame, a first set of cells includes a connector for connecting the frame to a delivery device, and a second set of cells does not include a connector. Typically, the first set of cells is shaped such that, in the frame's radially unconstrained configuration, the length of the first set of cells is the same as the length of the second set of cells, so that the connectors do not protrude from the end of the frame. Thus, when the frame is deployed within a subject's body (e.g., within the subject's heart), the connectors do not protrude from the end of the frame and may injure the subject's tissue. Furthermore, typically, the struts that define the first set of cells are longer than the struts that define the second set of cells, so that, in the frame's radially constrained configuration, the length of the first set of cells is greater than the length of the second set of cells, and the connectors protrude from the end of the frame. Thus, during delivery of the device, the connectors may be coupled to a portion of the delivery device, such as a fixation element, such as a clip or protrusion, within the delivery device (e.g., a fixation element within the nosecone of the delivery device).

[0013] In some applications of the present invention, the implantable frame is a valve frame for use with a prosthetic valve configured to be deployed within a native atrioventricular valve (e.g., a mitral valve or a tricuspid valve). In some such applications, the valve frame includes a valve frame body including a cylindrical portion and an atrial portion. Typically, the cylindrical portion is configured to support the prosthetic valve within the native atrioventricular valve. For example, the leaflets of the prosthetic valve may be sewn to and / or otherwise coupled to the cylindrical portion. Typically, the atrial portion is configured to be deployed at least partially within an atrium of the subject. Further typically, the cylindrical portion is configured to be deployed at least partially within a ventricle of the subject.

[0014] For some applications, the atrial portion includes a discoid portion (also referred to herein as a flange) and a frusto-conical portion. Typically, the discoid portion of the atrial portion is configured to seal the valve frame against tissue on the atrial side of the native atrioventricular valve annulus and further configured to prevent migration of the valve frame into the ventricle. Typically, the frusto-conical portion extends from the discoid portion of the atrial portion to the outer surface of the cylindrical portion. For some applications, including the frusto-conical portion between the discoid portion and the cylindrical portion (as opposed to directly bonding the discoid portion to the cylindrical portion) reduces the likelihood of reflux around the outer periphery of the cylindrical portion.

[0015] In some applications, multiple cord mobilization arms (e.g., more than two and / or less than twelve arms) extend from a portion of the valve frame body configured to be placed in a ventricle of a subject. For example, four cord mobilization arms or six cord mobilization arms may extend from the valve frame body. In some applications, a single cord mobilization arm extends from a portion of the valve frame body configured to be placed in a ventricle of a subject. Typically, the cord mobilization arm extends from a cylindrical portion of the valve frame body. More typically, the cord mobilization arm extends from the ventricular end of the cylindrical portion (i.e., the end of the valve frame body configured to be placed in a ventricle). Typically, the arm extends radially from the valve frame body in addition to extending axially from the ventricular end of the valve frame body toward the atrial end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the atrium). More typically, the arm curves along the outside of the valve frame body in a given circumferential curvature direction.

[0016] It should be noted that although cell designs are described herein in the context of particular types of implantable valve frames, the scope of the present disclosure includes applying such designs mutatis mutandis to frames of other medical devices, such as stents, and / or frames of other types of implantable valves.

[0017] Thus, according to some embodiments of the present invention there is provided an apparatus for use with a delivery device, the apparatus comprising: an implantable frame including struts that define cells; the cells are shaped to define a radially unconstrained configuration, and the frame is configured to be delivered into a subject's body while the frame is held within a delivery device in a radially constrained configuration; A device is provided in which at least a portion of the cells are configured to stretch and curve circumferentially about the longitudinal axis of the frame when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame, such that for each of a portion of the cells, the tip of the cell is no longer circumferentially aligned with the base of the cell.

[0018] In some embodiments, the implantable frame is made of a shape memory material, and a portion of the cells are shaped to stretch and curve circumferentially about the longitudinal axis of the frame when transitioning from a radially unconstrained configuration of the frame to a radially constrained configuration of the frame.

[0019] In some embodiments, within each cell within the subset of cells, the struts on one side of the cell are longer than the struts on the other side of the cell so as to cause the cell to elongate and curve circumferentially about the longitudinal axis of the frame when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame.

[0020] In some embodiments, in a radially constrained configuration of the frame, each cell in the cell subset is configured to have a shorter axial length than when the cell subset is configured such that the tip of the cell is circumferentially aligned with the base of the cell.

[0021] In some embodiments, the implantable frame is configured to be delivered through one or more curved blood vessels, and an axial length of a portion of the cells is configured to facilitate delivery of the implantable frame through the one or more curved blood vessels.

[0022] In some embodiments, the implantable frame is configured to be delivered through a cardiac chamber, and an axial length of a portion of the cells is configured to facilitate delivery of the implantable frame through the cardiac chamber.

[0023] In some embodiments, the implantable frame comprises an implantable stent.

[0024] In some embodiments, the implantable frame includes an implantable valve frame configured to be implanted in the subject's native valve, and the device further includes a plurality of prosthetic valve leaflets coupled to the implantable valve frame.

[0025] In some embodiments, the implantable valve frame comprises an implantable valve frame configured to be implanted in a subject's native atrioventricular valve.

[0026] In some embodiments, the implantable valve frame comprises: an atrial portion including a disc-shaped portion and a truncated cone-shaped portion configured to be deployed on the atrial side of the annulus of the atrioventricular valve; a barrel to which the prosthetic valve leaflets are coupled, the barrel configured to be deployed so that a ventricular end of the barrel is positioned within the subject's ventricle; Some of the cells configured to elongate and curve circumferentially about the longitudinal axis of the frame include cells in the discoid portion of the atrial section of the frame.

[0027] In some embodiments, the frusto-conical portion of the atrial section is coupled to the cylindrical portion such that there is axial overlap between at least the frusto-conical portion of the atrial section and the cylindrical portion.

[0028] In some embodiments, the frusto-conical portion of the atrial section is coupled to the cylindrical section such that the frusto-conical portion of the atrial section extends from an axial position along the cylindrical section that is the bottom 50 percent of the height of the cylindrical section.

[0029] In some embodiments, the implantable valve frame further includes a plurality of chordal tissue mobilizing arms configured to extend at least radially from the ventricular end of the barrel.

[0030] In some embodiments, the valve frame is configured to be delivered to the atrioventricular valve; Then, the plurality of chordal tissue recruitment arms are configured to be deployed between the chordal tissue of the native atrioventricular valve; Subsequently, at least a portion of the valve frame is configured to be rotated by the delivery device to mobilize and flex at least a portion of the chordal tissue, thereby causing the multiple chordal tissue mobilizing arms to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) twist the native atrioventricular valve around the valve frame.

[0031] According to some embodiments of the present invention, placing an implantable frame including struts defining the cells within a delivery device such that the frame transitions from a radially unconstrained configuration of the frame to a radially constrained configuration of the frame, thereby causing at least a portion of the cells to elongate and curve circumferentially about a longitudinal axis of the frame so that, for each of a portion of the cells, a tip of the cell is no longer circumferentially aligned with a base of the cell; delivering the implantable frame to a deployment location within the subject's body; and Releasing the implantable frame from the delivery device thereby transitioning the frame from the radially constrained frame configuration to the radially unconstrained frame configuration. There is further provided a method comprising:

[0032] According to some embodiments of the present invention there is provided an apparatus for use with a delivery device, the apparatus comprising: an implantable frame including struts that define cells; at an end of the frame, a first set of cells includes a coupling portion for coupling the frame to a delivery device, and a second set of cells does not include a coupling portion; the first set of cells are shaped such that in a radially unconstrained configuration of the frame, the length of the first set of cells is the same as the length of the second set of cells, so that the joint does not protrude beyond the end of the frame; The struts defining the first set of cells are longer than the struts defining the second set of cells, such that in a radially constrained configuration of the frame, the length of the first set of cells is greater than the length of the second set of cells, and the joints protrude beyond the ends of the frame. An apparatus is also provided.

[0033] In some embodiments, the frame is configured to assume its radially unconstrained configuration when deployed within a subject's body, and when the frame is in its radially unconstrained configuration, the joints do not protrude from the ends of the frame, thereby reducing the risk of the joints injuring the subject's tissue compared to if the joints protruded from the ends of the frame.

[0034] In some embodiments, the implantable frame comprises an implantable stent.

[0035] In some embodiments, the delivery device includes a fixation element configured to couple the coupling portion, the implantable frame is configured to be delivered into the body of a subject when placed within the delivery device in a radially constrained configuration, and the coupling portion is configured to protrude from an end of the frame to facilitate coupling of the coupling portion to the fixation element of the delivery device.

[0036] In some embodiments, the delivery device includes a distal nosecone including a fixation element, and the coupling portion is configured to protrude from an end of the frame to facilitate coupling of the coupling portion to the fixation element of the distal nosecone of the delivery device.

[0037] In some embodiments, when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame, at least some of the cells of the frame at the second end of the frame are configured to stretch and curve circumferentially about the longitudinal axis of the frame such that, for each of some of the cells, the tip of the cell is no longer circumferentially aligned with the base of the cell.

[0038] In some embodiments, in a radially constrained configuration of the frame, each cell in the cell subset is configured to have a shorter axial length than when the cell subset is configured such that the tip of the cell is circumferentially aligned with the base of the cell.

[0039] In some embodiments, the implantable frame is configured to be delivered through one or more curved blood vessels, and an axial length of a portion of the cells is configured to facilitate delivery of the implantable frame through the one or more curved blood vessels.

[0040] In some embodiments, the implantable frame is configured to be delivered through a cardiac chamber, and an axial length of a portion of the cells is configured to facilitate delivery of the implantable frame through the cardiac chamber.

[0041] In some embodiments, the implantable frame includes an implantable valve frame configured to be implanted in the subject's native valve, and the device further includes a plurality of prosthetic valve leaflets coupled to the implantable valve frame.

[0042] In some embodiments, the implantable valve frame comprises an implantable valve frame configured to be implanted in a subject's native atrioventricular valve.

[0043] In some embodiments, the implantable valve frame comprises: an atrial portion including a disc-shaped portion and a truncated cone-shaped portion configured to be deployed on the atrial side of the annulus of the atrioventricular valve; a barrel to which the prosthetic valve leaflets are coupled, the barrel configured to be deployed so that a ventricular end of the barrel is positioned within the subject's ventricle; The first set of cells and the second set of cells are positioned at the ventricular end of the cylindrical portion of the implantable valve frame.

[0044] In some embodiments, the frusto-conical portion of the atrial section is coupled to the cylindrical portion such that there is axial overlap between at least the frusto-conical portion of the atrial section and the cylindrical portion.

[0045] In some embodiments, the frusto-conical portion of the atrial section is coupled to the cylindrical section such that the frusto-conical portion of the atrial section extends from an axial position along the cylindrical section that is the bottom 50 percent of the height of the cylindrical section.

[0046] In some embodiments, the implantable valve frame further includes a plurality of chordal tissue mobilizing arms configured to extend at least radially from the ventricular end of the barrel.

[0047] In some embodiments, the valve frame is configured to be delivered to the atrioventricular valve; Then, the plurality of chordal tissue recruitment arms are configured to be deployed between the chordal tissue of the native atrioventricular valve; Subsequently, at least a portion of the valve frame is configured to be rotated by the delivery device to mobilize and flex at least a portion of the chordal tissue, thereby causing the multiple chordal tissue mobilizing arms to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) twist the native atrioventricular valve around the valve frame.

[0048] According to some embodiments of the present invention, placing an implantable frame including struts defining cells within a delivery device to transition the frame from a radially unconstrained configuration of the frame to a radially constrained configuration of the frame; placing the frame such that at an end of the frame, a first set of cells include couplings for coupling the frame to the delivery device and a second set of cells do not include couplings, and the struts defining the first set of cells are longer than the struts defining the second set of cells, such that in a radially constrained configuration of the frame, the length of the first set of cells is greater than the length of the second set of cells and the couplings protrude from the end of the frame; delivering the implantable frame to a deployment location within the subject's body; and Releasing the implantable frame from the delivery device, thereby transitioning the frame from the radially constrained frame configuration to the radially unconstrained frame configuration, wherein the first set of cells are shaped such that in the radially unconstrained frame configuration, the length of the first set of cells is the same as the length of the second set of cells, so that the bonds do not protrude beyond the ends of the frame. There is further provided a method comprising:

[0049] The present invention will be more fully understood from the following detailed description of its application, taken in conjunction with the drawings in which: [Brief explanation of the drawings]

[0050] [Figure 1A-C] 1A-1C are schematic diagrams of respective views of a valve frame configured to support a prosthetic valve within a subject's native atrioventricular valve, showing the valve frame positioned in a radially unconstrained configuration, in accordance with some applications of the present invention. [Figure 1D] 1A, 1B, and 1C in a radially unconstrained configuration, showing the valve leaflets and a coating material attached to the valve frame, in accordance with some applications of the present invention. [Figure 2A-B] 1A, 1B, and 1C, fully positioned within a delivery device (FIG. 2A), and with the chordal tissue mobilization arms of the valve frame in a "rotated configuration" (FIG. 2B), in accordance with some applications of the present invention. [Figure 3A-B] 1A-1C are schematic diagrams of respective views of the atrial portion of a valve frame, in accordance with some applications of the present invention. [Figure 4A-B] 1A-1C are schematic diagrams of top views of the atrial and cylindrical portions of a valve frame according to respective applications of the present invention. [Figure 5A] 1 is a schematic diagram of a side view of a cylindrical portion of a valve frame, according to some applications of the present invention. [Figure 5B] 1 is a schematic diagram of an atrial portion of a valve frame coupled to a cylindrical portion of a valve frame, in accordance with some applications of the present invention. [Figure 6A]10A-10C are schematic diagrams of chordal tissue mobilization arms of a valve frame, according to some applications of the present invention. [Figure 6B] FIG. 6B is a schematic diagram of the chordal tissue mobilization arms of FIG. 6A coupled to a cylindrical portion of a valve frame, according to some applications of the present invention. [Figure 7A-B] 7A and 7B are schematic diagrams of chordal tissue mobilization arms of a valve frame arranged in a radially unconstrained configuration (FIG. 7A) and when the lower ends of the arms are held within a delivery device but the upper ends of the arms are released from the delivery device (FIG. 7B), according to some applications of the present invention. [Figure 8A-C] 1A-1C are schematic diagrams of respective views of a valve frame in its radially unconstrained configuration, according to some applications of the present invention. [Figure 9A-B] 1A-1C are schematic diagrams of respective views of a valve frame body of a valve frame, according to some applications of the present invention. [Figure 10A-B] 12 is a schematic diagram of the atrial portion of a valve frame in which struts in the atrial portion have an undulating pattern, in accordance with some applications of the present invention. [Figure 10C-F] 1 is a schematic illustration of an atrial section undergoing crimping, in accordance with some applications of the present invention. [Figure 10G-J] 1 is a schematic diagram of an atrial portion of a valve frame undergoing crimping, in accordance with some applications of the present invention. [Figure 10K] FIG. 10C is a schematic diagram of a single repeating structure (i.e., a repeating structure) for the atrial portion of the valve frame configured as shown in FIGS. 10G-10J. [Figures 11A-F] 1A-1D are schematic illustrations of steps in the deployment of a prosthetic mitral valve via a transseptal approach, in accordance with some applications of the present invention. [Figure 12A-C] 10A-10C are schematic diagrams of cells at the distal end of the cylindrical portion of the valve frame in respective configurations, according to some applications of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0051] Reference is now made to Figures 1A, 1B, and 1C, which are schematic illustrations of respective views of a valve frame 20, illustrating the valve frame in its radially unconstrained configuration, in accordance with some applications of the present invention. Figure 1A illustrates a side view of the valve frame, Figure 1B illustrates a bottom view (i.e., a view from the ventricular end of the valve frame), and Figure 1C illustrates a top view (i.e., a view from the atrial end of the valve frame). Reference is also made to Figure 1D, which is a schematic illustration of a valve frame 20 having valve leaflets 23 coupled thereto, in accordance with some applications of the present invention.

[0052] Typically, the valve frame includes a valve frame body 21. For some applications, the valve frame body 21 includes a cylindrical portion 22 and an atrial portion 26. Typically, the cylindrical portion is configured to support a prosthetic valve within a native atrioventricular valve. For example, the leaflets 23 of the prosthetic valve may be sutured and / or otherwise coupled to the cylindrical portion, as shown, for example, in FIG. 1D . Typically, the atrial portion 26 is configured to be at least partially deployed within the atrium of a subject. For some applications, the atrial portion 26 includes a disc-shaped portion 28 (also referred to herein as a flange) and a frusto-conical portion 30.

[0053] Typically, the discoid portion of the atrial portion is configured to seal the valve frame against tissue on the atrial side of the mitral valve annulus and further configured to prevent migration of the valve frame into the left ventricle. The frustoconical portion typically extends from the discoid portion of the atrial portion to the outer surface of the cylindrical portion. In some applications, including the frustoconical portion between the discoid portion and the cylindrical portion (as opposed to directly bonding the discoid portion to the cylindrical portion) reduces the likelihood of regurgitation around the outer periphery of the cylindrical portion.

[0054] For some applications, the cylindrical portion and the atrial portion are formed as separate pieces and are joined together, for example, via sewing, gluing, welding, and / or other methods. Alternatively, the cylindrical portion and the atrial portion are part of a single, integrally formed piece, for example, as described below with reference to Figures 8A-8C.

[0055] Typically, the valve frame 20 is made of a shape-memory material (e.g., nitinol and / or a shape-memory alloy such as copper-aluminum-nickel) that is covered on one or both sides with a covering material 32 (shown in FIG. 1D ), such as a fabric and / or polymer (e.g., expanded polytetrafluoroethylene (ePTFE) or woven, knitted, meshed, and / or braided polyester). Typically, the shape-memory material in the cylindrical section 22 and the atrial section 26 is formed into a stent-like structure that includes struts and / or cells of shape-memory material. The covering material is typically connected to the shape-memory material via stitches 34 (shown in FIG. 1D ). It should be noted that, for illustrative purposes, FIGS. 1A-1C (and FIGS. 3A-10B ) show the valve frame 20 without the valve leaflets 23 and covering material 32. However, the valve leaflets 23 and covering material 32 may be observed in FIG. 1D .

[0056] In some applications, multiple cord mobilization arms 24 (e.g., more than two and / or less than twelve arms) extend from a portion of the valve frame body 21 configured to be placed in a ventricle of a subject. For example, four cord mobilization arms or six cord mobilization arms may extend from the valve frame body. In some applications, a single cord mobilization arm 24 extends from a portion of the valve frame body 21 configured to be placed in a ventricle of a subject. Typically, the cord mobilization arm extends from the cylindrical portion 22 of the valve frame body 21. More typically, the cord mobilization arm extends from the ventricular end of the cylindrical portion (i.e., the end of the valve frame body configured to be placed in a ventricle). Typically, in the radially unconstrained configuration of the valve frame (which the valve frame typically assumes when neither the valve frame body nor the chordae mobilization arms are constrained by a delivery device), the arms extend radially from the valve frame body in addition to extending axially from the ventricular end of the valve frame body toward the atrial end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the atrium).More typically, the arms curve along the outside of the valve frame body in a given circumferential curvature direction.

[0057] It should be noted that a description herein of an arm extending in a given direction from a valve frame body should not be construed as excluding additional directions in which the arm may be oriented. Rather, a description (or claim) of an arm as extending radially from the valve frame body should be construed to mean that the orientation of the arm relative to the valve frame body includes a radial component. Typically, in addition to extending radially from the valve frame body, the arms are curved circumferentially, and in some cases, the orientation of the arms includes an axial component. In some applications, along at least a portion of the arms, and at least in certain configurations of the arms, the arms are oriented tangentially relative to the valve frame body.

[0058] Typically, the valve frame 20 with the prosthetic valve leaflets 23 disposed therein is delivered to the native atrioventricular valve via a delivery device 40 (e.g., a delivery catheter shown in FIG. 2 ), which is configured to maintain the valve frame and prosthetic valve in a radially constrained configuration (i.e., a “crimped” configuration) during delivery. Depending on the application, the valve frame is delivered transapically (i.e., through the apex of the left ventricle), transseptally (i.e., through the vena cava, right atrium, and interatrial septum, as described in detail with reference to FIGS. 11A through 11F ), and / or via a different delivery route. In some applications, when the distal end of the delivery device is positioned within the subject's ventricle, the chord mobilizing arms 24 are deployed between the chords of the native atrioventricular valve. Typically, the chord mobilizing arms are deployed between the chords of the native atrioventricular valve by releasing them from the delivery device, with the chord mobilizing arms configured to extend from the valve frame body upon release from the delivery device. In some applications, additional techniques are used to release the cord mobilization arms from the delivery device, thereby allowing the cord mobilization arms to be deployed between the cords of the native atrioventricular valve. For example, the valve frame may include lever elements configured to radially extend the cord mobilization arms (e.g., as described below with reference to Figures 7A-7B). Alternatively or additionally, the arms are coupled to the barrel of the valve frame via stitches that act as hinges, so that the arms pivot about the stitches relative to the barrel, as described below. Typically, the cord mobilization arms are released from the delivery device while the valve frame body is still maintained in at least a partial radially constrained configuration by the delivery device. Typically, the valve frame is rotated while the cord mobilization arms and the valve frame body are configured in the aforementioned configuration. Thus, in this application, the configuration of the cord mobilization arms when the cord mobilization arms are released from the delivery device but the valve frame body is still maintained in at least a partial radially constrained configuration by the delivery device is referred to as the "rotated configuration" of the cord mobilization arms.

[0059] Reference is now made to Figures 2A and 2B. Figure 2A is a schematic illustration of a valve frame 20 fully disposed within a delivery device 40, typically including a proximal overtube 41 and a nosecone 43, according to some applications of the present invention. Figure 2B is a schematic illustration of a valve frame 20 with the chordal tissue mobilization arms disposed in its rotated configuration (i.e., when the chordal tissue mobilization arms 24 of the valve frame have been released from the delivery device 40, while the valve frame body 21 of the valve frame is still maintained in at least a partial radially constrained configuration by the delivery device), according to some applications of the present invention. It should be noted that Figure 2B shows a delivery device and arms configured for insertion from below the mitral valve (e.g., via transapical insertion). As shown, in some such applications, in its rotated configuration, the arms extend axially distally from the distal end of the delivery device (i.e., the end of the delivery device that is away from the insertion point of the delivery device and into the subject's body). In some applications where the delivery device is inserted above the mitral valve (e.g., via transseptal insertion, as described in more detail below with reference to FIGS. 11A-11F), in the rotated configuration, the arms extend axially from the distal end of the delivery device in a proximal direction (i.e., back toward the proximal end of the delivery device). In some applications, in the rotated configuration, the chordae mobilization arms extend radially from the valve frame and curve circumferentially along the valve frame, but are configured not to extend axially in either the proximal or distal direction. Rather, in such applications, in the rotated configuration, the arms are arranged in a single plane along the axial direction and extend radially from the valve frame.

[0060] After the chordal tissue mobilization arms 24 are deployed between the chordae of the native atrioventricular valve (and typically while the valve frame body 21 is still maintained in at least a partial radially constrained configuration by the delivery device, as shown in FIG. 2 ), the chordal tissue mobilization arms 24 mobilize and deflect at least a portion of the chordae, causing the chordal tissue mobilization arms 24 to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) rotate at least a portion of the valve frame 20 so as to twist the native atrioventricular valve around the valve frame. In some applications, the valve frame is rotated during ventricular systole when the native atrioventricular valve is closed, so that rotation occurs when the chordae are closest to the valve frame. Alternatively, the valve frame is rotated regardless of the phase of the subject's cardiac cycle (i.e., without attempting to synchronize the rotation with a particular phase of the subject's cardiac cycle).

[0061] After rotation of the valve frame, the cylindrical portion 22 and the atrial portion 26 are typically allowed to radially expand, e.g., by releasing the cylindrical portion and the atrial portion from the delivery device, so that the valve frame assumes its radially unconstrained configuration. Typically, the valve frame is configured to thereby capture the native valve leaflets in a partially closed, twisted configuration, thereby at least partially sealing the space between the native atrioventricular valve and the prosthetic valve. For example, the cylindrical portion may be configured to radially expand to capture the native valve leaflets between the cylindrical portion and the chordal tissue recruitment arms, and / or the atrial portion may be configured to radially expand to capture the native valve leaflets between the atrial portion and the chordal tissue recruitment arms.

[0062] Typically, the chord recruitment arms 24 are configured to curve in a given circumferential direction relative to the longitudinal axis of the valve frame, both when the arms are deployed between the chordae (i.e., when the arms are disposed in their rotated configuration), as described in more detail below, and when the cylindrical portion 22 and the atrial portion 26 are allowed to radially expand (i.e., when the valve frame is in its radially unconstrained configuration). For example, the arms may curve clockwise or counterclockwise relative to the longitudinal axis of the valve frame. Typically, after the chord recruitment arms 24 are deployed between the chordae of a native atrioventricular valve (and typically while the valve frame body 21 is still maintained in at least a partially radially constrained configuration by the delivery device, as shown in FIG. 2 , when the arms are disposed in their rotated configuration), the valve frame is rotated in the same circumferential direction as the circumferential curvature of the arms. In some applications, before rotating the valve frame in this direction, the valve frame is rotated in the opposite circumferential direction. For example, if the arms are curved in a clockwise circumferential direction, after the arms are deployed between the cords, the valve frame may first be rotated in a counterclockwise direction and then in a clockwise direction, which in some applications may facilitate mobilization of a larger portion of the cords than simply rotating the valve frame in the direction of the circumferential curvature of the arms.

[0063] As described in the paragraph above, in some applications, before rotating the valve frame in the same circumferential direction as the circumferential bending direction of the arms, the valve frame is rotated in the opposite circumferential direction. In some applications, the delivery device is configured to perform an initial rotation of the valve frame a given angle opposite to the circumferential bending direction of the arms, and then rotate the valve frame a predetermined angle in the circumferential bending direction of the arms. In some applications, in the rotational configuration of the cord-mobilizing arms, the outer surface of each arm has a smooth, convex curvature extending substantially along the entire length of the arm, so that during the initial rotation (opposite to the circumferential bending direction of the arms), the cords slide over the outer surface of the arm without being mobilized or captured by the arm. In some applications, this shape of the arms allows the initial rotation of the valve frame to position a relatively large number of cords to be mobilized by the respective arms in subsequent rotation steps. During subsequent rotations of the valve frame (in the circumferential bending direction of the arms), the cords are mobilized and deflected by the arms. Typically, in the rotational configuration of the chord mobilization arms, the inner surface of each arm has a concave curvature, and the chords are mobilized within the space defined by the concave curvature during subsequent rotation by the valve frame.

[0064] Referring again to FIG. 1D , in some applications, the covering material 32 defines slits 42. Typically, when the valve frame 20 is disposed within its radially constrained configuration within the delivery device, the cells of the valve frame are axially elongated. In some applications, the slits 42 are configured to allow the cells of the valve frame to elongate axially without tearing the covering material, with the axially elongated cells extending through the slits. Typically, when the valve frame is released from the delivery device and assumes its radially unconstrained configuration, the cells are reinserted into the slits so that they are covered by the covering material. Note that, for purposes of illustration, in FIG. 1D , the tips of the cells are shown protruding from the slits even in the radially unconstrained configuration of the valve frame.

[0065] Reference is now made to FIGS. 3A and 3B, which are schematic illustrations of respective views of the atrial section 26, according to some applications of the present invention. FIG. 3A illustrates a three-dimensional side view, and FIG. 3B illustrates a top view. As noted above, the atrial section 26 is typically configured to be at least partially deployed within a subject's atrium. In some applications, the atrial section 26 includes a discoid portion 28 (also referred to herein as a flange) and a frustoconical portion 30. The discoid portion is typically configured to rest on the native mitral valve annulus, with the frustoconical portion extending from the discoid portion of the atrial section to the cylindrical portion 22. The discoid portion of the atrial section is typically configured to seal the valve frame against tissue on the atrial side of the mitral valve annulus and further to prevent movement of the valve frame into the left ventricle. In some applications, the cells of the flange include spring portions 44. The spring portions are configured to provide flexibility to the cells, allowing the flange to adapt its shape to conform to changes in the shape of the atrial tissue with which it contacts during heart movement. Alternatively or additionally, the cells of the flange may have an undulating pattern of struts within the cells themselves, as described in more detail below with reference to Figures 10A-10B. In some applications, including a frustoconical portion between the discoid portion and the cylindrical portion (as opposed to directly connecting the discoid portion to the cylindrical portion) reduces the likelihood of regurgitation around the outer periphery of the cylindrical portion. Depending on the application, the flange may be positioned within a plane perpendicular to the longitudinal axis defined by the cylindrical portion, or at an angle relative to such a plane. For example, the flange may define an upward or downward angle relative to the plane perpendicular to the longitudinal axis defined by the cylindrical portion to best conform to the various anatomical structures surrounding the native atrioventricular valve in either the atrium or ventricle.

[0066] In some applications, the frustoconical portion defines holes 50 at the bottom of at least some of the cells of the frustoconical portion. Typically, the holes are configured to facilitate suturing of the atrial portion to the cylindrical portion of the valve frame. In some applications, pairs 52 of struts 54 extend from each cell of the discoid portion 28 of the atrial portion. The strut pairs converge at points 56. In some applications, the strut pairs are configured to pierce the tissue of the subject's heart (e.g., the tissue of the valve annulus) with the points 56. As described above, the valve frame is typically rotated to mobilize the chordae of the native valve, and the valve frame body is then allowed to radially expand. In some cases, the valve frame is subject to recoil and tends to rotate in a direction opposite to the direction of rotation. Typically, by piercing the tissue of the subject's heart with the points 56 (and becoming embedded in the tissue), the strut pairs are configured to act as anti-recoil elements by preventing rotation of the valve frame in a direction opposite to the direction of rotation.

[0067] Reference is now made to Figures 4A and 4B, which are schematic illustrations of top views of the atrial section 26 and cylindrical section 22, according to respective applications of the present invention. As described with reference to Figures 3A and 3B, in some applications, pairs 52 of struts 54 extend from each cell of the discoid portion 28 of the atrial section. Typically, the strut pairs are configured to act as anti-recoil elements by preventing rotation of the valve frame in the direction opposite to the direction of rotation. In some applications, the strut pairs further facilitate fixation of the atrial section to the native tissue.

[0068] As shown in FIG. 4A , in some applications, the strut pairs are curved circumferentially relative to the axis of the valve frame. Typically, the curvature of the strut pairs is configured to facilitate anti-recoil functionality, with the curved struts facing the direction in which the valve frame tends to rotate. For example, in the example shown in FIG. 4A , the valve frame is configured to initially rotate clockwise (when viewed from above, as shown in FIG. 4A ). Thus, in some cases, the valve frame tends to recoil and rotate counterclockwise. The curvature of the strut pairs is such that, as the valve frame begins to rotate counterclockwise, the pointy ends 56 of the strut pairs 52 are pushed into (and at least partially embedded within) the tissue of the subject's heart, thereby resisting further rotation of the valve frame.

[0069] Typically, each strut 54 of a given pair 52 is configured to extend from a strut on each side (i.e., left or right) of a cell of the atrial discoid portion 28. As shown in Figure 4A, in some applications, each strut 54 of a given pair 52 is configured to extend from a strut on each side of the outer half of a cell of the atrial discoid portion 28. Alternatively, as shown in Figure 4B, each strut 54 of a given pair 52 is configured to extend from a strut on each side (i.e., left or right) of an inner half of a cell of the atrial discoid portion 28.

[0070] In some applications, in addition to being curved (as described with reference to FIG. 4A ), the pair 52 of struts 54 is twisted relative to the cell from which it extends. For example, as shown in FIG. 4B , strut 58 is connected to strut 60 on the left medial side of the cell in the atrial discoid portion 28. Strut 62 is connected to strut 64 on the right medial side of the cell in the atrial discoid portion 28. Struts 60 and 64 form a junction 66. Strut 58 is connected to strut 60 at a location closer to junction 66 than the location of the connection between strut 62 and strut 64. This results in the pair 52 of struts 58 and 62 being twisted relative to the atrial discoid portion 28. In some applications, the twist of the strut pair 52 is configured to facilitate the anti-recoil function of the strut pair by allowing the struts to embed themselves more deeply into the tissue of the subject's heart (in response to the valve frame beginning to experience recoil) than would be the case if the struts did not have a twisted configuration. In some applications, the valve frame 20 does not include an anti-recoil element as described with reference to Figures 4A-4B.

[0071] Reference is now made to FIG. 5A, which is a schematic illustration of a side view of the cylindrical portion 22, in accordance with some applications of the present invention. Reference is also made to FIG. 5B, which is a schematic illustration of the atrial portion 26 coupled to the cylindrical portion 22, in accordance with some applications of the present invention. In some applications, a plurality of struts 61 protrude from the outside of the cylindrical portion 22. In some applications, the struts protrude from the outside of the cylindrical portion 22 such that their orientation relative to the cylindrical portion has radial and axial components. In some applications, along at least a portion of the struts, the struts are oriented tangentially to the cylindrical portion. Typically, the atrial portion is coupled to the cylindrical portion by being coupled to the protruding struts 61. For example, as described above, the frustoconical portion 30 of the atrial portion 26 may define holes 50 at the bases of at least some of the cells of the frustoconical portion. For some applications, the protruding struts 61 also define holes 65, and the atrial portion is coupled to the cylindrical portion by sewn sutures through the holes 50 defined by the atrial portion and the corresponding holes 65 defined by the protruding struts 61 in the cylindrical portion 22. Alternatively or additionally, the atrial portion is coupled to the protruding struts via other means, for example, by welding (such as laser welding), adhesive, and / or a different method.

[0072] It should be noted that during crimping of the valve frame, the protruding struts 61 typically pivot about the joints where they protrude from the cylindrical portion, resulting in high strain at these joints. If the atrial portion were directly connected to the cylindrical portion at these joints, this would mean that these ends of the valve frame that experience relatively high strains are also the ends where the two components are connected to each other, making the frame more susceptible to fatigue at these ends. In contrast, because the cylindrical portion includes the protruding struts 61 and the atrial portion is connected to the cylindrical portion via struts, there is a gap between the high strain end and the end where the atrial portion is connected to the cylindrical portion.

[0073] It is further noted that protruding struts typically protrude from an axial position along the cylindrical portion that is in the lower 90 percent (e.g., the lower 70 percent, or the lower 50 percent) of the cylindrical portion's height. Typically, the cylindrical portion has a height of at least 15 mm to accommodate the attachment of the valve leaflets to the cylindrical portion. If the protruding struts protrude from the top of the cylindrical portion (or if the atrial portion is directly attached to the cylindrical portion at the top of the cylindrical portion), the entire height of the cylindrical portion will be located below the atrial portion. In contrast, because the protruding struts protrude from the lower 90 percent (e.g., the lower 70 percent, or the lower 50 percent) of the cylindrical portion's height, there is typically axial overlap between the atrial portion of the valve frame and the cylindrical portion along the height of the cylindrical portion. Typically, if there is no axial overlap between the atrial portion of the valve frame and the cylindrical portion (reducing the cylindrical portion's presence in the ventricle reduces its constraint on the ventricle), a smaller portion of the cylindrical portion's height will protrude into the subject's ventricle. Similarly, when the valve frame 20 is configured to be placed within the subject's left ventricle, obstruction of the left ventricular outflow tract is typically reduced compared to when a greater portion of the cylindrical portion protrudes into the subject's ventricle. In this regard, it should be noted that, as described above, the chordal tissue mobilization arms 24 are typically configured to mobilize and deflect at least a portion of the chordal tissue of the native atrioventricular valve, thereby (a) pulling the native atrioventricular valve radially inward toward the valve frame and (b) twisting the native atrioventricular valve around the valve frame. Such mobilization and deflection of the chordal tissue typically helps to prevent obstruction of the left ventricular outflow tract by portions of the native mitral valve apparatus.

[0074] In some applications (not shown), the atrial portion is coupled directly to the cylindrical portion (i.e., not via protruding struts). For example, the atrial portion may be coupled directly to the cells and / or cell junctions of the cylindrical portion. In some applications, the atrial portion is coupled directly to the cylindrical portion using sutures. In some such applications, the sutures act as hinges, allowing the atrial portion to move relative to the cylindrical portion. Alternatively, the atrial portion is coupled directly to the cylindrical portion using a different method, such as welding, gluing, or another method. Typically, in such cases, the coupling is such that there is axial overlap between the atrial portion and the cylindrical portion of the valve frame along the height of the cylindrical portion, as described above. That is, typically, the frustum-shaped portion of the atrial portion is coupled to the cylindrical portion such that the frustum-shaped portion of the atrial portion extends from an axial position along the cylindrical portion that is in the lower 90 percent (e.g., the lower 70 percent, or the lower 50 percent) of the height of the cylindrical portion.

[0075] Reference is now made to FIG. 6A, which is a schematic illustration of a cord mobilization arm 24 of a valve frame 20, according to some applications of the present invention. Reference is also made to FIG. 6B, which is a schematic illustration of a cord mobilization arm coupled to a cylindrical portion 22 of the valve frame. As noted above, in some applications, multiple cord mobilization arms 24 (e.g., more than two and / or less than twelve arms) extend from a portion of the valve frame body 21 configured to be placed in a subject's ventricle. For example, four cord mobilization arms or six cord mobilization arms may extend from the valve frame body. In some applications, a single cord mobilization arm 24 extends from a portion of the valve frame body 21 configured to be placed in a subject's ventricle. Typically, the cord mobilization arm extends from the cylindrical portion 22 of the valve frame body 21, as shown in FIG. 6B.

[0076] In some applications, each of the chordal tissue mobilization arms 24 is defined by a pair 70 of struts 72 extending from respective junctions at the ventricular end of the barrel 22. Typically, the struts curve to contact one another and form junctions at the arm's tip 74. In some applications, all of the chordal tissue mobilization arms are cut from a single piece 76 of shape memory material (e.g., a shape memory alloy such as nitinol and / or copper-aluminum-nickel). The piece of shape memory material defining the arms is typically bonded to the barrel of the valve frame, as described in more detail below. Typically, the arms are covered with a covering material 32 (shown in FIG. 2), e.g., fabric and / or polymer (e.g., expanded polytetrafluoroethylene (ePTFE) and / or polyester).

[0077] Typically, the chordal tissue mobilization arms 24 of the valve frame are configured to be released from the delivery device 40 while the valve frame body 21 of the valve frame is still maintained in at least a partially radially constrained configuration by the delivery device, as described above with reference to FIG. 2 . In this first configuration of the chordal tissue mobilization arms (referred to herein as the rotated configuration of the chordal tissue mobilization arms), the arms are configured to be deployed between the chordal tissue of the native atrioventricular valve and to mobilize and flex at least a portion of the chordal tissue, thereby (a) pulling the native atrioventricular valve radially inward toward the valve frame and (b) twisting the native atrioventricular valve around the valve frame. The valve frame body can then be adapted to assume its radially unconstrained configuration by releasing the valve frame body from the delivery device. Typically, the adoption of the radially unconstrained configuration by the valve frame body causes the chordal tissue mobilization arms to change from their first configuration (i.e., their rotated configuration) to a second configuration different from the first configuration. In this second configuration, the chordal tissue mobilization arms 24 are configured such that the chordal tissue and / or native valve leaflets are captured between the arms and a portion of the valve frame body. Typically, the second configuration of the arms ensures a firm fixation between the captured chordal tissue and / or native valve leaflets relative to the valve frame body and the prosthetic valve leaflets.

[0078] Typically, the first strut 72 of a strut pair 70 that includes a chord recruitment arm is longer than the second strut of the pair. The strut pair is configured such that when the strut bases are held together (when the arms are in their rotated configuration), the arms are relatively long and thin, so that they spread among, and then recruit and deflect, a relatively large number of chords. For some applications, in this configuration, the length of each arm, measured along the axis of the arm, exceeds 10 mm (e.g., greater than 20 mm, or greater than 25 mm). Typically, when the arms are in the rotated configuration, the arms are configured such that: (a) they extend radially from the valve frame body; (b) they extend axially from the ventricular end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the ventricle) toward the atrial end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the atrium); and (c) they curve along the outside of the cylinder in a given circumferential direction. As noted above, in some applications, in the rotated configuration, the chord mobilization arms are configured to extend radially from the valve frame and curve circumferentially around the valve frame, but not extend axially in either the proximal or distal direction. Rather, in such applications, in the rotated configuration, the arms extend radially from the valve frame with the arms axially disposed in a single plane.

[0079] As further described above, in some applications, in the rotational configuration of the cord recruitment arms, the outer surface of each arm has a smooth, convex curvature extending substantially along the entire length of the arm, so that during initial rotation of the valve frame (opposite the circumferential curvature of the arm), the cords slide over the outer surface of the arm without being mobilized, caught, or damaged by the arm. In some applications, this arm shape allows the initial rotation of the valve frame to position a relatively large number of cords for recruitment by the respective arms in subsequent rotation steps. During subsequent rotations of the valve frame (in the circumferential curvature of the arm), the cords are recruited and deflected by the arms. Typically, in the rotational configuration of the cord recruitment arms, the inner surface of the arm has a concave curvature, and the cords are mobilized within the space defined by the concave curvature during subsequent rotation by the valve frame.

[0080] Typically, the arms are configured such that in the second configuration (i.e., in the radially unconstrained configuration of the valve frame), the arms are shorter and the bases of the struts are farther apart so that the arms are wider (at least at the bases of the arms). Typically, the arms define the three curvatures described above in the second configuration: when the arms are in the second configuration, (a) the arms extend radially from the valve frame body, (b) the arms extend axially from the ventricular end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the ventricle) toward the atrial end of the valve frame body (i.e., the end of the valve frame body configured to be placed in the atrium), and (c) the arms curve along the outside of the cylinder in a given circumferential curvature direction.

[0081] Typically, the pieces of shape memory material 76 that define the chordal tissue mobilization arms 24 are attached to the cylindrical portion of the valve frame by stitching. In some applications, one of the struts in each arm contacts one of the struts in the adjacent arm at a junction 78. In some applications, the shape memory material defines holes 79 at the junction through which a suture is inserted, and the suture is used to create stitches 82 that attach the shape memory material to the cylindrical portion of the valve frame body.

[0082] As described above with reference to FIG. 2, typically, the chordal tissue mobilization arms 24 of the valve frame are configured to be released from the delivery device 40 while the valve frame body 21 of the valve frame is still maintained in at least a partial radially constrained configuration by the delivery device. In some applications, even at this stage, the arms are still sewn to the barrel at an axial location where they will be released from the delivery device. In some such applications, the stitches act as a hinge, causing the arms to pivot about the stitches relative to the barrel. In some applications, this allows the arms to extend radially a greater distance than would be possible if the stitches did not provide the aforementioned hinge function. Alternatively, or additionally, the valve frame includes lever elements configured to radially extend the chordal tissue mobilization arms, as described below with reference to FIGS. 7A-7B.

[0083] As shown in FIGS. 6A and 6B, the tips 74 of the cord mobilization arms 24 are typically rounded. Alternatively or additionally, a thick layer of covering material 32 (not shown in FIGS. 6A-6B) may be placed over the tips 74 of the cord mobilization arms to cushion the arms' tips. For example, a cushion 75 is shown at the tips 74 of the cord mobilization arms in FIG. 2B. Typically, the rounded and / or cushioned tips are intended to prevent the arms from abrading. This also typically facilitates movement and rotation of the arms among the subject's cords, allowing the arms to mobilize and flex the cords without damaging the cords or other surrounding tissue. In some applications, the rounded and / or cushioned tips allow the cords to be guided around the tips during valve frame rotation (e.g., bidirectional valve frame rotation as described above). In some applications, using a thick layer of covering material 32 at the tips of the arms (i.e., providing a cushion 75) facilitates fixation of the captured chordae and native valve leaflets after release of the valve frame body from the delivery device.

[0084] In some applications, the covering material 32 (shown in FIG. 1D ) is configured to provide different functions to different regions of the valve frame. For example, areas of the valve frame that typically contact the chordal tissue (e.g., the chordal tissue mobilization arms and the ventricular rim of the barrel) are typically covered with a low-friction fabric (e.g., PTFE) to provide low friction against the chordal tissue and allow movement of these portions relative to the tissue without damaging the tissue. Typically, one or both of the inner and outer surfaces of the chordal tissue mobilization arms are covered with a low-friction fabric (e.g., PTFE) to provide low friction against the chordal tissue and allow movement of these portions relative to the tissue without damaging the tissue. Other areas of the valve frame may be covered with a fabric that encourages tissue ingrowth (e.g., a porous fabric) to anchor these areas to the subject's tissue. Such areas typically include the atrial portion 26 and / or portions of the barrel portion 22 that contact the native atrioventricular valve leaflets.

[0085] In general, the chordal tissue mobilization arms typically define (a) a radially constrained configuration when the arms are maintained in a crimped configuration within the delivery device, (b) a rotated configuration when the arms are released from the delivery device but the barrel is maintained in at least a partial radially constrained configuration by the delivery device, and (c) a fully deployed configuration when the entire valve frame body, including the barrel and atrial portions, is released from the delivery device. In the rotated configuration, the arms are configured to mobilize and deflect chordal tissue. For some applications, in the rotated configuration, the arms are configured to pivot outward relative to the barrel (e.g., by stitches 82, lever elements 80), thereby including a relatively large wingspan, which allows for the recruitment of multiple chordal tissues during rotation of the valve frame. Typically, because the arms pivot outward relative to the barrel, there is a relatively large gap between the tips of the arms and the valve frame body in this configuration. Furthermore, typically, in the fully deployed configuration (when the entire valve frame body, including the cylindrical portion and atrial portion, is released from the delivery device), the chordal tissue mobilization arms are configured to be positioned to define a relatively small gap G (defined below with reference to FIG. 8C ) between the tips of the arms and the outer surface of the valve frame body (e.g., the outer surface of the cylindrical portion), such that the native atrioventricular valve leaflets and / or chordal tissue are captured between the arms and the valve frame body (e.g., the outer surface of the cylindrical portion). For some applications, in the fully deployed configuration, the chordal tissue mobilization arms are configured such that the inner surfaces of the arms have a concave curvature, thereby defining pockets of space P (shown in FIG. 8B ) between them and the valve frame body (e.g., the outer surface of the cylindrical portion). Typically, the chordal tissue mobilized by the arms and / or tissue of the native valve leaflets is retained within these pockets of space.

[0086] Reference is now made to FIGS. 7A-7B, which are schematic illustrations of cord mobilization arms 24 disposed in a radially unconstrained configuration ( FIG. 7A ) and when the lower ends of the arms are retained within a delivery device 40 but the upper ends of the arms are released from the delivery device ( FIG. 7B ), in accordance with some applications of the present invention. Like many of the other figures, FIGS. 7A-7B show cord mobilization arms 24 without covering material 32 for illustrative purposes. In some applications, the shape memory alloy members 76 defining cord mobilization arms 24 define lever elements 80. The lever elements are configured to be retained within delivery device 40 when the arms are disposed in their rotated configuration (configured to mobilize and deflect cords after the arms are deployed between the cords). As shown in FIG. 7A , the lever elements are typically configured to extend from the base of arms 24 at an angle when the valve frame is disposed in its radially unconstrained configuration. When held within the delivery device, the lever elements are configured to pivot the arms radially outward, as shown in Figure 7B. This is indicated by arrows 86 and 88 in Figure 7A. As shown, by moving (or holding) the lever elements in the direction of arrow 86, the arm tips 74 are configured to pivot radially outward in the direction of arrow 88.

[0087] Reference is now made to FIGS. 8A, 8B, and 8C, which are schematic illustrations of respective views of valve frame 20, showing the valve frame in its radially unconstrained configuration, in accordance with some applications of the present invention. Certain features of valve frame 20 shown in FIGS. 8A-8C (as well as in FIGS. 9A-9B) differ from valve frame 20 described with reference to FIGS. 1A-7B, and such features are described below. In all other respects, valve frame 20 shown in FIGS. 8A-8C (as well as in FIGS. 9A-9B) is generally similar to valve frame 20 described with reference to FIGS. 1A-7B. Specific dimensions of valve frame 20 are described with reference to valve frame 20 shown in FIGS. 8A-8C and 9A-9B. Generally, generally similar dimensions are applicable mutatis mutandis to valve frame 20 shown in FIGS. 1A-7B.

[0088] For some applications, the cylindrical portion 22 and the atrial portion 26 of the valve frame 20 are made from one integrally formed piece of shape memory material, as shown in Figures 8A-8C.

[0089] 8A-8C, for some applications, the valve frame 20 is configured such that, in the absence of forces acting on the valve frame (e.g., in the valve frame's radially unconstrained configuration), the height H1 of each chordae mobilization arm 24 is greater than 5 mm (e.g., greater than 7 mm) and / or less than 20 mm (e.g., less than 15 mm), e.g., between 5 and 20 mm, or between 7 and 15 mm. For some applications, in this configuration of the valve frame, the overall height H2 of the valve frame is greater than 10 mm (e.g., greater than 15 mm) and / or less than 30 mm (e.g., less than 25 mm), e.g., between 10 and 30 mm, or between 15 and 25 mm.

[0090] 8A and 8B, for some applications, the valve frame 20 is configured such that, in the absence of forces acting on the valve frame (e.g., in the radially unconstrained configuration of the valve frame), the diameter D1 of the cylindrical portion 22 of the valve frame body 21 is greater than 20 mm (e.g., greater than 25 mm) and / or less than 40 mm (e.g., less than 35 mm), e.g., 20-40 mm or 25-35 mm. For some applications, with this configuration of the valve frame, the wingspan S1 defined by the chordae recruitment arms is greater than 22 mm (e.g., greater than 26 mm) and / or less than 45 mm (e.g., less than 40 mm), e.g., 22-45 mm or 26-40 mm. For some applications, in this configuration of the valve frame, the gap G between the tip 74 of each chordal tissue mobilization arm 24 and the outer surface of the valve frame body is greater than 0.1 mm (e.g., greater than 0.5 mm) and / or less than 6 mm (e.g., less than 5 mm), e.g., 0.1-6 mm, or 0.5-5 mm. In some applications, the gap G is between the tip of the chordal tissue mobilization arm and the cylindrical portion. Alternatively or additionally, the gap G is between the tip of the chordal tissue mobilization arm and the atrial portion 26 (e.g., the frustoconical portion 30 of the atrial portion 26). Referring to FIG. 8B, typically, in a radially unconstrained configuration of the valve frame, the chordal tissue mobilization arms are configured such that the inner surfaces of the arms have a concave curvature, thereby defining pockets of space P between themselves and the valve frame body (e.g., the outer surface of the cylindrical portion). Typically, chordal tissue mobilized by the arms and / or tissue of the native valve leaflets is retained within these pockets of space. For some applications, the valve frame is shaped so that in the valve frame's radially unconstrained configuration, there is no gap between the tip 74 of each chordae mobilization arm 24 and the outer surface of the valve frame body. For some applications, the arms are preloaded, for example, via the arm's shaping, so that the arms exert a force on the outer surface of the valve frame body (in such applications, with no frame blocking the arm tips, the gap G would be less than zero).

[0091] Referring again to FIG. 2, in some applications, when the valve frame's cord mobilization arms 24 are released from the delivery device 40 (i.e., when the cord mobilization arms are positioned in their rotated configuration) while the valve frame body 21 of the valve frame is still maintained in at least a partial radially constrained configuration by the delivery device, the cord mobilization arms 24 are configured to define a wingspan S2 that is greater than 20 mm (e.g., greater than 25 mm) and / or less than 40 mm (e.g., less than 35 mm), e.g., between 20 and 40 mm, or between 25 and 35 mm.

[0092] Reference is now made to Figures 9A and 9B, which are schematic illustrations of respective views of the valve frame body 21 of the valve frame 20, in accordance with some applications of the present invention. For purposes of illustration, Figures 9A-9B show the valve frame body without the chorda mobilization arms 24 of the valve frame.

[0093] As described above, the valve frame body 21 is typically a stent-like structure including struts of shape-memory material and shaped to define a generally cylindrical shape. In some applications, a plurality of extensions 90 extend radially from a portion of the valve frame body configured to extend into the atrium. Typically, the extensions are configured to prevent the prosthetic valve and / or valve frame from migrating into the subject's ventricle. Alternatively or additionally, the extensions are configured to capture the native valve leaflets between the extensions and the chordal tissue recruitment arms when the valve frame body radially expands. In some applications, the extensions are flexible (e.g., the extensions may be spring-shaped as shown) and configured to conform to the shape of the tissue of the mitral annulus on the atrial side of the mitral valve.

[0094] For some applications, the valve frame 20 is configured such that, in the absence of forces acting on the valve frame (e.g., in the valve frame's radially unconstrained configuration), the atrial portion 26 includes a radial distance D2 from the outer surface of the cylindrical portion 22 that is greater than 5 mm (e.g., greater than 10 mm) and / or less than 25 mm (e.g., less than 20 mm), e.g., between 5 and 25 mm, or between 10 and 20 mm. Referring again to FIG. 8B , for some applications, in this configuration of the valve frame, the atrial portion 26 is configured to define a wingspan S3 that is greater than 30 mm (e.g., greater than 35 mm) and / or less than 80 mm (e.g., less than 70 mm), e.g., between 30 and 80 mm, or between 35 and 70 mm.

[0095] Reference is now made to FIGS. 10A and 10B, which are schematic illustrations of the atrial portion 26 of the valve frame 20, in which the struts 92 have an undulating pattern, according to some applications of the present invention. FIG. 10A shows only the atrial portion of the valve frame, while FIG. 10B shows a top view of the atrial portion coupled to the cylindrical portion 22 and the chordal tissue recruitment arms 24. In some applications, the struts of the discoid portion (i.e., flange) 28 of the atrial portion have the undulating pattern shown. Typically, undulating struts are configured to provide flexibility to the flange cells 93, allowing the flange to adapt its shape to match changes in the shape of the tissue of the mitral annulus on the atrial side of the mitral valve that it contacts. In some applications, undulating struts are configured to provide the cells with better distribution of stress and strain when bending compared to straight struts. In some applications, the flange cells have a circumferential curvature, such that the outer tips 94 of the cells point in a given circumferential direction. Typically, the circumferential curvature of the cells is in a direction opposite to the circumferential curvature of the cord mobilization arms. In some applications, by defining this circumferential curvature, the flange cells are configured to act as anti-recoil elements and prevent rotation of the valve frame in a direction opposite to the direction in which the valve frame was rotated.

[0096] Reference is now made to Figures 10C, 10D, 10E, and 10F, which are schematic illustrations of the atrial portion 26 of the valve frame 20 undergoing crimping (i.e., radially constrained and axially stretched) in accordance with some applications of the present invention. Reference is also made to Figures 10G, 10H, 101, and 10J, which are schematic illustrations of the atrial portion 26 of the valve frame 20 undergoing crimping in accordance with some alternative applications of the present invention. As noted above, the valve frame 20 with the prosthetic valve leaflets 23 disposed thereon is typically delivered to the native atrioventricular valve via a delivery device 40 (e.g., the delivery catheter shown in Figure 2), which is configured to maintain the valve frame and prosthetic valve in a radially constrained configuration (i.e., a "crimped" configuration) during delivery.

[0097] As shown in Figures 10C-10F, in some applications, during crimping of the atrial portion of the valve frame, the cells 93 in the atrial portion of the valve frame elongate and extend substantially axially, such that the tip 94 of each cell is substantially circumferentially aligned with the base 96 of the cell. Alternatively, as shown in Figures 10G-10J, in some applications, during crimping of the atrial portion of the valve frame, the cells 93 in the atrial portion of the valve frame elongate but are configured to curve circumferentially about the longitudinal axis of the valve frame, such that the tip 94 of each cell is not circumferentially aligned with the base 96 of the cell. Typically, assuming the cells (i.e., flanges) of the atrial portion have a given length when the atrial portion is in the radially unconstrained configuration, when the atrial portion is configured as shown in Figures 10G-10J, the axial length of the atrial portion when the atrial portion is in the crimped configuration will be shorter than when the atrial portion is configured as shown in Figures 10C-10F. This is because, in addition to the cells extending axially, the cells also curve circumferentially about the axis of the valve frame. As a result, the overall length of the valve frame when it is in its crimped configuration is typically shorter. In some cases, this is advantageous because, although the valve frame is relatively stiff when in its crimped configuration, during delivery the valve frame typically must traverse curves in, for example, curved blood vessels and / or heart chambers, such as the left atrium.

[0098] Reference is now made to FIG. 10K, which is a schematic illustration of a single repeating (i.e., repeating) structure of the atrial section 26 of the valve frame 20, configured as shown in FIGS. 10G-10J. Typically, the cells of the atrial section 26 of the valve frame 20 (like the cells in the remainder of the valve frame) are made of a shape-memory material (e.g., a shape-memory alloy such as nitinol and / or copper-aluminum-nickel). For some applications, the cells are configured as described with reference to FIGS. 10G-10J due to cell shape setting. Alternatively or additionally, in each cell, the struts 98 on one side of the cell are longer than the struts 99 on the other side of the cell, causing the cells to curve circumferentially about the longitudinal axis of the valve frame as they are axially stretched during crimping.

[0099] It should be noted that while the cell designs described with reference to Figures 10G to 10J are described in the context of a particular type of implantable valve frame, the scope of the present disclosure includes applying such designs mutatis mutandis to frames of other medical devices, such as stents, and / or frames of other types of implantable valves.

[0100] Reference is now made to FIGS. 11A, 11B, 11C, 11D, 11E, and 11F, which are schematic illustrations of respective steps in the delivery and deployment of a mitral valve prosthesis via a transseptal approach according to some applications of the present invention. Typically, a mitral valve prosthesis includes a valve frame body as described above, with prosthetic valve leaflets 23 sutured to a cylindrical portion and / or otherwise coupled to a cylindrical portion 22 of the valve frame, as shown, for example, in FIG. 1D. As described above, according to respective applications, the mitral valve prosthesis is delivered transseptally (i.e., via the vena cava, right atrium, and atrial septum), transapically (i.e., via the apex of the left ventricle), and / or via a different delivery route. FIGS. 11A through 11F illustrate, by way of illustration and not limitation, the steps in the delivery and deployment of a mitral valve prosthesis via a transseptal approach.

[0101] Typically, a delivery device 40 (e.g., a delivery catheter) is guided over a guidewire 102 toward a subject's native mitral valve 100. As shown in FIG. 11A, typically, the distal end of the delivery device 40 is advanced through the atrial septum 106 and into the subject's left atrium 104. As shown in FIG. 11B, the distal end of the delivery device is advanced toward the native mitral valve, past the leaflets 108 of the native mitral valve, and into the left ventricle 110. When the distal end of the delivery device is positioned within the left ventricle, the chordae mobilization arms 24 can at least partially radially expand and assume their rotated configuration, as shown in FIG. 11C. In some applications, the arms can be positioned in a radially unconstrained configuration by releasing the arms from radial constraint by the delivery device, for example, by partially retracting the proximal overtube 41 and / or partially advancing the distal nosecone 43. Typically, the chord mobilization arms are configured to extend radially from the valve frame body 21 and curve circumferentially (e.g., clockwise as shown) around the valve frame body when in their rotated configuration. In some applications, the chord mobilization arms are also configured to extend axially toward the atrium of the subject. Typically, the chord mobilization arms are configured to be deployed between the chordae 112 of the native mitral valve upon release from the delivery device.

[0102] As shown in FIG. 11D , after the chord recruitment arms 24 are deployed between the chordae of the native mitral valve, at least a portion of the valve frame 20 is rotated in the direction of arrow 114 to mobilize and flex at least a portion of the chordae, causing the chord recruitment arms 24 to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) twist the native atrioventricular valve around the valve frame. Typically, the chord recruitment arms 24 are configured to curve in a given circumferential direction relative to the longitudinal axis of the valve frame. For example, the arms may curve clockwise or counterclockwise relative to the longitudinal axis of the valve frame. Typically, after the chord recruitment arms 24 are deployed between the chordae of the native mitral valve, the valve frame is rotated in the same circumferential direction as the arms' circumferential curvature. In the example shown in FIG. 11D , the arms curve in a clockwise circumferential direction (as viewed from the left atrium 104), causing the valve frame to rotate in this direction.

[0103] As described above, in some applications, before rotating the valve frame in the same circumferential direction as the circumferential curvature of the arms, the valve frame is rotated in the opposite circumferential direction. In some applications, the delivery device 40 is configured to automatically perform an initial rotation of the valve frame a given angle opposite to the circumferential curvature of the arms, and then rotate the valve frame the predetermined angle in the circumferential curvature of the arms. In some applications, in the rotated configuration of the arms (shown in FIGS. 11C-11D), the outer surface of each arm has a smooth, convex curvature extending substantially along the entire length of the arm, so that during the initial rotation (opposite to the circumferential curvature of the arms), the cords slide over the outer surface of the arm without being recruited or captured by the arm. In some applications, this shape of the arms positions a relatively large number of cords by the initial rotation of the valve frame to be recruited by the respective arms in subsequent rotation steps. During subsequent rotation of the valve frame (in the direction of the circumferential curvature of the arms, e.g., in the direction of arrow 114 shown in FIG. 11D), the cord-like tissue is recruited and flexed by the arms. Typically, in the rotated configuration of the arms (shown in FIGS. 11C-11D), the inner surface of the arms has a concave curvature, and the cord-like tissue is recruited within the space defined by the concave curvature during subsequent rotation by the valve frame.

[0104] After the chordal tissue mobilization arms 24 are released and the valve frame 20 is rotated, the valve frame body 21 (i.e., the cylindrical portion 22 and atrial portion 26 of the valve frame) can assume its radially unconstrained configuration. In some applications, the atrial portion can assume its radially unconstrained configuration by releasing the atrial portion from the delivery device, e.g., by retracting the proximal overtube 41. In some applications, the cylindrical portion can assume its radially unconstrained configuration by releasing the cylindrical portion from the delivery device, e.g., by advancing the distal nosecone 43. FIG. 11E shows both the cylindrical portion 22 and the atrial portion 26 in their radially unconstrained (i.e., radially expanded) configurations. Typically, by the valve frame body assuming its radially unconstrained configuration, the valve frame body is configured to at least partially seal the space between the native mitral valve and the prosthetic valve by capturing the native valve leaflets 108 in a partially closed, twisted configuration. For example, the cylindrical portion may be configured to radially expand to capture the native valve leaflets between the cylindrical portion and the chordal tissue mobilization arms, and / or the atrial portion may be configured to radially expand to capture the native valve leaflets between the atrial portion and the chordal tissue mobilization arms. In some applications, capturing the native valve leaflets 108 in a partially closed, twisted configuration is achieved by capturing the chordal tissue (attached to the leaflets) in a twisted configuration. After the above steps are performed, the delivery device 40 is typically fully retracted from the subject's left atrium, as shown by arrow 120 in FIG. 11F.

[0105] 12A, 12B, and 12C, which are schematic illustrations of cells 130A and 130B at the distal end of cylindrical portion 22 of valve frame 20 in their respective configurations, according to some applications of the present invention. Typically, the cells of cylindrical portion 22 of valve frame 20 (as well as the cells in the remainder of the valve frame) are made of a shape-memory material (e.g., a shape-memory alloy such as nitinol and / or copper-aluminum-nickel). As noted above, in some applications, the distal end of the cylindrical portion is held in a radially constrained configuration within a delivery device (e.g., within distal nosecone 43) during delivery of the valve frame to a subject's mitral valve.

[0106] Figure 12A is a schematic diagram of the cell configured when the frame is cut from the shape memory material, Figure 12B is a schematic diagram of the cell configured when the frame is shape-set to its radially unconstrained configuration, and Figure 12C is a schematic diagram of the cell configured when the barrel is maintained in a radially constrained configuration within a delivery device.

[0107] For some applications, some cells (cells 130A) include a connector 132 (e.g., a ring-shaped connector) at the distal end of the frame's cylindrical portion for connecting the distal end of the cylindrical portion to a delivery device, while other cells (cells 130B) do not include such a connector. As shown in FIG. 12A , for some applications, cell 130A is first cut to be longer than cell 130B. For some applications, the widths of cells 130A and 130B are similar or identical to each other, as shown. In the configuration shown in FIG. 12A , the end of cell 130A (including the connector) protrudes beyond the distal end of the cylindrical portion of the valve frame relative to the end of cell 130B. As shown in FIG. 12B , cell 130A is shaped relative to the end of cell 130B so that the end of cell 130A does not protrude beyond the distal end of the cylindrical portion of the valve frame. Typically, this is done by introducing curvature into the struts of cell 130A, shortening the length of cell 130A to equal the length of cell 130B. For example, the struts may be shaped so that the cells define an omega or heart shape. Typically, when deployed in a subject's mitral valve, the cells assume the configuration shown in FIG. 12B when the cylindrical portion of the valve frame is in its radially unconstrained configuration. Thus, the struts defining cell 130A are longer than the struts defining cell 130B, but the struts defining cell 130A are shaped such that cell 130A is not longer than cell 130B. In this way, when the frame is deployed, no joints protrude beyond the edges of the frame, which could potentially injure the subject's tissue.

[0108] Referring to FIG. 12C, in a radially constrained (i.e., crimped) configuration of the cylindrical portion of the valve frame, both cells 130A and 130B are axially elongated. Because the struts defining cell 130A are longer than the struts defining cell 130B, the distal end of cell 130A protrudes from the distal end of the cylindrical portion of the valve frame relative to the end of cell 130B. Because connector 132 is located at the end of cell 130A, the connector protrudes from the distal end of the cylindrical portion of the valve frame, thereby allowing the connector to be coupled to a delivery device. Thus, during delivery of the device, the connector may be coupled to a portion of the delivery device, such as a fixation element 46 (schematically shown in FIG. 2B) within the delivery device (e.g., a fixation element within the distal nosecone of the delivery device). In some applications, the fixation element includes a clip, a protrusion, a recess, a snap-fit ​​element, and / or other types of fixation elements.

[0109] In some applications (not shown), instead of or in addition to the coupling 132, a suture is tied to the distal end of the valve frame and used to couple the distal end of the valve frame to the delivery device.

[0110] It should be noted that although the cell designs described with reference to Figures 12A-12C are described in the context of a particular type of implantable valve frame, the scope of the present disclosure includes applying such designs mutatis mutandis to frames of other medical devices, such as stents, and / or frames of other types of implantable valves.

[0111] The devices and methods described herein are typically performed on a subject's mitral valve and / or on a subject's tricuspid valve, and although some embodiments of the devices and methods have been described primarily with reference to the mitral valve, the scope of the invention includes applying any of the above devices and methods to the tricuspid valve, mutatis mutandis.

[0112] For some applications, the devices and methods described herein are implemented in conjunction with devices and methods described in US2015 / 0173897 to Raanani and / or WO21 / 028867 to Agian, both publications of which are incorporated herein by reference.

[0113] It will be understood by those skilled in the art that the present invention is not limited to what has been particularly shown and described herein, but rather the scope of the present invention includes both combinations and subcombinations of the various features described herein, as well as variations and modifications thereof that are not in the prior art and that would occur to one skilled in the art upon reading the foregoing description.

Claims

1. 1. An apparatus for use with a delivery device, said apparatus comprising: an implantable frame having struts defining cells; the cells are shaped to define a radially unconstrained configuration, and the frame is configured to be delivered into a subject's body while the frame is held within the delivery device in a radially constrained configuration; the device being configured such that when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame, at least a portion of the cells stretch and curve circumferentially about a longitudinal axis of the frame such that, for each of the portions of the cells, a tip of the cell is no longer circumferentially aligned with a base of the cell.

2. 2. The device of claim 1, wherein the implantable frame is made of a shape memory material and a portion of the cells are configured to stretch and curve circumferentially about a longitudinal axis of the frame when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame.

3. 2. The apparatus of claim 1, wherein within each cell of the portion of cells, struts on one side of the cell are longer than struts on the other side of the cell to cause the cell to elongate and curve circumferentially about a longitudinal axis of the frame when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame.

4. 2. The apparatus of claim 1, wherein in the radially constrained configuration of the frame, each cell in the portion of the cells is configured to have a shorter axial length than when the portion of cells is configured so that the tip of the cell is circumferentially aligned with the base of the cell.

5. 2. The device of claim 1, wherein the implantable frame is configured to be delivered through one or more curved blood vessels, and the axial length of the portion of the cells is configured to facilitate delivery of the implantable frame through the one or more curved blood vessels.

6. 2. The device of claim 1, wherein the implantable frame is configured to be delivered through a heart chamber, and the axial length of the portion of the cells is configured to facilitate delivery of the implantable frame through the heart chamber.

7. The device of claim 1 , wherein the implantable frame comprises an implantable stent.

8. 7. The device of claim 1, wherein the implantable frame includes an implantable valve frame configured to be implanted in a subject's native valve, and the device further comprises a plurality of artificial valve leaflets coupled to the implantable valve frame.

9. 10. The apparatus of claim 8, wherein the implantable valve frame comprises an implantable valve frame configured to be implanted in a subject's native atrioventricular valve.

10. the implantable valve frame comprising: an atrial section including a disc-shaped portion and a truncated cone-shaped portion configured to be deployed on the atrial side of the annulus of the atrioventricular valve; a barrel having the artificial valve leaflets coupled thereto, the barrel being configured to be deployed so that a ventricular end of the barrel is positioned within the subject's ventricle; 10. The device of claim 9, wherein the portion of the cells configured to elongate and curve circumferentially about the longitudinal axis of the frame includes cells of the discoid portion of the atrial section of the frame.

11. 11. The device of claim 10, wherein the frusto-conical portion of the atrial section is coupled to the cylindrical portion such that there is axial overlap between at least the frusto-conical portion of the atrial section and the cylindrical portion.

12. 12. The device of claim 11, wherein the frusto-conical portion of the atrial section is coupled to the cylindrical section such that the frusto-conical portion of the atrial section extends from an axial position along the cylindrical section that is at the bottom 50 percent of the height of the cylindrical section.

13. 10. The device of claim 9, wherein the implantable valve frame further comprises a plurality of chordal tissue mobilization arms configured to extend at least radially from the ventricular end of the barrel.

14. the valve frame is configured to be delivered to the atrioventricular valve; the plurality of chord recruitment arms are then configured to be deployed between the chords of the native atrioventricular valve; 14. The apparatus of claim 13, wherein at least a portion of the valve frame is subsequently rotated by the delivery device to mobilize and flex at least a portion of the chordal tissue, thereby causing the plurality of chordal tissue mobilizing arms to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) twist the native atrioventricular valve around the valve frame.

15. placing an implantable frame including struts defining cells within a delivery device such that the frame transitions from a radially unconstrained configuration of the frame to a radially constrained configuration of the frame, thereby causing at least a portion of the cells to elongate and curve circumferentially about a longitudinal axis of the frame, such that, for each of the portions of the cells, a tip of the cell is no longer circumferentially aligned with a base of the cell; delivering the implantable frame to a deployment location within a subject's body; and The method includes transitioning the implantable frame from the radially constrained configuration of the frame to the radially unconstrained configuration of the frame by releasing the implantable frame from the delivery device.

16. 1. An apparatus for use with a delivery device, said apparatus comprising: an implantable frame having struts defining cells; a first set of cells at an end of the frame including a coupling portion for coupling the frame to the delivery device, and a second set of cells not including the coupling portion; the first set of cells are shaped such that, in a radially unconstrained configuration of the frame, the length of the first set of cells is the same as a length of the second set of cells, so that the joint does not protrude beyond the end of the frame; the struts defining the first set of cells are longer than the struts defining the second set of cells such that in a radially constrained configuration of the frame, the length of the first set of cells is greater than the length of the second set of cells, and the joints protrude from the end of the frame.

17. 17. The device of claim 16, wherein the frame is configured to assume its radially unconstrained configuration when deployed within a subject's body, and wherein the coupling portion does not protrude from the end of the frame when the frame is in its radially unconstrained configuration, thereby reducing the risk of the coupling portion injuring tissue of the subject compared to if the coupling portion protruded from the end of the frame.

18. The device of claim 16 , wherein the implantable frame comprises an implantable stent.

19. 19. The apparatus of any one of claims 16 to 18, wherein the delivery device comprises a fixation element to which the coupling portion is configured to be coupled, the implantable frame is configured to be delivered into the body of a subject when positioned within the delivery device in the radially constrained configuration, and the coupling portion is configured to protrude from the end of the frame to facilitate coupling of the coupling portion to the fixation element of the delivery device.

20. 20. The apparatus of claim 19, wherein the delivery device comprises a distal nosecone comprising the fixation element, and the coupling portion is configured to protrude from the end of the frame to facilitate coupling of the coupling portion to the fixation element of the distal nosecone of the delivery device.

21. 19. The device of claim 16, wherein when transitioning from the radially unconstrained configuration of the frame to the radially constrained configuration of the frame, at least a portion of the cells of the frame at the second end of the frame are configured to stretch and curve circumferentially about a longitudinal axis of the frame such that, for each of the portions of the cells, a tip of the cell is no longer circumferentially aligned with a base of the cell.

22. 22. The apparatus of claim 21, wherein in the radially constrained configuration of the frame, each cell in the portion of the cells is configured to have a shorter axial length than when the portion of cells is configured so that the tip of the cell is circumferentially aligned with the base of the cell.

23. 23. The device of claim 22, wherein the implantable frame is configured to be delivered through one or more curved blood vessels, and the axial length of the portion of the cells is configured to facilitate delivery of the implantable frame through the one or more curved blood vessels.

24. 23. The device of claim 22, wherein the implantable frame is configured to be delivered through a cardiac chamber, and the axial length of the portion of the cells is configured to facilitate delivery of the implantable frame through the cardiac chamber.

25. 18. The device of claim 16 or claim 17, wherein the implantable frame includes an implantable valve frame configured to be implanted in a subject's native valve, and the device further comprises a plurality of artificial valve leaflets coupled to the implantable valve frame.

26. 26. The apparatus of claim 25, wherein the implantable valve frame comprises an implantable valve frame configured to be implanted in a subject's native atrioventricular valve.

27. the implantable valve frame comprising: an atrial section including a disc-shaped portion and a truncated cone-shaped portion configured to be deployed on the atrial side of the annulus of the atrioventricular valve; a barrel having the artificial valve leaflets coupled thereto, the barrel being configured to be deployed so that a ventricular end of the barrel is positioned within the subject's ventricle; 27. The device of claim 26, wherein the first set of cells and the second set of cells are positioned at the ventricular end of the cylindrical portion of the implantable valve frame.

28. 28. The device of claim 27, wherein the frusto-conical portion of the atrial section is coupled to the cylindrical portion such that there is axial overlap between at least the frusto-conical portion of the atrial section and the cylindrical portion.

29. 29. The device of claim 28, wherein the frusto-conical portion of the atrial section is coupled to the cylindrical section such that the frusto-conical portion of the atrial section extends from an axial position along the cylindrical section that is at the bottom 50 percent of the height of the cylindrical section.

30. 27. The device of claim 26, wherein the implantable valve frame further comprises a plurality of chordal tissue mobilization arms configured to extend at least radially from the ventricular end of the barrel.

31. the valve frame is configured to be delivered to the atrioventricular valve; the plurality of chord recruitment arms are then configured to be deployed between the chords of the native atrioventricular valve; 31. The apparatus of claim 30, wherein at least a portion of the valve frame is subsequently rotated by the delivery device to mobilize and flex at least a portion of the chordal tissue, causing the plurality of chordal tissue mobilizing arms to (a) pull the native atrioventricular valve radially inward toward the valve frame and (b) twist the native atrioventricular valve around the valve frame.

32. placing an implantable frame including struts defining cells within a delivery device to transition the frame from a radially unconstrained configuration of the frame to a radially constrained configuration of the frame; placing the implantable frame, the frame configured such that at an end of the frame, a first set of cells include couplings for coupling the frame to the delivery device and a second set of cells do not include the couplings, and the struts defining the first set of cells are longer than the struts defining the second set of cells, such that in the radially constrained configuration of the frame, the length of the first set of cells is greater than the length of the second set of cells, and the couplings protrude from the end of the frame; delivering the implantable frame to a deployment location within a subject's body; and releasing the implantable frame from the delivery device, thereby transitioning the frame from the radially constrained configuration of the frame to the radially unconstrained configuration of the frame, wherein the first set of cells is shaped such that in the radially unconstrained configuration of the frame, the length of the first set of cells is the same as the length of the second set of cells, so that the joint does not protrude beyond the end of the frame. A method comprising:

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