artificial semi-heart valve

Abstract

A prosthetic half heart valve for treating a diseased heart valve having a native anterior leaflet and a prosthetic posterior leaflet includes a stingray- and crescent-shaped stent with extending tabs configured as a safety mechanism. At least one prosthetic leaflet attached to the inner surface of the stent includes a free edge, two commissure attachment regions, an attachment edge, a coaptation region, an abdominal region, and at least one leg structure connecting a portion of one or more leaflets to the lower ventricular portion of the stent. A seal skirt is bonded to the inner surface of the stent to attach the one or more leaflets and form a paravalvular seal with the atrial portion of the prosthetic half valve. The prosthetic half heart valve further includes a plurality of dual guide fixation members for securing the atrial flaring portion of the stent to the posterior portion of the native annulus.

Description

[Technical Field]

[0001] This application relates generally to replacement heart valves, for example, for replacing diseased mitral and / or tricuspid valves. More particularly, embodiments of the subject matter relate to tissue-based, collapsible and expandable replacement heart valves.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of co-pending U.S. Provisional Application No. 63 / 007,418, filed April 9, 2020, and is a continuation-in-part of co-pending U.S. Provisional Application No. 15 / 453,518, filed March 8, 2017, which claims the benefit of co-pending U.S. Provisional Application Nos. 62 / 305,204, filed March 8, 2016, 62 / 413,693, filed October 27, 2016, and 62 / 427,551, filed November 29, 2016, and is a continuation-in-part of co-pending U.S. Provisional Application No. 17 / 121,615, filed December 14, 2020. This is a continuation application of International Application No. PCT / US2019 / 037476, filed June 17, 2019, which claims the benefit of U.S. Provisional Application No. 62 / 685,378, filed June 15, 2018, and a continuation-in-part of co-pending application No. 17 / 198,097, filed March 10, 2021, which claims the benefit of U.S. Provisional Application No. 62 / 988,253, filed March 11, 2020, the entire disclosures of which, including the specification and drawings, are incorporated herein by reference in their entirety. [Background technology]

[0003] The mitral valve (MV) has two distinct major leaflets, or cusps. As shown in Figure 1A, the MV is located on the left side of the heart, between the left atrium and the left ventricle. The mitral valve apparatus consists of the mitral annulus, two valve leaflets, chordae tendineae ("chordae"), two papillary muscles, and left ventricular myocardium. As shown in Figure 1B, the mitral annulus is subdivided into an anterior and a posterior portion. Normally, the anterior mitral valve leaflet (AML) is connected to the aortic valve via the aortic curtain, and the posterior mitral valve leaflet (PML) is rotatably fixed to the posterior mitral annulus. The chordae arise from the two major papillary muscles or from multiple minor muscle bundles attached to the ventricular wall and connect to the free end of the mitral valve. The chordae are primarily composed of collagen bundles, which provide them with high rigidity and maintain minimal stretch to prevent the valve leaflets from billowing into the left atrium during systole.

[0004] When the mitral valve is closed, the anterior and posterior leaflets are in close contact to form a single appositional area. As those skilled in the art will appreciate, normal mitral valve function involves a proper balance of forces, with each of its components working in unison during the cardiac cycle. Pathological changes affecting any of the mitral valve components, such as ruptured chordae, annular dilation, papillary muscle displacement, leaflet calcification, and myxomatous disease, can lead to altered mitral valve function and cause mitral regurgitation (MR).

[0005] Mitral regurgitation is a malfunction of the mitral valve that causes abnormal leakage of blood from the left ventricle back into the left atrium during systole (i.e., the ejection phase of the cardiac cycle, when blood moves from the left ventricle to the aorta). While minimal mitral regurgitation can be seen in healthy patients, moderate to severe mitral regurgitation is one of the most common forms of valvular heart disease. The most common causes of mitral regurgitation include ischemic heart disease, nonischemic heart disease, and valvular degeneration. Both ischemic heart disease (primarily due to coronary artery disease) and nonischemic heart disease (e.g., idiopathic dilated cardiomyopathy) can cause functional or secondary mitral regurgitation through various mechanisms, including left ventricular wall dysfunction, left ventricular dilation, and papillary muscle displacement or dysfunction. In functional mitral regurgitation, the mitral valve apparatus remains normal. Incomplete coaptation of the valve leaflets results from enlargement of the mitral annulus secondary to left ventricular and, possibly, left atrial dilation. Additionally, patients with functional mitral regurgitation may exhibit displacement of the papillary muscles due to left ventricular enlargement, resulting in excessive restriction of the valve leaflets. In contrast, degenerative (or organic) mitral regurgitation is caused by structural abnormalities of the mitral valve leaflets and / or subvalvular apparatus, including stretching or rupture of the chordae tendineae.

[0006] Current treatments for mitral valve disease include surgical repair and replacement of the mitral valve. Mitral valve repair has benefited from an improved understanding of mitral valve mechanics and function and is now considered preferable to complete mitral valve replacement. However, the complex physiology and three-dimensional anatomy of the mitral valve and its surrounding structures present significant challenges when performing these repair procedures.

[0007] In one early example of a transcatheter mitral valve replacement device, Endovalve-Herrmann (Micro Interventional Devices, Inc.) developed a mitral valve prosthesis with a collapsible nitinol-based valve with a sealing skirt. Similarly, Tendyne Holdings, Inc. manufactures a prosthetic mitral valve replacement device that includes a pericardial valve with a self-expanding nitinol stent. This device is designed for transapical delivery and includes a ventricular fixation anchor. CardiAQ uses a pericardial valve with a self-expanding nitinol stent in its mitral valve replacement device. Finally, Tiara (Neovasc, Inc.) uses a mitral valve replacement system that can be delivered transapically with a 30 French catheter with an anchor structure and a pericardial valve on a self-expanding stent with a D-shaped atrial portion and a ventricular portion with an outer coating. These devices and the technology for delivering prosthetic mitral valves into their working position are still in the developmental stage, and although promising, challenges to the effectiveness of these devices continue to exist.

[0008] The noted challenges to effective mitral valve replacement devices generally include operational delivery challenges, positioning and fixation challenges, sealing and paravalvular leakage challenges, and hemodynamic function challenges such as left ventricular outflow tract (LVOT) obstruction. With regard to the operational delivery challenges, conventional mitral valve prostheses are larger than conventional aortic prostheses, making it more difficult to collapse and compress the larger prosthetic mitral valve into a catheter for deployment and retrieval by either conventional transapical or transfemoral delivery techniques.

[0009] Regarding the challenges of positioning and fixation, instability and migration are the most prominent obstacles because the mitral valve is subjected to high, cyclic stresses during the cardiac cycle, with high transvalvular pressure gradients that range from near-zero during diastole to over 120 mmHg during systole, and can rise to systolic pressures exceeding 150 mmHg in patients with aortic stenosis and systemic hypertension. Furthermore, lack of calcium distribution in the mitral annulus impacts device stability and fixation. Furthermore, transcatheter mitral valve replacements can easily become dislodged as the heart moves during each cardiac cycle.

[0010] Regarding sealing and paravalvular leakage, a good fit between the native annulus and the prosthesis is desirable to minimize paravalvular leakage. Because the mitral annulus is large, prosthetic mitral valves typically have a large, overhanging atrial portion or flare, which can prevent leakage. However, the problem is that a large valve size is required at the ventricular level so that the prosthesis can be securely attached to the native mitral valve. Traditionally, prosthetic mitral valves are smaller than the diseased native valve, and additional material is added around the prosthesis to compensate for the large native mitral annulus. Unfortunately, adding more material to the prosthetic valve increases the size of the delivery system.

[0011] Finally, with regard to maintaining hemodynamic function, as discussed above, the operating position of a conventionally large prosthetic mitral valve must not obstruct the LVOT at the anterior portion of the mitral annulus and must not interfere with the associated structures of the native mitral valve.

[0012] It would therefore be beneficial to have a heart valve leaflet replacement system that does not suffer from the drawbacks and deficiencies of conventional valve prostheses. It is desirable to secure a prosthetic mitral valve replacement system to the native mitral valve annulus. It is also desirable to improve positioning of the prosthetic mitral valve and prevent blood leakage between the prosthetic and native mitral valve. It is also desirable to prevent further dilation of the native mitral valve annulus. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, when considered in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the Invention

[0013] Described herein are examples of prosthetic heart hemivalves or semi-prosthetic valves and methods for securing the prosthetic semi-valves to one of the native valve annuli. It is contemplated that the methods for securing the prosthetic semi-valves to one of the native valve annuli are configured to prevent the prosthetic semi-valve from detaching from the annulus and ensure proper coaptation between the leaflets of the implanted prosthetic semi-valve and the remaining native valve leaflets. It is contemplated that the prosthetic semi-valves may be implanted via open surgery or percutaneously via a catheter. In one aspect, the prosthetic semi-valve may include a plurality of dual guide and fixation (DGF) members, as described elsewhere herein, configured to secure the prosthetic semi-valve to the native mitral valve. In a further aspect, a related method may be configured to implant a replacement valve prosthesis and help prevent further dilation of the native mitral valve annulus. For clarity, the present disclosure focuses on the treatment of functional mitral regurgitation, but it is contemplated that the heart valve leaflet replacement systems and related methods may be used or otherwise configured for use to treat other valvular diseases, such as degenerative mitral regurgitation, to replace other valves in the human heart (e.g., the tricuspid valve), or in other mammals afflicted with valvular defects as well.

[0014] In one embodiment, the prosthetic half-valve can be configured or otherwise sizable to be crimped and accommodated within a delivery sheath, and then selectively re-expanded to an operational size and position upon removal from the delivery sheath within the heart. In a further embodiment, at least a portion of the prosthetic half-valve can have a stent shape including an upper atrial portion and a lower ventricular portion. In one embodiment, the atrial portion can be configured to facilitate stent fixation, thereby helping to prevent paravalvular leakage and stent dislodgement. Furthermore, the ventricular portion can displace a diseased native valve leaflet out of the blood flow path and accommodate at least one prosthetic leaflet. In another embodiment, the prosthetic half-valve can include a lining skirt that can be coupled to at least a portion of the inner and / or outer surface of the stent. In one exemplary embodiment, at least one prosthetic leaflet can be attached to the inner lumen of the stent and / or at least a portion of the exterior of the stent, which can function in place of at least one native valve leaflet to restore normal valve function, e.g., to prevent mitral regurgitation.

[0015] In one aspect, at least one prosthetic leaflet of the prosthetic half-valve can be configured with at least one leg structure that prevents the leaflet from billowing into the atrium and prolapse. The at least one leg structure acts to distribute prosthetic leaflet stress and promote coaptation with at least one of the native mitral valve leaflets, thereby replicating the proper closing anatomy of the native mitral valve with sufficient coaptation length and height and appropriate leaflet angulation during systole.

[0016] In one aspect, delivery of the prosthetic semi-valve can be performed using several desired delivery access approaches, such as, but not limited to, surgical, transseptal, transatrial, or transapical approaches, similar to the methods disclosed in the applications incorporated herein by reference. In one exemplary aspect, the transseptal approach can include creating an opening in the internal jugular or femoral vein for subsequent minimally invasive delivery of a portion of the prosthetic semi-valve via the superior vena cava, which drains into the right atrium of the heart. In this exemplary aspect, the access path for the transseptal approach crosses the interatrial septum of the heart, and once achieved, components of the prosthetic semi-valve can be operably positioned within the left atrium, native mitral valve, and left ventricle. In one aspect, it is contemplated that a main delivery catheter can be positioned along the access path to allow operably placement of the desired components of the prosthetic semi-valve in the left atrium without complications.

[0017] In one embodiment, the prosthetic half-valve has a unique crescent shape, forming a half-valve or hemi-valve. The prosthetic half-valve has a ventricular portion positioned in the left ventricle and configured to displace at least one diseased native mitral valve. The atrial portion of the half-valve is configured to prevent paravalvular leakage and engage with a DGF member to secure the entire prosthetic half-valve to the mitral valve annulus. An angled neck region forms a transition between the ventricular and atrial portions of the half-valve.

[0018] In a further aspect, the stent is configured to span at least a portion or the entire circumference of the native posterior mitral valve leaflet via a network of compressible, self-expanding diamond-shaped cells, occupying a non-uniform semi-elliptical shape of varying lengths to avoid interference with the surrounding native valve structure. In a further aspect, the stent can assume an asymmetric, semi-conical, or semi-circular cross-sectional profile.

[0019] In one aspect, the atrial portion of the stent includes a plurality of cells shaped to fit the natural mitral valve annulus, an atrial stent tip curved to avoid interference with the atrial wall, and a plurality of through-holes that curve downward along the natural mitral valve annulus and connect to a neck region that transitions into the ventricular portion of the stent.

[0020] In a further aspect, the through-holes in the atrial portion of the stent are configured to receive a DGF locking member for securing the prosthetic half-valve in place in the mitral valve.

[0021] In one aspect, the neck region transitions from the atrial portion to the ventricular portion of the stent, the ventricular portion of the stent including at least one prosthetic leaflet coupled to an interior surface, the prosthetic leaflet configured to form a C-shape and expand to a D-shape during systole in the actuated position.

[0022] In one aspect, the ventricular portion of the stent can be configured with a plurality of through-holes to facilitate attachment of at least a portion of the prosthetic valve leaflets.

[0023] In one aspect, multiple tabs extend from the ventricular portion of the stent, giving the stent a stingray-like shape, for example. The tabs can extend directly from the tip of the stent or can be connected via extending struts. The tabs are configured to provide a safety feature for the prosthetic valve throughout the housing, positioning, and locking process.

[0024] In one embodiment, the prosthetic half-valve component is at least one dome-shaped prosthetic leaflet that is attached to the inner surface of the ventricular portion of the stent frame and is capable of displacing at least one diseased native posterior mitral valve leaflet.

[0025] In one mode of operation, the prosthetic valve includes multiple dome-shaped leaflets configured to be flexible and movable throughout the cardiac cycle. During systole, at least one prosthetic leaflet expands radially outward from the stent to form a D-shape and coapt with its own healthy anterior leaflet, thereby preventing transvalvular leakage and mitral regurgitation. During diastole, at least one prosthetic leaflet is configured to move toward the stent in a C-shape to allow ventricular filling.

[0026] It is contemplated that the semi-valve nature of the device allows for the use of thicker leaflet material, increasing the durability of the prosthetic valve. Additionally, the semi-valves can be shrunk to a smaller profile compared to a full valve, allowing a larger proportion of the at-risk population to undergo transcatheter mitral valve replacement.

[0027] In one exemplary embodiment, at least one prosthetic leaflet can mimic the configuration of the native posterior mitral valve leaflet, with three adjacent semilunar leaflets extending from the neck of the stent into the ventricle, and a central leaflet extending further inferiorly and radially inward than the two smaller lateral leaflets. In further embodiments, each prosthetic leaflet can include a parabolic attachment line, two commissures, an abdominal region, a coaptation region, and, optionally, at least one leg.

[0028] In one embodiment, the central leaflet attachment lines are configured to be symmetrical about the axial midline, with the central prosthetic leaflet spanning 1 / 3 to 2 / 3 of the ventricular portion of the stent, and the two side leaflets are configured to be mirror images of each other on either side of the central leaflet, spanning 1 / 6 to 1 / 3 of the ventricular portion of the stent, and are asymmetrical about their respective axial midlines.

[0029] In one exemplary aspect, the prosthetic valve includes a plurality of prosthetic leaflets configured with arm structures extending from the commissures that stabilize the commissure regions of the prosthetic leaflets by limiting posterior movement of the prosthetic leaflets toward the stent frame during the diastolic phase of the cardiac cycle.

[0030] In one aspect, the arm structure can be configured to fold a portion of at least one prosthetic leaflet over itself to increase leaflet thickness in the commissure region. Exemplary embodiments contemplate that the arm structure is triangular, rectangular, or irregularly shaped.

[0031] In a further embodiment, the prosthetic leaflet can be provided with at least one dogbone-shaped, rectangular, cylindrical, or conical leg structure that can be attached to the stent frame and configured to extend radially away from the stent frame. Those skilled in the art will appreciate that the leg structure mimics the natural aponeurosis in that it can prevent overextension and prolapse of the prosthetic leaflet, which is particularly necessary for larger prosthetic leaflets. The leg structure also helps distribute forces across the prosthetic leaflet and frame.

[0032] In one embodiment, the prosthetic half-valve is configured to occupy approximately half of the mitral valve orifice in a D-shaped configuration when coapted with the native anterior mitral valve leaflet. The prosthetic half-valve is designed to extend radially inward to, but not beyond, the lateral edges of the stent.

[0033] In one embodiment, a skirt is bonded to at least a portion of the inner and outer surfaces of the stent, and serves the dual purpose of acting as a means for attaching the prosthetic leaflets to the ventricular portion of the stent and forming a paravalvular seal along the atrial portion of the stent.

[0034] In one aspect, the skirt material can be made of polymers, fabrics, biological tissues, etc. An important feature of the skirt is that it is biaxially oriented, allowing it to stretch both axially and laterally during contraction and expansion of the prosthetic half-valve.

[0035] In one embodiment, the skirt can be a single piece of material, or alternatively, the skirt can be constructed from multiple separate pieces of material that are connected to the stent via one or more non-absorbable sutures or strings.

[0036] In one embodiment, a sealing ring can be bonded to the periphery of the prosthetic half-valve to promote tissue growth and protect the natural mitral valve surrounding structures from abrasion by the prosthetic valve.

[0037] In one embodiment, multiple DGF elements can be operably positioned and implanted into the native annulus at desired locations prior to delivery of the replacement prosthetic half-valve. In this embodiment, the DGF elements can improve subsequent positioning and fixation of the replacement prosthetic half-valve. In a further embodiment, the multiple DGF elements can help prevent blood leakage between the operably positioned prosthesis and the native mitral valve.

[0038] In one exemplary embodiment, the DGF member can include a permanent head and body portion with a removable, flexible tail portion. The DGF head member can include a coil shape that is operably embedded within the annulus tissue. The DGF body member can be coupled to a plurality of DGF locking members to secure the prosthetic semi-valve device to the native mitral valve annulus. The DGF tail member can be configured as a tether element extending from a proximal portion of the DGF body and connecting the DGF member to a shortened prosthetic semi-valve within a prosthetic semi-valve delivery and implantation system.

[0039] In one aspect, the DGF member body is coupled to a plurality of DGF locking members. In one embodiment, the DGF locking member includes a plurality of radially compressible legs, e.g., forming a conical shape. In a further embodiment, the tip of the cone is configured to have a smaller diameter than the legs of the cone, which is smaller than the diameter of the hole in the atrial portion of the stent, while the legs of the cone have a larger diameter than the hole in the atrial portion of the stent.

[0040] In one embodiment, tension is applied to the DGF tail to pull the DGF locking element through the hole in the atrial portion of the stent, thereby compressing the legs of the DGF locking element inward and allowing the DGF locking element to pass through the hole in the atrial portion of the stent. After passing through the hole in the atrial portion of the stent, the legs of the DGF locking element re-expand to their activated position, preventing rearward movement of the DGF locking element through the hole in the atrial flaring portion of the stent and effectively locking the prosthetic half-valve in the activated position.

[0041] The various embodiments described herein may include additional systems, methods, features, and advantages that are not necessarily expressly disclosed herein, but will become apparent to one of ordinary skill in the art upon review of the following detailed description and the accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within this disclosure and protected by the accompanying claims. [Brief explanation of the drawings]

[0042] A better understanding of the features and advantages of the present subject matter will be obtained by reference to the following detailed description setting forth illustrative embodiments and the accompanying drawings, in which features and components are shown to emphasize the general principles of the present disclosure. Corresponding features and components throughout the drawings may be designated by corresponding reference numerals for consistency and clarity.

[0043] [Figure 1] Figure 1A is a posterior oblique cross-sectional view of a healthy native mitral valve during systole. Figure 1A shows the mitral valve leaflets coapting to form a "fish-mouth"-like coaptation line. Figure 1B is a perspective view of the native mitral valve after the left ventricle has been distended to reveal the mitral valve anatomy. The mitral valve leaflets are divided into two parts, the anterior and posterior, and each part is subdivided into three sections. The posterior leaflet has three adjacent semilunar leaflets: P1, P2, and P3. The P2 leaflet is the largest and extends the furthest into the ventricle, while the P1 and P3 leaflets are smaller and shorter. The anterior mitral valve leaflet similarly has areas that coapt with P1, P2, and P3, respectively, during systole. [Figure 2] Figure 2A shows a native mitral valve as viewed from the atrium. The native anterior leaflet is clearly larger than the native posterior leaflet. The native posterior leaflet forms a C-shape along the posterior annulus. Figure 2B is a schematic diagram of an exemplary embodiment of a prosthetic half-valve device including three prosthetic leaflets attached to the inner surface of a frame in an operating, pressurized, contracted state. Prosthesis P1, prosthesis P2, and prosthesis P3 are shown mated with the native anterior mitral valve leaflet. [Figure 3] Figure 3A is a schematic front view of an exemplary embodiment of a prosthetic half-valve frame including multiple cells that may be included in a prosthetic half-valve such as that shown in Figure 2B. The frame includes an upper atrial portion and a lower ventricular portion separated by a neck region. The atrial portion of the frame has multiple through-holes and a curved stent tip. The lower ventricular portion has multiple through-holes for attachment of prosthetic leaflets and is configured with a variable stent height along its circumference. Figure 3B shows an alternative embodiment of a stent frame in which a central extension member with tabs extends from the tip of the central cell of the ventricular portion of the stent. Figure 3C shows an alternative embodiment of a stent frame in which a central and at least one peripheral extension member with tabs extends downwardly from the ventricular portion of the stent. [Figure 4] 4 is a schematic diagram of an exemplary embodiment of a prosthetic half-valve in a crimped configuration. The lateral free ends of the stents are configured with attachment sites that engage with each other during the crimping process, thereby maintaining the valve in a cylindrical shape during crimping. The elongated member is the longest portion of the crimped device, and a portion of the delivery system can be configured to engage a tab at the tip of the elongated member without affecting the remainder of the valve. [Figure 5] FIG. 5 is a schematic illustration of an atrial skirt that forms a paravalvular seal around the atrial portion of a valve such as the prosthetic half-valve of FIG. 2B. [Figure 6] FIG. 6 is a schematic diagram of a frame covered with atrial and ventricular sealing skirts and bilateral marginal sealing rings. [Figure 7]7 is a schematic diagram of one embodiment of a prosthetic half-valve having three dome-shaped prosthetic leaflets attached to the inner surface of a frame. In this embodiment, the assembly of prosthetic leaflets includes one large central leaflet and two small side leaflets. [Figure 8] FIG. 8 shows an exemplary embodiment of a large central prosthetic leaflet that includes a dome-shaped body, two legs, and two arms. [Figure 9] 9A and 9B show examples of small lateral prosthetic leaflets, each including a dome-shaped body and two arms. [Figure 10] 10 is a schematic ventricular view of an exemplary embodiment of a prosthetic half-valve device showing the prosthetic leaflets in a pressurized contracted state superimposed with the prosthetic leaflets in an unpressurized resting state, where the prosthetic leaflets expand radially away from the frame under systolic pressure. [Figure 11] 11 is a schematic diagram of an exemplary embodiment of a DGF member locking unit, in which the locking unit includes a through-hole for attachment to a tether and multiple legs. DETAILED DESCRIPTION OF THE INVENTION

[0044] The present invention may be more readily understood by reference to the following detailed description, examples, figures, and claims, as well as the accompanying text. However, before the present devices, systems, and / or methods are disclosed and described, it is to be understood that the present invention is not limited to the particular devices, systems, and / or methods disclosed, unless otherwise specified, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0045] The following description is provided as an enabling teaching of the invention in its best currently known embodiment. To this end, those skilled in the art will recognize and appreciate that many variations can be made to the various aspects of the invention described herein while still obtaining the beneficial results of the invention. It will also be apparent that some of the desired advantages of the invention can be obtained by selecting some of the features of the embodiments described herein without utilizing other features.

[0046] Accordingly, those skilled in the art will recognize that many modifications and adaptations are possible and can even be desirable in particular circumstances and are a part of the present invention. Accordingly, the following description is provided as an illustration of the principles of the invention, not in limitation.

[0047] For clarity, it should be understood that the present disclosure focuses on the treatment of functional mitral regurgitation, however, it is contemplated that the heart valve leaflet replacement systems and related methods may be used or otherwise configured to be used to treat other types of mitral regurgitation or to replace other diseased valves in the human heart, such as the tricuspid valve, or in other mammals similarly afflicted with valve defects.

[0048] As used throughout, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to a "valve leaflet" can include two or more such leaflets unless the context dictates otherwise.

[0049] Ranges can be expressed herein as from "approximately" one particular value and / or to "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. Further, it will be understood that the endpoints of each range are significant both in relation to the other endpoint and independently of the other endpoint.

[0050] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event or circumstance occurs and cases where it does not occur.

[0051] As used herein, the word "or" means any one element of a particular list and also includes any combination of elements of that list. Furthermore, it should be noted that conditional language, particularly "can," "could," "might," or "may," unless otherwise specified or understood within the context in which it is used, is generally intended to convey that certain aspects include certain features, elements, and / or steps, while other aspects do not. Thus, such conditional language is generally not intended to imply that features, elements, and / or steps are somehow required for one or more particular aspects, or that one or more particular aspects necessarily include logic for determining whether or not those features, elements, and / or steps are included or performed in any particular embodiment, with or without user input or prompting.

[0052] Components are disclosed that can be used to implement the disclosed methods and systems. These and other components are disclosed herein, and when combinations, subsets, interactions, groups, etc. of these components are disclosed, it is to be understood that, although specific reference to each of their various individual and collective combinations and permutations is not expressly disclosed, each is specifically contemplated and described herein for all methods and systems. This applies to all aspects of this application, including, but not limited to, steps in the disclosed methods. Thus, where there are various additional steps that can be performed, it is to be understood that each of those additional steps can be performed in any specific embodiment or combination of embodiments of the disclosed methods.

[0053] The present method and system may be more readily understood by reference to the following detailed description of exemplary embodiments.

[0054] Throughout this specification, the terms "artificial valve," "prosthesis," "valve stent," "heart valve leaflet replacement device," and "valve device" are used interchangeably and are intended to refer to the heart valve replacement devices described herein.

[0055] Referring to FIG. 1A, the mitral valve leaflets consist of an anterior leaflet 6 and a posterior leaflet 10, which arise from the annulus and extend into the left ventricle 3. In a healthy patient, the anterior mitral leaflet 6 and the posterior mitral leaflet 10 coapt together during systole to prevent regurgitation through the mitral valve 4. The posterior mitral leaflet 10 forms a "C" shape extending from the posterior annulus, as shown in FIG. 2A. In diseased conditions, the posterior leaflet 10 may not fully coapt with the anterior leaflet 6 due to tethering of the posterior leaflet 10 and / or dilation of the mitral annulus, thereby resulting in mitral regurgitation.

[0056] Turning to the drawings, there is shown one exemplary embodiment of a prosthetic semi-valve device 1 designed to treat mitral regurgitation in patients with regurgitation and normal anterior mitral valve leaflet 6 movement by replacing the posterior mitral valve leaflet 10, as shown in FIG. 2B , for example. The prosthetic semi-valve device 1 comprises a crescent-shaped frame or stent 100 that is anchored to the posterior mitral valve annulus and, during operation, positions at least one prosthetic leaflet 200 over the native posterior leaflet 10 to form a coaptation region 204 with the native anterior mitral valve leaflet 6 during systole. In this embodiment, one or more prosthetic leaflets 200 extend from the stent 100 to form a C-shape similar to the native posterior leaflet 10, but notably, can further expand radially to coapt with the native anterior mitral valve leaflet 10 in a dilated heart.

[0057] In one exemplary embodiment, the prosthetic semi-valve device 1 can include a crescent-shaped stent 100, at least one dome-shaped prosthetic leaflet 200, and at least one sealing skirt 300 to facilitate sealing and attachment of the prosthetic leaflet 200 to the stent 100. The prosthetic semi-valve device 1 is configured such that, during operation, the at least one prosthetic leaflet 200 coapts with at least one native anterior leaflet 6 during the systolic phase of the cardiac cycle, as shown, for example, in FIG. 2B .

[0058] In one aspect, it is contemplated that, in the expanded configuration, stent 100 defines a substantially semicircular cross-sectional profile. It is further contemplated that stent 100 may be configured such that the surface of stent 100 defines a non-circular cross-sectional profile, including, but not limited to, a semi-elliptical cross-sectional profile or an asymmetric cross-sectional profile, e.g., to at least partially conform to the shape of the native valve annulus. As used herein, the term "asymmetric cross-sectional profile" includes any non-circular cross-sectional shape.

[0059] In one embodiment, as shown in Figure 3A, stent 100 is configured to have a crescent shape to form a semi-valve or hemi-valve. In this embodiment, stent 100 can have a semi-conical shape. Semi-conical stent 100 includes an upper atrial portion 104, a lower ventricular portion 110, and a neck region 109 between and defining a longitudinal axis therebetween, i.e., aligned along the length of stent 100.

[0060] 3A, the semi-valve stent 100 can be made from a self-expanding or balloon-expandable material formed into a network or mesh of cells. In this embodiment, the stent frame 100 can be laser cut or woven from a deformable biocompatible material, such as stainless steel or cobalt chrome for a balloon-expandable device, or nitinol for a self-expandable device with shape-memory properties. In a further embodiment, the stent 100 can be configured to be collapsed, contracted, and expanded to desired loading and actuation positions, respectively.

[0061] In one embodiment, the atrial portion 104 of the stent may be configured to be placed at or over the native mitral valve annulus to facilitate fixation and sealing of the prosthetic half-valve 1 .

[0062] Additionally or alternatively, the atrial portion 104 of the stent may be configured to span at least a portion or all of the native mitral valve annulus.

[0063] In one embodiment, the atrial portion 104 of the stent is configured to span radially across part or all of the posterior annulus of the native mitral valve. In this embodiment, the upper atrial portion 104 may be configured with at least one row of cells. In the illustrated example, the cells include struts oriented in a collapsible diamond configuration that extend radially outward from the neck portion 109 of the stent. In this embodiment, the diameter of the upper atrial portion 104 is smallest near the neck portion 109 and increases outward toward the atrial crown 117 and the left atrial wall.

[0064] Referring to FIG. 3A, the atrial portion 104 of the stent is configured with compressible cells. In one embodiment, the atrial portion 104 of the stent includes at least one row of cells. The cells comprise a collapsible network of struts oriented in a diamond configuration that extend radially outward from the neck portion 109 of the stent. The height of the cells can be approximately six to twelve millimeters (6-12 mm). In the illustrated example, each cell is formed of four struts: two upper struts and two lower struts. The upper and lower struts may be the same or different in size. The upper and lower struts are connected to each other by cell bridges, referred to as connectors 103. The connectors 103 can be designed to allow the entire stent 100 to be compressible or non-compressible.

[0065] In an exemplary embodiment, some of the connections 103 in the atrial portion of the stent can be configured with through-holes or holes 108. In this embodiment, the through-holes 108 are used to anchor and secure the stent 100 onto the mitral valve annulus. The holes 108 can be configured to have an inner diameter of approximately one-half to three millimeters (0.5-3 mm), and approximately five to fifteen holes can be configured along the atrial portion 104 of the stent. The holes 108 in the atrial portion 104 of the stent are configured to allow passage of the locking member 131 in only one direction.

[0066] In alternative embodiments, fixation of the stent 100 to the mitral annulus can be achieved by other methods, such as by using adhesives, or by one or more of grasping, capturing and suturing tissue.

[0067] In optional embodiments, the holes 108 can have a circular, rectangular, square, or oval shape.

[0068] In one embodiment, due to the half aspect of the prosthetic valve 1, the side edges 107 of the side cells 106 of the atrial portion 104 of the stent do not share a joint 103 with adjacent cells.

[0069] In this embodiment, the bonds 103 of the side cells 106 can be configured to have bond sites at the side edges 107. In this embodiment, the bond sites at the side edges 107 of the stent can be configured to have matching corresponding shapes so that they fit snugly together and maintain the cylindrical shape of the stent during crimping. In this embodiment, the shape of one bond 103 on one side can be configured to match and mate with the shape of the other bond on the opposite side.

[0070] In one exemplary embodiment, the binding sites can be straight, zigzag, wavy, semicircular, semi-elliptical, rectangular or irregularly shaped struts.

[0071] In one aspect, the atrial portion 104 of the stent is configured to conform to the valve annulus during operation. The upper struts of the cells of the atrial portion 104 of the stent, also referred to as the crown or free stent tip, can be configured with a curved tip 117, as shown in FIG. 3A, for example, to avoid interference with the left atrial wall 2 during operation. In an exemplary embodiment, the angle of curvature of the tip 117 can be approximately 90° to 145° relative to the rest of the upper flared portion 104. Such a curvature allows the atrial portion 104 of the stent to conform to the left atrial wall 2. In this example, the lower struts of the cells of the atrial portion 104 of the stent curve downward to connect to the neck region 109 and transition at an angle ranging from 65° to 120° relative to the ventricular portion 110 of the stent.

[0072] In an optional aspect, the stent tip 117 of the atrial portion 104 of the stent can be configured with a curvature that lies approximately parallel to the mitral annulus during operation.

[0073] In one exemplary embodiment, the atrial portion 104 of the stent may be configured with two rows of cells, with the row of cells near the neck region 109 having a smaller dimension than the other row of cells toward the stent tip 117. In this embodiment, the additional row of cells may be configured with bend struts having angles between 90° and 145°.

[0074] In another embodiment, the two rows of cells in the atrial portion 104 of the stent can have the same dimensions.

[0075] In one embodiment, a neck region 109 connects the atrial portion 104 and the ventricular portion 110 of the stent. In this embodiment, the neck region 109 is continuous with the upper atrial portion 104 and the lower ventricular portion 110 of the stent. The neck region 109 can be comprised of at least one row of cells, for example, having a height of approximately one to seven millimeters (1.0 to 7.0 mm). The upper portion of the neck 109 is curved or angled to facilitate the transition between the atrial portion 104 and the neck portion 109 of the stent. Similarly, the lower portion of the neck 109 is curved or angled to facilitate the transition between the neck portion 109 and the ventricular portion 110 of the stent.

[0076] In one exemplary embodiment, as shown in FIG. 3A, neck region 109 includes a single row of cells. The cells of neck region 109 are formed by struts in atrial portion 104 and struts in ventricular portion 110, with the lower struts in atrial portion 104 forming a collapsible half-cell and connecting to a thin, thick, straight strut, and the upper struts in ventricular portion 110 forming the other half of the collapsible cell. In this example, neck region 109 is configured to bend so that the angle between atrial portion 104 and ventricular portion 110 is in the range of approximately 65° to 120°. In this embodiment, the atrial portion 104 of the stent is approximately parallel to the valve annulus.

[0077] In one embodiment shown in FIG. 3A, the ventricular portion 110 of the stent can assume an asymmetric semi-conical or semi-circular cross-sectional profile.

[0078] In one exemplary embodiment, the ventricular portion 110 of the stent is configured to span at least a portion or all of the posterior leaflet 10 of the native mitral valve 4. Optionally, the lateral edges 112 of the stent can extend circumferentially to the native mitral valve commissures 14 (not shown, see, e.g., FIG. 1B ) to provide at least partial or complete coaptation between the anterior leaflet 6 of the native mitral valve and at least one prosthetic leaflet 200 coupled to the inner surface of the ventricular portion 110 of the stent.

[0079] In one aspect, in the expanded configuration, the stent 100 is configured to have an anterior-posterior (AP) dimension. In an exemplary embodiment, the AP dimension at the ventricular level is in the range of approximately ten to forty millimeters (10-40 mm) and / or the AP dimension at the atrial level is in the range of approximately twenty to sixty millimeters (20-60 mm). In a further example, the length from the anterior commissure to the posterior commissure, i.e., the intercommissural (CC) length, can be in the range of approximately twenty to sixty millimeters (20-60 mm) and / or the CC length at the atrial level can be in the range of approximately thirty to ninety millimeters (30-90 mm). The ventricular portion 110 of the stent is configured to form a "C-shape" in the activated position, thereby displacing the native posterior mitral valve leaflet 10 and allowing at least one prosthetic leaflet 200 to radially expand to the lateral edge of the stent 100 and coapt with the native anterior leaflet 6.

[0080] In one aspect, the ventricular portion 110 of the stent is configured to have different heights along its circumference so as not to interfere with the papillary muscles 14 .

[0081] In a presently preferred embodiment of the ventricular portion 110 of the stent, the stent height at the center of the valve may be in the range of approximately ten to forty millimeters (10-40 mm), and the stent height at the sides of the stent 112 may be in the range of approximately five to fifteen millimeters (5-15 mm).

[0082] In one embodiment, the ventricular portion 110 of the stent can include at least one row of cells. The row of cells can span all or a portion of the circumference of the ventricular portion 110 of the stent.

[0083] In one exemplary embodiment, the ventricular portion 110 of the stent is configured with three rows of cells. Row I 134, Row II 135, and Row III 136 are configured at the top, middle, and bottom of the ventricular portion 110 of the stent, respectively. Each row is configured with multiple connected struts that form foldable diamond-shaped cells with a height of 7-8 mm and a width of 4-6 mm. Each row can include the same number of cells or have a different number of cells.

[0084] In one aspect, row I cells 134 are attached to neck region 109 at the top of the cell and share row II cells 135 with the bottom strut 101. Optionally, one or more of row I cells 134 are configured to be covered with a sealing skirt 300, which can facilitate docking of the prosthetic leaflets 200 and prevent leakage.

[0085] In an additional embodiment, row II cells 155 share an upper portion with row I cells 154 and a lower portion with row III cells 156. In one embodiment, multiple row II cells 155 located behind at least one prosthetic leaflet 200 can optionally be configured to be open cells without being covered by skirt 300. This configuration facilitates radial expansion of at least one prosthetic leaflet 200 and prevents stagnation of blood behind one or more leaflets 200. The cells covered by skirt 300 include leaflet attachment lines, for example, for coupling multiple prosthetic leaflets 200 to stent 100.

[0086] In another embodiment, the cells 136 in row III share an upper portion with the cells 135 in row II and are separate at the lower portion. The two side edges 112 are configured to be covered with at least one layer of fabric 300. The portions of the cells 136 in row III corresponding to the attachment areas of the prosthetic leaflets 200 are configured to be covered with the sealing skirt 300, while other areas can optionally be left open without the skirt 300.

[0087] In one embodiment, the height and width of the cells in each column can be the same. In another embodiment, the height and width of the cells in each column can be different.

[0088] In one embodiment, the ventricular portion 110 of the stent can be configured with a semi-conical shape, with its diameter being smallest near the neck portion 109 and increasing downward toward the ventricle 3 during operation.

[0089] In one optional embodiment, as shown in FIG. 4, the stent can include attachment sites on the side edges 112 of the ventricular portion 110 of the stent to facilitate crimping. In this embodiment, the attachment sites 112 can be configured to include at least one row of ventricular cells and, optionally, at least one row of atrial cells. In this embodiment, the side edges 112 of the stent can be configured with corresponding shapes to fit snugly together and maintain the stent in a cylindrical shape throughout crimping. In one exemplary embodiment, the attachment sites 112 can be configured as straight, zigzag, semicircular, semi-elliptical, or rectangular struts.

[0090] In one aspect, the bond 103 can be configured as a non-linear section of the side edge 112, with opposing side edges 112 configured to engage each other during crimping 18 of the stent.

[0091] In one aspect, one or more cell struts can be configured with through holes 113 that provide a mechanism for attaching at least a portion of the prosthetic leaflet 200 to the frame without the need for skirt 300 material on the cell.

[0092] In one exemplary embodiment of the prosthetic half-valve device 1, one or more struts in row III 136 of the ventricular portion 110 of the stent can be configured with through-holes 113 for direct attachment of at least one prosthetic leaflet 205 to the strut. In this aspect, the diameters of the plurality of through-holes 113 can range from approximately 0.1 mm to 1 mm. Optionally, the strut including the through-hole 113 can be configured to be approximately 1.1 to 2.5 times wider than the other struts to accommodate the presence of the through-hole 113.

[0093] In one exemplary embodiment, the ventricular portion 110 of the stent is configured such that at least one prosthetic leaflet commissure 201 is attached to the frame 100 at one or more of the ventricular stent tips 118, thereby allowing the stent tips 118 to flex radially when the leaflets 200 are loaded.

[0094] As shown in FIG. 3A, in one exemplary embodiment, the ventricular portion 110 of the stent is configured to have a stingray shape, extending furthest in the center of the ventricle 3 and having shorter sides 112 to prevent interference with the native papillary muscles 16 during operation.

[0095] As shown in Figures 3B and 3C, the stingray design of stent 100 can have at least one stingray tail or extension member 114 configured to extend vertically downward from the lower strut joint 103 of the ventricular section 110 of the stent. One or more extension members 114 can extend from a lower central cell of the ventricular section 110 of the stent, or optionally from any other portion of the stent 100. In an exemplary embodiment, extension member 114 can have a width of approximately 0.3 to 5.5 mm and a length of approximately 1.0 to 10.0 mm. The distal end of extension member 114 can be configured with a central tab 115.

[0096] In another embodiment, extension members 114 having central tabs 116 can extend from different cells around the circumference of the stent's ventricular portion 110. In this embodiment, the length of extension members 114 can be approximately 1.0-5.0 mm to avoid interference with surrounding structures.

[0097] In another embodiment, as shown in Figures 3B and 3C, at least one circumferential tab 116 can be configured to be attached to different cells around the circumference of the ventricular portion 110 of the stent without the use of an extension member 114.

[0098] In another embodiment, at least a portion of the ventricular section 110 is configured so that the lowest end 118 bends radially inward. In one example, the bend angle can be configured to be between 10° and 50° relative to the axial direction of the stent 100.

[0099] In one exemplary embodiment, tabs 115, 116 can include at least one hole. Tabs 115, 116 can be configured with various shapes for various delivery system engagement mechanisms, including but not limited to magnetic engagement mechanisms, male-female mating engagement mechanisms, rotational locks, etc., that can selectively engage at least a portion of the delivery system throughout the valve deployment process, thereby stabilizing the deployment process.

[0100] In one embodiment, tabs 115, 116 can be made of the same or different material as stent 100 and can be permanently connected to stent 110 via various attachment means such as adhesives, magnetic engagement, etc. Tabs 115, 116 and their extension structures 114 can be connected to the delivery system in different orientations. In a further embodiment, tabs 115, 116 can be detached from stent 100 after stent deployment.

[0101] In one embodiment, at least one prosthetic leaflet 200 is attached to a skirt 300 that is coupled to the ventricular portion of the stent 110 via non-absorbable sutures. The stent 100 can be configured to allow natural dynamic movement of one or more remaining native leaflets to coapt with one or more prosthetic leaflets 200.

[0102] In one aspect, the ventricular portion 110 of the stent is configured to displace the posterior leaflet 10 of the native mitral valve within the left ventricle 3 of the heart and place at least one prosthetic leaflet 200 in its place.

[0103] The sealing skirt 300 is coupled to at least a portion of the inner and outer surfaces of the stent 100 and is configured to prevent leakage between the prosthetic half-valve frame 100 and the at least one prosthetic valve leaflet 200 and to provide a base for mounting the at least one prosthetic valve leaflet 200.

[0104] The skirt 300 can be made of synthetic or natural biocompatible, non-permeable materials, including, but not limited to, polymers, fabrics, biological materials, etc. The skirt 300 can be cut from a similar or different material to the valve leaflets 200 to ensure compatibility within the body. The skirt 300 can be laser cut, stamped, or hand cut to optimize uniformity and precision of the desired dimensions. In one exemplary embodiment, the thickness of the skirt 300 can range from approximately 0.1 mm to 0.15 mm.

[0105] In one aspect, the skirt 300 can be configured to exhibit a biaxial orientation with the fibers aligned circumferentially, which allows the skirt 300 to stretch axially during the crimping and release processes, allowing the skirt 300 to conform to the elongated stent shape without tearing or damaging the prosthetic valve leaflets 200.

[0106] Optionally, the impermeable sealing skirt 300 further comprises an atrial portion 302 and a ventricular portion 301. In this option, the atrial portion 302 and the ventricular portion 301 may be constructed as a single piece. In another option, the atrial portion 302 and the ventricular portion 301 may be constructed as two separate pieces.

[0107] In one embodiment, the skirt 300 is coupled to the stent 100 via one or more of sutures, adhesives and / or other biocompatible materials.

[0108] In one embodiment, a ventricular skirt 301 is used as a structure for attaching the prosthetic leaflets 200 to the stent 100. In this embodiment, the ventricular skirt 301 can be configured to cover at least a portion of the ventricular portion 110 of the stent to facilitate attachment of the prosthetic leaflets 200.

[0109] In one embodiment, the ventricular portion of the skirt 301 is configured with a plurality of tabs configured to wrap around the struts of the stent in the commissure regions to prevent movement of the skirt during crimping.

[0110] In one aspect, a ventricular skirt 301 can be configured to fit over the inner surface of the ventricular portion 110 of the stent. The upper edge of the ventricular skirt covers the neck region 109 of the stent and also provides a path for a connecting wire 303 to attach the ventricular skirt 301 to the atrial skirt 302. The ventricular skirt 301 is configured to cover selected cells of the ventricular portion 110 of the stent.

[0111] In one aspect, the prosthetic leaflets 200 are configured to attach to the ventricular skirt 301 along an engineered parabolic leaflet attachment line. The ventricular skirt 301 is configured to cover the stent portion 110 along which the leaflet attachment line should align to facilitate attachment of at least one prosthetic leaflet 200 to the stent 100.

[0112] In one embodiment, as seen in Figure 5, the enlarged tabs 312 of the atrial skirt 302 are folded over to form multiple pockets for paravalvular sealing. In a further embodiment, the enlarged tabs 312 are folded over to form a uniform layer of the skirt 302 on the dorsal side of the valve 100 that is in direct contact with the atrial tissue 2. This layer of folded enlarged tabs 312 prevents paravalvular leakage.

[0113] In one aspect, an atrial skirt 302 is used to facilitate a paravalvular seal in the atrium 2 and further secure the valve 1 to the annulus. The atrial skirt 302 is configured to conform to the inherent curvature of the atrial portion 104 of the stent.

[0114] In one embodiment, the atrial skirt 302 can be constructed of a material that can be penetrated by the DGF member head so that after the valve 1 is deployed and locked in place, additional DGF members can be implanted through the atrial skirt 302 to further secure the valve 1.

[0115] In the example shown in FIG. 5 , the atrial skirt 302 has two side tabs 309. These tabs 309 are configured to fold over the side edges 106 of the atrial portion of the stent to form the side skirts. The lower portions of the side tabs 306 of the atrial skirt 302 engage with the larger tabs of the ventricular skirt 301 by folding under the corresponding larger tabs. The larger tabs of the ventricular skirt 301 and the side tabs 309 of the atrial skirt 302 fold over on themselves. This feature is noteworthy because this area is in direct contact with the commissures 14 of the native mitral valve 4. The side skirts thereby serve two functions. First, the side skirts prevent the sharp edges of the stent 100 from cutting into the native mitral valve commissures 14. Second, the side skirts provide attachment for the sealing rings 316 to form a paravalvular seal around the edges of the valve 1.

[0116] Optionally, as shown in FIG. 6, sealing rings 316 can be attached to the lateral edges 107, 112 of the valve to form paravalvular seals along the commissures 14 of the native mitral valve 4 and to provide a cushion between the lateral edges 107, 112 of the stent 100 and the surrounding tissue.

[0117] In one embodiment, a sealing ring 316 can be attached to at least a portion of the atrial portion 104 of the frame to form a paravalvular seal along the annulus.

[0118] The sealing ring 316 can be made of a flexible synthetic or natural biocompatible material, including, but not limited to, a polymer, fabric, biomaterial, etc. The sealing ring 316 can surround the lateral and superior edges of the valve 1 that may contact the native tissue during operation, while avoiding the inferior edge of the valve 1 so as not to interfere with the movement of the valve leaflets. The sealing ring 316 can be permanently secured to the valve 1 with, for example, one or more sutures, adhesives, and / or other biocompatible materials.

[0119] In one embodiment of the prosthetic half-valve device 1, at least one dome-shaped prosthetic leaflet 200 can be attached to the inner surface of the frame. In one embodiment, the at least one prosthetic leaflet 200 can be attached to the inner surface of the lower ventricular portion 110 of the frame. The at least one prosthetic leaflet 200 can have multiple leaflets, and it is contemplated that all of the prosthetic leaflets 200 can have the same shape and size, or one or more of the multiple leaflets 200 have different shapes and / or sizes.

[0120] 7 and 8, each dome-shaped prosthetic leaflet 207 can include two commissures 201, a curved attachment edge 202, an abdominal region 203, a coaptation region 204, and, optionally, at least one arm 215 and at least one leg 205. In one exemplary embodiment, the attachment edge 202 of at least one leaflet 207 can be attached to the inner lumen of the stent 100 or skirt 300 using, for example, non-absorbable sutures. In another embodiment, the foot 214, i.e., the free end of at least one leg 205, can be attached to the inner lumen of the stent 100 or skirt 300 using, for example, non-absorbable sutures.

[0121] In one aspect, the dome-shaped prosthetic leaflet(s) 207 are configured to be movable throughout the cardiac cycle such that the abdominal and coaptation regions expand radially inward from the frame 100 during systole to prevent central valve regurgitation or commissural leakage, and move toward the frame 100 during diastole to allow ventricular filling. The prosthetic leaflet commissures 201, attachment edges 202, and feet 214 of the legs 205 attached to the stent 100 are stationary relative to the stent 100.

[0122] In one embodiment, at least one prosthetic leaflet 207 can be configured with at least one arm 215 extending from the leaflet commissure 201 .

[0123] In one aspect, the dome-shaped valve leaflet(s) 207 can be configured to exhibit limited collapsibility and radial expansion so that they do not strike the frame 100 when the valve is open and, during operation, cannot extend beyond the radius of the frame 100 when the valve is closed.

[0124] In one embodiment, the dome-shaped prosthetic leaflet(s) 207 can be configured to coapt with the native anterior mitral valve leaflet 6 during systole during operation. Referring to FIG. 1A , a healthy native mitral valve 4 during systole, the posterior mitral valve leaflet 10 extends radially to form a C-shape and coapt with the anterior mitral valve leaflet 6. In patients with functional mitral regurgitation, the native mitral valves 6, 10 cannot extend sufficiently toward each other to fully coapt. As shown in FIG. 2B , it is contemplated that the prosthetic leaflet 200 can be configured to form a C-shape with the native posterior leaflet 10 and extend beyond this line into a D-shape to coapt with the native anterior mitral valve 6 in patients with functional mitral regurgitation.

[0125] The anchoring mechanism of the prosthetic semi-valve device 1 can be configured to resist separation from the posterior mitral annulus during systole and device migration during operation. In one embodiment, the prosthetic semi-valve device 1 can be configured to cover approximately half or two-thirds of the mitral valve orifice during systole. In this embodiment, given the half-valve nature of the prosthetic semi-valve 1, only approximately half of the total force induced by blood flow during systole acts on the prosthetic semi-valve device 1, and therefore only half of the total force acts on the anchoring mechanism. The remaining force induced by blood flow acts on the anterior mitral valve leaflet 6 and the annulus. For this reason, it is contemplated that the prosthetic semi-valve 1 can be more easily secured to the mitral valve annulus than a full-circumferential prosthetic valve. Those skilled in the art will appreciate that securing a full-circumferential prosthetic valve device in mitral position remains a challenge.

[0126] 2B , in one embodiment of the prosthetic half-valve device 1, the multiple dome-shaped prosthetic leaflets 200 can be formed from a flat piece of flexible material and sewn or otherwise attached to the frame 100 so that they are movable throughout the cardiac cycle and resist separation from the frame 100. In another embodiment, the multiple dome-shaped prosthetic leaflets 200 can be pre-formed into a 3D dome shape by casting, deformation, molding, braiding, thermal or chemical treatment, 3D printing, electrospinning, or other manufacturing methods.

[0127] In one embodiment, the plurality of prosthetic leaflets 200 may comprise pericardial tissue, or other biological or tissue-engineered materials, polymers, fabrics, or flexible metallic materials, etc. In this embodiment, it is contemplated that the movable, flexible prosthetic leaflets 200 will exhibit resilience when interacting with the native anterior leaflet 6, thereby minimizing damage induced to the native leaflet 6 by repeated contact.

[0128] Due to the nature of the device's half-valves 1, it is contemplated that the prosthetic leaflets 200 may be constructed with thicker leaflet material than other prosthetic mitral valves intended to be implanted via a catheter, while still having a small, reduced device profile, which is desirable for procedural feasibility and patient safety. Those skilled in the art will appreciate that thicker prosthetic leaflets 200 are desirable for the durability of the prosthetic valve 1.

[0129] 1B, the native mitral valve posterior leaflet 10 includes three adjacent semilunar shaped leaflets: P1 leaflet 11, P2 leaflet 12, and P3 leaflet 13. P2 leaflet 12 is the largest and extends the furthest into the ventricle 3, while P1 leaflet 11 and P3 leaflet 13 are smaller and shorter, particularly laterally. In one exemplary embodiment of the prosthetic half-valve device 1, as shown in FIG. 7, the plurality of prosthetic leaflets 200 can include two smaller lateral leaflets 206, 208 and a larger central leaflet 207 that mimics the anatomy of the native posterior leaflet 10.

[0130] 7, in one embodiment, the prosthetic leaflets 200 can be configured as multiple dome-like structures that extend radially inward away from the stent 100. In another optional embodiment, the prosthetic P2 (PP2) leaflet 207 can extend further down into the left ventricle 3 during operation than the sides of the prosthetic P1 (PP1) leaflet 206 and the prosthetic P3 (PP3) leaflet 208, similar to the natural posterior mitral valve leaflet 10.

[0131] 9A and 9B, the PP1 leaflet 206 and the PP3 leaflet 208 can be configured as mirror images of each other, with shorter lateral edge heights corresponding to shorter frame heights at the lateral edges and taller central edge heights, with the central PP1 and PP3 commissures 210 aligned with the PP2 commissure. Additionally, as one skilled in the art can appreciate, having shorter PP1 and PP3 lateral commissures 209 can desirably reduce the collapsed profile of the prosthetic half-valve device 1 because the amount of leaflet material is greatest at the leaflet commissures 201, and having the lateral commissures 209 at a different height than the central commissure 210 reduces the amount of material at the central commissure 210, thereby allowing for collapse to a smaller diameter.

[0132] In one embodiment of the prosthetic half-valve device 1, the prosthetic leaflets 200 can be configured to be attached to the frame 100, starting just below the neck region 109 of the frame 100 and extending axially to the tip 118 of the ventricular portion of the frame, wrapping around the periphery of the ventricular portion 110 of the frame. In other optional aspects, the prosthetic leaflets 200 can be configured to wrap around the side edges of the frame 112, or to cover only a portion of the circumference of the frame 100. Furthermore, the prosthetic leaflets 200 can be configured to extend axially from the upper flared portion 104 or neck portion 109 of the frame to the ventricular portion 110 of the frame. Optionally, the prosthetic leaflets 200 can be configured to cover only a portion of the ventricular portion 110 of the frame.

[0133] In one aspect, the prosthetic leaflets 200 are attached to the frame 100 along leaflet attachment lines 320 , which include a plurality of parabolas that each outline the prosthetic leaflets 200 .

[0134] In one aspect, leaflet attachment line 320 is configured to be symmetrical about the center of skirt 300. In an optional aspect, leaflet attachment line 320 is configured to be asymmetrical.

[0135] 7, the leaflet attachment lines 320 are configured as three adjacent parabolic shapes for attaching three different prosthetic valve leaflets 200. In this aspect, the leaflet attachment lines 206, 207, 208 for PP1, PP2, PP3 can be configured to have the same size and shape or can be configured to have different sizes and shapes, and can be either symmetrical or asymmetrical.

[0136] Optionally, PP2 leaflet attachment line 320 is configured to span approximately 1 / 3 to 2 / 3 of the circumference of stent 100 and is symmetrical about its axial midline.

[0137] Additionally or alternatively, the PP1 and PP3 leaflet attachment lines 320 can be configured as mirror images of each other, spanning approximately 1 / 6 to 1 / 3 of the stent circumference, and are configured to be shorter at the lateral edges and asymmetrical about their respective axial midlines.

[0138] In one aspect, the multiple leaflets 200 can be configured as separate, individual pieces of flexible material that are attached to the frame 100 along each of the parabolic leaflet attachment lines 320. Each leaflet 206, 207, 208 can be made of the same or a different material. In another optional aspect, the multiple leaflets 200 can be formed from a single piece of flexible material by attaching the material to the frame 100 along each of the parabolic leaflet attachment lines 320.

[0139] In one aspect, the parabolic shape of the leaflet attachment line 320 can be configured to distribute blood flow-induced forces throughout the prosthetic leaflets 200 and frame 100. One skilled in the art can appreciate that distributing forces throughout the device 1 can prevent localized high stress areas that can adversely affect the durability of the device 1.

[0140] In one embodiment, the leaflet attachment lines 320 can be configured to align with the stent struts, particularly in high stress areas, so that blood flow forces acting on the leaflets 200 are partially distributed directly to the stent 100. In a further embodiment, the leaflet attachment lines 320 can be configured so that the prosthetic leaflet commissures 201 align with the ventricular stent tips 118, allowing the ventricular stent tips 118 to deflect radially inward, e.g., approximately 5° to 15°, when a pressure load is applied to the prosthetic leaflets 200. In this embodiment, the deflection of the stent tips 118 can cushion the prosthetic leaflets 200 from forces acting on them, which has been shown to be important for the durability of the bioprosthetic valve 1.

[0141] In another optional embodiment, as shown in FIG. 3C , leaflet attachment lines 320 can be configured so that the prosthetic leaflet commissures 201 align with tabs 116 extending from the lower ventricular portion 110 of the frame. In this embodiment, tabs 116 can be configured with at least one through-hole to facilitate attachment of the commissures 201 to the frame 100. Optionally, tabs 116 can be configured at the ends of extension members 115 to allow the tabs to deflect radially inward, e.g., approximately 5° to 15°, when a pressure load is applied to the prosthetic leaflets 200.

[0142] In one embodiment, the prosthetic leaflet 200 can be attached to the frame 100 so that the stent cells behind the ventral region 203 of the prosthetic leaflet 200 are open, free of the skirt 300 material. By leaving these cells open, it is contemplated that blood flow can more quickly reach the ventral region 203 of the prosthetic leaflet 200, causing the prosthetic leaflet 200 to expand quickly so that it can cover the mitral orifice during systole and prevent backflow. Furthermore, this embodiment is believed to reduce the incidence of thrombus formation due to flow stagnation by increasing blood outflow between the prosthetic leaflet 200 and the frame 100.

[0143] 8 , in one exemplary embodiment, the larger PP2 leaflet 207 can be configured with multiple leg structures 205, the feet 214 of which are attached to the ventricular portion of the frame 110. In this aspect, the leaflet legs 205 are configured to limit the radial expansion of the leaflet abdomen 203 and coaptation region 204, preventing billowing and prolapse. Additionally, the leaflet legs 205 can help distribute forces across the leaflets 200 and frame 100, which is especially important for larger leaflets that are subject to greater blood flow-induced forces.

[0144] Those skilled in the art will appreciate that proper dome shape overall balance must be maintained for proper function, i.e., radial expansion, of the prosthetic leaflet 200. For simplicity, consider the height-to-width ratio of a two-dimensional dome; for example, a small height-to-width ratio allows the prosthetic leaflet 200 to expand radially to a large extent but may also prolapse during operation; whereas a large height-to-width ratio may limit the radial expansion of the prosthetic leaflet 200 and prevent it from expanding far enough to cover the regurgitant orifice region.

[0145] Referring to the example shown in FIG. 8 , the PP2 leaflet 207 has a small height-to-width ratio of approximately 0.4-0.7, which allows for a large degree of radial expansion but also makes it more susceptible to prolapse. Therefore, the PP2 leaflet 207 has two legs 205 that are configured to attach to the frame 100 to limit radial expansion of the PP2 leaflet 207 beyond a length of the legs 205 that is approximately 70-100% of the anterior-posterior dimension of the frame. In this embodiment, the leg structures 205 are a design feature that prevents prolapse of leaflets with small height-to-width ratios and large degrees of radial expansion. In this embodiment, the leg structures 205 have a length-to-width ratio of approximately 4-7.

[0146] Referring to the example shown in Figures 9A and 9B, the PP1 and PP3 leaflets 206, 208 in this embodiment do not require legs 205 because they have a large maximum height-to-width ratio of approximately 1 to 1.5, resulting in a smaller degree of radial expansion.

[0147] The height-to-width ratio that determines leaflet prolapse also depends on the angle of the ventricular portion 110 of the stent relative to the atrial portion 104 of the stent, with angles less than 90° helping to prevent leaflet prolapse at low height-to-width ratios. Furthermore, the height-to-width ratio also depends on the opening angle of the leaflet 200, i.e., the angle between the two commissures 201 and the center point of the frame 100, with larger angles helping to prevent leaflet 200 prolapse at low height-to-width ratios. Therefore, the height-to-width ratios of the leaflets 200 shown here are illustrative to illustrate the effect of the leg structures 205 and are not intended to be limiting.

[0148] Those skilled in the art can appreciate that as a patient's mitral regurgitation progresses, the mitral annulus often becomes increasingly dilated, and therefore a greater degree of radial expansion of the prosthetic leaflet 200 may be desirable without requiring a proportional increase in the height of the prosthetic leaflet 200. As such, in some embodiments, the prosthetic leaflet 200 may require one or more additional leg structures 205, including smaller leg structures for the side prosthetic leaflets 206, 208. In some other embodiments, the prosthetic leaflet 200 may require one or more additional leaflets to achieve a four- or five-leaflet valve.

[0149] Those skilled in the art will also appreciate that it would be beneficial for the prosthetic half-valve device 1 to have prosthetic valve leaflets 200 that, by design, have limited radial expansion, without requiring additional ventricular anchors, regardless of patient characteristics.

[0150] In one aspect, the prosthetic leaflet feet 214 at the ends of the leaflet legs 205 can be attached directly to the stent 100 at the through holes 113 for the foot attachment portions 214 so that no additional skirt material 300 is required in this area.

[0151] 10, the prosthetic leaflet 200 can be configured to form a C-shape in a resting, unpressurized state, similar to that formed by the native posterior mitral leaflet 10 of a healthy mitral valve 4, as shown, for example, in FIG. 2A. Additionally, the prosthetic leaflet 200 can be configured to form a D-shape in a systolic pressurized state, as shown in FIG. 10, to cover approximately half of the mitral orifice area.

[0152] 10 , it can be seen that the addition of the leg structures 205 to the PP2 leaflet 207 helps create a C-shape such that the PP2 207 expands radially to approximately the same distance across its width as the native P2 leaflet 12. It can be seen that without the leg structures 205, the PP2 207 would create a rounded or pointed shape that extends radially the furthest in the center and less at the sides.

[0153] FIG. 10 shows a ventriculogram of the prosthetic half-valve 1 with the prosthetic leaflets 200 in pressurized states 211, 212, and 213, i.e., systole, superimposed with the prosthetic leaflets in resting, unpressurized states 206, 207, and 208. It can be seen that each of the prosthetic leaflets 200 expands radially away from the stent 100 under pressure, with the degree of expansion being greatest at the center of the prosthetic valve 1 at PP2 207 and least at the lateral edges at PP1 206 and PP3 207. FIG. 10 also shows that the legs 205 extending from the bottom of the dome shape of PP2 207 to the frame 100 are straight and untwisted in both states. When fully expanded, the prosthetic leaflets 200 can be seen to join together to form a D-shape that covers nearly the entire lumen of the half-valve stent 100. This allows the prosthetic leaflets 200 to cover nearly half of the mitral orifice area during operation. Those skilled in the art can appreciate that this design can prevent mitral valve leakage in patients with a native anterior mitral valve leaflet 6 that covers more than half of the mitral orifice area during systole.

[0154] Those skilled in the art can appreciate that the native anterior mitral valve leaflet 6 typically covers approximately two-thirds of the mitral orifice area during systole. For this reason, the prosthetic leaflets 200 of FIG. 2B are not expected to need to expand significantly, if at all, beyond their resting position to coapt with the native anterior mitral valve leaflet 6. The extra prosthetic leaflet expansion enabled by this exemplary design is a precautionary measure to provide sufficient coverage of the mitral orifice and a large coaptation area 204 for the native anterior mitral valve leaflet 6, even in a dilated heart.

[0155] Referring to FIG. 10, in one exemplary embodiment, the leg structures 205 can be configured such that when the prosthetic valve leaflet 200 is loaded, the leg structures 205 move radially away from the frame 100 in a straight line without twisting.

[0156] Additionally, one skilled in the art will appreciate that the leg structures 205 act similarly to the natural aponeurosis 15 in that they may prevent over-expansion and prolapse of the prosthetic leaflet 200 .

[0157] In one embodiment, the PP1 leaflet 206 and the PP3 leaflet 208 can be configured to have leg structures 205, especially for larger prostheses in which the PP1 leaflet 206 and the PP3 leaflet 208 are large.

[0158] Alternatively, the PP1 leaflet 206 and the PP3 leaflet 208 can be configured without the leg structures 205, especially in the case of a compact prosthesis where the PP1 leaflet 206 and the PP3 leaflet 208 are small.

[0159] In one embodiment, the feet 214 of the leg structures 205 can be configured at an angle to facilitate attachment to the angled struts of a stent having through holes 113 .

[0160] In one embodiment, the plurality of leg structures 205 may be configured with a dogbone shape that is wider at the foot 214 that attaches to the frame 113 and at the base that extends from the bottom of the dome shape, and relatively narrow in the middle region. In this embodiment, the added width reduces stress on the leg structures 205 in the areas that experience the highest forces. Those skilled in the art will appreciate that the dogbone-shaped design distributes mechanical stress throughout the legs 205, which is important for durability.

[0161] In further embodiments, it may be desirable to fabricate the multiple leg structures 205 from a single piece of the same material as the remainder of the prosthetic leaflet 200 .

[0162] In one exemplary embodiment, the PP2 leaflet 207 can be configured to have a maximum height in the center of the leaflet (abdominal region 203 and coaptation region 204) and a shorter height at each of the commissures 201, corresponding to the natural mitral valve posterior leaflet 12 structure, as shown, for example, in FIG. 2B.

[0163] In one example of a prosthetic half-valve 1, a plurality of dome-shaped prosthetic leaflets 200 are constructed as individual flat pieces of flexible material.

[0164] In one exemplary embodiment, the prosthetic half-valve includes a stent 100 coupled to a skirt 300 on an inner surface of the stent 100 and a portion of an outer surface of the stent 100. Additionally, a plurality of prosthetic leaflets 200 are coupled to the inner surface of the skirt 300. In a further embodiment, one or more sutures are used to couple the skirt 300 to the stent 100 and the prosthetic leaflets 200 to the skirt 300.

[0165] Those skilled in the art can appreciate the advantages of a half-valve over a full-circumferential valve in terms of a reduced profile: the reduced stent 100, leaflet 200, and skirt 300 material allows the prosthetic half-valve to be crimped onto a lower profile catheter, allowing a higher risk patient population to undergo heart valve replacement surgery.

[0166] In one embodiment, the prosthetic half-valve device 1 is secured to the posterior mitral valve leaflet by multiple DGF members that can be operatively positioned and implanted in a desired location in the native annulus prior to delivery of the prosthetic valve 1, similar to the systems and methods described in the applications incorporated herein by reference. In this embodiment, the DGF members can guide the subsequent precise positioning and fixation of the prosthesis 1. In a further embodiment, the multiple DGF members can help prevent blood leakage between the operatively positioned prosthesis 1 and the native mitral valve annulus.

[0167] In one aspect, each DGF member can be configured to have a removable component and a permanent component, where the removable component can help guide the prosthetic half-valve device 1 into an operable position and then be removed from the patient's body after securing the prosthesis 1, while the permanent component can remain within the patient's body and keep the prosthetic half-valve device 1 secured to the patient's own annulus.

[0168] In one exemplary embodiment, each DGF member can include a head component, a body component, and a tail component. In one embodiment, each DGF head member can be configured to have a coiled shape so that it can be operably inserted into and implanted in valve annulus tissue. In one embodiment, each DGF body member can be configured to include a DGF locking member 131 for securing the prosthetic half-valve device 1 to the native mitral valve annulus, as shown in FIG. 11 . In one embodiment, the DGF tail member can be configured as a flexible component extending from a proximal portion of the DGF body and connecting the DGF member to the shortened prosthetic half-valve 1 in a prosthetic half-valve delivery and implantation system. In this embodiment, the tail portion can be manipulated at the proximal end of the delivery system to guide and securely steer the prosthetic half-valve 1 to the native mitral valve. Optionally, the DGF tail can be configured to be selectively detachable so that it can be removed from the body upon completion of the heart valve leaflet replacement system implantation procedure.

[0169] In one embodiment, the prosthetic half-valve can be configured to engage with the DGF locking member 131 through multiple holes 108 in the atrial flaring portion 104 of the stent. In this embodiment, each DGF tail member is a tether, with one end of the tether attached to the DGF body member and the other end capable of exiting the body. The tether can then be inserted through the holes 108 in the atrial flaring portion 104 of the stent, thereby enabling the prosthetic half-valve device 1 to be delivered through the DGF tail members and the atrial flaring portion 104 of the stent to be precisely delivered to the DGF body member embedded in the valve annulus.

[0170] In one embodiment, the DGF locking member 131 can be configured to pass through the holes 108 in the atrial flaring portion 104 of the stent in only one direction.

[0171] In one aspect, the DGF locking member 131 can be configured to be selectively compressed to a diameter smaller than the diameter of the hole 108 in the atrial flaring portion 104 of the stent so as to be able to pass through the hole 108, and then selectively re-expand to its original size larger than the diameter of the hole 108 in the flaring portion 104 of the stent to prevent the DGF locking member 131 from moving backward through the hole 108.

[0172] 11 , each DGF locking member 131 is configured with multiple radially compressible legs 132 that form a conical shape, with the proximal tip of the cone having a smaller diameter than the hole 108 in the atrial portion 104 of the stent and the distal base of the cone having a larger diameter than the hole 108 in the atrial portion 104 of the stent. In operation, the DGF tail can be tensioned to draw the proximal tip of the DGF locking member 131 into the hole 108 in the atrial portion 104 of the stent, and when the locking member legs 132 contact the edge of the hole 108, the legs can be radially compressed to completely retract the DGF locking member 131 through the hole 108. Once the locking member 131 has passed completely through the stent 100, the DGF locking member legs 132 can be re-expanded to their full size to prevent rearward movement of the DGF locking member 131 through the holes 108 in the atrial portion 104 of the stent, effectively locking the prosthetic half-valve 1 in an operative position.

[0173] 11 , locking member 131 is configured to be selectively compressible from a cross-sectional profile larger than the diameter of hole 108 in the atrial portion 104 of the stent to a cross-sectional profile smaller than the diameter of hole 108 in the atrial portion 104 of the stent, thereby allowing it to pass through hole 108 in the atrial portion 104 of the stent, and then re-expand to its original size to prevent locking member 131 from passing through hole 108 in the opposite direction. In this embodiment, locking member 131 can be configured to have a conical, dome-shaped, arrow-shaped, or wedge-shaped structure with multiple slits using a rigid material, or optionally a deformable rubbery cork or stopper structure in the shape of a cone, dome, wedge, or sphere, or optionally a clamp, clip, or snap structure.

[0174] In an alternative embodiment, locking member 131 is configured to be selectively expandable from a cross-sectional profile smaller than the diameter of hole 108 to a cross-sectional profile larger than the diameter of hole 108, thereby allowing it to pass through hole 108 in the atrial portion 104 of the stent and then selectively expand to prevent it from passing through hole 108 in the opposite direction. In this embodiment, locking member 131 can be formed, for example, from a shape memory material and a mechanism that selectively holds locking member 131 in a contracted state, allowing locking member 131 to be selectively released to re-expand.

[0175] 11 , in one embodiment, each of the locking members 131 includes a conical shape with radially outwardly extending legs 132. The legs 132 of the locking members 131 radially compress as they pass through the holes 108 in the atrial portion 104 of the stent, and expand again once they have passed completely through the holes 108 and are positioned above the atrial portion 104 of the stent. The expanded legs 132 of the locking units 131 prevent rearward movement through the holes 108, thereby locking the prosthetic half-valve 1 in place.

[0176] It should be emphasized that the above-described embodiments are merely examples of possible implementations and merely illustrate a clear understanding of the principles of the present disclosure. Many changes and modifications can be made to the above-described embodiments without substantially departing from the spirit and principles of the present disclosure. All such modifications and variations are intended to be within the scope of the present disclosure, and all possible claims directed to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure. Moreover, although specific terms are employed in this specification and in the claims that follow, they are used in a generic and descriptive sense only and not for the purpose of limiting the described invention and the claims that follow.

Claims

1. 1. A prosthetic half-valve for replacing the native leaflets of a diseased heart valve, comprising: a stent frame including an upper atrial portion configured to span at least a portion of the native valve annulus, a lower ventricular portion configured to span only a portion of the native valve annulus and to allow dynamic movement of at least one other native valve leaflet in an operative position, and a neck portion between the upper atrial portion and the lower ventricular portion, defining a longitudinal axis therebetween; a damping seal ring attached to at least a portion of the stent frame; a sealing skirt including upper atrial and lower ventricular portions attached to corresponding portions of the stent frame; at least one dome-shaped prosthetic valve leaflet extending radially inward from an inner surface of the stent frame, the at least one prosthetic valve leaflet being configured, in an actuated position, to be movable from an open position to a closed position over a cardiac cycle; at least one dual guiding and anchoring member including a portion configured to be embedded within the native tissue and a portion configured to selectively engage the stent frame and guide and anchor the stent frame to the native annulus in an actuated position; a lower ventricular portion of the stent frame comprising a crescent shape having an anterior-posterior (AP) dimension in the range of about ten to forty millimeters (10-40 mm) and an intercommissural (CC) dimension in the range of about twenty to sixty millimeters (20-60 mm), the ventricular portion displacing at least one native valve leaflet in an operative position.

2. 10. The prosthetic half-valve of claim 1, The stent frame comprises a network of cells or wires configured to be radially collapsible and expandable.

3. A prosthetic half-valve for replacing the native leaflets of a diseased heart valve, comprising: a stent frame including an upper atrial portion configured to span at least a portion of the native valve annulus, a lower ventricular portion configured to span only a portion of the native valve annulus and to allow dynamic movement of at least one other native valve leaflet in an operative position, and a neck portion between the upper atrial portion and the lower ventricular portion, defining a longitudinal axis therebetween; a damping seal ring attached to at least a portion of the stent frame; a sealing skirt including upper atrial and lower ventricular portions attached to corresponding portions of the stent frame; at least one dome-shaped prosthetic valve leaflet extending radially inward from an inner surface of the stent frame, the at least one prosthetic valve leaflet being configured, in an actuated position, to be movable from an open position to a closed position over a cardiac cycle; at least one dual guiding and anchoring member including a portion configured to be embedded within the native tissue and a portion configured to selectively engage the stent frame and guide and anchor the stent frame to the native annulus in an actuated position; an upper atrial portion of the stent frame configured with at least one row of cells, the cells including struts oriented in a collapsible diamond configuration extending radially outward from a neck portion of the stent frame, the diameter of the upper atrial portion being smallest near the neck portion and increasing away from the neck portion; The stent frame comprises a network of cells or wires configured to be radially collapsible and expandable.

4. In the artificial half valve according to claim 3, 1. A prosthetic half-valve, comprising: at least a portion of a strut toward an upper free end of the upper atrial portion of the stent frame configured to be curved or angled upward at an angle between 90° and 145° relative to the remainder of the upper atrial portion.

5. 10. The prosthetic half-valve of claim 1, The prosthetic half-valve, wherein the upper atrial portion of the stent frame comprises a plurality of through-holes, each having a diameter of about 0.5 to 3 millimeters (0.5-3 mm).

6. In the artificial half valve according to claim 5, The prosthetic half-valve, wherein the dual guide fixation member is configured to be fixed to the native annulus through the plurality of through-holes, thereby fixing the upper atrial portion relative to the native annulus.

7. 10. The prosthetic half-valve of claim 1, the upper atrial portion of the stent frame includes attachment sites on opposite side edges of the stent frame, thereby allowing the opposite side edges to come together and engage with each other during radial compression.

8. The artificial half valve according to claim 7, The prosthetic half-valve, wherein the attachment sites are configured with mating corresponding structures to provide a snug fit and maintain the stent frame in a generally cylindrical shape during crimping.

9. The artificial half valve according to claim 7 or 8, The artificial half-valve, wherein the connecting portion is linear, zigzag, wavy, semicircular, semi-elliptical, rectangular or irregular in shape.

10. 10. The prosthetic half-valve of claim 1, A prosthetic half-valve wherein the axial height of the lower ventricular portion of the stent frame varies around the circumference of the stent frame.

11. The artificial half valve according to claim 7, A prosthetic half-valve characterized by an axial height in the range of about five to forty millimeters (5-40 mm) around its circumference.

12. 10. The prosthetic half-valve of claim 1, A prosthetic half-valve, wherein the lower ventricular portion of the stent frame has a shorter axial height at the lateral edges of the stent frame.

13. The artificial half-valve of claim 12, A prosthetic half-valve characterized by an axial height of about five to fifteen millimeters (5-15 mm).

14. In the artificial half valve of claim 1, A prosthetic half-valve, wherein the lower ventricular portion of the stent frame has a shorter axial height at a mid-portion along the circumference.

15. The artificial half-valve of claim 1, a lower ventricular portion of the stent frame having free stent tips for attachment of the prosthetic leaflet commissures; 16. The artificial half-valve of claim 1, a lower ventricular portion of the stent frame including a semi-conical shape defining a diameter that is smallest near the upper atrial portion and that increases with distance from the upper atrial portion.

17. The artificial half-valve of claim 1, The prosthetic half-valve is characterized in that the lower ventricular portion of the stent frame includes one or more tabs extending from a tip of the stent.

18. The artificial half-valve of claim 17, The one or more tabs are configured to selectively engage one or more portions of a delivery system.

19. 10. The prosthetic half-valve of claim 1, The prosthetic half-valve is characterized in that the lower ventricular portion of the stent frame comprises at least one extending member having a tab at its lower tip.

20. The artificial half-valve of claim 19, The prosthetic half-valve, wherein the tabs are configured to selectively engage one or more portions of a delivery system.

21. 10. The prosthetic half-valve of claim 1, 1. A prosthetic half-valve, wherein at least a portion of the lower ventricular portion of the stent frame is configured so that the tip of the lower end of the stent frame is bent radially inward relative to an axis.

22. 10. The prosthetic half-valve of claim 1, the lower ventricular portion of the stent frame defines an angle of about 65° to 120° relative to the axis and the upper atrial portion; and The prosthetic half-valve, wherein the neck portion includes at least one row of cells between the atrial and ventricular portions of the frame.

23. The artificial half-valve of claim 22, The prosthetic half-valve, wherein the axial height of the neck portion is between about 1 and 7 millimeters (1.0 and 7.0 mm).

24. A prosthetic half-valve for replacing the native leaflets of a diseased heart valve, comprising: a stent frame including an upper atrial portion configured to span at least a portion of the native valve annulus, a lower ventricular portion configured to span only a portion of the native valve annulus and to allow dynamic movement of at least one other native valve leaflet in an operative position, and a neck portion between the upper atrial portion and the lower ventricular portion, defining a longitudinal axis therebetween; a damping seal ring attached to at least a portion of the stent frame; a sealing skirt including upper atrial and lower ventricular portions attached to corresponding portions of the stent frame; at least one dome-shaped prosthetic valve leaflet extending radially inward from an inner surface of the stent frame, the at least one prosthetic valve leaflet being configured, in an actuated position, to be movable from an open position to a closed position over a cardiac cycle; at least one dual guiding and anchoring member including a portion configured to be embedded within the native tissue and a portion configured to selectively engage the stent frame and guide and anchor the stent frame to the native annulus in an actuated position; the at least one dome-shaped prosthetic valve leaflet comprises a C-shape about an axis, spans at least a portion of the inner circumference of the stent frame, and is radially expandable to form a D-shape under systolic pressure in an actuated position; and / or The at least one dome-shaped prosthetic leaflet is attached to the stent frame along a parabolic leaflet attachment line.

25. The artificial half-valve of claim 24, The parabolic leaflet attachment line spans the axial dimension of the ventricular portion of the stent frame from the lower edge of the neck portion to the tip of the ventricular stent.

26. 10. The prosthetic half-valve of claim 1, The at least one dome-shaped prosthetic valve leaflet comprises a central dome-shaped leaflet and two side dome-shaped leaflets that are smaller than the central dome-shaped leaflet.

27. The artificial half-valve of claim 26, The central dome-shaped leaflet comprises at least one leg structure attached to the stent frame at its foot.

28. The artificial half-valve of claim 27, The central dome-shaped leaflet spans approximately one-third to two-thirds of the circumference of the stent frame.

29. The artificial half-valve of claim 27 or 28, The central dome-shaped leaflet has a body height-to-width ratio of about 0.4-0.7 and a leg length-to-width ratio of about 4-7.

30. The artificial half-valve of claim 27 or 28, The lateral dome-shaped leaflets span approximately 1 / 6 to 1 / 3 of the circumference of the stent frame and have a maximum body height-to-width ratio of approximately 1 to 1.

5.

31. 10. The prosthetic half-valve of claim 1, The prosthetic half-valve, wherein the upper atrial portion and the lower ventricular portion comprise separate pieces.

32. 10. The prosthetic half-valve of claim 1, The prosthetic half-valve, wherein the buffer sealing ring is attached to at least a portion of the side edge of the stent frame.

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