Low profile prosthetic semi-heart valve devices and methods of use thereof

Abstract

A low profile prosthetic semi-valve for use in the treatment of a reflux heart valve. In one example, a prosthetic valve includes a larger upper portion for anchoring in an expanded annulus and a smaller open lower portion that, when implanted, suspends in a blood flow path near a native leaflet coaptation line. The prosthetic valve includes at least one flexible prosthetic leaflet that moves with a native leaflet of the valve between an open configuration and a closed position. In operation, the at least one prosthetic leaflet acts as a conformable engagement surface of the at least one native leaflet and the posterior side of the lower portion of the frame acts as an engagement surface of the at least one prosthetic leaflet to completely seal the native mouth. Optionally, the frame may include open flow channels to enhance diastolic filling of the ventricle.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of co-pending U.S. provisional application serial number 63 / 425,650, filed on November 15, 2022, and is related to U.S. publication numbers 2021 / 0212824 and 2017 / 0258589, the entire disclosures of which are expressly incorporated herein by reference. Technical Field

[0002] The present application relates generally to replacement heart valves, for example, for replacing a diseased mitral and / or tricuspid valve. More particularly, the present application relates to tissue-based, collapsible and expandable replacement heart valves and to systems and methods for implanting such valves. Background Art

[0003] The mitral valve (MV) has two distinct, large cusps or leaflets. Figure 1A As shown, the MV is located on the left side of the heart, between the left atrium and left ventricle. Figure 1B The mitral valve apparatus consists of the mitral annulus, two leaflets, chordae tendineae ("chords"), two papillary muscles, and the left ventricular myocardium. The mitral annulus is subdivided into anterior and posterior parts. Normally, the anterior mitral leaflet is connected to the aortic valve by the aortic-mitral curtain, and the posterior mitral leaflet is hinged to the posterior mitral annulus. The chords originate from two major papillary muscles or from multiple small muscle bundles that are attached to the ventricular wall and connected to the free edges of the mitral leaflets. The chords are primarily composed of collagen bundles, which give the chords high stiffness and maintain minimal expansion to prevent the leaflets from billowing into the left atrium during systole.

[0004] When the mitral valve is closed, the corresponding anterior and posterior leaflets come into close contact, forming a single coaptation zone. Those skilled in the art will appreciate that normal mitral valve function involves an appropriate balance of forces, with each of its components working in unison during the cardiac cycle. Pathological changes affecting any component of the mitral valve, such as chordal disruption, annular dilatation, papillary muscle displacement, leaflet calcification, and myxomatous disease, can lead to altered mitral valve function and result in mitral regurgitation (MR).

[0005] Mitral regurgitation, shown in Figure 2, refers to mitral valve dysfunction that results in abnormal leakage of blood from the left ventricle back into the left atrium during systole (the ejection phase of the cardiac cycle, during which blood flows from the left ventricle into the aorta). Although mild mitral regurgitation may be present in recovered 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 (primarily due to coronary artery disease) and non-ischemic (e.g., idiopathic dilated cardiomyopathy) heart disease can cause functional or secondary mitral regurgitation through various mechanisms, including impaired left ventricular wall motion, left ventricular dilation, and papillary muscle displacement and dysfunction. In functional mitral regurgitation, the mitral valve apparatus remains normal. Incomplete coaptation of the valve leaflets is due to enlargement of the mitral valve annulus, which is secondary to left ventricular dilation and, possibly, left atrial dilation. Furthermore, patients with functional mitral regurgitation may have papillary muscle displacement due to left ventricular enlargement, which results in excessive tethering of the valve leaflets. In contrast, degenerative (or organic) mitral regurgitation is caused by structural abnormalities of the mitral valve leaflets and / or the subvalvular apparatus, which may include stretching or rupture of the chordae tendineae.

[0006] Current treatment options for mitral valve disease include surgical repair and mitral valve replacement. Mitral valve repair has benefited from a better understanding of mitral valve mechanics and function and may now be preferred to total mitral valve replacement. However, the complex physiology and three-dimensional anatomy of the mitral valve and its surrounding structures pose significant challenges when performing these repair procedures.

[0007] In an early example of a transcatheter mitral valve replacement device, Endovalve-Herrmann (Micro-Inventional Devices) developed a mitral valve prosthesis with a collapsible nitinol-based valve with a sealing skirt. Similarly, Tendyne Holdings produces a prosthetic mitral valve replacement device that includes a pericardial valve with a self-expandable nitinol stent. The device is designed for transapical delivery and has a ventricular anchor. CardiAQ uses a pericardial valve with a nitinol self-expandable stent in their mitral valve replacement device. Finally, Tiara (Neovasc) uses a mitral valve replacement system that can be delivered transapically using a 30Fr catheter with an anchoring structure and a pericardial valve on a self-expandable stent with a D-shaped atrial portion and a ventricular portion with an outer coating. These devices and the technology for delivering mitral valve prostheses to the surgical site are still in the development stage, and although promising, the effectiveness of these devices remains challenging.

[0008] The challenges faced by effective mitral valve replacement devices generally include surgical delivery challenges; positioning and fixation challenges; sealing and paravalvular leak challenges; and hemodynamic function challenges, such as left ventricular outflow tract (LVOT) obstruction and possible mitral stenosis. With regard to the noted surgical delivery challenges, because conventional mitral valve prostheses are larger than conventional aortic prostheses, it is more difficult to fold and compress the larger mitral valve prosthesis into a catheter for deployment and retrieval via conventional transapical or transfemoral delivery techniques.

[0009] Regarding positioning and fixation challenges, instability and migration are the most prominent obstacles, as the mitral valve is subjected to high and repetitive loads during the cardiac cycle. High transvalvular pressure gradients approach zero during diastole and can rise to 120 mmHg or higher during systole, with systolic pressure exceeding 150 mmHg in patients with aortic stenosis and systemic hypertension. Lack of calcium distribution at the mitral annulus can also affect device stability and anchoring. Furthermore, transcatheter mitral valve replacements are susceptible to migration as the heart moves with each beating cycle.

[0010] Regarding sealing and paravalvular leakage, a good seal between the native annulus and the prosthesis is desirable to minimize paravalvular leakage. Traditionally, prosthetic mitral valves are smaller than the diseased native valve, and additional material is added around the prosthetic valve to compensate for the larger native mitral annulus. Undesirably, adding more material to the prosthetic valve increases the size of the delivery system. Furthermore, this can create an elevated forward flow pressure gradient across the valve, potentially causing stenosis.

[0011] Finally, with regard to preservation of hemodynamic function, as described above, the surgical positioning of the traditionally larger prosthetic mitral valve should not obstruct the mitral orifice during diastole nor the LVOT anterior to the mitral annulus during systole.

[0012] Posterior mitral valve repair techniques, such as Polares and Half-moon, consist of a non-removable posterior coaptation surface applied to the native anterior mitral valve, thus avoiding LVOT obstruction.

[0013] Therefore, it would be beneficial to have a heart valve leaflet replacement system that is not subject to the shortcomings and deficiencies of conventional valve prostheses. For example, it may be desirable to secure a prosthetic mitral valve replacement system to the native mitral valve annulus. It may also be desirable to improve the positioning of the mitral valve prosthesis and prevent blood leakage between the mitral valve prosthesis and the native mitral valve without causing stenosis. Likewise, it may be desirable to prevent further dilation of the native mitral valve annulus. Moreover, other desired features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the Invention

[0014] The present application relates generally to artificial heart valves and methods of implanting artificial heart valves, and more particularly to low-profile artificial half heart valves or artificial half valves that are configured to fill a regurgitant orifice area during systole to treat mitral regurgitation without restricting diastolic filling of the left ventricle. It is contemplated that the low-profile artificial half valves herein may be implanted percutaneously via open surgery or via a transcatheter procedure. For clarity, it should be understood that while the present disclosure may focus on treating functional mitral regurgitation, it is contemplated that the low-profile artificial half valves and related methods may be used or otherwise configured for treating other valvular disease conditions, such as degenerative mitral regurgitation and regurgitation of other valves of the human heart (e.g., the tricuspid valve), or may also be used or otherwise configured for use in other mammals suffering from valvular defects.

[0015] In one aspect, the low-profile prosthetic half-valve can be configured or otherwise resized to be crimped to fit within a delivery catheter and subsequently selectively re-expanded to a surgical size and position after removal from the delivery catheter within the heart. In a further aspect, the low-profile prosthetic half-valve can include a stent having an open lower ventricular portion attached to a radially flared upper portion, wherein an angled neck forms a transition between the upper and lower portions of the half-valve.

[0016] In one aspect, the upper portion can be configured to facilitate anchoring of the stent, which helps prevent the stent from dislodging. The lower portion can be suspended in the blood flow path and house at least one flexible artificial valve leaflet. In another aspect, the artificial half-valve can include a sealing skirt that can be connected to at least a portion of the inner surface and / or outer surface of the stent.

[0017] In one exemplary aspect, at least one artificial valve leaflet can be mounted on the inner cavity of the stent and / or on at least a portion of the outer side of the stent. At least one flexible artificial valve leaflet can be configured to be movable throughout the cardiac cycle and to engage with at least one natural valve leaflet. The lower portion of the stent frame can also be configured as an engagement surface for one or more natural heart valve leaflets.

[0018] In one aspect, the upper portion of the low-profile prosthetic half-valve is configured with a large diameter and flared shape for annular anchoring and atrial coaptation. The lower portion of the low-profile prosthetic half-valve has a fish-mouth shape that resembles the coaptation line of a healthy native mitral valve. A sloped neck region forms a transition between the upper and lower portions of the half-valve.

[0019] In one example, a low-profile artificial half-valve device can include a partially elliptical upper support portion configured to anchor the posterior mitral annulus from one trigone to the other. The lower portion of the frame can include a smaller fishmouth shape, with a larger major axis corresponding to the anatomical direction of commissure to commissure and a smaller minor axis corresponding to the anterior-to-posterior anatomical direction of the mitral annulus. In this example, the lower portion is attached to the upper portion so that it is suspended in the blood flow path near the line of coaptation of the native mitral valve in the surgical position. At least one flexible artificial valve leaflet can be attached to the inner surface of the lower portion of the frame, wherein it is configured to move throughout the cardiac cycle and engage with at least a portion of the anterior leaflet of the native mitral valve. Furthermore, in this example, the native posterior mitral valve leaflet and the commissural leaflets are not disturbed and can move normally and engage with the outer surface of the lower portion of the frame so that during systole, the entire mitral valve orifice is sealed closed. During diastole, blood flow can push at least one artificial valve leaflet toward the inner surface of the lower portion of the frame so that flow between the device and the anterior leaflet of the native mitral valve is not inhibited. Furthermore, in this example, the frame can include at least one flow channel in the upper portion and / or neck portion of the frame to facilitate diastolic flow between the posterior leaflet of the native mitral valve and the lower outer surface of the frame.

[0020] In another example, the upper stent portion can be configured as a full annulus anchored on the mitral annulus.

[0021] It will be appreciated by those of ordinary skill in the art that in some cases it may be desirable to have a larger upper stent portion to facilitate device anchoring, as many mitral regurgitation patients have a larger, dilated mitral annulus, but to have a smaller lower portion supporting at least one prosthetic leaflet so that the device can be more easily crimped to a low-profile diameter for safer transcatheter delivery and implantation. Additionally, a smaller structure within the native valve and ventricle may be desirable because it minimizes the impact on the surrounding native tissue. In cases of functional mitral regurgitation, the mitral valve organ is typically functional; the regurgitant orifice is a result of a dilated heart. The native leaflets are no longer able to fully engage each other, but still help to seal around the implant. At least one flexible prosthetic leaflet can cover the regurgitant orifice. Smaller prosthetic leaflets also contribute to the durability of the implant because they have less surface area and are subject to less load.

[0022] In some cases, it is desirable for the effective orifice area of ​​the prosthetic valve to be similar to that of the native valve. Otherwise, the patient may experience an increased pressure gradient or stenosis across the replacement valve. It will be appreciated by those skilled in the art that by implanting a prosthetic valve with a diameter smaller than that of the native annulus, the effective orifice area of ​​the mitral valve is naturally reduced. In this example, at least one flow channel passing through the frame can significantly increase the effective orifice area of ​​the prosthetic half-valve and help maintain the normal function of the native mitral valve leaflets.

[0023] In one example, the minor axis of the lower portion of the frame is smaller than the minor axis of the upper portion. The major axis of the lower portion of the frame is the same or similar in size to the smallest major axis of the upper portion of the frame. In this example, the lower portion of the frame follows a shallower curve than the upper portion. Thus, the neck of the device at the minor axis extends radially inward from the upper portion of the frame to the lower portion. The neck of the device at the major axis is nearly vertical.

[0024] In one aspect, at least one artificial valve leaflet can be mounted to the inner surface of the lower portion of the stent frame. The artificial valve leaflet can be configured to be flexible and movable throughout the cardiac cycle. During the systolic phase, at least one artificial valve leaflet extends by expanding radially outward from the lower portion of the frame to engage with the natural anterior valve leaflet to prevent leakage between the anterior surface of the implant and the natural anterior valve leaflet, while the natural posterior valve leaflet expands to engage with the outer surface of the lower portion of the frame to prevent leakage between the posterior surface of the implant and the natural posterior valve leaflet. During diastole, at least one artificial valve leaflet is configured to move toward the lower portion of the frame to allow blood to flow from the left atrium to the left ventricle between the anterior surface of the implant and the natural anterior valve leaflet, while at least one flow channel in the neck region of the frame allows blood to flow from the left atrium to the left ventricle between the posterior surface of the implant and the natural posterior valve leaflet.

[0025] In one example, at least one prosthetic leaflet can mimic the configuration of a native posterior mitral valve leaflet, with three adjacent semilunar cusps on a lower portion of the stent.

[0026] In one aspect, the sealing skirt material can be made of a polymer, fabric, biological tissue, or the like. The skirt can be a single piece of material, or alternatively, the skirt can be constructed from multiple separate pieces of material connected to the frame via non-absorbable sutures or cords. It is contemplated that the skirt material can be configured to promote tissue growth at the annulus and prevent abrasion between the frame and surrounding anatomical structures.

[0027] In one aspect, delivery of the low-profile prosthetic half-valve can be performed using several desired delivery access routes, such as, but not limited to, a surgical approach, a transseptal approach, a transatrial approach, or a transapical approach. In one exemplary aspect, the transseptal approach can include creating an opening in the internal jugular vein or the femoral vein for subsequent minimally invasive delivery of portions of the low-profile prosthetic half-valve through the superior vena cava, which flows into the right atrium of the heart. In this exemplary aspect, the transseptal approach's entry path passes through the atrial septum of the heart, and once achieved, the components of the prosthetic half-valve can be operably positioned in the left atrium, the native mitral valve, and the left ventricle. In one aspect, it is contemplated that a main delivery catheter can be placed in the entry path to allow the desired components of the prosthetic half-valve to be operably positioned in the left atrium without complications.

[0028] It will be understood by those of ordinary skill in the art that due to the nature of the implant being designed to fill the regurgitant orifices between the native leaflets, rather than the entire native leaflets and / or valve, it naturally has a smaller profile compared to a full valve or large coaptation surface, allowing a larger proportion of the high-risk population to undergo transcatheter mitral valve replacement surgery.

[0029] In one aspect, multiple dual guide and fixation members can be operably positioned and implanted in desired locations in the native annulus prior to delivery of the replacement artificial half valve. In this aspect, the dual guide and fixation members can improve subsequent positioning and anchoring of the replacement artificial half valve.

[0030] The various embodiments described in this application may include additional systems, methods, features, and advantages that are not necessarily explicitly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within this application and be protected by the following claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] It is believed that the invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals represent like elements, and in which: Figure 1A Schematic diagram of a healthy native mitral valve during systole from a surgeon's perspective. Figure 1A The mitral valve leaflets are shown coapting to form the "fish-mouth" coaptation line. The mitral valve has two leaflets: the anterior leaflet and the posterior leaflet. The posterior leaflet consists of three adjacent semilunar shapes.

[0032] Figure 1B Schematic diagram of a long-axis cross-section of the native mitral valve leaflets coapting during systole.

[0033] Figures 2A-2H The mitral valve is shown in systole in a mitral regurgitation disease state. Figure 2A Schematic diagram from a surgeon's perspective of a type I regurgitant mitral valve with normal movement of the native leaflets. Figure 2B This is a long-axis cross-section of a heart with type I mitral regurgitation. Figure 2C Schematic diagram from a surgeon's perspective of type II regurgitation, in which there is increased motion of one or more native leaflets. Figure 2D This is a long-axis cross-section of a heart with type II mitral regurgitation. Figure 2E is a schematic diagram of type IIIa regurgitation, in which the motion of one or more native valve leaflets is restricted during systole and diastole. Figure 2F This is a long-axis cross-section of a heart with type IIIa mitral regurgitation. Figure 2G Schematic diagram from a surgeon's perspective of type IIIb regurgitation, in which one or more native valve leaflets are restricted in systolic motion. Figure 2HThis is a long-axis cross-section of a heart with type IIIb mitral regurgitation.

[0034] Figure 3A and 3B Depicted is an example of a low-profile prosthetic half-valve device for treating mitral regurgitation having a stent frame, three prosthetic leaflets, a sealing skirt, and a posterior flow channel created by windows in the skirt. Figure 3A A front view of the device is shown. Figure 3B A side view of the device is shown.

[0035] Figure 4A Schematic diagram of exemplary aspects of a low-profile prosthetic half-valve device having a flared upper frame portion configured for annular anchoring and a smaller, fish-mouth-shaped lower portion. Three prosthetic leaflets are mounted on the inner surface of the lower frame portion. A fabric skirt material covers the upper portion of the frame, which will contact the annulus during operation. The frame neck has a window through the skirt that, during operation, will be positioned above the mitral valve orifice to allow flow passage through the device.

[0036] Figure 4B This is the surgeon's perspective. Figure 4A Illustration of the low-profile half-valve device implanted in the native mitral valve during systole. In this view, the native anterior leaflet can be seen expanding radially outward toward the prosthetic leaflet. The prosthetic leaflet mates with the coaptation area of ​​the anterior leaflet.

[0037] Figure 4C yes Figure 4A and 4B Schematic long-axis cross-section of the low-profile prosthetic half-valve device during systole. In this view, the native anterior mitral leaflet is seen coapting with the prosthetic leaflet mounted on the inner surface of the lower frame portion, and the posterior mitral leaflet is seen coapting with the posterior side of the lower frame portion.

[0038] Figure 5A Schematic diagram of a surgeon's perspective of a low-profile prosthetic half-valve implanted in the mitral valve during diastole. The native mitral valve leaflets have moved radially outward, and the prosthetic leaflets have moved toward the inferior portion of the frame, allowing blood to flow from the left atrium to the left ventricle through posterior flow channels between the anterior side of the prosthetic half-valve and the native anterior leaflet, and between the posterior side of the prosthetic half-valve and the native posterior leaflet.

[0039] Figure 5B yes Figure 5A Schematic diagram of the long-axis cross-section of the low-profile prosthetic half valve implanted in the mitral valve during diastole.

[0040] Figure 6A and 6B A schematic diagram of an exemplary dual guiding and fixing (DGF) mechanism is shown, which stabilizes a low-profile prosthetic half-valve to the native annulus during surgery. Figure 6ADepicted are DGF member embodiments having a screw-like anchor for engaging tissue, a locking mechanism for engaging a low-profile prosthetic half-valve frame, and a tail for guiding device deployment. Figure 6B Schematic cross-section of the deployment of a low-profile prosthetic half-valve device guided by the tail of a previously implanted anchor.

[0041] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including ways not necessarily depicted in the drawings. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects of the invention and, together with the description, serve to explain the principles of the invention; it should be understood, however, that the invention is not limited to the precise arrangements shown. DETAILED DESCRIPTION

[0042] The apparatus and methods herein may be more readily understood by reference to the following detailed description, examples, drawings, and claims, and the descriptions preceding and following them. However, before disclosing and describing the present apparatus, systems, and / or methods, it should be understood that, unless otherwise indicated, the present invention is not limited to the specific apparatus, systems, and / or methods disclosed, and as such may, of course, vary. It should also be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0043] The following description is provided as an enabling teaching for various aspects and examples of the present invention. To this end, those skilled in the relevant art will recognize and understand that many changes can be made to the various aspects and examples described herein while still achieving the beneficial results of the apparatus and methods described herein. It will also be apparent that some of the intended benefits of the apparatus and methods described herein can be achieved by selecting some features of the examples described without utilizing other features.

[0044] Therefore, those skilled in the art will recognize that many modifications and adaptations to the apparatus and methods herein are possible, even desirable in certain circumstances, and are a part of the present invention. Therefore, the following description is provided as an illustration of the principles of the present invention, and not in limitation thereof.

[0045] For clarity, it will be understood that the present disclosure will focus on the treatment of functional mitral regurgitation, but it is contemplated that the heart valve leaflet replacement systems and associated methods may be used or otherwise configured to treat other types of mitral regurgitation or to replace other diseased valves of the human heart, such as the tricuspid valve, or may also be used or otherwise configured for use in other mammals suffering from valve defects.

[0046] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a leaflet" can include two or more leaflets unless the context clearly dictates otherwise.

[0047] 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 is understood that the particular value forms another aspect. It will be further understood that the endpoints of each range are significant relative to the other endpoint, and independent of the other endpoint.

[0048] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0049] As used herein, the term "or" refers to any one member of a particular list, and also includes any combination of members of that list. Furthermore, it should be noted that, unless expressly stated otherwise, or understood otherwise in the context of use, conditional language, such as "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. Thus, such conditional language generally does not imply that one or more particular aspects in any way require features, elements, and / or steps, or that one or more particular aspects necessarily include logic for determining, with or without user input or prompting, whether such features, elements, and / or steps are included in or are to be performed in any particular embodiment.

[0050] Disclosed are components that can be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed, while specific reference to each different individual and collective combination and permutations of such combinations may not be explicitly disclosed, all methods and systems are specifically contemplated and described herein. This applies to all aspects of this application, including, but not limited to, steps in the disclosed methods. Therefore, if there are various additional steps that can be performed, it is understood that each of these additional steps can be performed with any specific embodiment or combination of embodiments of the disclosed methods.

[0051] The present methods and systems may be understood more readily by reference to the following detailed description of the preferred embodiments.

[0052] Throughout the specification, the terms "prosthetic valve," "prosthesis," "valve stent," and "heart valve leaflet replacement device," and "valve device" are used interchangeably and are considered to be the heart valve replacement devices described herein.

[0053] refer to Figure 1A and Figure 1B The mitral valve consists of an anterior leaflet 1 and a posterior leaflet 2, which originate from the valve annulus 3 and extend to the left ventricle 4. In recovered patients, the anterior leaflet 1 and the posterior leaflet 2 come together and coapt during systole to prevent mitral regurgitation. The mitral valve coaptation line 6 has the following characteristics: Figure 1A The characteristic "fish mouth" shape shown. Figure 1B The chordae tendineae 5 hold the free edges of the leaflets down in the ventricle so that they can coapt to the coaptation zone 7 of approximately 1 to 5 mm during systole and prevent blood from flowing from the left ventricle 4 to the left atrium 8.

[0054] In diseased states of mitral regurgitation, e.g. Figures 2A-2H As depicted in FIG, the native coaptation area 7 is lost or incomplete, resulting in a gap or regurgitant hole 9 in the systolic valve, which allows blood to leak from the left ventricle 4 back into the left atrium 8 during systole. Mitral regurgitation may occur when the mitral valve leaflets move normally due to cardiac dilation, e.g., Figure 2A and Figure 2B Regurgitation may occur due to excessive motion of the native leaflets resulting from chordal disruption, e.g. Figure 2C and Figure 2D As shown in . Systolic leaflet motion is restricted, e.g. Figure 2G and Figure 2H or limited diastolic and systolic leaflet motion, as demonstrated in Figure 2E and Figure 2F As shown in , it may also cause reflux.

[0055] The low-profile artificial half-valve devices, systems, and methods presented herein can be used to treat mitral regurgitation in patients with normal native mitral valve leaflets and chordae by filling the regurgitant orifice 9 during systole. Figure 3 depicts an example of a low-profile artificial half-valve device. The low-profile artificial half-valve may include a stent frame having a plurality of diamond-shaped cells 25, an open lower ventricular portion 11 attached to a radially open upper portion 10, wherein an inclined neck 12 forms a transition between the upper portion 10 and the lower portion 11 of the device. Portions of the frame may be covered in a sealing skirt 15. At least one flexible and movable artificial valve leaflet 16 may be mounted on the lower portion 11 of the frame. The low-profile artificial half-valve device may include an upper portion 10 configured for anchoring to the mitral valve annulus 3. In operation, the neck 12 will be located within the native valve annulus and the lower portion 11 will be suspended in the left ventricle 4.

[0056] It is contemplated that the device has a major axis 13 and a minor axis 14 at the neck of the frame, wherein the major axis 13 corresponds to the anatomical direction of commissure to commissure and the minor axis 14 corresponds to the anatomical direction of the mitral annulus from anterior to posterior. In one example, the upper portion 10 of the frame has a minor axis 14 that is greater than the lower portion 11 of the frame, i.e., greater than 5 mm, and a major axis 13 that is similar or greater than the lower portion 11 of the frame. The lower portion 11 of the frame is configured as an open shape. The upper portion of the frame can be configured as an open or closed shape.

[0057] The artificial leaflet 16 can be configured to be flexible and movable throughout the cardiac cycle. During the systolic phase, at least one artificial leaflet 16 extends by extending radially outward from the lower portion of the frame to engage with the natural anterior leaflet 1 to prevent leakage between the anterior engagement surface 17 of the implant and the natural anterior leaflet 1, while the natural posterior leaflet 2 extends to engage with the outer surface of the lower portion 11 of the frame to prevent leakage between the posterior engagement surface 18 of the implant and the natural posterior leaflet 2. During the diastolic phase, at least one artificial leaflet 16 is configured to move toward the lower portion 11 of the frame to allow blood to flow from the left atrium 8 to the left ventricle 4 between the anterior engagement surface 17 of the implant and the natural anterior leaflet 1. In addition, the neck 12 can be configured with a posterior flow channel 19 that allows blood to flow from the left atrium to the left ventricle between the posterior engagement surface 18 of the implant and the natural posterior leaflet 2.

[0058] Figure 3A An example of a front view of a device having a sealing skirt and three prosthetic leaflets 16 is shown with an anterior engagement surface 17 and a posterior flow channel 19 formed by a plurality of windows in the sealing skirt 15 . Figure 3BA side view of the device is shown, which allows for a better understanding of the posterior engagement surface 18 and the difference in minor axis 14 dimensions between the upper and lower frame portions 10, 11. In this example, the upper portion 10 of the frame is configured to open toward the anterior mitral leaflet 1 and be anchored along the posterior annulus from the medial trigone to the lateral trigone. Additionally, the lower portion 11 of the frame is configured to open toward the anterior mitral leaflet 1 and be suspended in the mitral valve orifice from the medial commissure to the lateral commissure.

[0059] It is contemplated that the prosthetic leaflet 16 may be composed of a thin, flexible material including human or animal tissue, polymers, or fabrics.

[0060] It is contemplated that the upper portion 10, lower portion 11, and neck 12 of the frame may be made of a metallic material, such as one or more of Nitinol, cobalt chromium, or stainless steel, or a polymeric material.

[0061] It is contemplated that the sealing skirt 15 may be constructed from a thin, flexible material including one or more of human or animal tissue, a polymer, or a fabric.

[0062] It is contemplated that the upper portion 10 of the frame can be configured to facilitate anchoring the device to the native annulus 3. In operation, the upper portion 10 can be anchored to the native annulus 3 so that the lower portion 11 is suspended in the left ventricle 4 and parallel to the blood flow. In one example of treating mitral regurgitation, the lower portion 11 of the frame can be configured to resemble a fish mouth shape of the natural coaptation line 6. Figure 4A As shown, at least one prosthetic leaflet 16 can be configured with three distinct cusps, similar to natural leaflets. Figure 4B yes Figure 4A Schematic diagram of a low-profile artificial half valve embodiment of the present invention being implanted in the heart during systole. In operation, the artificial valve leaflet 16 can radially extend from the inner surface of the lower portion 11 of the frame during systole to form an anterior engagement surface 17 for engaging with the natural anterior valve leaflet 1. It will be appreciated that the open nature of the lower portion of the frame allows the natural anterior valve leaflet 1 to radially extend within the confines of the low-profile artificial half valve device frame so that it can engage with the anterior engagement surface 17 of the device. Figure 4B As shown, the device can recreate the characteristic fish-mouth coaptation line 6 seen in a healthy native mitral valve. The flexible nature of the artificial leaflet 16 enables it to conform to the native anterior leaflet 1 to seal the mitral valve orifice. The natural posterior leaflet 2 can be seen through the device's posterior flow channel 19 engaging the device's posterior coaptation surface 18 on the posterior side of the lower portion 11 of the frame. Figure 4CThe figure is a schematic long-axis cross-section of a low-profile artificial half-valve implanted in the heart during systole. Artificial leaflet 16 serves as a conformable anterior engagement surface 17 for contact with the native anterior leaflet 1, while the posterior side of the frame's lower portion 11 serves as a posterior engagement surface 18 for contact with the native posterior leaflet 2. Together with the artificial leaflet 16, the native anterior and posterior leaflets 1 and 2 seal the entire mitral valve orifice.

[0063] It is contemplated that the posterior engagement surface 18 may be encased in or made of a soft, thin material, such as human or animal tissue, polymer, or fabric, to protect the natural posterior leaflet 2 from damage over time. It is further contemplated that the posterior engagement surface 18 may be comprised of at least one artificial leaflet 16 or movable surface to engage with the natural posterior leaflet 2.

[0064] Reference again Figure 4B ,and Figure 4A The flexible nature of the artificial leaflet 16 enables it to change shape significantly compared to its static shape in the anterior valve leaflet 1 to fit over the natural anterior valve leaflet 1 during systole. It will be understood by those skilled in the art that because the device relies on both the natural anterior valve leaflet 1 and the artificial leaflet 16 to seal the mitral valve orifice, the durability of the implant depends on the long-term function of the natural anterior valve leaflet 1 and the artificial leaflet 16. Therefore, it is desirable to inflict minimal damage to the anterior valve leaflet 1 during operation. By engaging the flexible artificial leaflet 16 with the flexible natural leaflet, impact damage is minimized. Due to the lower surface area, the smaller artificial leaflet 16 in the low-profile half-valve design will also have improved durability compared to the larger leaflet.

[0065] Reference again Figure 4A It is contemplated that the sealing skirt material may be attached to the upper portion of the frame along anchoring lines 30 that will contact the native annulus during operation. Optionally, the sealing skirt may comprise a material with a high surface area to volume ratio so that it can be easily crimped and may promote tissue ingrowth.

[0066] It is contemplated that the upper portion 10 of the frame can be configured in a closed or open shape. Those skilled in the art will appreciate that, since the upper portion of the frame will be located on the left atrium 8 side of the annulus during operation, it should not affect or hinder native leaflet function. It is further contemplated that the upper portion 10 of the frame can be configured in a fully or partially elliptical, circular, or D-shaped shape to better fit the annulus 3 and left atrium 8.

[0067] It is contemplated that the lower portion 11 of the frame may be configured with various other open shapes, such as a partial elliptical, circular, or parabolic shape, to help treat valvular regurgitation. For example, it is contemplated that the lower portion 11 of the frame may be configured with a more V-shaped shape to mimic the coaptation line between the anterior and posterior leaflets and the septal leaflet in the tricuspid valve, thereby treating tricuspid regurgitation. It is also contemplated that the lower portion 11 of the frame may be configured to have various heights along the long axis. For example, it is contemplated that the lower portion 11 of the frame may be configured to have a shorter vertical height on either side of the open frame to avoid contact with the papillary muscle heads in the left ventricle.

[0068] It is contemplated that the lower portion 11 of the frame can be configured with a major axis 13 that is similar to or slightly larger than the native annulus, making it wide enough to allow the native valve leaflets to fit within the confines of the lower portion 11 of the frame, engaging with the prosthetic valve leaflets 16. Furthermore, it is contemplated that the lower portion 11 of the frame can be configured with a minor axis 14 that is smaller than the minor axis of the native annulus, such that the overall device footprint within the left ventricle and the crimp profile are desirably lower.

[0069] As will be appreciated by those skilled in the art, it would be desirable to have a device that can anchor well, reduce mitral regurgitation, without negatively impacting surrounding anatomy and function, and that can be housed in a low-profile delivery catheter for improved patient safety. The upper portion 10 of the device proposed in the present disclosure has a large diameter for anchoring to the dilated mitral annulus 3 and has minimal material, allowing it to be easily crimped to a small diameter. The lower portion 11 of the device has more material, including multiple prosthetic leaflets 16, but is smaller in size, particularly the secondary shaft 14, allowing the rest to also be crimped to a small diameter.

[0070] Figure 5A and 5B Schematic diagram showing an example of a low-profile prosthetic half-valve device implanted in the mitral valve during diastole. Figure 5A The surgeon's perspective diagram in Figure 1 shows that during diastole, the native anterior and posterior leaflets 1, 2 move radially outward toward the wall of the left ventricle 4, and the prosthetic leaflet 16 moves toward the lower portion 11 of the frame. Thus, there are two blood flow paths through the mitral valve orifice: one between the native anterior leaflet 1 and the anterior coaptation surface 17 of the device, i.e., the anterior flow path 22, and another through the device's posterior flow path 19 formed by the multiple windows in the sealing skirt 15. These two diastolic flow paths together create a large effective valve orifice area, which is desirable for cardiac function. Figure 5B A long axis cross-section of the device in the mitral valve during diastole is shown. This view shows the posterior flow channel 19 located above the gap between the natural posterior leaflet 2 and the posterior coaptation surface 18 of the device.

[0071] It is contemplated that the low-profile prosthetic half-valve device can be configured with multiple posterior flow channels 19 of varying sizes and shapes, or optionally without any posterior flow channels 19, such that there is only one blood flow channel through the mitral valve orifice, namely the anterior flow channel 22. The flexible and movable prosthetic leaflet 16 can be configured such that the anterior coaptation surface 17 is significantly away from the native anterior leaflet 1 during diastole to allow adequate flow from the left atrium 8 to the left ventricle 4.

[0072] It is contemplated that the frame may be configured with a plurality of diamond-shaped cells 25 such that the frame may be selectively curled and loaded into a small diameter catheter. In a preferred embodiment, the upper portion 10 of the frame may span the posterior annulus in a "D-shape," from the medial trigone to the lateral trigone, which is designed to conform to the mitral annulus and the left atrial wall 8. Furthermore, in this example, the lower portion 11 of the frame may span the mitral coaptation line 6 from the medial commissure to the lateral commissure in a "fish mouth" shape similar to the natural mitral coaptation line 6. The exposed tips of the diamond-shaped cells in the frame may optionally be bent radially inward to avoid interference with surrounding tissue, including the left atrium 8, the natural posterior leaflet 2, the chordae tendineae 5, and the natural anterior leaflet 1.

[0073] The upper portion 10 of the frame may optionally be configured with a plurality of eyelets for engaging an anchoring mechanism, a crimping mechanism, and / or a loading mechanism into a catheter for transcatheter delivery within a patient.

[0074] The lower portion 11 of the frame may optionally be configured with a plurality of eyelets to facilitate crimping and / or loading the crimped device into a catheter for transcatheter delivery within a patient.

[0075] In one exemplary method, a low-profile prosthetic half-valve device may be provided by Figure 6A and Figure 6B A plurality of dual guide fixation (DGF) members 26 are shown guided and fixed to the annulus. Additional information regarding DGF members and systems and methods for delivering them can be found in U.S. Publication No. 2021 / 0212824, the entire disclosure of which is expressly incorporated herein by reference.

[0076] refer to Figure 6A , the DGF member 26 may include a screw-like anchor 27 configured to engage with the annulus tissue at a distal end and to engage with a long tail member 28 at a proximal end. Figure 6B In operation, a plurality of DGF member anchors 27 can first be implanted in the annular tissue. The tail member 28 can then be passed through the eyelets of the upper portion 10 of the frame to guide the low-profile artificial half-valve device to be deployed to the annulus 3. Optionally, an additional locking mechanism 29 can then be passed over the tail 28 to clamp the upper portion 10 of the frame to the implanted anchors 27. Once the implant is fixed in place, the DGF member tail can be configured to be selectively removable.

[0077] It should be emphasized that the above aspects are merely possible examples of embodiments and merely illustrate a clear understanding of the principles of the present disclosure. Many changes and modifications may be made to the above embodiments without substantially departing from the spirit and principles of the present disclosure. All such modifications and variations are intended to be included within the scope of the present disclosure, and all possible claims for various aspects or combinations of elements or steps are intended to be supported by the present disclosure. In addition, although subordinate terms are used herein and in the claims, they are used only in a general and descriptive sense and not for the purpose of limiting the described invention or claims.

Claims

1. A heart valve repair device, comprising: a stent frame having an upper portion configured for annular anchoring, an open lower portion configured to float in a blood flow path of a native valve within the heart, and a neck transition portion between the upper and lower portions, wherein a minor axis of the lower portion is smaller than a minor axis of the upper portion; at least one flexible prosthetic valve leaflet mounted on a lower portion of the frame that moves from an open position to a closed position by normal heart function; and A sealing skirt is attached to at least a portion of the frame.

2. The heart valve repair device of claim 1, wherein the stent frame comprises a network of cells configured to be radially foldable and expandable at the surgical site.

3. The heart valve repair device of claim 2, wherein the upper portion comprises a plurality of cells, the cells comprising free stent cell tips configured to bend radially inwardly relative to the rest of the cells.

4. The heart valve repair device of claim 2, wherein the lower portion comprises a plurality of cells, the cells comprising free stent cell tips configured to bend radially inwardly relative to the rest of the cells. The heart valve repair device according to claim 1 , wherein the upper portion comprises a plurality of through holes. The heart valve repair device according to claim 1 , wherein the lower portion comprises a plurality of through holes.

7. The heart valve repair device according to claim 1, wherein the at least one artificial valve leaflet comprises three leaflets.

8. The heart valve repair device of claim 1, wherein the stent frame is configured with at least one open flow channel.

9. The heart valve repair device according to claim 5, wherein the plurality of through holes are configured to receive passage of a plurality of dual guide and fixation member tails and a locking member.

10. The heart valve repair device according to any one of claims 1 to 9, wherein the stent frame has a partial elliptical shape between the upper portion and the lower portion.

11. The heart valve repair device according to any one of claims 1-9, wherein the upper portion has an open shape for annular anchoring and atrial coaptation, and the lower portion has a fish mouth shape, similar to a healthy natural mitral valve coaptation line.

12. The heart valve repair device according to any one of claims 1 to 9, wherein the neck region forms a transition between the upper portion and the lower portion.

13. A heart valve repair device according to any one of claims 1-9, wherein the upper portion has a partially elliptical shape, which is configured for anchoring the posterior mitral annulus from one trigone to another, and the lower portion includes a fishmouth shape, which has a larger major axis dimension and a smaller minor axis dimension, the major axis dimension corresponding to the anatomical direction of the natural valve from commissure to commissure, and the minor axis dimension corresponding to the anatomical direction of the natural valve from front to back.

14. The heart valve repair device of claim 13, wherein the minor axis dimension of the lower portion of the frame is smaller than the minor axis dimension of the upper portion, and wherein the major axis dimension of the lower portion is the same as or similar to the major axis dimension of the upper portion.

15. The heart valve repair device of claim 14, wherein the lower portion follows a shallower curve than the upper portion, and the neck portion at the minor axial dimension of the device extends radially inwardly from the upper portion to the lower portion.

16. The heart valve repair device according to any one of claims 1 to 9, wherein the sealing skirt covers the upper portion and the lower portion.

17. A method for implanting the artificial half-valve device according to any one of claims 1 to 9, comprising: introducing the stent frame into the patient's heart adjacent to the native valve annulus; and The upper portion is anchored to the native valve annulus such that the lower portion is suspended in the blood flow passage of the native valve.

18. The method of claim 17, wherein the lower portion provides an engagement surface for one or more native heart valve leaflets of the native valve.

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