Low-profile artificial hemiheart valve device and method of use

Abstract

This is a low-profile prosthetic half-valve for treating regurgitant heart valves. In one example, the prosthetic valve includes a large upper portion for fixation to the dilated annulus and a small open lower portion that, when implanted, is suspended in the blood flow path near the junction line of the patient's own valve leaflets. The prosthetic valve includes at least one flexible prosthetic leaflet that moves between open and closed positions together with the patient's own valve leaflets. During operation, at least one prosthetic leaflet acts as a symmetrical junction surface for at least one of the patient's own valve leaflets, and the posterior side of the lower portion of the frame acts as a junction surface for at least one of the patient's own valve leaflets to completely seal the valve orifice of the patient's own valve. Optionally, the frame may include an open flow path to facilitate diastolic filling of the ventricle.

Description

Technical Field

[0001] This application generally relates to replacement heart valves, for example, for replacing a diseased mitral and / or tricuspid valve. More particularly, this application relates to tissue-based foldable and expandable replacement heart valves, and systems and methods for implanting such valves.

[0002] Cross-reference of related applications This application claims the benefit of co-pending U.S. Provisional Application No. 63 / 425,650, filed Nov. 15, 2022, and is related to U.S. Application Publications Nos. 2021 / 0212824 and 2017 / 0258589. The disclosures of those applications are hereby expressly incorporated herein by reference in their entirety.

Background Art

[0003] The mitral valve (MV) has two different large cusps or leaflets. The MV is on the left side of the heart and is located between the left atrium and the left ventricle, as shown in FIG. 1A. As shown in FIG. 1B, the mitral valve apparatus is composed of a mitral annulus, two leaflets, chordae tendineae ("chords"), two papillary muscles, and the left ventricular myocardium. The mitral annulus is subdivided into an anterior and a posterior portion. Typically, the anterior cusp of the mitral valve is connected to the aortic valve via the aortic-mitral curtain, and the posterior cusp of the mitral valve is pivotally fixed to the posterior mitral annulus. The chords originate from two major papillary muscles, or multiple small fascicles attached to the ventricular wall, and are connected to the free edges of the mitral valve. The chords are mainly composed of collagen bundles, which give the chords high rigidity and maintain minimal elongation to prevent the leaflets from bulging into the left atrium during systole.

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

[0005] Mitral regurgitation (mitral valve insufficiency), as shown in Figure 2, is a dysfunction of the mitral valve that causes abnormal leakage of blood from the left ventricle back to 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 mild mitral regurgitation can occur 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 valve degeneration. Both ischemic heart disease (mainly 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 motion disorders, left ventricular dilation, and papillary muscle displacement or dysfunction. In functional mitral regurgitation, the mitral valve organ remains normal. Incomplete junction of the valve leaflets results in dilation of the mitral annulus, which is secondary to left ventricular dilation and, in some cases, left atrial dilation. Furthermore, patients with functional mitral regurgitation may exhibit papillary muscle displacement due to left ventricular dilation, resulting in excessive restriction of the valve leaflets. In contrast, degenerative (or organic) mitral regurgitation is caused by structural abnormalities of the mitral valve leaflets and / or subvalvular organs, including stretching or rupture of the chordae tendineae.

[0006] Current treatments for mitral valve disease include surgical repair and replacement of the mitral valve. Mitral valve repair has benefited from a deeper understanding of the valve's mechanism and function, and is now considered preferable to complete mitral valve replacement. However, the complex physiological and three-dimensional anatomical structure of the mitral valve and its surrounding structures present significant challenges when performing these repair procedures.

[0007] In one early example of transcatheter mitral valve replacement devices, Endovalve-Herrmann (Micro Interventional Devices, Inc.) has developed an artificial mitral valve with a collapsible nitinol-based valve with a seal skirt. Similarly, Tendyne Holdings, Inc. manufactures an artificial mitral valve replacement device that includes a pericardial valve with a self-expanding nitinol stent. This device is designed for transapical delivery and features a ventricular anchor. CardiAQ uses a pericardial valve with a self-expanding nitinol stent in its mitral valve replacement device. Finally, Tiara (Neovasc, Inc.) uses a mitral valve replacement system that can be delivered transapically via a 30Fr 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. The technology for delivering these devices and artificial mitral valves to the working position is still under development and promising, but challenges to the effectiveness of these devices remain.

[0008] The challenges identified for effective mitral valve replacement devices generally include operational delivery challenges, positioning and fixation challenges, sealing and paravalvular leakage challenges, and hemodynamic challenges such as left ventricular outflow tract (LVOT) occlusion and potential mitral stenosis. Regarding the operational delivery challenges mentioned above, conventional mitral valve prostheses are larger than conventional aortic prostheses, making it more difficult to fold and compress the larger prostheses within the catheter for deployment and retrieval using either conventional transapical or transfemoral delivery techniques.

[0009] Turning to the challenges of positioning and fixation, the mitral valve is exposed to high repetitive loads during the cardiac cycle, with a high transvalvular pressure gradient that is nearly zero during diastole and can rise to systolic pressures of over 120 mmHg, and over 150 mmHg in patients with aortic stenosis and systemic hypertension, making instability and migration the most significant obstacles. In addition, the lack of calcium distribution in the mitral annulus affects the stability and fixation of the device. Furthermore, transcatheter mitral valve replacement can easily become dislodged because the heart moves during each beating cycle.

[0010] Regarding sealing and paravalvular leakage, a good seal between the prosthesis and the native valve annulus is desired to minimize paravalvular leakage. Traditionally, artificial mitral valves are smaller than the affected native valve, and additional material is added around the prosthesis to compensate for the larger native mitral annulus. Naturally, adding more material to the prosthesis increases the size of the delivery system. Furthermore, this can lead to an increased pressure gradient in the forward flow across the valve or even stenosis.

[0011] Finally, regarding the maintenance of hemodynamic function, as mentioned above, the operating position of conventionally large artificial mitral valves must not obstruct the mitral valve orifice during diastole or the LVOT (left ventricular orifice) at the anterior part of the mitral valve ring during systole.

[0012] Posterior mitral valve repairs such as Polares and Half-moon create a non-movable posterior suture surface relative to the patient's own anterior mitral valve, thereby avoiding LVOT occlusion.

[0013] Therefore, it would be beneficial to have a heart valve leaflet replacement system that is not plagued by the shortcomings and defects of conventional artificial valves. For example, it is desirable to fix the artificial mitral valve replacement system to the patient's own mitral annulus. It is also desirable to improve the positioning of the artificial mitral valve and prevent blood leakage between the artificial mitral valve and the patient's own mitral valve without causing stenosis. Similarly, it is desirable to prevent further expansion of the patient's own mitral annulus. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the attached claims, in conjunction with the attached drawings and the aforementioned technical and background art. [Overview of the project]

[0014] This application generally pertains to artificial heart valves and methods for implanting artificial heart valves, and more specifically to low-profile hemi-valves or hemi-valves configured to treat mitral regurgitation by blocking the regurgitation region during systole without restricting diastolic filling of the left ventricle. The low-profile hemi-valves described herein are envisioned to be implanted by open surgery or percutaneously by catheter. For clarity, while this disclosure focuses on the treatment of functional mitral regurgitation, the low-profile hemi-valves and associated methods are envisioned to be used, or otherwise configured to be used, in other ways, to treat other valvular conditions such as degenerative mitral regurgitation and regurgitation of other valves (e.g., tricuspid valve) in the human heart, or to be used, or otherwise configured to be used, in other mammals suffering from similar valve defects.

[0015] In one embodiment, a low-profile prosthetic valve can be configured to selectively re-expand to a operable size and position when it is removed from the delivery catheter within the heart after being compressed to fit within the delivery catheter, or is otherwise sizing-adjustable. In a further embodiment, the low-profile prosthetic valve may comprise a stent having an open lower ventricular portion attached to a radially spreading upper portion, with an angled neck portion forming a transition between the upper and lower portions of the valve.

[0016] In one embodiment, the upper portion can be configured to facilitate the fixation of the stent, thereby preventing the stent from falling out. The lower portion is suspended within the blood flow path and can accommodate at least one flexible artificial valve leaflet. In another embodiment, the artificial half-valve may include a seal skirt that can be coupled to at least a portion of the inner and / or outer surface of the stent.

[0017] In one exemplary embodiment, at least one prosthetic valve leaflet can be attached to the inner lumen of the stent and / or to at least a portion of the outer surface of the stent. At least one flexible prosthetic valve leaflet may be movable throughout the cardiac cycle and configured to junction with at least one of the patient's own valve leaflets. Additionally, the lower portion of the stent frame may be configured as a junction surface for one or more of the patient's own cardiac valve leaflets.

[0018] In one embodiment, the upper portion of the low-profile artificial valve is configured with a large diameter and flared edges for fixation to the valve annulus and juxtaposition in the atrium. The lower portion of the low-profile artificial valve has a fish-mouth shape, similar to the junction of a healthy, autologous mitral valve. An angled neck region forms the transition between the upper and lower portions of the valve.

[0019] In one example, a low-profile artificial half-valve device may comprise a partially elliptical upper stent portion configured to fix to the posterior mitral annulus from one triangular portion to the other. The lower portion of the frame may include a small fish-mouth shape having a large long axis corresponding to the anatomical direction from commissure to commissure and a small short axis corresponding to the anatomical direction from anterior to posterior of the mitral annulus. In this example, the lower portion is attached to the upper portion so as to be suspended in the blood flow path near the patient's own mitral valve junction in the operating position. At least one flexible artificial valve leaflet may be attached to the inner surface of the lower portion of the frame, in which case it is movable throughout the cardiac cycle and configured to junction with at least a portion of the patient's own anterior mitral valve leaflet. Furthermore, in this example, the patient's own posterior and commissurate mitral valves can be junctioned with the outer surface of the lower portion of the frame so as to be able to move normally without obstruction and so as to be able to seal the entire mitral valve orifice during systole. During diastole, blood flow can press at least one prosthetic valve leaflet toward the inner surface of the lower portion of the frame, so that flow between the device and the patient's own anterior mitral valve leaflet is not obstructed. Furthermore, in this example, the frame may include at least one flow path in the upper portion and / or neck portion of the frame, thereby facilitating diastolic flow between the patient's own posterior mitral valve leaflet and the outer surface of the lower portion of the frame.

[0020] In another example, the upper stent portion can be configured as a complete ring that is fixed to the mitral valve annulus.

[0021] Those skilled in the art will understand that, in some situations, it is desirable to enlarge the upper stent portion to facilitate device fixation. This is because many patients with mitral regurgitation have a greatly dilated mitral annulus, but the lower portion supporting at least one prosthetic leaflet is small, and as a result, the device can be more easily compressed to a low-profile diameter for safer transcatheter delivery and implantation. Furthermore, reducing the size of the patient's own valve and ventricular structures may be desirable as it minimizes the impact on surrounding autologous tissue. In cases of functional mitral regurgitation, the mitral valve organ is often functional, and the regurgitant orifice is a result of cardiac dilation. The patient's own leaflets can no longer fully join to each other, but they still serve to seal around the implant. At least one flexible prosthetic leaflet can cover the regurgitant orifice. Smaller prosthetic leaflets also benefit the durability of the implant because they have a smaller surface area and less load.

[0022] In some situations, it may be desirable for the prosthetic valve to have an effective opening area equivalent to that of the patient's own valve. Otherwise, the patient may experience an increased pressure gradient or stenosis of the replacement valve. Those skilled in the art will understand that the effective opening area of ​​the mitral valve naturally decreases with the implantation of a prosthetic valve having a smaller diameter than the patient's own annulus. At least one flow path through the frame in this example significantly increases the effective opening area of ​​the prosthetic half-valve and helps maintain the normal function of the patient's own mitral valve leaflets.

[0023] In one example, the minor axis of the lower part of the frame is shorter than the minor axis of the upper part. The major axis of the lower part of the frame is the same as or equivalent to the minimum major axis dimension of the upper part of the frame. In this example, the lower part of the frame has a shallower curve than the upper part. Therefore, the neck portion of the device's minor axis extends radially inward from the upper part of the frame to the lower part. The neck portion of the device's major axis is nearly vertical.

[0024] In one embodiment, at least one artificial valve leaflet can be attached 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 systole, at least one artificial valve leaflet extends radially outward from the lower portion of the frame to junction with the patient's own anterior leaflet, thereby preventing leakage between the front surface of the implant and the patient's own anterior leaflet, while the patient's own posterior leaflet extends to junction with the outer surface of the lower portion of the frame, thereby preventing leakage between the posterior surface of the implant and the patient's own posterior leaflet. During diastole, at least one artificial valve leaflet is configured to move toward the lower portion of the frame, thereby allowing blood to flow from the left atrium to the left ventricle between the front surface of the implant and the patient's own anterior leaflet, while at least one 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 patient's own posterior leaflet.

[0025] In one example, at least one artificial valve leaflet can mimic the configuration of the patient's own mitral valve leaflet, which has three adjacent semilunar leaflets in the lower portion of the stent.

[0026] In one embodiment, seal skirt materials can be made from polymers, fabrics, biological tissues, etc. The skirt may consist of a single piece of material, or alternatively, multiple separate pieces of material attached to the frame by non-absorbable sutures or cords. The skirt material is envisioned to be configured to promote internal tissue growth in the annulus and to protect against abrasion between the frame and surrounding anatomical structures.

[0027] In one aspect, the delivery of a rope profile prosthetic heart valve can be performed using any of several desired delivery access approaches, such as, for example, a surgical approach, a transseptal approach, a transatrial approach, or a transapical approach, but is not limited thereto. In an exemplary aspect, a transseptal approach can include forming an opening in the internal jugular vein or femoral vein, and then, through the superior vena cava that flows into the right atrium of the heart, a portion of the rope profile prosthetic heart valve can be minimally invasively delivered. In this exemplary aspect, the access path of the transseptal approach crosses the atrial septum of the heart, and once the access path is secured, the components of the prosthetic heart valve can be operably positioned in the left atrium, its mitral valve, and the left ventricle. In one aspect, it is contemplated to place a main delivery catheter in the access path and operably position the desired components of the prosthetic heart valve in the left atrium without complications.

[0028] One of ordinary skill in the art will understand that due to the nature of the implant designed to occlude the regurgitant opening between its own leaflets rather than its own leaflets and / or the entire valve, the profile will naturally be smaller compared to a complete valve or large junction surface, thereby enabling more of the at-risk population to undergo transcatheter mitral valve replacement.

[0029] In one aspect, a plurality of dual guide fixation members can be operably positioned and implanted at a desired location of its own valve annulus prior to delivery of the replacement prosthetic heart valve. In this aspect, the dual guide fixation members can improve the subsequent placement and fixation of the replacement prosthetic heart valve.

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

[0031] The present invention will be better understood by reading the following description of specific embodiments in conjunction with the accompanying drawings. In those drawings, similar reference numerals indicate the same elements. [Figure 1] Figure 1A is a schematic diagram of a healthy, autologous mitral valve in systole, from a surgeon's perspective. Figure 1A shows how the mitral valve leaflets join to form a "fish mouth" shaped junction. The mitral valve has two leaflets: an anterior leaflet and a posterior leaflet. The posterior leaflet has three adjacent crescent shapes. Figure 1B is a schematic diagram of a longitudinal cross-section of an autologous mitral valve leaflet joining in systole. [Figure 2] Figures 2A to 2H show the mitral valve in systole in mitral regurgitation. Figure 2A is a schematic view from the surgeon's perspective of a mitral valve in type I regurgitation, in which the patient's own leaflets are moving normally. Figure 2B is a longitudinal section of the heart in type I mitral regurgitation. Figure 2C is a schematic view from the surgeon's perspective of type II regurgitation, in which the movement of one or more mitral leaflets is increased. Figure 2D is a longitudinal section of the heart in type II mitral regurgitation. Figure 2E is a schematic view of type IIIa regurgitation, in which the movement of one or more of the patient's own leaflets is restricted during systole and diastole. Figure 2F is a longitudinal section of the heart in type IIIa mitral regurgitation. Figure 2G is a schematic view from the surgeon's perspective of type IIIb mitral regurgitation, in which the movement of one or more of the patient's own leaflets is restricted during systole. Figure 2H is a longitudinal cross-sectional view of a heart with type IIIb mitral regurgitation. [Figure 3] Figures 3A and 3B show an example of a low-profile artificial half-valve device for the treatment of mitral regurgitation, which has a posterior flow path formed by a stent frame, three artificial valve leaflets, a seal skirt, and a window in the skirt. Figure 3A is a front view of the device. Figure 3B is a side view of the device. [Figure 4]Figure 4A is a schematic diagram of an exemplary embodiment of a low-profile mitral valve prosthesis device having a flared upper stent portion configured to be fixed to the valve annulus and a smaller fish-mouth shaped lower portion. Three prosthetic leaflets are attached to the inner surface of the lower portion of the frame. A fabric skirt material covers the upper portion of the frame that contacts the valve annulus during operation. The neck portion of the frame has a window that penetrates the skirt, which is positioned above the mitral valve orifice during operation to ensure a passage through the device. Figure 4B is a schematic diagram from the surgeon's perspective of the low-profile mitral valve prosthesis device of Figure 4A implanted in the patient's own mitral valve during systole. In this diagram, the anterior leaflet of the patient's own mitral valve is seen extending radially toward the prosthetic leaflet. The prosthetic leaflet fits into the junction zone of the anterior leaflet. Figure 4C is a schematic diagram of the long-axis cross-section of the low-profile mitral valve prosthesis device of Figures 4A and 4B during systole. This diagram shows how the patient's own anterior mitral valve leaflet connects to an artificial leaflet attached to the inner surface of the lower part of the frame, and how the posterior mitral valve leaflet connects to the rear of the lower part of the frame. [Figure 5] Figure 5A is a schematic surgeon's view of a low-profile prosthetic valve implanted in a diastolic mitral valve. The patient's own mitral valve leaflets are moved radially laterally, and the prosthetic leaflets are moved toward the lower portion of the frame, allowing blood to flow from the left atrium to the left ventricle through the posterior passage between the anterior portion of the prosthetic valve and the patient's anterior leaflet, and between the posterior portion of the prosthetic valve and the patient's posterior leaflet. Figure 5B is a schematic longitudinal section of the low-profile prosthetic valve of Figure 5A implanted in a diastolic mitral valve. [Figure 6] Figures 6A and 6B show schematic diagrams of exemplary dual guide fixation (DGF) mechanisms for stabilizing a low-profile prosthetic valve on its own annulus during operation. Figure 6A shows an embodiment of a DGF member having a threaded anchor that engages with tissue, a locking mechanism that engages with the low-profile prosthetic valve frame, and a trailing tail that guides the deployment of the device. Figure 6B is a schematic cross-sectional view of the deployment of the low-profile prosthetic valve device guided by the tail of a previously implanted anchor.

[0032] The drawings are not intended to be limiting, and it is assumed that various embodiments of the present invention can be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings are incorporated herein and constitute part of it. While these drawings illustrate some aspects of the present invention and help to illustrate the principles of the present invention together with this specification, it should be understood that the present invention is not limited to the exact arrangements shown. [Modes for carrying out the invention]

[0033] The devices and methods described herein can be more readily understood by referring to the following detailed description, examples, drawings, and claims, as well as the preceding and following descriptions. However, before the devices, systems, and / or methods of the present invention are disclosed and described, it should be understood that the present invention is not limited to any specific device, system, and / or method disclosed unless otherwise specified, and is therefore naturally subject to change. It should also be understood that the terms used herein are intended solely to describe specific embodiments and are not intended to limit them.

[0034] The following description is provided as effective teaching of various aspects and examples of the present invention. Those skilled in the art will therefore recognize and understand that many modifications can be made to the various aspects and examples described herein while obtaining the beneficial results of the devices and methods described herein. It will also be apparent that some of the desired advantages of the devices and methods described herein can be obtained by selecting some of the features of the described examples without utilizing other features.

[0035] Therefore, those skilled in the art will recognize that many modifications and adaptations to the devices and methods described herein are possible, and may even be desirable in certain circumstances, and are part of the present invention. Accordingly, the following description is provided to illustrate the principles of the present invention and is not intended to limit it.

[0036] For clarity, please understand that this disclosure focuses on the treatment of functional mitral regurgitation. However, it is intended that cardiac valve leaflet replacement systems and related methods may be used, or otherwise configured to be used, to treat other types of mitral regurgitation, or to replace other affected valves of the human heart, such as the tricuspid valve, or may be used, or otherwise configured to be used, in other mammals that suffer similarly from valve defects.

[0037] As used throughout, the singular forms "a," "an," and "the" can refer to multiple objects unless the context clearly indicates otherwise. For example, a reference to "valve leaflets" can refer to two or more such leaflets unless the context indicates otherwise.

[0038] In this specification, a range can be expressed as "approximately" from one particular value to and / or "approximately" another particular value. When such a range is expressed, the other aspect includes one particular value to and / or another particular value. Similarly, the use of the antecedent "approximately" will be understood to mean that when a value is expressed as an approximation, a particular value forms another aspect. Furthermore, it will be understood that each endpoint of a range is important both in relation to other endpoints and independently of other endpoints.

[0039] In this specification, the terms “optional” or “optional” mean that the events or circumstances described thereafter may or may not occur, and that such descriptions include both cases in which such events or circumstances occur and cases in which they do not occur.

[0040] As used herein, the word “or” means any one element of a given list, and also includes any combination of elements of that list. Furthermore, note that conditional language, in particular, such as “can,” “may,” “might,” or “may,” is generally intended to convey that a particular embodiment includes certain features, elements, and / or steps, but other embodiments do not, unless otherwise specifically stated or understood in the context in which they are used. For this reason, such conditional language is not generally intended to mean that features, elements, and / or steps are required in any way to one or more particular embodiments, or that one or more particular embodiments necessarily include logic for determining whether those features, elements, and / or steps are included in or performed in any particular embodiment, with or without user input or prompting.

[0041] Components that can be used to carry out the disclosed methods and systems are disclosed herein. These and other components are disclosed herein, and where combinations, subsets, interactions, groups, etc., of these components are disclosed, specific references to each of the various individual and collective combinations and substitutions thereof are not expressly disclosed, but each should be understood to be specifically intended and described herein for all methods and systems. This applies to all aspects of the Application, including but not limited to steps in the disclosed methods. Therefore, where there are various additional steps that can be carried out, it should be understood that each of these additional steps can be carried out in any particular embodiment or combination of embodiments of the disclosed methods.

[0042] This method and system can be more readily understood by referring to the following detailed description of preferred embodiments.

[0043] Throughout this specification, the terms “artificial valve,” “prosthesis,” “valve stent,” “cardiac valve leaflet replacement device,” and “valve device” are used interchangeably and are intended to refer to the cardiac valve replacement devices described herein.

[0044] Referring to Figures 1A and 1B, the mitral valve consists of an anterior leaflet 1 and a posterior leaflet 2, originating from the annulus 3 and extending into the left ventricle 4. In healthy patients, the anterior leaflet 1 and posterior leaflet 2 of the mitral valve join together during systole to prevent regurgitation through the mitral valve. The mitral valve junction line 6 has the characteristic "fish mouth" shape shown in Figure 1A. Referring to Figure 1B, the chordae tendineae 5 hold the free ends of the valve leaflets toward the ventricle, and they join together in a junction zone 7 of approximately 1-5 mm during systole, preventing blood from flowing from the left ventricle 4 to the left atrium 8.

[0045] In mitral regurgitation, for example, as shown in Figures 2A-2H, the junctional zone 7 is lost or incomplete, creating a gap or regurgitation opening 9 in the valve during systole, leading to leakage of blood from the left ventricle 4 back to the left atrium 8 during systole. Mitral regurgitation can also occur due to normal mitral valve leaflet movement caused by cardiac expansion, as shown in Figures 2A and 2B. Regurgitation can also occur due to excessive movement of the mitral valve leaflets caused by a ruptured ligament, as shown in Figures 2C and 2D. Furthermore, regurgitation can also occur due to restricted leaflet movement, for example during systole, as shown in Figures 2G and 2H, or during both diastole and systole, as shown in Figures 2E and 2F.

[0046] The low-profile prosthetic half-valve devices, systems, and methods presented herein can be used to treat mitral regurgitation in patients with normal mitral valve leaflets and chordae tendineae by blocking the regurgitation opening 9 during systole. Figure 3 shows an example of a low-profile prosthetic half-valve device. This low-profile prosthetic half-valve may comprise a stent frame having a plurality of rhomboid cells 25, with an open lower ventricular portion 11 attached to a radially spreading upper portion 10, and an angled neck portion 12 forming a transition between the upper portion 10 and the lower portion 11 of the device. Part of the frame is covered with a seal skirt 15. At least one flexible, movable prosthetic leaflet 16 is attached to the lower portion 11 of the frame. The low-profile prosthetic half-valve device may comprise an upper portion 10 configured to be fixed to the mitral annulus 3. During operation, the neck portion 12 is within the patient's own annulus, and the lower portion 11 is suspended within the left ventricle 4.

[0047] The device is envisioned to have a long axis 13 and a short axis 14 in the neck portion of the frame, with the long axis 13 corresponding to the anatomical direction from commissure to commissure and the short axis 14 corresponding to the anatomical direction from anterior to posterior of the mitral valve annulus. In one example, the upper portion 10 of the frame has a short axis 14 that is larger than (e.g., larger than 5 mm) than the lower portion 11 of the frame, and a long axis 13 that is equal to or larger than the lower portion 11 of the frame. The lower portion 11 of the frame is configured to open. The upper portion of the frame can be configured in an open or closed shape.

[0048] The artificial valve leaflets 16 can be configured to be flexible and mobile throughout the cardiac cycle. During systole, at least one artificial valve leaflet 16 extends radially outward from the lower portion of the frame to join with the patient's own anterior leaflet 1, preventing leakage between the anterior junction surface 17 of the implant and the patient's own anterior leaflet 1, while the patient's own posterior leaflet 2 extends to join with the outer surface of the lower portion 11 of the frame, preventing leakage between the posterior junction surface 18 of the implant and the patient's own posterior leaflet 2. During diastole, at least one artificial valve leaflet 16 is configured to move toward the lower portion 11 of the frame, thereby allowing blood to flow from the left atrium 8 to the left ventricle 4 between the anterior junction surface 17 of the implant and the patient's own anterior leaflet 1. Furthermore, the neck portion 12 can be configured to have a posterior channel 19 that allows blood to flow from the left atrium to the left ventricle between the posterior junction surface 18 of the implant and the patient's own posterior leaflet 2.

[0049] Figure 3A shows a front view of an example of a device having a seal skirt, three artificial valve leaflets 16 including an anterior joint surface 17, and a posterior flow path 19 formed by multiple windows in the seal skirt 15. Figure 3B shows a side view of the device, clearly showing the posterior joint surface 18 and the difference in dimensions of the short axes 14 of the upper frame portion 10 and the lower frame portion 11. In this example, the upper portion 10 of the frame is configured to open toward the anterior mitral valve leaflet 1 and be fixed along the posterior valve ring from the medial triangular portion to the lateral triangular portion. Furthermore, the lower portion 11 of the frame is configured to open toward the anterior mitral valve leaflet 1 and be suspended within the mitral valve orifice from the medial commissure to the lateral commissure.

[0050] The artificial valve leaflet 16 is thought to be made of a thin, flexible material including human or animal tissue, polymer, or fabric.

[0051] The upper portion 10, lower portion 11, and neck portion 12 of the frame can be made of metallic materials such as one or more of nitinol, cobalt-chromium, or stainless steel, or polymer materials.

[0052] The seal skirt 15 is thought to be made of a thin, flexible material containing one or more of human or animal tissue, polymer, or fabric.

[0053] The upper portion 10 of the frame can be configured to facilitate attachment of the device to the patient's own valve annulus 3. During operation, the upper portion 10 can be fixed to the patient's own valve annulus 3 so that the lower portion 11 is suspended within the left ventricle 4 and parallel to the blood flow. In one example of treatment for mitral regurgitation, the lower portion 11 of the frame can be configured to have a fish-mouth shape similar to the patient's own junction line 6. At least one prosthetic leaflet 16 can be configured as three different leaflets similar to the patient's own posterior leaflet, as shown in Figure 4A. Figure 4B is a schematic diagram of an embodiment of the low-profile prosthetic half-valve of Figure 4A implanted in a systolic heart. During operation, the prosthetic leaflet 16 can extend radially from the inner surface of the lower portion 11 of the frame during systole to form an anterior junction surface 17 that junctions with the patient's own anterior leaflet 1. Due to the opening property of the lower portion of the frame, it will be understood that the patient's own anterior leaflet 1 can extend radially within the range of the low-profile prosthetic half-valve device frame and junction with the anterior junction surface 17 of the device. This device can replicate the characteristic fish-mouth-like junction line 6 found in a healthy, autologous mitral valve, as shown in Figure 4B. The flexible nature of the prosthetic leaflets 16 allows them to conform to the patient's own anterior leaflet 1, sealing the mitral valve orifice. The patient's own posterior leaflet 2 is seen joining with the posterior junction surface 18 of the device at the rear of the lower portion 11 of the frame, through the device's posterior channel 19. Figure 4C is a schematic longitudinal cross-section of a low-profile prosthetic half-valve implanted in a systolic heart. The prosthetic leaflets 16 function as an anterior junction surface 17 to which the patient's own anterior leaflet 1 can conform, and the rear of the lower portion 11 of the frame functions as a posterior junction surface 18 for the patient's own posterior leaflet 2 to conform. The patient's own anterior and posterior leaflets 1 and 2, together with the prosthetic leaflets 16, seal the entire mitral valve orifice.

[0054] The posterior bonding surface 18 is envisioned to be wrapped in or made of a soft, thin material such as human or animal tissue, polymer, or fabric, in order to prevent the patient's own posterior leaflet 2 from being damaged over time. Furthermore, the posterior bonding surface 18 is envisioned to consist of at least one artificial valve leaflet 16 or movable surface for bonding with the patient's own posterior leaflet 2.

[0055] Referring again to Figure 4B, the flexible nature of the artificial valve leaflet 16 allows it to substantially change shape compared to the static shape in Figure 4A, and to adapt to the patient's own anterior leaflet 1 during systole. Those skilled in the art will understand that, since the device seals the mitral valve orifice using the patient's own anterior leaflet 1 together with the artificial valve leaflet 16, the durability of the implant depends on the long-term function of both the patient's own anterior leaflet 1 and the artificial valve leaflet 16. For this reason, it is desirable to minimize damage to the anterior leaflet 1 during operation. By joining the flexible artificial valve leaflet 16 with the patient's own flexible leaflet, damage from impact can be minimized. In addition, the small artificial valve leaflet 16 in a low-profile half-valve design has a smaller surface area, resulting in improved durability compared to a larger leaflet.

[0056] Referring again to Figure 4A, the seal skirt material is assumed to be bonded to the upper portion of the frame along anchor lines 30 that contact its own valve ring during operation. Optionally, the seal skirt can be made of a material with a high surface area-to-volume ratio, thereby allowing it to be easily compressed and promoting tissue growth.

[0057] The upper portion 10 of the frame is envisioned to be configured in either a closed or open shape. Those skilled in the art will understand that, because the upper portion of the frame is located on the left atrium 8 side of the valve annulus during operation, it will not impair or interfere with its own valve leaflet function. Furthermore, the upper portion 10 of the frame is envisioned to be configured to have an elliptical, circular, or D-shape, either as a whole or in part, to better fit the valve annulus 3 and the left atrium 8.

[0058] The lower portion 11 of the frame is envisioned to be configured to have various other opening shapes, such as a partial elliptical, circular, or parabolic shape, in order to assist in the treatment of valvular regurgitation. For example, the lower portion 11 of the frame could be configured to have a more V-shape to simulate the junction line between the anterior and posterior leaflets and the septal leaflet of the tricuspid valve in the treatment of tricuspid regurgitation. The lower portion 11 of the frame is also envisioned to be configured to have varying heights along the long axis. For example, the lower portion 11 of the frame could be configured to have shorter vertical heights on both sides of the open frame to avoid contact with the papillary muscle heads of the left ventricle.

[0059] The lower portion 11 of the frame can be configured to have a long axis 13 that is equal to or slightly larger than the long axis of the patient's own valve annulus, thereby having sufficient width to allow the patient's own valve leaflets to fit within the range of the lower portion 11 of the frame and connect with the artificial valve leaflets 16. Furthermore, the lower portion 11 of the frame can be configured to have a short axis 14 that is shorter than the short axis of the patient's own valve annulus, thereby, it is expected that the overall device footprint and reduced profile within the left ventricle will be, preferably, smaller.

[0060] Those skilled in the art will understand that it is desirable to have a device that can be securely fixed, reduce mitral regurgitation without adversely affecting the surrounding anatomical structure and function, and can be fitted into a low-profile delivery catheter to improve patient safety. The upper portion 10 of the device shown in this disclosure has a large diameter for fixation to the dilated mitral annulus 3, but can be easily reduced to a small diameter because the material is kept to a minimum. The lower portion 11 of the device has more material, including multiple artificial valve leaflets 16, but can also be easily reduced to a small diameter because it is smaller in size (particularly the short axis 14).

[0061] Figures 5A and 5B show schematic diagrams of an example of a low-profile prosthetic half-valve device implanted in a diastolic mitral valve. The surgeon's view schematic diagram in Figure 5A shows that in diastole, the patient's own anterior leaflet 1 and posterior leaflet 2 move radially laterally toward the left ventricular 4 wall, and the prosthetic leaflet 16 moves toward the lower portion 11 of the frame. Thus, there are two blood flow channels through the mitral valve orifice: one is the anterior channel 22 between the patient's own anterior leaflet 1 and the anterior junction surface 17 of the device, and the other is the posterior channel 19 of the device formed by multiple windows in the seal skirt 15. These two blood flow channels in diastole work together to create a large effective opening area desirable for cardiac function. Figure 5B shows a longitudinal cross-sectional view of the device in a diastolic mitral valve. This diagram shows that the posterior channel 19 is located above the gap between the patient's own posterior leaflet 2 and the posterior junction surface 18 of the device.

[0062] The low-profile artificial half-valve device may be configured to have multiple posterior channels 19 of various sizes and shapes, or optionally, to have no posterior channels 19 and to have only one anterior channel 22 for blood flow through the mitral valve orifice. The flexible, movable artificial valve leaflet 16 may be configured so that the anterior junction surface 17 moves substantially away from the patient's own anterior leaflet 1 during diastole, allowing sufficient flow from the left atrium 8 to the left ventricle 4.

[0063] The frame can be composed of multiple rhomboid cells 25, thereby allowing the frame to be selectively retracted and loaded into a small-diameter catheter. In a preferred embodiment, the upper portion 10 of the frame is "D-shaped" and designed to conform to the mitral annulus and left atrial wall 8, and can straddle the posterior annulus from the medial to the lateral triangular portion. Furthermore, in this example, the lower portion of the frame 10 is "fish mouth" shaped and similar to the patient's own mitral valve junction line 6, and can straddle the mitral valve junction line 6 from the medial to the lateral commissure. The exposed tips of the rhomboid cells within the frame can optionally be bent radially medially to avoid interference with the surrounding tissues, including the left atrium 8, the patient's own posterior leaflet 2, chordae tendineae 5, and the patient's own anterior leaflet 1.

[0064] The upper portion 10 of the frame may optionally be configured to have a plurality of small holes for engaging an anchoring mechanism, a compression mechanism, and / or a catheter loading mechanism for transcatheter delivery to the patient.

[0065] The lower portion 11 of the frame may optionally be configured to have a plurality of small holes to facilitate compression and / or loading of the compressed device into the catheter for transcatheter delivery to the patient.

[0066] In an exemplary manner, a low-profile artificial half-valve device can be guided and secured in place on the valve annulus via a plurality of dual guide-fixing (DGF) members 26, as shown in Figures 6A and 6B. Additional information regarding DGF members and systems and methods for delivering them is described in U.S. Patent Publication No. 2021 / 0212824, all of which are expressly incorporated herein by reference.

[0067] Referring to Figure 6A, the DGF member 26 may have a threaded anchor 27 configured to engage with the annular tissue at its distal end and a long trailing tail member 28 at its proximal end. Referring to Figure 6B, during operation, multiple DGF member anchors 27 can be initially embedded in the annular tissue. The trailing tail member 28 can then be guided through a small hole in the upper portion 10 of the frame to deploy the low-profile artificial half-valve device onto the annulus 3. Optionally, an additional locking mechanism 29 can be passed over the trailing tail member 28 to clamp the upper portion 10 of the frame against the embedded anchors 27. The tail of the DGF member may be configured to be selectively removable once the implant is secured in place.

[0068] It should be emphasized that the embodiments described above are merely possible examples and only demonstrate a clear understanding of the principles of this disclosure. Many changes and modifications can be made to the embodiments described above without substantially departing from the spirit and principles of this disclosure. All such changes and modifications are intended to be within the scope of this disclosure, and all possible claims for individual embodiments or combinations of elements or steps are intended to be supported by this disclosure. Furthermore, certain terms are used in this specification and the subsequent claims, but they are used only in a general and descriptive sense and are not used to limit the invention and the subsequent claims described herein.

Claims

1. A heart valve repair device, A stent frame having an upper portion configured to be fixed to the valve annulus, an open lower portion configured to be suspended in the blood flow path of the heart's own valve, and a neck transition portion between the upper portion and the lower portion, wherein the short axis of the lower portion is shorter than the short axis of the upper portion. Attached to the lower portion of the frame, at least one flexible artificial valve leaflet moves from an open position to a closed position by the normal function of the heart, A heart valve repair device characterized by comprising a seal skirt attached to at least a portion of the frame.

2. In the heart valve repair device according to claim 1, A heart valve repair device characterized in that the stent frame includes a network of cells configured to be radially foldable and expandable in the operating position.

3. In the heart valve repair device according to claim 2, A heart valve repair device characterized in that the upper portion includes a stent cell free end, which comprises a plurality of cells, and these plurality of cells are configured to bend radially inward relative to the remaining cells.

4. In the heart valve repair device according to claim 2, A heart valve repair device characterized in that the lower portion includes a stent cell free end, which comprises a plurality of cells, and these plurality of cells are configured to bend radially inward relative to the remaining cells.

5. In the heart valve repair device according to claim 1, A heart valve repair device characterized in that the upper portion comprises a plurality of through holes.

6. In the heart valve repair device according to claim 1, A heart valve repair device characterized in that the lower portion comprises a plurality of through holes.

7. In the heart valve repair device according to claim 1, A heart valve repair device characterized in that the at least one artificial valve leaflet includes three valve leaflets.

8. In the heart valve repair device according to claim 1, A heart valve repair device characterized in that the stent frame is configured to have at least one open channel.

9. In the heart valve repair device according to claim 5, A heart valve repair device characterized in that the plurality of through holes are configured to accept the passage of tail members and locking members of a plurality of dual guide fixing members.

10. In a heart valve repair device according to any one of claims 1 to 9, A heart valve repair device characterized in that the stent frame has a partially elliptical shape between the upper portion and the lower portion.

11. In a heart valve repair device according to any one of claims 1 to 9, A heart valve repair device characterized in that the upper portion has a flared edge shape for fixation to the valve annulus and juxtaposition with the atrium, and the lower portion has a fish mouth shape similar to the healthy mitral valve junction of the patient.

12. In a heart valve repair device according to any one of claims 1 to 9, A heart valve repair device characterized in that the neck region forms a transition area between the upper portion and the lower portion.

13. In a heart valve repair device according to any one of claims 1 to 9, A heart valve repair device characterized in that the upper portion has a partially elliptical shape configured to be fixed to the posterior mitral valve annulus from one triangular portion to the other, and the lower portion has a fish mouth shape having a large major axis dimension corresponding to the anatomical direction of the valve from commissure to commissure and a small minor axis dimension corresponding to the anatomical direction of the valve from anterior to posterior.

14. In the heart valve repair device according to claim 13, A heart valve repair device characterized in that the minor axis dimension of the lower portion of the frame is smaller than the minor axis dimension of the upper portion, and the major axis dimension of the lower portion is the same as or equivalent to the major axis dimension of the upper portion.

15. In the heart valve repair device according to claim 14, A heart valve repair device characterized in that the lower portion has a shallower curve than the upper portion, and the neck portion extends radially inward from the upper portion to the lower portion in the short-axis dimension of the device.

16. In a heart valve repair device according to any one of claims 1 to 9, A heart valve repair device characterized in that the seal skirt covers both the upper portion and the lower portion.

17. A method for implanting an artificial half-valve device according to any one of claims 1 to 9, The steps include introducing the stent frame into the patient's heart adjacent to the patient's own valve annulus, A method characterized by comprising the step of fixing the upper portion to the valve ring of the same valve so that the lower portion is suspended within the blood flow path of the same valve.

18. In the method according to claim 17, A method characterized in that the lower portion provides a bonding surface to one or more of the own heart valve leaflets.

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