Artificial heart valve that reduces its own valve

Abstract

An artificial heart valve configured to expand within a self-valve ring, engage surrounding tissue, and contract the tissue inwardly to enhance contact between the tissue and the valve. The heart valve may have a structural valve stent having an outer contraction structure with tissue engagement members. The contraction structure may be endogenous or exogenous. One endogenous version includes a plurality of arms arranged to contract inwardly toward a central valve portion, or a cloth structure having tissue anchors and surrounding an inner valve member may be tightened to pull the tissue inwardly.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 352,777, filed on Jun. 16, 2022, the entire content of which is hereby incorporated herein by reference.

[0002] This application generally relates to expandable artificial heart valves, such as replacement mitral or tricuspid valves, that are well - fixed by an annulus and remodel it.

Background Art

[0003] In vertebrates, the heart is a hollow muscular organ with four pumping chambers, namely, a left atrium and a right atrium, and a left ventricle and a right ventricle, each with its own one - way valve. Natural heart valves are identified as the aortic valve, mitral valve (or bicuspid valve), tricuspid valve, and pulmonary valve, each having flexible valve leaflets that join against each other to prevent backflow.

[0004] Artificial organs exist to correct problems associated with defective heart valves. For example, mechanical tissue - based artificial heart valves can be used to replace defective natural heart valves. Recently, significant efforts have been made in the development of replacement heart valves, particularly tissue - based replacement heart valves that can be delivered to patients with less trauma compared to open - heart surgery. Replacement valves are designed to be delivered by minimally invasive procedures or even percutaneous procedures. Such replacement valves often include a tissue - based valve body connected to an expandable frame that is subsequently delivered through a catheter or other such access tube.

[0005] Expandable valves, like surgically implanted valves sutured in place, may not seal as well against the native annulus, leading to paravalvular leakage. Further, expandable valves are typically radially outwardly pressed against the surrounding annulus, which can exacerbate underlying disease and remodel the heart in an undesirable manner. Still further, replacement valves can sometimes contact surrounding tissue (e.g., ventricular wall) with attendant adverse effects. As a result, there is a need for an expandable heart valve that can pull surrounding tissue inwardly to form a better seal, remodel the heart in a more favorable manner, and avoid contact with the heart wall. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] Disclosed herein is an expandable artificial heart valve, such as a mitral or tricuspid valve for replacement, that is better fixed by the annulus and, in some cases, remodels the annulus. The expandable artificial heart valve can have a structure that is fixed to the surrounding annulus tissue, pulls the tissue inwardly, and in many cases remodels the annulus and potentially the ventricle beneath the annulus. Advantages of these features include minimizing the device profile required to treat a very large annulus, providing a conformable platform for treating a range of annuli with one or very few valve sizes, and, depending on the anchor mechanism, being able to guide the procedure primarily via fluoroscopy. MEANS FOR SOLVING THE PROBLEM

[0007] An example of an artificial heart valve assembly is for replacing one's own mitral or tricuspid valve. The artificial heart valve assembly includes a self-expandable stent having a body with an inlet end portion and an outlet end portion. The stent may be made of a shape memory material such as nitinol. The valve portion is positioned within the passage of the body to allow blood flow through the passage in only one direction, thereby replacing the function of the native valve. At least one anchor and preferably a plurality of anchors are disposed along the outer surface of the artificial heart valve assembly for engaging the surrounding tissue. The artificial heart valve assembly is adapted to reduce the diameter of the native valve annulus by pulling the surrounding tissue inwardly. Reducing the diameter of the valve annulus can provide many advantages such as treating the underlying disease (e.g., performing annuloplasty), reducing the device profile within the body, and forming a better seal around the outside of the device.

[0008] The artificial heart valve assembly may include an annular flange extending radially outwardly from the body, such as from the inlet end portion. One or more tissue engaging anchors may be disposed on the annular flange, such as along the lower surface or around the perimeter. The anchor may include a barb, a helical screw, or any other suitable tissue engaging mechanism. The annular flange may be able to transition from a larger diameter to a smaller diameter to contract the valve annulus of the native valve. In one embodiment, the annular flange may comprise a plurality of radially extending arms, each arm being configured to decrease in length to pull the tissue inwardly, thereby contracting the valve annulus of the native valve. The decrease in the length of the arm can be achieved using a bioabsorbable material that initially maintains the arm in an elongated state and is resorbed in the body to transition the arm to a shortened state.

[0009] In an artificial heart valve assembly having an annular flange, a tightening mechanism may connect each of the anchors. The tightening mechanism may be adapted to pull the anchors radially inwardly to contract the valve annulus of the native valve.

[0010] In an artificial heart valve assembly having an annular flange, the anchor can be deployed separately from the heart valve so that the anchor is not incorporated into the heart valve.

[0011] In an artificial heart valve assembly having an annular flange, the annular flange can be coupled to the body and configured to reduce its diameter during radial expansion of the body.

[0012] In an artificial heart valve assembly having an annular flange, the annular flange may comprise a plurality of helically arranged arms having tips that together define a circle of rotation having a diameter D1 when expanded, and rotation of the valve portion about its axis pulls the arms inwardly so that the tips together define a reduced diameter D2.

[0013] The artificial heart valve assembly may further comprise one or more ventricular anchors extending from the body, such as from an outlet end portion. The ventricular anchor may be shaped to capture a self-valve tip between the ventricular anchor and the stent body. Alternatively, the ventricular anchor may be shaped to be disposed inside the self-valve tip and may have an outer surface for engaging surrounding tissue. In a preferred embodiment, the ventricular anchor generally transitions (i.e., inverts) from a generally straight shape to a curved shape upon deployment.

[0014] Another example of an artificial heart valve assembly comprises a stent having a body, a valve portion positioned within a passage of the body, and a plurality of anchors disposed along an outer surface of the stent for engaging surrounding tissue. The stent may be made of a shape memory material such as nitinol. The stent may be adapted to be radially over-expanded by an expansion mechanism to a diameter larger than its set shape diameter to ensure that the anchors engage and / or penetrate the surrounding tissue firmly. The expansion mechanism is then removed to allow the stent to return towards its set shape diameter. As the stent returns to its set shape diameter (i.e., the diameter decreases), the surrounding tissue is pulled inwardly.

[0015] The expansion mechanism may be a balloon or any other suitable mechanism for temporarily expanding the stent. The stent may comprise an annular flange extending radially outwardly from the body, and the anchor is disposed along the surface of the annular flange. Alternatively, the stent may comprise at least one ventricular anchor extending from the body. The ventricular anchor is desirably shaped to capture the native leaflet between the ventricular anchor and the body of the stent. Still further, the stent may comprise an annular flange extending radially outwardly from the inlet end portion of the body and at least one ventricular anchor for capturing the native leaflet between the ventricular anchor and the body of the stent. The cloth seal may cover at least a portion of the stent.

[0016] Another artificial heart valve assembly may be configured to replace its mitral or tricuspid valve. The artificial valve assembly includes a self-expanding valve stent made of a shape memory material and covered with cloth. The valve stent has a tubular valve portion having an inlet end portion and an outlet end portion, and a peripheral flange formed by an array of struts or arms that extend radially outwardly and are connected from the inlet end portion when expanded. The array has an inherent radial contraction mechanism and tissue engagement members. The valve portion is positioned within the passage of the body. The valve portion comprises a plurality of leaflets made from the pericardium. The valve portion allows one-way blood flow through the passage to replace the function of the native valve. The artificial heart valve assembly is adapted to radially contract the annulus of the native valve upon deployment by fixing the tissue engagement members to the tissue surrounding the annulus.

[0017] The array may include petal-shaped struts connected to the valve portion such that expansion of the valve portion radially contracts the struts. Alternatively, the array may comprise struts configured to bend outwardly and then inwardly towards the valve portion when an external restraint around the valve is removed from the inflow end. The struts have a return portion on the outer tip that defines the tissue engagement member.

[0018] The array may comprise a plurality of radially extending arms, each having a contraction mechanism for reducing the length of the incorporated arm. The contraction mechanism may include an extended structure biased to a contracted length and held extended by a bioabsorbable suture. As another method, the contraction mechanism may include an extended structure biased to a contracted length and held extended by a reinforcing wire. Only a portion of the radially extending arm may have a tissue engagement member thereon, and the radially extending arms may have different lengths.

[0019] In yet another embodiment, the array may comprise a plurality of helically arranged arms having tips that together define a circle of rotation having a diameter D1 when expanded, and rotation of the valve portion about its axis pulls the arms inwardly so that the tips together define a diameter D2 that is contracted.

[0020] In another variation, the valve stent may have an outer anchor stent and an inner valve stent, the array comprising a plurality of radial arms extending from struts connected only to the lower ends of the anchor stents, and rotation of the anchor stents following fixation of the return portions at the tips of the radial arms rotates the struts in a helical shape and pulls the tips inwardly, and then the inner valve stent expands within the outer anchor stent.

[0021] Another example of an artificial heart valve assembly for replacing one's own mitral or tricuspid valve includes a self-expanding valve stent made of a shape memory material and covered with fabric, the valve stent having a tubular valve portion with an inlet end portion and an outlet end portion. An array of arms may extend radially outwardly from and be connected to the outlet end portion of the valve portion and be configured to bend (e.g., 180 degrees) toward the inlet end portion. The array has an intrinsic radial contraction mechanism and tissue engagement members. The valve portion is positioned within a passage of the body, the valve portion comprising a plurality of valve leaflets made from pericardium, the valve portion allowing one-way blood flow through the passage to replace the function of the native valve. The artificial heart valve assembly is adapted to secure the tissue engagement members to the native valve leaflets and pull the leaflets toward the tubular valve portion upon deployment.

[0022] In another embodiment, the intrinsic radial contraction mechanism may comprise a reinforcing tube attached around a lower U-shaped bend on each of the arms, the reinforcing tube having a radius of curvature greater than that of the U-shaped bend to force the arms to an outward position, the reinforcing tube being bioabsorbable after a specific time in the body to allow the arms to return to their radially inward shape.

[0023] In another embodiment, the intrinsic radial contraction mechanism may comprise one or more reinforcing plugs positioned within recesses on the inner diameter of each of the arms, the reinforcing plugs holding the arms in an outward position, the reinforcing plugs being bioabsorbable after a specific time in the body to allow the arms to return to their radially inward shape.

[0024] A system for contracting a transplantable artificial heart valve configured to be implanted into its own mitral or tricuspid valve annulus includes a heart valve having a self-expanding valve stent covered with cloth, the valve stent having a tubular valve portion and a valve member with valve leaflets attached therein, the valve further having a peripheral flange including an array of generally annular struts or arms that extend radially outwardly and are connected at the inflow end of the valve portion when expanded, the array having tissue engagement members configured to grip and secure tissue surrounding the valve annulus. After deployment of the tissue engagement members, an external radial contraction mechanism is provided for pulling the tissue surrounding the valve annulus inwardly. The external radial contraction mechanism may comprise a flexible tightening portion having a length threaded through each of the tissue engagement members and sufficient to extend from outside the body for connection and sliding therethrough, wherein the tension of the tightening portion contracts the array and pulls the tissue surrounding the valve annulus inwardly.

[0025] The tissue engagement members may comprise valve anchors that are separated from the peripheral flange and deployed through the peripheral flange when the heart valve seats on the valve annulus.

[0026] The array may comprise a plurality of radially extending arms and the tissue engagement members may comprise retention tabs secured to the outer ends of at least a portion of the arms.

[0027] Another system for contracting a transplantable artificial heart valve configured to be implanted into one's own mitral or tricuspid valve annulus includes a heart valve having a self-expanding valve stent covered with cloth, the valve stent having a tubular valve portion and a valve member with valve leaflets attached therein, the valve further having a peripheral flange including an array of generally annular struts or arms covered with cloth that extend radially outwardly and are connected thereto from the inflow end of the valve portion, the array having tissue engagement members configured to grip and secure tissue surrounding the valve annulus, the peripheral flange being radially separated at its free end exposed on its inflow side. An external radial contraction mechanism is provided for pulling inwardly the tissue surrounding the valve annulus after deployment of the tissue engagement members, the external radial contraction mechanism being sufficient to extend from outside the body and being screwed through a pair of radially spaced anchors embedded in the valve annulus tissue through the peripheral flange and extending circumferentially along the peripheral flange and attached to its free end and having a length for connection and sliding therealong of a pair of flexible tethers, the tension on the tethers contracting the peripheral flange and pulling inwardly the tissue surrounding the valve annulus.

[0028] Another system for contracting a transplantable artificial heart valve configured to be implanted into one's own mitral or tricuspid valve annulus includes a heart valve having a self-expanding valve stent covered with cloth, the valve stent having a tubular valve portion and a valve member with valve leaflets attached therein, the valve further having a peripheral flange including an array of generally annular struts or arms covered with cloth that extend radially outwardly and are connected thereto from the inflow end of the valve portion. The valve further has at least one tissue anchor configured to be separated from the artificial heart valve and embedded within the tissue surrounding the valve annulus. The external radial contraction mechanism is configured to pull inwardly the tissue surrounding the valve annulus after deployment of the tissue anchor, the external radial contraction mechanism extending from outside the body, extending through the peripheral flange, and having a plurality of flexible tethers of sufficient length to extend radially outwardly and secure to the tissue anchor, the tension on the tethers pulling inwardly the tissue surrounding the tissue anchor and the peripheral flange.

[0029] A contractile artificial heart valve for implantation into a patient's mitral or tricuspid valve annulus includes a self-expandable valve stent covered with fabric. The valve stent has a tubular valve portion and a valve member with valve leaflets attached therein. The valve further has an array of fabric-covered arms that extend radially outwardly from the outflow end of the valve portion and are connected thereto, and are bent 180 degrees toward the inflow end. The array has tissue engagement members configured to grip and secure the valve leaflets attached to the valve annulus. An external radial contraction mechanism is configured to pull the valve leaflets attached to the valve annulus inwardly after deployment of the tissue engagement members. The external radial contraction mechanism is long enough to extend from outside the body and is provided with a flexible tightening portion that is screwed through and around the fabric covering the array for connection and sliding therearound. The tension of the tightening portion contracts the fabric-covered array and pulls the valve leaflets inwardly.

[0030] Another contractile artificial heart valve for implantation into a patient's mitral or tricuspid valve annulus includes a self-expandable valve stent covered with fabric. The valve stent has a tubular valve portion and a valve member with valve leaflets attached therein. The valve further has an outer fabric-covered tube that is spaced radially outwardly from the valve portion and is connected thereto by upper and lower flexible skirts. The outer tube has tissue engagement members configured to grip and secure the valve leaflets attached to the valve annulus. An external radial contraction mechanism is configured to pull the valve leaflets attached to the valve annulus inwardly after deployment of the tissue engagement members. The external radial contraction mechanism is long enough to extend from outside the body and is provided with a flexible tightening portion that is screwed through and around the fabric covering the outer tube for connection and sliding therearound. The tension of the tightening portion contracts the fabric-covered outer tube and pulls the valve leaflets inwardly.

[0031] A method of contracting an artificial heart valve implanted in one's own mitral or tricuspid valve annulus includes providing a heart valve having a self-expandable valve stent covered with cloth, the valve stent having a tubular valve portion and a valve member with valve leaflets attached therein, the valve portion having a relaxed expanded size, the valve further having a peripheral flange including an array of generally annular struts or arms extending radially outwardly and connected thereto from an inflow end of the valve portion, the array having tissue engagement members configured to grip and secure tissue surrounding the valve annulus. The heart valve is crimped around a balloon and constrained in a contracted state within an access sheath. The heart valve is advanced within the access sheath in a contracted state toward the valve annulus. The heart valve is preferably discharged from the access sheath within the valve annulus. The balloon is inflated beyond the expanded size of the valve portion of the valve stent, thereby fixing or embedding the tissue engagement members into the tissue surrounding the valve annulus. The balloon is then deflated to allow the valve portion to contract the peripheral flange and pull inwardly.

[0032] Another way to contract an artificial heart valve implanted in one's mitral or tricuspid valve annulus is to provide a self-expandable valve stent covered with cloth, the valve stent having a tubular valve portion and a valve member with valve leaflets attached therein, the valve portion having a relaxed expanded size, the valve further having an array of cloth-covered arms that extend radially outwardly from the outflow end of the valve portion and are connected thereto and bend toward the inflow end, the array having tissue engagement members configured to grip and secure to the valve leaflets attached to the valve annulus. The heart valve is prepared for implantation by curling the heart valve around a balloon and constraining the heart valve in a contracted state within an access sheath. The heart valve advances to the valve annulus in a contracted state within the access sheath. The heart valve is released from the access sheath within the valve annulus and the balloon is inflated to overly expand the valve portion of the valve stent (i.e., beyond its shaped diameter), thereby fixing the tissue engagement members within the valve leaflets. The balloon is then deflated to allow the valve portion to contract to its expanded size and pull the array inwardly.

[0033] A further understanding of the nature and advantages of the present invention will become apparent by reference to the remainder of the specification and drawings.

[0034] The features and advantages of the present invention will be recognized as the same become better understood by reference to the specification, claims, and appended drawings.

Brief Description of the Drawings

[0035]

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DETAILED DESCRIPTION OF THE INVENTION

[0036] Valve replacement in the mitral or tricuspid valve annulus is a primary focus of the present application, but certain features of the delivery systems described herein may be equally applicable to other valve implant locations and, thus, the claims should not be limited to mitral or tricuspid valve replacement, unless expressly so limited. Replacement heart valves can be delivered to the mitral valve annulus or other heart valve locations of a patient's heart in a variety of manners, such as via open chest surgery, minimally invasive surgery, and percutaneous or transcatheter delivery through the patient's vasculature. Examples of the transfemoral approach can be found in U.S. Patent Nos. 10,004,599 and 10,813,757, which are hereby incorporated by reference in their entirety. All techniques of valve delivery are contemplated by the present application.

[0037] Figure 1A is a cutaway view of a human heart in systole. The right ventricle RV and left ventricle LV are separated from the right atrium RA and left atrium LA by the tricuspid valve TV and mitral valve MV, respectively, i.e., the atrioventricular valves. Further, the aortic valve AV separates the left ventricle LV from the ascending aorta (not specified), and the pulmonary valve PV separates the right ventricle from the pulmonary artery (likewise, not specified). Each of these valves has flexible valve leaflets that extend inwardly across the individual valve orifices and come together or "coapt" in the flow to form a one-way fluid occluding surface. The right atrium RA receives deoxygenated blood from the venous system through the superior vena cava SVC and inferior vena cava IVC (the former enters the right atrium from above and the latter from below). The coronary sinus CS is a collection of joined veins that forms a large vessel that collects deoxygenated blood from the heart muscle (myocardium) and delivers it to the right atrium RA.

[0038] During the diastolic phase or diastole, venous blood accumulating in the right atrium RA is drawn through the tricuspid valve TV by the expansion of the right ventricle RV. Similarly, oxygenated blood is drawn through the mitral valve MV by the expansion of the left ventricle LV. During the higher-pressure systolic phase or systole, as seen in Figure 1A, the myocardium compresses both the right ventricle RV and the left ventricle LV, forcing venous blood into the lungs through the pulmonary valve PV and the pulmonary artery, and forcing arterial blood through the aortic valve AV, the ascending aorta, and the body. During this high-pressure phase, the leaflets of the tricuspid valve TV and the mitral valve MV close to prevent blood from returning to their respective right atrium RA and left atrium LA.

[0039] Figure 1B is the same figure as Figure 1A but shows a heart in which the left ventricle LV has enlarged (dilated), often referred to as dilated cardiomyopathy (DCM). Such a condition tends to pull the leaflets of the mitral valve MV apart, and as a result, they do not close properly and often lead to mitral regurgitation, as indicated by a jet of blood leaking through the seemingly closed MV. The regurgitation reduces the pressure generated in the left ventricle LV and thus the pressure gradient across the aortic valve AV, which reduces the amount of blood pumped through the body.

[0040] Similarly, Figure 1C is the same figure showing a heart in which the right ventricle RV has enlarged, and the condition is caused by various factors. The annulus of the tricuspid valve TV expands outward toward the free walls of the anterior and posterior RV, which can lead to tricuspid valve insufficiency, as shown. The reduced pump output to the lungs through the pulmonary valve PV reduces the overall efficiency of the oxygenation process and leads to various snowman-like health problems.

[0041] This application provides some solutions to problems posed by either dilated cardiomyopathy (DCM) or tricuspid regurgitation. Generally, implanting an expandable artificial heart valve for replacement within an enlarged valve annulus can result in secondary problems of paravalvular leakage due to the enlargement of the valve annulus. First, commercially available expandable artificial heart valves have a cylindrical exterior that does not closely match the non-circular peripheral shape of either the mitral valve annulus or the tricuspid valve annulus. Second, the stent frame of an expandable artificial heart valve is either self-expanding or balloon-expandable. Balloon-expandable stent frames exert a more outward force on the valve annulus, but neither type of stent frame is immune to potential leakage around the outside.

[0042] This application contemplates an expandable artificial heart valve that grasps the surrounding annulus tissue and radially inwardly pulls it relative to the outside of the valve. This not only helps to reduce paravalvular leakage but may also contribute over time to remodeling of the annulus and subvalvular structures. For example, an expandable heart valve of the type described herein implanted in the tricuspid annulus radially inwardly pulls the annulus, which also radially inwardly pulls the adjacent wall of the right ventricle RV. Over time, the improved blood flow and radial constriction of the tricuspid annulus are thought to assist in remodeling of the right ventricle RV and reduction of its dilation. Another potential benefit of the expandable heart valve described herein is the ability to minimize the device profile required to treat very large annuli. That is, instead of selecting a heart valve of a larger size, an appropriately sized valve is used, which then radially inwardly pulls the annulus around it. Further, the constricting heart valves described herein provide a conformable valve platform that can treat a wide range of annulus sizes using a small number of valve sizes. Current artificial heart valves are available in 2 mm increments from 19 mm to a maximum size of 31 mm or 33 mm. The constricting heart valves disclosed herein may be provided, for example, in size 19 mm for annuli of 19 - 21 mm, size 23 mm for annuli of 23 - 25 mm, etc., thus reducing the inventory of required valve sizes. Finally, the various heart valves described herein may be implanted with the aid of fluoroscopy, similar to current expandable heart valves.

[0043] Figure 2A is a partial cross-sectional view through the left side of the heart showing the mitral valve and annulus above the left ventricular structure, and Figure 2B is a plan view of the mitral valve showing the well-known nomenclature of the annulus and valve leaflets. The mitral valve MV mainly includes a pair of joined valve leaflets, namely, an anterior leaflet AL and a posterior leaflet PL, fixed around its outer edge to the fibrous mitral annulus MA. The inner edges of the anterior leaflet AL and the posterior leaflet PL are connected to string-like chordae tendineae CT extending into the left ventricle LV and are joined by papillary muscles PM extending upward from the myocardial muscle M that defines the left ventricular cavity. As the main pumping chamber of the heart, the myocardial muscle M contracts during systole, which reduces the tension in the chordae tendineae CT and enables the valve leaflets AL, PL to be brought together or joined.

[0044] As shown in FIG. 2B, the surrounding mitral annulus MA is often described as having a D-shape with somewhat straighter sides adjacent to the anterior leaflet AL and more rounded or convex sides adjacent to the posterior leaflet PL. The leaflets are shaped such that the line of junction resembles a smiley face that is approximately parallel to the posterior surface of the mitral annulus MA. The anterior leaflet AL extends over a smaller peripheral surface around the mitral annulus MA than the posterior leaflet PL, but the anterior leaflet AL has a single cusp with a convex free edge that further extends into the opening defined by the mitral annulus MA. Typically, the anterior leaflet AL has three marked regions or cusps A1, A2, A3 around its periphery. On the other hand, the posterior leaflet PL is typically divided by a fold into three cusps P1, P2, P3 around its periphery and generally has a concave free edge. The two commissures, namely the anterior commissure AC and the posterior commissure PC, generally define the intersection points of the junction lines between the two leaflets AL, PL and the mitral annulus MA. The tricuspid valve TV is not described in detail but is often described as an irregular oval. The tricuspid annulus has three different leaflets that extend inwards for co-joining.

[0045] Of course, any of the heart valve stents disclosed herein may be shaped to conform to the D-shaped mitral annulus MA as shown in FIG. 2B. That is, all stents are shown as tubular bodies that accommodate and support the leaflets. Instead of the circular plan views as shown in FIGS. 3A - 3B and 4C, the body may be D-shaped, with somewhat straighter sides being implanted adjacent to the anterior leaflet AL and more rounded or convex sides being implanted adjacent to the posterior leaflet PL.

[0046] Some of the embodiments of the contracting heart valve described herein are shown as being implanted within the mitral valve MV, but it should be understood that the same valve can also be utilized in the tricuspid valve TV. In fact, all of the embodiments of the heart valve described herein can be used interchangeably in any of the atrioventricular valves.

[0047] Figure 3A is a partial cross-sectional view of the mitral valve annulus MA and left ventricle LV similar to that of FIG. 2A after implantation of the expandable artificial heart valve 20 of the present application, but before the final step of deployment. Figure 3B is the same view after the final step of radially contracting the outer skirt fixed to the mitral valve annulus. Also refer to FIGS. 4A-4C showing an exemplary valve stent without fabric covering and valve leaflets.

[0048] The artificial heart valve 20 includes an inner expandable valve member 22 that supports flexible valve leaflets 24 therein. Typically, there are three valve leaflets 24 that join free edges within the flow opening through the valve member 22 to each other and have a peripheral valve leaflet edge sutured to the surrounding structure. Since this is a replacement mitral valve, the sutured valve leaflet edge 25 of the valve leaflet 24 is shown, and blood flow is permitted only downward through the valve member 22 from the left atrium to the left ventricle LV. For the same artificial heart valve 20 implanted in the tricuspid valve annulus TA, a similar arrangement is contemplated in which blood flow passes unidirectionally downward to the right ventricle RV.

[0049] The peripheral skirt 26 circumferentially surrounds the inner valve member 22, and the contracting suture 27 extends around the upper edge of the skirt. The valve member 22 and the skirt 26 include a fabric covering 28 sutured to the structural stent frame 30. The upper edge of the inner valve member 22 is characterized by a plurality of equally spaced eyelets 32 formed by the stent frame 30. The eyelets 32 can be used to facilitate delivery of the expandable valve 20. For example, sutures or wires can pass through the eyelets 32 to control the advancement and radial expansion / contraction of the valve.

[0050] Referring now to FIGS. 4A - 4C, the stent frame 30 includes a generally tubular inner portion 34 that defines the shape of the inner valve member 22. The outlets 32 are shown at the upper portions of a number of converging struts 36 that define the inner portion 34. In the illustrated embodiment, the struts 36 are formed in a generally serpentine pattern axially and are fixed to each other at nodes to form cells or openings therebetween. This structure is foldable to a minimum state for delivery and then expandable to the shown shape. It should be understood that the particular configuration of the struts 36 can be modified as is well known in the art. For example, another common pattern of the struts 36 defines a series of connected diamonds that form cells of a similar shape therebetween.

[0051] The plurality of outer arms 38 includes generally arcuate posts 40 joined to the tubular inner portion 34 at lower bends 42. Each of the arms 38 features one or more outwardly projecting returns for securing to the surrounding tissue. In the illustrated embodiment, there are three returns 44a, 44b, 44c extending outwardly from each of the posts 40. The first return 44a is angled downwardly while the other two returns 44b, 44c are angled upwardly. The entire stent frame 30 is covered with a biocompatible fabric, but the returns 44a, 44b, 44c project outwardly through it such that when the artificial valve 20 is expanded, they are embedded within the surrounding valve annulus tissue. As described below, various different types of returns are contemplated and are generally interchangeable. The fabric - covered arms 38 define a peripheral skirt 26.

[0052] In the illustrated embodiment, as shown in the top view of FIG. 4C and the flat view of FIG. 5, twelve outer arms 38 are evenly arranged around the tubular inner portion 34. The 180-degree bend 42 connects each of the arms 38 to a pair of converging struts 36 at the lower end of the inner portion 34. The serpentine struts 36 extend upwardly, connect to two adjacent struts, and finally converge with one of the adjacent struts to define the eyelets 32. Thus, there are twelve eyelets 32. Of course, the number of outer arms 38 and the strut configuration of the tubular inner portion 34 can vary, and can be as few as six and as many as eighteen in practice.

[0053] The material of the stent frame 30 can be compressed into a small outer shape to pass through a delivery tube or access tube, while also being able to expand into a shape such as that shown where the diameter of the tubular inner portion 34 can be 33 mm in size. For a self-expanding stent frame 30, the material is desirably a superelastic metal such as nitinol. For a balloon-expandable stent frame 30, the material is desirably a cobalt-chromium alloy such as stainless steel or Elgiloy. The struts 36 and posts 40 are shown with a square or rectangular cross-section, reflecting a common manufacturing technique of laser cutting the stent frame from a first tubular blank. Of course, round wire may alternatively be used to form the stent frame 30.

[0054] Referring again to FIGS. 3A and 3B, as well as FIGS. 6A - 6C, the implantation and deployment of the artificial heart valve 20 are illustrated. FIGS. 6A - 6C are sequential views showing the expandable valve stent 30 being discharged from the access tube 50 and its deployment steps. This valve stent 30 is shown without being covered by cloth and without valve leaflets or other soft structures. The valve stent 30 defines the overall shape of the heart valve 20. Thus, initially, the pusher 52 biases the valve stent 30 (i.e., the heart valve 20) from the distal end of the access tube 50. The posts 40 that define the arms 38 are initially held in a linear and distally facing orientation by the access tube 50. When emerging from within the access tube 50, the arms 40 bend 180 degrees in the proximal direction due to their inherent spring bias. Again, it is desirable that the self - expanding stent frame 30 be formed of nitinol, which can be easily shaped to take on its final configuration.

[0055] As the pusher 2 continues to discharge the valve stent 30, the tubular inner portion 34 is finally released and expands to its final diameter. FIG. 6C shows the valve stent 30 expanded to its maximum diameter. The outer arms 38 that form the peripherally covered skirt 26 first contact the self - valve leaflets and embed the return portion 44 itself into the tissue. A tether or wire 54 is shown extending from the valve stent 30 back into the access tube 50. Such a tether or wire can be used to maneuver the valve to a third (to third). For example, the wire can pass through the eyelet 32 at the proximal end of the tubular inner portion 34 and be initially held firmly to prevent the expansion of the tubular inner portion as it is discharged from the tube 50. Then, the tether or wire 54 can be slowly released to allow the expansion of the inner portion 34. Conversely, if the positioning of the heart valve 20 is inaccurate, the tether or wire 54 can be retracted into the access tube 50 to allow the valve stent 32 to contract and adjust its position.

[0056] Referring again to FIG. 3B, the peripheral skirt 26 is shown radially contracted. This can be achieved by extending a suture or constriction 27 that contracts around the upper edge of the skirt 26. For example, a fabric tunnel or pocket can be formed around the periphery of the upper edge of the skirt 26 through which the suture or constriction 27 passes. By pulling on the constriction 27, the upper edge of the skirt 26 is pulled inwardly closer to the inner valve member 22. Thanks to the return portion 44, the surrounding tissue including the valve annulus and valve tip is also pulled inwardly.

[0057] The process of constricting the surrounding tissue in this way can be achieved after closing the access incision and under fluoroscopy. The suture or constriction 27 can extend out of the body through the sealed incision (i.e., the purse-string suture), typically through an elongated flexible tubular sheath (not shown). The constricting suture or constriction 27 is an example of an external actuator that can be used post-implantation to simultaneously pull the valve annulus inwardly and reduce the overall diameter of the heart valve 20 for the fixed return portion 44. Such an external constriction mechanism is in contrast to the internal constriction mechanisms disclosed elsewhere in this specification, as will become apparent.

[0058] Referring now to FIG. 7, an alternative expandable artificial heart valve 60 of the present application is shown having a generally cylindrical valve member 62 with an upper peripheral flange 64. The valve member 62 and the peripheral flange 64 may be defined by a valve stent 66 covered with a biocompatible fabric 68. In the illustrated embodiment, the valve stent 66 has a plurality of connected struts that define the cylindrical valve member 62, as well as radial arms that extend outwardly at the proximal end of the valve member to define the peripheral flange 64. As described elsewhere, the valve stent 66 may be formed of a single self-expanding nitinol stent or may be balloon-expandable as desired. As previously described, the flexible valve leaflets 70 are sewn inside the valve member 62 and define a surface that occludes one-way flow. Again, the artificial heart valve 60 is configured to be implanted in one of the atrioventricular valves.

[0059] A plurality of separate valve anchors 72 are shown in a disassembled state above the artificial heart valve 60 before deployment through the peripheral flange 64. The valve anchors 72 in this case are not incorporated into the heart valve 60 but are instead deployed separately to ultimately form part of a fixed implant. In the illustrated embodiment, each of the anchors 72 has an upper head 73 and a lower corkscrew-like tissue anchor 74. Of course, the specific configuration of the tissue anchor 74 may be other than a corkscrew, such as a straight or curved return portion. A lanyard or tightening portion 76 passes through the head 73 of each of the anchors 72. The free end 78 of the tightening portion preferably extends proximally out of the body after passing through one of the anchors 72. Pulling on the free end 78 reduces the outer circumference of the tightening portion 76.

[0060] FIG. 8A is a cross-sectional view through the left ventricle showing the expandable artificial heart valve 60 of FIG. 7 prior to the final step of deployment within the mitral valve annulus. The valve stent 66 is expanded such that the valve member 62 contacts the valve leaflets of the mitral valve. The anchors 72 are deployed around the peripheral stent 64 such that they are embedded in the mitral valve annulus MA. The free end 78 of the tightening portion 76 typically exits the body through a tubular sheath (not shown). FIG. 8B is the same view after the final step of radially contracting the peripheral flange 64 fixed to the mitral valve annulus MA by pulling on the free end 78 of the tightening portion 76. This causes the anchors 72 to be pulled inwardly, which in turn pulls the surrounding tissue leaflets and annulus into better contact with the outside of the valve member 62. Again, FIGS. 8A and 8B show only the valve stent 66 for clarity, but it will be understood that the fabric covering 68 and valve leaflets are part of the completed valve 60. Here too, the tightening portion 76 acts as an external contraction mechanism that operates from outside the body or is at least not endogenous to the heart valve itself or carried by the heart valve itself.

[0061] FIG. 9A is a perspective view of yet another expandable artificial heart valve 80 having a valve portion 82 and an upper peripheral flange 84, similar to the valve shown in FIG. 7. The valve 80 can be reformed by a structural valve stent 86 covered with a cloth 88.

[0062] A plurality of anchors 90 are shown deployed around the peripheral stent 84. The anchors 90 may be as described above, such that only the head is shown as a corkscrew or another tissue penetrating member (not shown) embedded in the valve annulus tissue through the flange 84. Two anchors 92 are radially spaced from each other at positions around the peripheral stent 84 and each has a tether 94 extending therethrough. The tether 94 passes through the anchor 92, extends circumferentially through or over the peripheral flange 84, and is connected to its free edge 96. The peripheral flange 84 is discontinuous at the free edge 96, and as a result, has a variable circumferential profile. FIG. 9B shows the final step of circumferentially tightening the peripheral flange 84 by pulling on the tether 94 to cause its radial contraction. The free edge 96 is pulled towards the anchor 92 that tightens the peripheral flange 84. The reduction in the circumference of the flange 84 causes the surrounding tissue to be pulled inwards towards the valve member 82.

[0063] FIG. 10A is an elevation view of an alternative heart valve stent 100 having a tubular valve portion 102 with a fixed return portion 106 and an upper peripheral flange 104. As shown, a fixed return portion 106 extending radially outwardly from the valve portion 102 may also be provided. In this embodiment, the struts of the valve stent 100 are formed in a diamond shape and the return portion 106 is defined by sharp points. As seen elsewhere in this application, the stent 100 is shown without an outer cloth cover and valve leaflets. The assembled heart valve may be formed by a single expandable superelastic stent 100 covered with a cloth, and flexible valve leaflets are supported within the valve portion 102 to allow one-way blood flow through the valve (downward for this mitral valve).

[0064] Figure 10B shows an example of the fixation return part 106. The return part 106 may include a shaft extending vertically or at an angle from a specific host structure (such as a flange, a body, etc.), and small hooks 107 or other such devices are near the end to help prevent the return part from being pulled by the tissue and becoming free. There may be a plurality of such hooks 107.

[0065] Figure 10C shows a similar valve stent 100' comprising a body 102' and an upper peripheral flange 104' extending radially outward from the upper end 105' of the body 102'. In this embodiment, the upper peripheral flange 104' extends substantially perpendicular to the stent opening defined by the upper end 105'. The ventricular anchor 106' curves downward about 180 degrees from the lower end 108' of the stent body 102' and then bends back upward. The ventricular anchor 106' is shaped to capture the self-valve tip between the ventricular anchor and the body 102' of the stent. In combination with or in place of the contracting return part on the upper peripheral flange 104', the ventricular anchor 106' may be configured to contract after implantation, such as by providing a clamping portion around its periphery as in the embodiments of FIGS. 7 - 8. The disc-like upper peripheral flange 104' is positioned flat across the upper surface of the mitral annulus MA and can provide an increased surface area contact for the ingrowth of tissue.

[0066] The body 102' may have an outward return part 106, similar to the stent 100 of FIG. 10A. Further, inward return parts 106a may be provided along each of the ventricular anchors 106', and the return parts are the same as those shown and described with respect to FIG. 10B.

[0067] Figure 10D shows the valve stent 100' implanted in the mitral annulus MA. The ventricular anchor 106' is deployed outside the mitral valve leaflet and is configured to contract inwardly as shown. This helps to ensure that the valve has the stent 100' within the annulus.

[0068] Figures 11A and 11B are two views showing the deployment process of the valve stent 100'' similar to that in FIG. 10A, where the expansion of the central valve portion 102'' causes a radial contraction of the upper peripheral flange 104''. That is, the radial expansion of the valve portion 102'' expands the petal-shaped struts 108a of the peripheral flange 104'' circumferentially (as seen at 108b), thereby radially contracting their outer tips from the initial diameter seen at 109. Since the return portions on the struts 108a are already embedded in the surrounding valve annulus tissue, this pulls the tissue towards the valve. This is an example of an endogenous contraction mechanism where the radial contraction of the valve and the surrounding valve annulus is caused by a structure carried by the heart valve or a structure endogenous to the heart valve, rather than requiring an external contraction device.

[0069] Figures 12A - 12C are sequential views showing a further valve stent 110 being discharged from the access tube 112 to illustrate its deployment process. As described above, the pusher 114 may be used to advance the valve stent 110 from within the tube 112, potentially in conjunction with the retraction of the tube as shown in FIG. 12B. Initially, the tubular valve portion 160 remains within the access 112 while the peripheral flange 118 radially expands to a first diameter D1. As it is further discharged from the tube 112, the peripheral flange 118 rounds and then bends back onto the access tube 112, during which process the radially outer tip contracts inwards to a second diameter D2 that is smaller than D1. Similar to the embodiment shown in FIG. 10, the tip of the peripheral flange 118 has return portions embedded in the valve annulus tissue such that this decrease in diameter pulls the tissue inwards around the continuously expanding valve portion 116. Again, this is an endogenous contraction mechanism since the radial force is generated by the change in the shape of the valve stent 110 itself.

[0070] Figures 13A and 13B are a top view and a side elevation view, respectively, of an exemplary expanded artificial heart valve 120 defining a tubular valve portion 122 having a peripheral stent 124. As described elsewhere, the valve 120 may be defined by an expandable valve stent 126 covered with a fabric 127 via a plurality of connecting sutures or stitches 128. FIG. 13A shows a radial arm 130 of the valve stent 126 that extends outwardly from the inlet (proximal) end of the valve portion 122 and defines a peripheral flange 124 together with a fabric skirt 131. One or more tissue anchors 132 may be fixed to each radial arm 130, or the outer ends may be reinforced to receive separately deployed anchors as described above with respect to the anchor 72 shown in FIG. 7. The anchors are shown at the ends of each radial arm, but the anchors may be included along the length of each arm 130 as shown by the anchor 133 of one arm. The anchors 132, 133 may be as described elsewhere in this application. This particular configuration of the heart valve 120 can be seen as a model of a number of embodiments described herein in which the fabric-covered peripheral flange at the proximal end of the fabric-covered valve member provides a structure for contracting tissue in the form of various contracting arms connected by the fabric. Although the flange is illustrated as having a particular shape, it should be understood that the flange can have different shapes and is preferably adaptable to the shape of the surrounding tissue, such as along the upper portion of the valve annulus.

[0071] FIG. 13C is an enlarged portion of FIG. 13A showing details of the peripheral flange 124 and one particular embodiment of the contracting arm 130. Each of the arms 130 comprises a series of elongated diamond-shaped struts 134 that are connected in series and extend from the inner valve portion 122 to each anchor 132. The diamond-shaped struts 134 form extended springs that are biased to a contracted length and held in an extended state. That is, a filament or suture 135 is coiled along and through the diamond-shaped struts 134. The struts 134 are held in tension by the suture 135 such that they expand radially when the heart valve 120 is implanted in the valve annulus using the anchors 132.

[0072] Figure 13D is an enlarged view showing the contraction mechanism of each arm 130. That is, the suture 135 is biodegradable in the body after a certain period. The upper part shows that the suture 135 has dissolved, but part of it remains near the inner valve portion 122. The strut 136 within the portion without the coiled suture 135 is folded so that the diamond-shaped opening is much smaller here due to the elasticity of the strut. The inward radial arrow indicates the overall contraction of the arm 130 pulling the anchor 132 inward, and thus tightening the surrounding valve ring tissue toward the inner valve portion 122. The degradation rate of the suture 135 can be adjusted so that the inward tightening occurs more rapidly, such as within a few days, to more slowly, such as over one or two months, as needed. Again, a slightly different endogenous contraction mechanism is seen where the degradation of the suture 135 and the decrease in the length of the contraction arm 130 generate a radial force.

[0073] FIG. 14 is a top view of the upper peripheral flange of an exemplary valve stent 150 of the present application, defined by a plurality of radial arms 152 having an anchor 154 at their outer ends. As best seen in FIGS. 14A and 14B, the actuation of one radial arm before and after radial contraction involves removing a reinforcing wire or member 156 such that the arm 152 folds. More specifically, the arms 152 are desirably set to a radially contracted shape and maintained in their straight configuration by the reinforcing members 156. The shaped arms 152 form extended springs that are biased to a contracted length and held extended by the reinforcing members 156. The reinforcing member 156 may be a generally flexible wire having sufficient column stiffness to resist folding of the arm 152. The reinforcing member 156 desirably extends along the arm 152 and through holes formed within the anchor 154. Each of the reinforcing members 156 releases and folds each of the arms 152. Of course, the valve is first expanded and the anchor 154 is implanted into tissue before pulling all of the reinforcing members 156 free, at which point the arms 152 and the peripheral flange defined thereby fold radially. This requires the removal of the external element, the reinforcing member 156, but then is a hybrid type of contraction mechanism where radial contraction is produced by a decrease in the length of the radially internal arms 152 of the heart valve. Thus, the hybrid type of contraction mechanism requires an external “trigger” action, but the source of the contraction force is part of or carried by the heart valve and remains implanted. Conversely, if the radial arms 152 are configured to be bioabsorbable, the contraction mechanism is completely internal to the heart valve.

[0074] Another example of an endogenous contraction mechanism of the same type is shown in FIG. 14C, where the reinforcing member 156' is a rod or stick carried by the stent 150 and configured to dissolve after a certain period of time. For example, the reinforcing member 156' may be resorbed within minutes after exposure to blood, which provides sufficient time to firmly embed the tissue anchor before the radial arms 152 are folded and the flange pulls the surrounding tissue inward.

[0075] FIG. 15A is a top view of an exemplary artificial heart valve 160 having a central valve member 162 and a peripheral flange 164 similar to the structure of FIG. 13A. The inner stent frame has a peripheral flange as shown in FIG. 14. That is, the flange 164 has arms 166 that terminate in outer anchors 168. The arms 166 are radially foldable, and the anchors 168 may have a return portion or be fixed to the valve annulus tissue with separate anchors. Optionally, the arms 166 may be folded as shown in FIG. 15B, causing radial contraction of the peripheral flange 164. The anchors 168 pull the surrounding tissue inwardly with respect to the central tubular valve member 162, thus ensuring a tighter fit. As described herein, the arms 166 as shown may be configured to fold in various ways, and similarly, the valve structure covered with the cloth shown in FIG. 15A may be adapted in various ways. The radial arms 166 may provide an endogenous contraction mechanism or may be of a hybrid exogenous / endogenous type if external release wires or sutures are used.

[0076] For a completely endogenous example, FIGS. 16A and 16B are top views of another exemplary valve stent 170 having a central valve portion 172 and a radially contracting peripheral flange having a series of outer petals 174. The anchors or eyelets 176 shown are provided on the outer ends of the petals 174, and the stent structure is covered with fabric as described herein. As shown in FIG. 16A, after expansion at the implantation site, the peripheral flange has a diameter D1 defined by a circle 178 of rotation of the anchor 176. Thereafter, a return portion on the anchor 176 or a separate return portion passing through the anchor 176 is deployed within the valve annulus tissue. FIG. 16B shows the valve stent 170 after radial contraction. The petals 174 are preferably superelastic and expand circumferentially when the central valve portion 172 expands radially. This contracts the outer ends of the petals 174 to a circle of rotation having a diameter D2 and thus pulls the surrounding tissue inward.

[0077] FIGS. 17A and 17B are top views of another exemplary valve stent 180 having a central valve portion 182 and a radially contracting peripheral flange defined by a series of helically arranged arms 184. The stent 180 may also have two or more ventricular anchors or arms 183 positioned to expand around the outside of the valve tip, similar to the ventricular anchor 106' seen in FIG. 10C. The arms 183 curve downwards approximately 180 degrees from the lower or outflow end of the stent body and then bend back upwards. Again, the outer ends of the arms 184 have anchors or eyelets 186 that, when expanded together, define a circle of rotation 188 having a diameter D1. After expanding the valve and fixing the anchor or eyelet 186 to the surrounding tissue, the central valve portion 182 rotates about its own axis to pull the anchor or eyelet 186 inward. That is, as the valve portion 182 rotates the inner ends of the arms 184, they pull the outer ends to a contracted diameter D2. The rotation of the valve portion 182 must be initiated externally, but the radial contraction of the heart valve is generated by an endogenous mechanism. That is, this is a hybrid type of contraction mechanism.

[0078] In a slightly different configuration, FIGS. 18A - 18C are schematic elevation views of an expandable artificial heart valve stent assembly 190 of a bipartite construction, showing some of the steps in its deployment. The assembly 190 includes a cylindrical inner valve member 192 that ultimately expands outwardly to contact the surrounding anchor stent 194. The stent 194 has a plurality of struts 196 in which radial arms 198 are constructed. Although not shown, each of the arms 198 has a return portion at its distal end.

[0079] First, the anchor stent 194 is advanced through an access tube to a deployment position within one of the atrioventricular valves. Expansion of the anchor stent 194 is achieved simultaneously as the radial arms 198 are embedded in the surrounding tissue. The inner valve member 192 is positioned within the anchor stent 194 but remains unexpanded. Thereafter, as shown in FIG. 18B, the anchor stent 194 rotates about its axis such that the struts 196, which are connected at the lower end of the anchor stent, rotate in a helical shape. Since the outer arms 198 are fixed to the tissue, this tends to pull the tissue inwardly. Finally, the inner valve member 192 is expanded as shown in FIG. 18C. Because the anchor stent 194 pulls on the surrounding tissue, the fit of the valve member 192 is improved. Again, this is a hybrid type of constriction mechanism that requires an external input to rotate the anchor stent 194, but ultimately, the radial constriction is generated by an endogenous mechanism constructed within the heart valve.

[0080] Figure 19 is an elevation view of another valve stent 200 having a central valve portion 201 with an upper inlet 202. Radially retractable arms 203, distributed around the upper peripheral portion and through the inlet 202, form a peripheral flange. Only two arms 203 are shown, but the stent 200 may have six or up to eighteen such arms. Each arm 203 is connected to an externally actuated tether 204 configured to pull the arm radially inwardly, and a return portion 206 on the outer end of the arm is embedded within the valve annulus tissue. FIG. 19A illustrates the inward retraction of one of the arms that utilizes a ratchet mechanism 208 to prevent outward movement. The tether 204 may be pulled simultaneously to contract the peripheral flange formed by the convergent arms 203, and thus contract the valve annulus around the central valve portion 201.

[0081] Figures 20A and 20B are perspective views of an outer fabric structure 210 useful for contracting an expandable artificial heart valve in both an initially deployed configuration and a contracted configuration, respectively. The fabric structure 210 comprises a generally tubular outer wall 212 having an upper flexible skirt 214 secured by a suture line 216. Although not shown, the fabric structure 210 may include a superelastic inner skeleton that defines its overall cylindrical shape, is easily folded for delivery, and is later easily refolded while the structure contracts.

[0082] The outer wall 212 has a series of axial or perpendicular struts 220 on its outer side, each of the struts being characterized by one or more outwardly projecting return portions 222. The struts 220 extend to an annular horizontal junction of the wall 212 that forms a circular pocket 224 for a pair of flexible clamping elements 226. The clamping elements 226 pass through a tubular sheath 228 before entering the pocket 224 and spreading around the outer periphery of the wall 212. Thus, pulling the clamping elements 226 from an external location enables contraction of the tubular wall 212, as shown in FIG. 20B.

[0083] FIG. 21 is a perspective view of an assembly of the outer fabric structure 210 of FIG. 20A with an artificial heart valve 230 mounted therein. The heart valve 230 may be similar to those described above, and the flexible valve tip 232 is stitched into a valve stent 234 covered with a tubular fabric. The circular opening inside the flexible skirt 214 may be fixed to the upper edge of the heart valve 230 via a stitch 236.

[0084] FIGS. 22A and 22B are top views of the assembly of FIG. 21 before and after radial contraction of the outer fabric structure 210. More specifically, after delivering the assembly to a position within the target valve annulus, both the fabric structure 210 and the heart valve 230 are expanded. As a result, the returns on the outer wall 212 of the fabric structure 210 engage the valve annulus tissue. As shown in FIG. 22B, before or after closing the surgical site, the tightening element 226 is pulled to reduce the size of the fabric structure 210. This causes the surrounding valve annulus to be pulled inwardly toward the cylindrical heart valve 230, thus improving the contact between them. This is another extrinsic contraction mechanism.

[0085] FIG. 23A is an elevation view of another valve stent 240 having a tubular valve portion 242 and a plurality of radially retractable arms 244 on the outside. Each of the arms 244 is coupled to the lower end of the valve portion 242, cantilevered therefrom, and has a return 246 on its distal end. Referring to the enlargement of FIG. 23B, the retraction mechanism of each of the arms 244 will be described. That is, each arm 244 is fixed to an axial post 248 fixed to the lower end of the valve portion 242, for example, by a brace 250. The collar 252 is arranged to move vertically upward along the post 248 when pulled by an external tether 254. The collar 252 is limited in its upward movement by a series of ratchet teeth 256 provided on the axial post 248.

[0086] Figures 23C and 23D are schematic diagrams showing the operation of the retraction arms 244. Specifically, pulling the external tether 254 upward lifts the collars 252 along each of the posts 248. Since the arms 244 are biased in a gently outward arc, the collars 252 cam-drive each of the arms radially inward. Separation occurs after the expansion of the heart valve within the valve ring such that the return portions 246 on each of the arms 244 engage the surrounding tissue. Under fluoroscopy, the desired amount of contraction of the surrounding tissue may be determined. Again, this enhances the engagement between the surrounding tissue and the artificial heart valve.

[0087] Figure 24 is an elevation view of yet another valve stent 260 having a central tubular valve portion 262 connected to a plurality of outer generally axially oriented arms 264 via a lower U-shaped bend 266. Each of the arms 264 has an outer return portion 268 thereon and is biased slightly inwardly toward the valve portion 262. That is, each of the arms 264 has an inward bias that creates a slight inward angle Θ from vertical. The angle Θ may be between 5 and 20 degrees.

[0088] Figures 25A and 25B are views of one of the arms 264 of the valve stent 260 before and after dissolution of a temporary means for holding the arms outwardly. More specifically, each of the arms 264 initially has a reinforcing tube 270 attached thereto, preferably at the lower U-shaped bend 266. The reinforcing tube 270 has a radius of curvature greater than that of the U-shaped bend 266 to force the arm 264 into a more vertical orientation. Each of the tubes 270 is bioabsorbable after a specific time in the body, after which, as shown in Figure 25B, the arm 264 returns to its initial inward angle. In one embodiment, the reinforcing tube 270 acts after a period of one week to one month in the body, which serves to pull the surrounding tissue inwardly by the engagement of the return portion 268. This is completely endogenous to the heart valve.

[0089] Figures 26A and 26B are views of one of the arms 264 before and after dissolution of another temporary means for holding the arm outwardly. In this version, a number of seated reinforcement plugs 272 are initially positioned within recesses 274 on the inside of the arm 264. The reinforcement plugs 272 are also bioabsorbable such that after dissolution, the arm 264 is biased inwardly into its relaxed orientation again. Those skilled in the art will understand that there are various ways to create such a delayed inward movement of the arm 264.

[0090] Figure 27 is an elevation view of yet another valve stent 280 having an inner tubular valve portion 282 connected to a plurality of axially oriented outer arms 284 by a lower U-shaped bend 286. Each of the arms 284 has an active tissue anchor 288 at its distal end. An "active" tissue anchor in this sense means an anchor that can be operated to grasp tissue as a return portion type of anchor that is simply pressed against and engaged with the tissue.

[0091] Figure 27A is an enlarged view of one of the active tissue anchors 288, which mainly includes a generally rectangular frame 290 having opposing projecting levers 292 on each end. The rectangular frame 290 defines a central opening to the projections of a plurality of teeth 294. The tissue anchor 288 may be formed of a superelastic material and has a flat relaxed configuration as shown in the top view of Figure 28C.

[0092] The orientation of the clamping anchor 288 can be different from that of the hinge / bending levers 292 on the top and bottom, such that the teeth 294 are oriented inwardly at right angles to the hinge / bending levers 292 from the left and right sides, or instead of the left or right sides, and the teeth 294 are also oriented inwardly from the top and bottom. It should be noted that the position where either of the levers 292 is attached to the frame can be relocated to a low-strain region so as not to interfere with the hinge / bending side of the anchor 288. That is, instead of positioning the lower hinge / bending lever 292 at the connection to the U-shaped bend 286, the anchor 288 can be horizontally oriented so as to separate the bending of the lever from the bending of the U-shaped bend 286.

[0093] Figures 28A - 28C are top views of one of the active tissue anchors 288 showing several deployment stages. First, using the external tension member 296, the tissue anchor 288 is held in a tensioned configuration as seen in Figure 28A. That is, the tension member 296 comprises a flexible filament or suture passing through each opening of the lever 292 that projects outwardly. By pulling on the lever 292 through the use of the outer sheath 298, the frame 290 is bent back relative to itself such that the teeth 294 project radially outwardly. When the heart valve is introduced and expanded within the valve annulus, the outwardly projecting teeth 294 pierce the surrounding tissue. Thereafter, the tension member 296 is relaxed as shown in Figure 28B, which allows the two springs of the frame 292 to move rearward toward their flat and relaxed configuration, which in turn pivots the teeth 294 inwardly toward each other. By this action, the tissue is firmly grasped between the jaws, like a bear trap.

[0094] The active tissue anchor 288 can be utilized, for example, instead of a snare, with any of the various valve stent embodiments described herein. After gripping the tissue with the active tissue anchor 288, a clamping mechanism is deployed to pull the tissue inwardly toward the central valve portion 282. The clamping mechanism can be any of the content described herein.

[0095] This application presents a number of expandable artificial heart valves configured to contract a target valve annulus during or after implantation to enhance engagement therewith. A number of embodiments contemplate manipulating components of the heart valve from outside the body when the valve is implanted. This technique involves snaking sutures or other such control elements from the target valve annulus through a sealed incision to the outside of the body. Similarly, guide sutures pre-attached around the target valve annulus may be used to control and / or direct the heart valve as it is advanced toward the valve annulus. An additional technique more commonly used with surgically implanted heart valves that are implanted using open heart surgery involves pre-attaching tissue anchors around the valve annulus and then lowering an expandable heart valve under an array of sutures connected to the tissue anchors. By placing the tissue anchors around the outside of the valve annulus and then advancing a smaller sized heart valve under the array of sutures, the valve annulus can be contracted simultaneously with the delivery of the heart valve without the need for further manipulation.

[0096] For example, FIG. 29 is a partial cross-sectional view through the left side of the heart showing a mitral valve and valve annulus having tissue anchors 320 pre-attached therein. An expanded artificial heart valve 322 is shown with an array of guide sutures 324 being advanced downward to the valve annulus. The heart valve 322 is shown to have a configuration generally similar to some of those described above where an inner generally tubular valve portion 330 and a peripheral flange 332 extend radially outwardly from its proximal end. As described above, it is desirable for the valve portion 330 and the peripheral flange 332 to be formed by a single expandable superelastic stent 334 covered with fabric 336. Flexible valve leaflets 338 are supported within the valve portion 330 to allow one-way blood flow through the valve 322 (downward with respect to this mitral valve).

[0097] Although not shown, the heart valve 322 is implanted onto the beating heart and thus is initially delivered in a folded configuration to a position adjacent to the target valve annulus via an access tube or sheath. For example, as shown in FIG. 29, the heart valve 322 is delivered folded through a tube into the left atrium above the mitral valve annulus and then discharged from the tube and expanded to its larger shape. Similarly, the tricuspid heart valve 322 is delivered to and expanded in the right atrium above the tricuspid valve annulus. The guide suture 324 passes through the peripheral flange 332 of the valve 322 and desirably is pre-attached and delivered with the valve and has a free end remaining outside the body for manipulation.

[0098] The tissue anchors 320 can take various forms, including those having a corkscrew-type lower anchor portion attached to an upper head. Each anchor 320 features a small ring or shackle 340 through which the guide suture 324 loops. That is, each of the tissue anchors 320 is remotely implanted with the loop of the guide suture 324 either pre-attached or later passed through the shackle 340. The tissue anchors 320 are spaced apart around the valve annulus so as to define an outer perimeter larger than the outer perimeter of the peripheral flange 332 of the heart valve 322. As shown in FIG. 30, when the heart valve 322 advances under the array of sutures 324, the difference in diameter between the peripheral flange 332 and the outer perimeter defined by the tissue anchors 320 causes an inward contraction of the valve annulus. In FIG. 29, only the guide sutures 324 of four joined tissue anchors 320 are shown equally spaced around the valve annulus 90 degrees apart. However, a more uniform contraction of the valve annulus can be achieved using eight or more anchors 320 and sutures 324, most preferably twelve spaced 30 degrees circumferentially apart.

[0099] The length of each pair of guide sutures 324 passes through the peripheral flange 332 before looping through one of the shackles 340 of the tissue anchor 320. The guide suture 324 can pass through a suture clip 342 attached to the peripheral flange 332, as will be described in more detail below. Alternatively, the guide suture 324 may pass through a reinforced area of the peripheral flange 332 and may then be used to secure the peripheral flange to each tissue anchor 320 by tying a knot or the like. For example, the heart valve 322 may be advanced downward until the peripheral flange 332 contacts the target annulus and the tissue anchor 320 is pulled inward and beneath the flange. Then, as is known, each pair of lengths of the guide suture 324 can be secured above the peripheral flange 332 using a knot pusher. However, for ease of the implantation process, the suture clip 342 is preferably incorporated into the peripheral flange 332.

[0100] Figure 30 shows the artificial heart valve 322 advancing substantially downward to the annulus and pulling the pre-attached tissue anchor 320 radially inward. At a particular point, the position of the heart valve 322 within the annulus allows the valve leaflets 338 to begin operation and take over the task of regulating blood flow through the annulus from the native leaflets. At this point, the surgeon can evaluate the effectiveness of the newly implanted heart valve using fluoroscopy, echocardiography, or other such visualization techniques. The degree of contraction of the surrounding annulus can vary such that the tissue anchor 320 may remain somewhat separated from the peripheral flange 332 or may be fully tightened against the peripheral flange for maximum contraction, which can also be seen using fluoroscopy or the like. For example, the tissue anchor 320 may be radiopaque, and radiopaque elements may also be sewn into the peripheral flange 332 to compare relative sizes. As described above, the suture clip 342 can be used to secure the guide suture 324 at various stages of annulus contraction. However, as will be described below, the suture clip 342 can also be used to connect directly to the tissue anchor 320.

[0101] The system described in connection with FIGS. 29 - 30 can operate as either an exogenous or endogenous regarding the constriction mechanism. That is, if the guide suture 324 remains connected after the valve has begun to function and while the surgeon is evaluating the effectiveness of the valve implant, any further tension or slack in the suture 324 is clearly an external actuator and the system is exogenous. However, if the valve is simply lowered into place and the guide suture 324 is cut and tied off, the resulting valve annulus constriction is carried out by the native heart valve acting on or using a structure coupled to the native heart valve.

[0102] FIGS. 31A and 31B show the engagement between a flat suture clip 342 on the peripheral flange 332 of the heart valve 322 and one of the tissue anchors 320. Pulling on the guide suture 324 ultimately pulls the shackle 340 on the tissue anchor 320 upward through the opening 344 in the suture clip 342. Next, one strand of each guide suture 324 can be simply disengaged from engagement with the shackle 340 of the anchor 320 and removed from the body.

[0103] The clip 342 can be formed of a superelastic or otherwise elastic metallic material such that the opening 344 bends upward to allow one - way passage of the guide suture 324 and the shackle 340, but elastically closes to clamp onto either the guide suture 324 or the shackle 340 to prevent back - movement. A particular suture clip 342 is disclosed in U.S. Patent No. 9,592,048, issued to Edwards Lifesciences, Inc., of Irvine, California, the content of which is hereby incorporated by reference herein. However, various suture clips are known and thus the clip 342 can be configured in different forms.

[0104] Yet another technique for shrinking the annulus after implantation involves the use of a balloon to pre-expand the artificial heart valve before securing it to the annulus, followed by removal of the balloon to allow the valve to contract through its inherent elasticity, thereby pulling the annulus inward. For example, FIG. 32A shows a valve stent 420 similar to the stent 100 of FIG. 10A held in an expanded state by a delivery balloon 422. Since the overall implantation procedure is maintained through a vasculature having a heartbeat, the expansion of balloon 422 occurs only when the valve having valve stent 420 is adjacent to the target annulus, in this case the mitral annulus MA. Valve stent 420 has a tubular valve portion 424 and an upper peripheral flange 426. The assembled heart valve may be formed by a single expandable superelastic stent 420 covered with fabric, and the flexible valve tip is supported within valve portion 424 to allow one-way blood flow through the valve (downward for this mitral valve).

[0105] Balloon 422 expands the valve portion to a diameter approximately the same as the size of the native valve, which may be expanded according to a particular configuration. The surgeon advances the valve having valve stent 420 over guidewire 428 into the annulus such that the tubular valve portion 424 fits closely within the annulus and the peripheral flange 426 engages the atrial side of the annulus. Peripheral flange 426 may have tissue anchors such as return portion 430 as shown, which penetrate the atrial side of the annulus. Alternatively, separate tissue anchors may be deployed around peripheral flange 426 when seated against the annulus.

[0106] Thereafter, as shown in FIG. 32B, balloon 422 contracts and is removed from the implant site. As a result, valve stent 420 can assume a smaller, relaxed shape that pulls the valve annulus inwardly due to anchors 430 on peripheral flange 426. Also, as seen in FIG. 10D and as described below with respect to FIGS. 33A-33B, ventricular anchors such as anchor 106' may also be part of valve stent 420, and although a secondary positioning step is required, it is understood that pulling the valve leaflets inwardly is possible. Balloon 442 first expands and is then used to enable contraction of the valve, but the contraction of the valve annulus occurs only by the valve or by a structure carried by or connected to the valve, and thus the contraction mechanism is intrinsic to the valve.

[0107] FIG. 33A shows another type of heart valve stent 440, similar to stent 100' of FIG. 10C, held in an expanded state by delivery balloon 442 and advancing toward mitral valve annulus MA. Since the overall implantation procedure is maintained through a vasculature having a heartbeat, the expansion of balloon 442 occurs only when the heart valve having stent 440 is adjacent to the target annulus.

[0108] Valve stent 440 has a tubular valve portion 444 without an upper peripheral flange, but has a ventricular anchor 446 that curves downwardly about 180 degrees from the lower end of stent body 444 and then bends back upward. Ventricular anchor 446 can be configured to contract after implantation, such as by providing a clamping portion around its periphery, as in the embodiments of FIGS. 7-8. Balloon 442 expands the valve portion to approximately the same diameter as the size of the native valve, which can be expanded according to a particular configuration. The surgeon advances the valve having valve stent 440 within the valve annulus over guidewire 448 such that tubular valve portion 444 fits closely within the annulus and ventricular anchor 446 is deployed outside the mitral valve leaflets and is configured to contract inwardly, as shown.

[0109] Thereafter, as shown in FIG. 33B, the balloon 442 contracts and is removed from the implant site. This allows the valve stent 440 to assume a smaller relaxed shape, which, as indicated by the arrow showing movement, is pulled inwardly on the valve annulus by the ventricular anchors 446 around the valve leaflets. Again, this is an endogenous contraction mechanism.

[0110] FIG. 34 is a perspective view of yet another heart valve stent 460 having a tubular valve portion 462 shown as being formed by diamond pattern struts for contraction / expansion. The struts of the valve portion 462 converge at the inflow (upper) end of the junction 464 from which radial arms 466 tipped with fixation returns 468 extend. The arms 466 radiate outwardly in a circular pattern to form an upper peripheral flange and, in the illustrated embodiment, there are six arms, although there may be slightly more or less than four and six. In the assembled valve, the arms 466 are covered with a circular panel of fabric as seen at 131 in FIG. 13A.

[0111] FIG. 35 is a separated view of one segment of the valve stent 460 having the fixed arms 466. The struts 470 of the valve portion 462 are shown in an elongated radially contracted delivery state and the fixed arms 466 extend in alignment linearly. As described, the superelastic stent 460 is held in a linearly contracted state during transvascular delivery through an access tube or catheter. When the valve reaches the implant site, the surrounding restraint is removed such that the valve portion 462 expands radially within the tube and the fixed arms 466 bend radially outwardly relative to the generally perpendicular orientation seen in FIG. 34.

[0112] Figures 36A - 36C illustrate the sequence for delivering and implanting a heart valve having the stent 460 of FIG. 34 through the tubular sheath 472. The sheath 472 may have a tapered nose cone 474 that is disengagable from the proximal section of the sheath, as shown, and the sheath is typically flexible to follow a guide wire 476 pre - positioned at the implant site. A suture or tether 478 passing through the sheath 472 from outside the body may be attached to the proximal end of the stent 460, in this case the fixation loop 468.

[0113] First, in FIG. 36A, the heart valve is collapsed and held within the tubular sheath 472, at least partially within the tapered nose cone 474. Advancing the sheath 472 over the guide wire 476 brings the nose cone 474 into the target valve annulus.

[0114] FIG. 36B shows the removal of the nose cone 474 from the larger sheath 472 after passing through the target valve annulus and further advancement. This first releases the restraint on the fixation arms 466, allowing them to bend perpendicular to the tubular valve portion 462. As shown, the fixation loop 468 is configured to be embedded in the surrounding valve annulus tissue and may be assisted by further distal movement of the nose cone 474 using an inner shaft (not shown) of the delivery system. As shown in FIG. 34, the arms 466 have a serpentine configuration that may initially extend linearly but contract upon release from the delivery sheath 472. This pulls the surrounding valve annulus inwardly, as indicated by the radial arrows. Of course, any of the various contraction mechanisms described herein may be utilized for the arms 466, such as, for example, the embodiments described in connection with FIGS. 13 - 16 or other embodiments described herein.

[0115] FIG. 36C shows a stent 460 in which a tubular valve portion 462 radially expanded within the self-valve tip and a proximal flange defined by radial arms 466 fixed within the surrounding tissue are fully released. Radial contraction from the arms 466 pulls the valve ring inwardly against the valve portion 462, thus improving fixation around the valve and reducing paravalvular leakage around the valve. Subsequent suture 478 is shown released or loosened, which induces better fixation of the return portion 468 described below.

[0116] The use of an externally controlled suture 478 in the active return portion 468 means that this configuration is a hybrid type of contraction mechanism, although the radial contraction force is endogenous and generated only by the arms 466. If instead the return portion 488 is passive and simply embedded within the tissue or automatically activated upon implantation, the entire contraction mechanism is considered endogenous.

[0117] Figures 37A and 37B illustrate one configuration of the retention bend portion 468 of the stent 460 activated by the suture 478 under tension. Each retention bend portion 468 includes a flat plate-like member 480 oriented to be placed against tissue surrounding the target valve. The flexible portion 482 bends from the plane of the plate-like member 480 from a similar cutout portion 484. The flexible portion 482 includes a thin bent finger 486 that is cantilevered from within the cutout portion 484 and terminates at a return or fork-shaped end 488. In this embodiment, the suture 478 passes through an outer through-hole of the plate-like member 480 and loops through a hole formed within the flexible portion 482. By maintaining tension on the suture 478, the flexible portion 482 bends from the cutout portion 484. When the tension on the suture 478 is released, the flexible portion 482 is allowed to bend back into the cutout portion 484 as shown in FIG. 37B. The tension may be released by simply enabling one strand of the looped suture 478 to be released, such that the entire suture can then be removed from the stent 460 by pulling on the other strand. As the flexible portion 482 bends back to its relaxed position, the return or fork-shaped end 488 is embedded deeper into the annulus tissue and thus secures the valve stent 460 better.

[0118] Figures 38 and 39 illustrate two alternative configurations of the fixing loop portion of the stent of FIG. 34. In FIG. 38, the tension suture 478 is replaced by a rigid strut 490 having a forked end that engages the flexible portion 482. For example, the forked end may be connected to a bent finger 486. In this embodiment, the flexible portion 482 is maintained in its bent position by the pressing force from the rigid strut 490, but can bend back towards the cutout portion 484 when the strut 490 is removed. FIG. 39 shows a block of bioabsorbable material 492 that fills the cutout portion 484, which forces the flexible portion 482 to remain bent. After a period of time of the implant in the body, perhaps 15 minutes, the bioabsorbable material 492 dissolves, thereby allowing the flexible portion 482 to return to its relaxed shape within the cutout portion 484. The embodiment of FIG. 39 within the stent 460 is an example of a completely endogenous contraction mechanism.

[0119] FIG. 40 is a perspective view of a heart valve stent 500 that is similar to that of FIG. 34, but has a fixing loop portion only on a part of the radially extending arm. Again, the stent 500 has a tubular valve portion 502 that defines a central axis and in which a valve member (not shown) having a valve tip is attached. A plurality of arms 504 extend radially outward from the inflow end of the valve portion 502 when the stent is expanded. Six arms 504 are shown, but only every other arm has a fixing loop portion 506 on its outer end. As described above, there may be as few as four and more than six arms 504, and the fixing loop portions 506 may be distributed differently, for example, every third arm. However, it is preferred that the fixing loop portions 506 are evenly distributed circumferentially around the peripheral flange defined by the arms 504.

[0120] Figure 40A is an enlarged view of a type of fixing return part 510 that is different from that shown in FIG. 34 and other places. The fixing return part 510 has a bear's claw type configuration similar to that described above with respect to FIGS. 27-28. The return part 510 includes a generally rectangular frame member 512 having an opening in a number of inwardly directed teeth 514. Levers 516 protruding on opposite sides of both ends of the frame 512 can be bent towards each other using a tension suturing thread 520 to bend the frame 512 and open the jaws defined by the teeth 514. When the tension of the suturing thread 520 is released, as described above, the jaws bend again and close. Also in this case, this is a hybrid type of contraction mechanism where the external suturing thread 520 is used to activate the return part 510, but the contraction force is intrinsic to the valve structure.

[0121] Figure 41 is a perspective view of yet another heart valve stent 530 that is similar to that of FIG. 34 but has radially extending arms of different lengths. The tubular valve portion 532 connects at its upper end to a plurality of radially extending arms, a long arm 534 extending to the outer periphery 536, and a short arm 538 extending to a smaller outer periphery 540. Each of the arms 534, 538 terminates at a fixing return part 542, but as described above, part of the arm may not have a fixing return part. Also in this case, the number of arms may vary, and the pattern of short and long arms may also vary from the alternating pattern shown.

[0122] Figure 41A is an enlarged view of another type of fixing return part 550. A generally circular or elliptical frame 552 defines an opening 554 in which several teeth 558 extend. Oppositely protruding levers 556 provide through holes for a tension suturing thread 560. By pulling the suturing thread 560, the lever 526 bends and opens the frame 552 so that the teeth 558 protrude in a common direction. When the tension of the suturing thread 560 is released, the teeth 558 come together again.

[0123] The various structures disclosed herein provide significant potential benefits. For example, rather than pushing outward on the annulus (as opposed to an anchor), shrinking the valve annulus will result in better treatment of the underlying disease by remodeling the heart to its original shape. Further, pulling on the valve annulus reduces the likelihood of the frame contacting the ventricular wall because the final shrunken diameter is smaller. A tighter seal is also created by the shrinkage, which naturally reduces paravalvular (PV) leakage. Additionally, positively gripping or fixing the inner valve frame to the valve annulus may eliminate the need for an outer frame as used in some current solutions. Finally, shrinking the valve annulus around the valve means a generally smaller valve than one that expands outward, which results in a reduced delivery profile and provides certain advantages in terms of less traumatic delivery.

[0124] The foregoing is a complete description of the preferred embodiments of the invention, but various alternatives, modifications, and equivalents may be used. Further, it will be apparent that certain other modifications may be made within the scope of the appended claims.

Claims

1. An artificial heart valve assembly for replacing the patient's own mitral valve or tricuspid valve, wherein the artificial heart valve assembly is A self-expandable stent having a body with an inlet end portion and an outlet end portion, wherein the stent is made of a shape memory material and has an annular flange extending radially outward from the inlet end portion, A plurality of anchors configured to engage with surrounding tissue and positioned along the surface of the annular flange, wherein the annular flange is adapted to radially contract the valve ring of the self-valve when deployed, A valve portion positioned within the passage of the main body, wherein the valve portion comprises a plurality of valve leaflets made from the pericardium, and the valve portion allows blood to flow through the passage in one direction in order to replace the function of the self-valve, An artificial heart valve assembly equipped with the following features.

2. The artificial heart valve assembly according to claim 1, wherein the annular flange is coupled to the main body and is configured to transition from a larger diameter to a smaller diameter in order to contract the valve ring of the own valve.

3. The artificial heart valve assembly according to claim 2, wherein the annular flange comprises a plurality of radial arms, each arm configured to reduce in length to contract the annulus of the own valve.

4. The artificial heart valve assembly according to claim 3, wherein each radial arm includes a bioabsorbable material that is reabsorbed in the body to initially maintain the arm in an elongated state and then transition to a shortened state.

5. The artificial heart valve assembly according to claim 1, wherein the anchor includes a return portion.

6. The artificial heart valve assembly according to claim 1, wherein the anchor includes a helical screw.

7. The artificial heart valve assembly according to claim 1, wherein a tightening mechanism connects each of the anchors, and the tightening mechanism is adapted to pull the anchors radially inward to contract the valve ring of the own valve.

8. The artificial heart valve assembly according to claim 1, wherein the anchor is not incorporated into the heart valve and is deployed separately from the heart valve.

9. The artificial heart valve assembly according to Claim 1, wherein the annular flange comprises a plurality of helically arranged arms having tips that together define a circle of rotation having a diameter D 1 when expanded, and the rotation of the valve portion about its axis pulls the arms inward such that the tips together define a diameter D 2 when contracted.

10. The artificial heart valve assembly according to claim 1, further comprising at least two ventricular anchors extending from the outlet end portion of the main body.

11. The artificial heart valve assembly according to claim 10, wherein each of the ventricular anchors is shaped to capture the own valve leaflets between the ventricular anchor and the body of the stent.

12. The artificial heart valve assembly according to claim 10, wherein the ventricular anchor has an outer surface for engaging with surrounding tissue.

13. An artificial heart valve assembly for replacing the patient's own mitral valve or tricuspid valve, wherein the artificial heart valve assembly is A self-expandable valve stent made from a shape memory material and covered with cloth, wherein the valve stent comprises a tubular valve portion having an inlet end portion and an outlet end portion, and a peripheral flange formed by an array of supports or arms extending radially outward from the inlet end portion and connected to the inlet end portion when expanded, wherein the array comprises an intrinsic radial contraction mechanism and tissue engagement members, A valve portion positioned within the passage of the main body, wherein the valve portion comprises a plurality of valve leaflets made from the pericardium, and the valve portion allows blood to flow through the passage in one direction in order to replace the function of the self-valve, An artificial heart valve assembly wherein the tissue engagement member is fixed to the tissue surrounding the valve annulus, and is adapted to contract radially during deployment to contract the valve annulus of the own valve.

14. The artificial heart valve assembly according to claim 13, wherein the array includes a petal-shaped support connected to the valve portion such that the expansion of the valve portion causes the support to contract radially.

15. The artificial heart valve assembly according to claim 13, wherein the array comprises a plurality of radially extending arms, each of which has a retraction mechanism for reducing the length of the incorporated arm.

16. The artificial heart valve assembly according to claim 15, wherein the contraction mechanism includes an extension structure that is biased to a contracted length and held in an extended state by bioabsorbable sutures.

17. The artificial heart valve assembly according to claim 15, wherein the contraction mechanism includes an extension structure that is biased to a contracted length and held in an extended state by a reinforcing wire.

18. The artificial heart valve assembly according to claim 15, wherein only a portion of the radially extending arm has a tissue engagement member thereon.

19. The artificial heart valve assembly according to claim 15, wherein the radially extending arms have different lengths.

20. When the array is expanded, its diameter D １ The valve portion comprises a plurality of helically arranged arms, each having a tip that jointly defines a circle of rotation having a diameter D, and the rotation of the valve portion around its axis is such that the tips are contracted together to form a diameter D ２ The artificial heart valve assembly according to claim 13, wherein the arm is pulled inward to define the area.

21. The artificial heart valve assembly according to claim 13, wherein the valve stent comprises an outer anchor stent and an inner valve stent, and the array comprises a plurality of radial arms extending from a strut connected only to the lower end of the anchor stent, wherein rotation of the anchor stent following the fixing of a return portion at the tip of the radial arm causes the strut to rotate in a helical shape, pulling the tip inward, and then the inner valve stent expands within the outer anchor stent.

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