JP7733920B2 - artificial semi-heart valve - Google Patents

Description

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

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, which is a continuation 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.

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 leaflet (AML) is connected to the aortic valve via the aortic curtain, and the posterior mitral leaflet (PML) is pivotally fixed to the posterior mitral annulus. The chordae arise from the two major papillary muscles or from several 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 leaflets from billowing into the left atrium during systole.

When the mitral valve is closed, the anterior and posterior leaflets are in close contact, forming a single area of apposition. As one 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 potentially cause mitral regurgitation (MR).

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, non-ischemic heart disease, and valvular degeneration. Both ischemic heart disease (primarily due to coronary artery disease) and non-ischemic 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 valve leaflet restriction. In contrast, degenerative (or organic) mitral regurgitation is caused by structural abnormalities of the mitral valve leaflets and/or subvalvular apparatus, including stretched or ruptured chordae tendineae.

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.

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. manufactured 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 deliverable 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 techniques for delivering prosthetic mitral valves into working position are still in the developmental stage and, although promising, challenges to the effectiveness of these devices continue to exist.

Notable challenges to effective mitral valve replacement devices generally include operational delivery challenges, positioning and fixation challenges, sealing and paravalvular leakage challenges, and hemodynamic performance challenges such as left ventricular outflow tract (LVOT) obstruction. Regarding 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 via either conventional transapical or transfemoral delivery techniques.

Turning to 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 can rise from near-zero during diastole to over 120 mmHg during systole, and even exceed 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.

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.

Finally, with regard to maintaining hemodynamic function, as previously mentioned, the operating position of a conventionally large prosthetic mitral valve must not obstruct LVOT in the anterior portion of the mitral annulus or interfere with the associated structures of the native mitral valve.

Therefore, it would 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 leakage of blood between the prosthetic and native mitral valve. Similarly, it is 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.

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-valve to one of the native valve annuli are configured to prevent disengagement of the prosthetic semi-valve from the annulus and ensure proper coaptation between the leaflets of the implanted prosthetic semi-valve and the remaining native valve leaflets. The prosthetic semi-valves are contemplated for implantation via open surgery or percutaneously via a catheter. In one aspect, the prosthetic semi-valve includes a plurality of dual guide and fixation (DGF) members, as described elsewhere herein, that may be configured to secure the prosthetic semi-valve to the native mitral valve. In a further aspect, related methods may be configured to implant a replacement valve prosthesis and help prevent further dilation of the native mitral valve annulus. For clarity, this 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.

In one aspect, 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 aspect, 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 aspect, the atrial portion can be configured to facilitate stent fixation, thereby helping to prevent paravalvular leakage and stent dislodgement. Additionally, the ventricular portion can displace diseased native valve leaflets out of the blood flow path and accommodate at least one prosthetic leaflet. In another aspect, 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 aspect, 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.

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.

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, a 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 transseptal access path crosses the atrial 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.

In one aspect, the prosthetic half-valve has a unique crescent shape, forming a semi-valve or hemi-valve. The prosthetic half-valve has a ventricular portion that is placed in the left ventricle and is 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 the 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.

In a further aspect, the stent is configured to span at least a portion of 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.

In one aspect, the atrial portion of the stent includes multiple cells shaped to fit the native mitral valve annulus. The atrial portion of the stent includes an atrial stent tip that is curved to avoid interference with the atrial wall and multiple through-holes. It curves downward along the native mitral valve annulus and connects to a neck region that transitions into the ventricular portion of the stent.

In a further aspect, the through-holes in the atrial portion of the stent are configured to receive a DGF locking element to secure the prosthetic half-valve in place in the mitral valve.

In one aspect, the neck region transitions from the atrial portion to the ventricular portion of the stent. The ventricular portion of the stent includes 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.

In one aspect, the ventricular portion of the stent may be configured with multiple through-holes to facilitate attachment of at least a portion of the prosthetic valve leaflets.

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.

In one aspect, the prosthetic half-valve component is at least one dome-shaped prosthetic leaflet. The at least one prosthetic leaflet 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 leaflet of the mitral valve.

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.

The semi-valve nature of the device contemplates the use of thicker leaflet material, increasing the durability of the prosthetic valve. Furthermore, the semi-valves can be shrunk to a smaller profile compared to a complete valve, allowing a larger proportion of the at-risk population to undergo transcatheter mitral valve replacement.

In one exemplary embodiment, at least one prosthetic leaflet can mimic the configuration of the natural 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 side 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.

In one embodiment, the central leaflet attachment line is configured to be symmetrical about the axial midline, with the central prosthetic leaflet spanning one-third to two-thirds of the ventricular portion of the stent. The two side leaflets are configured to be mirror images of each other on either side of the central leaflet, spanning one-sixth to one-third of the ventricular portion of the stent, and are asymmetrical about their respective axial midlines.

In one exemplary embodiment, 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.

In one aspect, the arm structure may be configured to fold a portion of at least one prosthetic leaflet over itself to increase leaflet thickness in the commissure region. In exemplary embodiments, it is contemplated that the arm structure may be triangular, rectangular, or irregularly shaped.

In a further aspect, 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. One skilled in the art will appreciate that the leg structure mimics the natural aponeurosis in that it can prevent over-expansion 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.

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.

In one aspect, a skirt is bonded to at least a portion of the inner and outer surfaces of the stent. The skirt 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.

In one embodiment, the skirt material can be made of a polymer, fabric, biological tissue, 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.

In one aspect, the skirt can be a single piece of material, or alternatively, the skirt can be constructed from multiple separate pieces of material attached to the stent via one or more non-absorbable sutures or strings.

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 surrounding structures from abrasion by the prosthetic valve.

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

In one exemplary aspect, 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 half-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 half-valve within a prosthetic half-valve delivery implantation system.

In one aspect, the DGF member body is coupled to multiple DGF locking members. In one embodiment, the DGF locking member includes multiple 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 in turn has a smaller diameter than 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.

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 flared portion of the stent and effectively locking the prosthetic half-valve in the activated position.

The various embodiments described herein may include additional systems, methods, features, and advantages that are not necessarily explicitly 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.

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. Features and components in the following drawings 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.

Figure 1A is a posterior perspective 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 dilated to reveal the mitral valve anatomy, with the leaflets divided into two parts, anterior and posterior, and each part subdivided into three sections. The posterior leaflet has three adjacent semilunar leaflets: the P1 leaflet, the P2 leaflet, and the P3 leaflet. 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 the P1, P2, and P3 leaflets during systole. 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 coupled with the native anterior mitral valve leaflet. 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 a central cell in 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. 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. 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. FIG. 6 is a schematic diagram of a frame covered with atrial and ventricular sealing skirts and bilateral peripheral sealing rings. 7 is a schematic illustration of one embodiment of a prosthetic half-valve having three dome-shaped prosthetic leaflets attached to the inner surface of a frame. In this version, the assembly of prosthetic leaflets includes one large central leaflet and two small side leaflets. FIG. 8 shows an exemplary embodiment of a large central prosthetic leaflet that includes a dome-shaped body, two legs, and two arms. 9A and 9B show examples of small lateral prosthetic leaflets, each including a dome-shaped body and two arms. 10 is a schematic ventricular view of one 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. 11 is a schematic diagram of one 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.

The present invention may be understood more readily by reference to the following detailed description, examples, drawings, and claims, as well as the accompanying text. However, before the devices, systems, and/or methods of the present invention are disclosed and described, it is to be understood that the 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.

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 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.

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.

For clarity, it should be understood that this disclosure focuses on the treatment of functional mitral valve regurgitation. However, it is contemplated that the heart valve leaflet replacement system and related methods may be used or otherwise configured for use to treat other types of mitral valve 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.

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.

Ranges may be expressed herein as from "about" one particular value and/or to "about" another particular value. When such a range is expressed, another aspect 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 aspect. Further, it will be understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint.

As used herein, the terms "optional" or "optionally" mean that the subsequently described event or circumstance may or may not occur, and that the description includes both cases where the event or circumstance occurs and cases where it does not occur.

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," is generally intended to convey that certain aspects include certain features, elements, and/or steps, while other aspects do not, unless otherwise specified or understood within the context in which it is used. 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 those features, elements, and/or steps are included or performed in any particular embodiment, with or without user input or prompting.

Disclosed are components 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 may be performed, it is to be understood that each of those additional steps may be performed in any specific embodiment or combination of embodiments of the disclosed methods.

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

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.

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.

Turning to the drawings, as shown in FIG. 2B, for example, there is shown an exemplary embodiment of a prosthetic semi-valve device 1 designed to treat mitral regurgitation in patients with regurgitation and normal anterior mitral leaflet 6 motion by replacing the posterior mitral leaflet 10. The prosthetic semi-valve device 1 comprises a crescent-shaped frame or stent 100 that is anchored to the posterior mitral 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 leaflet 6 during systole. In this aspect, 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 leaflet 10 in a dilated heart.

In one exemplary embodiment, the prosthetic half-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 for facilitating sealing and attachment of the prosthetic leaflet 200 to the stent 100. The prosthetic half-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.

In one aspect, it is contemplated that, in the expanded configuration, the stent 100 defines a substantially semicircular cross-sectional profile. It is further contemplated that the stent 100 may be configured such that the surface of the 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.

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

With further reference to FIG. 3A, the hemivalve 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 operating positions, respectively.

In one aspect, the atrial portion 104 of the stent can be configured to be placed at or above the native mitral valve annulus to facilitate fixation and sealing of the prosthetic half-valve 1.

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.

In one aspect, 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 aspect, 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 aspect, 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.

With reference to FIG. 3A, the atrial portion 104 of the stent is configured with compressible cells. In one aspect, 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 extending 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 sizes. 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.

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 on 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.

In another aspect, fixation of the stent 100 to the mitral valve annulus can be achieved by other methods, such as using adhesives or one or more of grasping, capturing, and suturing tissue.

In an optional aspect, the holes 108 may have a circular, rectangular, square, or oval shape.

In one aspect, due to the half aspect of the prosthetic valve 1, the side edges 107 of the side cells 106 in the atrial portion 104 of the stent do not share joints 103 with adjacent cells.

In this embodiment, the bond portions 103 of the side cells 106 can be configured to have bond sites on the side edges 107. In this embodiment, the bond sites on 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 portion 103 on one side can be configured to match and mate with the shape of the other bond portion on the opposite side.

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

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 remainder 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.

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 valve annulus during operation.

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

In another aspect, the two rows of cells in the atrial portion 104 of the stent can have the same dimensions.

In one aspect, a neck region 109 connects the atrial portion 104 and the ventricular portion 110 of the stent. In this aspect, 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 having a height of, for example, 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.

In one exemplary embodiment, as shown in FIG. 3A, the neck region 109 includes a single row of cells. The cells of the neck region 109 are formed by struts in the atrial portion 104 and struts in the ventricular portion 110, with the lower struts in the atrial portion 104 forming a collapsible half-cell and connecting to the elongated, thick, straight struts, and the upper struts in the ventricular portion 110 forming the other half of the collapsible cell. In this example, the neck region 109 is configured to bend so that the angle between the atrial portion 104 and the 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.

In one embodiment, shown in Figure 3A, the ventricular portion 110 of the stent can have an asymmetric semi-conical or semi-circular cross-sectional profile.

In one exemplary aspect, 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.

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.

In one aspect, the ventricular portion 110 of the stent is configured to have different heights along its circumference to avoid interference with the papillary muscles 14.

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

In one aspect, 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.

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 to be located 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 the number of cells can vary.

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

In an additional aspect, row II cells 155 share an upper portion with row I cells 154 and a lower portion with row III cells 156. In one aspect, 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 the skirt 300. This configuration facilitates radial expansion of the at least one prosthetic leaflet 200 and prevents blood stagnation behind one or more leaflets 200. Cells covered by the skirt 300 include leaflet attachment lines, for example, for connecting multiple prosthetic leaflets 200 to the stent 100.

In another aspect, 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.

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.

In one aspect, 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.

In one optional aspect, 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 aspect, 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 aspect, the side edges 112 of the stent can be configured to have corresponding shapes to fit snugly together and maintain the stent in a cylindrical shape throughout crimping. In one exemplary aspect, the attachment sites 112 can be configured as straight, zigzag, semicircular, semi-elliptical, or rectangular struts.

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

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.

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 multiple through-holes 113 can range from approximately 0.1 mm to 1 mm. Optionally, the struts including the through-holes 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-holes 113.

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 radial deflection of the stent tips 118 when the leaflets 200 are loaded.

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 side portions 112 to prevent interference with the native papillary muscles 16 during operation.

As shown in Figures 3B and 3C, the stingray design of the stent 100 can have at least one stingray tail or extension member 114 configured to extend vertically downward from the lower strut bond 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, the 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 the extension member 114 can be configured with a central tab 115.

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

In another aspect, as shown in Figures 3B and 3C, at least one peripheral 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.

In another aspect, 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.

In one exemplary aspect, tabs 115, 116 may include at least one aperture. Tabs 115, 116 may 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 may selectively engage at least a portion of the delivery system throughout the valve deployment process, thereby stabilizing the deployment process.

In one aspect, 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 aspect, tabs 115, 116 can be detached from stent 100 after stent deployment.

In one aspect, 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.

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.

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 at least one prosthetic valve leaflet 200 and to provide a base for mounting the at least one prosthetic valve leaflet 200.

The skirt 300 can be made of synthetic or natural biocompatible, non-permeable materials, including, but not limited to, polymers, fabrics, biological materials, and the like. The skirt 300 can be cut from the same material as the valve leaflets 200 or from a different material 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 skirt 300 can have a thickness ranging from approximately 0.1 mm to 0.15 mm.

In one aspect, the skirt 300 can be configured to exhibit a biaxial orientation with the fibers aligned circumferentially, allowing the skirt 300 to expand 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.

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.

In one aspect, the skirt 300 is attached to the stent 100 via one or more of sutures, adhesives, and/or other biocompatible materials.

In one aspect, a ventricular skirt 301 is used as a structure for attaching the prosthetic valve leaflets 200 to the stent 100. In this aspect, 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 valve leaflets 200.

In one aspect, 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 migration of the skirt during crimping.

In one aspect, the ventricular skirt 301 can be configured to fit 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 for attaching 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.

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.

In one embodiment, as seen in FIG. 5, the multiple enlarged tabs 312 of the atrial skirt 302 are folded 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 posterior side of the valve 100 that directly contacts the atrial tissue 2. This layer of folded enlarged tabs 312 prevents paravalvular leakage.

In one aspect, the 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.

In one aspect, 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.

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 lateral edges 106 of the atrial portion of the stent to form the side skirt. 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 region is in direct contact with the commissures 14 of the native mitral valve 4. The side skirts thereby serve two functions. First, they prevent the sharp edges of the stent 100 from cutting into the native mitral valve commissures 14. Second, they provide attachment for the sealing rings 316 to form a paravalvular seal around the edges of the valve 1.

Optionally, as shown in FIG. 6, sealing rings 316 can be attached to the lateral edges 107, 112 of the valve to form a paravalvular seal 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.

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.

The sealing ring 316 may be made of a flexible synthetic or natural biocompatible material, including, but not limited to, a polymer, fabric, biomaterial, etc. The sealing ring 316 may 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 leaflet movement. The sealing ring 316 may be permanently secured to the valve 1 with, for example, one or more sutures, adhesives, and/or other biocompatible materials.

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

In the exemplary embodiment shown in FIGS. 7 and 8, each dome-shaped prosthetic valve 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 aspect, 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 aspect, 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.

In one aspect, one or more dome-shaped prosthetic valve leaflets 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.

In one aspect, at least one prosthetic leaflet 207 can be configured to have at least one arm 215 extending from the leaflet commissure 201.

In one aspect, the dome-shaped 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.

In one aspect, during operation, the dome-shaped prosthetic leaflet(s) 207 can be configured to coapt with the native anterior mitral valve leaflet 6 during systole. 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 in a D-shape to coapt with the native anterior mitral valve 6 in patients with functional mitral regurgitation.

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 movement during operation. In one aspect, 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 aspect, 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 remainder of the force induced by blood flow acts on the anterior leaflet 6 and the annulus of the prosthetic semi-valve. For this reason, it is contemplated that the prosthetic semi-valve 1 can be more easily secured to the mitral annulus compared to a circumferential prosthetic valve. Those skilled in the art will appreciate that securing a circumferential prosthetic valve device in mitral valve position continues to be a challenge.

In one aspect of the prosthetic half-valve device 1, with continued reference to FIG. 2B, 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 aspect, 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.

In one aspect, the plurality of prosthetic leaflets 200 may comprise pericardial tissue, or other biological or tissue-engineered materials, polymers, fabrics, or flexible metallic materials. In this aspect, the movable, flexible prosthetic leaflets 200 are intended to exhibit resilience when interacting with the anterior valve leaflet 6, thereby minimizing damage induced to the anterior valve leaflet 6 by repeated contact.

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.

Referring to FIG. 1B, the native mitral valve posterior leaflet 10 includes three adjacent semilunar shaped leaflets: P1 leaflet 11, P2 leaflet 12, and P3 leaflet 13. The P2 leaflet 12 is the largest and extends furthest into the ventricle 3, while the P1 leaflet 11 and P3 leaflet 13 are smaller and shorter, particularly on the lateral sides. 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.

With further reference to FIG. 7 , in one aspect, the prosthetic leaflets 200 can be configured as multiple dome-like structures that extend radially inward away from the stent 100. In another optional aspect, the prosthetic P2 (PP2) leaflet 207 can extend further downward 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.

In the exemplary embodiment shown in FIGS. 9A and 9B, the PP1 leaflet 206 and the PP3 leaflet 208 may 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 will appreciate, having shorter PP1 and PP3 lateral commissures 209 desirably reduces 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.

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, covering the circumference 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.

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

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

In one exemplary embodiment, as shown in FIG. 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, and PP3 can be configured to have the same size and shape or different sizes and shapes, and can be either symmetrical or asymmetrical.

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

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

In one aspect, the multiple leaflets 200 may 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 may be made of the same or a different material. In another optional aspect, the multiple leaflets 200 may 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.

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

In one aspect, 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 aspect, 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 aspect, 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.

In another optional aspect, as shown in FIG. 3C, the leaflet attachment line 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 aspect, the tabs 116 can be configured with at least one through-hole to facilitate attachment of the commissures 201 to the frame 100. Optionally, the tabs 116 can be configured at the ends of the extension members 115 so that the tabs can deflect radially inward, for example, approximately 5° to 15°, when a pressure load is applied to the prosthetic leaflets 200.

In one aspect, the prosthetic leaflet 200 can be attached to the frame 100 so that the stent cells behind the abdominal 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 abdominal region 203 of the prosthetic leaflet 200, allowing the prosthetic leaflet 200 to expand quickly so that it can cover the mitral valve orifice during systole and prevent regurgitation. Furthermore, this aspect is believed to reduce the incidence of thrombus formation due to stagnant flow by increasing blood outflow between the prosthetic leaflet 200 and the frame 100.

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 manner, the leaflet legs 205 are configured to limit 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 leaflet 200 and frame 100, which is particularly important for larger leaflets that are subject to greater blood flow-induced forces.

Those skilled in the art will appreciate that proper dome shape overall balance must be maintained for proper prosthetic leaflet 200 function, i.e., radial expansion. 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.

Referring to the example shown in FIG. 8, the PP2 leaflet 207 has a small height-to-width ratio of approximately 0.4 to 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 to 100% of the anterior-posterior dimension of the frame. In this embodiment, the leg structure 205 is a design feature that prevents prolapse of a leaflet with a small height-to-width ratio and a large degree of radial expansion. In this embodiment, the leg structure 205 has a length-to-width ratio of approximately 4 to 7.

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.

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; angles less than 90° will help prevent leaflet prolapse when the height-to-width ratio is low. Furthermore, the height-to-width ratio 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; larger angles will help prevent leaflet 200 prolapse when the height-to-width ratio is low. Therefore, the height-to-width ratio of the leaflet 200 shown here is illustrative to illustrate the effect of the leg structure 205 and is not intended to be limiting.

Those skilled in the art will 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. Therefore, in some aspects, 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 aspects, the prosthetic leaflet 200 may require one or more additional leaflets to achieve a four- or five-leaflet valve.

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, regardless of patient characteristics, without requiring additional ventricular anchors.

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, eliminating the need for additional skirt material 300 in this area.

Referring to the example shown in FIG. 10, the prosthetic valve 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. Furthermore, the prosthetic valve leaflet 200 can be configured to form a D-shape in a pressurized systolic state, as shown in FIG. 10, to cover approximately half of the mitral orifice area.

With further reference to FIG. 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 with the greatest radial extension in the center and less extension at the sides.

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 for PP2 207 and least at the lateral edges for 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 will appreciate that this design can prevent mitral valve leakage in patients whose native anterior mitral valve leaflet 6 covers more than half of the mitral orifice area during systole.

Those skilled in the art will appreciate that the native anterior mitral valve leaflet 6 typically covers approximately two-thirds of the mitral orifice area during systole. Therefore, 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.

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.

Furthermore, 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 valve leaflets 200.

In one aspect, particularly in the case of larger prostheses in which the PP1 leaflet 206 and the PP3 leaflet 208 are large, the PP1 leaflet 206 and the PP3 leaflet 208 can be configured to have leg structures 205.

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

In one aspect, the foot portion 214 of the leg structure 205 can be configured at an angle to facilitate attachment to the angled struts of a stent having a through hole 113.

In one aspect, the 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 aspect, 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 design distributes mechanical stress throughout the legs 205, which is important for durability.

In a further aspect, 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 valve leaflet 200.

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 structure of the native mitral valve posterior leaflet 12, as shown, for example, in FIG. 2B.

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

In one exemplary embodiment, the prosthetic half-valve includes a stent 100 that is coupled to a skirt 300 on the inner surface of the stent 100 and a portion of the 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, the skirt 300 is coupled to the stent 100 and the prosthetic leaflets 200 are coupled to the skirt 300 using one or more sutures.

Those skilled in the art can appreciate the advantages of a half-valve over a full-circumferential valve in terms of its reduced profile. The reduced stent 100, leaflets 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.

In one aspect, the prosthetic half-valve device 1 is secured to the posterior mitral valve leaflet by multiple DGF members, which can be operably positioned and implanted at 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 aspect, the DGF members can guide the subsequent precise positioning and fixation of the prosthesis 1. In a further aspect, the multiple DGF members can help prevent blood leakage between the operably positioned prosthesis 1 and the native mitral valve annulus.

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 in the patient's body and maintain the prosthetic half-valve device 1 secured to the patient's own annulus.

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 for operative insertion into and implantation 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 the proximal portion of the DGF body and connecting the DGF member to the shortened prosthetic half-valve 1 in the 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 toward the native mitral valve. Optionally, the DGF tail can be configured to be selectively detachable for removal from the body upon completion of the heart valve leaflet replacement system implantation procedure.

In one aspect, 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 aspect, 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 via 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.

In one aspect, the DGF locking member 131 can be configured to pass through the hole 108 in the atrial flaring portion 104 of the stent in only one direction.

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.

In one exemplary embodiment, as shown in FIG. 11 , each DGF locking member 131 is configured to have 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 retract 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 retract the DGF locking member 131 completely 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 the operative position.

11, the locking member 131 is configured to be selectively compressible from a cross-sectional profile larger than the diameter of the hole 108 in the atrial portion 104 of the stent to a cross-sectional profile smaller than the diameter of the hole 108 in the atrial portion 104 of the stent, thereby allowing it to pass through the hole 108 in the atrial portion 104 of the stent, and then re-expand to its original size to prevent the locking member 131 from passing through the hole 108 in the opposite direction. In this aspect, the 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 rubber-like cork or stopper structure in the shape of a cone, dome, wedge, or sphere, or optionally, a clamp, clip, or snap structure.

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

In one embodiment, referring again to FIG. 11 , each of the locking members 131 includes a conical shape with legs 132 that flare outward radially. 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 then expand again once they have completely passed 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.

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 (32)

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 . 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. 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;
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. The prosthetic half-valve of 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. 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. The prosthetic half-valve of 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. 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 prosthetic half-valve of 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 of 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. 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. 8. The prosthetic half-valve of 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. 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 prosthetic half-valve of claim 12,
A prosthetic half-valve characterized by an axial height of about five to fifteen millimeters (5-15 mm). 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 a mid-portion along the circumference. 10. The prosthetic half-valve of claim 1,
a lower ventricular portion of the stent frame having free stent tips for attachment of the prosthetic leaflet commissures; 10. The prosthetic 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. 10. The prosthetic 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 prosthetic half-valve of claim 17,
The one or more tabs are configured to selectively engage one or more portions of a delivery system. 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 prosthetic 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. 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. 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 neck portion includes at least one row of cells between the atrial and ventricular portions of the frame. 23. The prosthetic 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). 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;
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 prosthetic 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. 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 prosthetic 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 prosthetic 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 prosthetic 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. 29. The prosthetic 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. 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. 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.