US-12616575-B2 - Leaflet extension for cardiac valve leaflet

US12616575B2US 12616575 B2US12616575 B2US 12616575B2US-12616575-B2

Abstract

Leaflet extension devices for cardiac valve leaflets and methods of treating cardiac valve leaflets. Several embodiments are devices for resolving regurgitation in a cardiac valve comprising an expandable member and a cover. The expandable member has a stabilizing portion, a fixation member in opposition to the stabilizing portion, and a coaptation portion between the stabilizing portion and the expandable member. The stabilizing portion and the fixation member clamps the first native leaflet between the stabilizing portion and the fixation member. The coaptation portion projects from the stabilizing portion and the fixation member inwardly with respect to a first native leaflet of a cardiac valve such that the coaptation portion functionally extends the first native leaflet. The cover is attached to at least the coaptation portion of the expandable member.

Inventors

Hanson S. Gifford, III
Matthew McLean
Gaurav Krishnamurthy

Assignees

MEDTRONIC, INC.

Dates

Publication Date: 20260505
Application Date: 20181114

Claims (20)

1 . A device for resolving regurgitation in a cardiac valve, comprising: an expandable member having a stabilizing portion, a fixation member in opposition to the stabilizing portion, and a coaptation portion between the stabilizing portion and the fixation member, wherein the stabilizing portion and the coaptation portion comprise a plurality of interconnected struts and together define a hollow volume, wherein the stabilizing portion and the fixation member are configured to clamp a first native leaflet of the cardiac valve between the stabilizing portion and the fixation member, and wherein the coaptation portion is configured to project from the stabilizing portion and the fixation member inwardly with respect to the first native leaflet such that the coaptation portion is positioned to at least partially coapt with a second native leaflet of the cardiac valve; and a cover attached to at least the coaptation portion of the expandable member.
2 . The device of claim 1 wherein at least one of the stabilizing portion and the fixation member are formed of a super-elastic material configured to resume a native shape in the absence of a countervailing force, and wherein the stabilizing portion and the fixation member are configured to clamp the first native leaflet solely by a compressive force exerted between the stabilizing portion and the fixation member.
3 . The device of claim 1 , wherein the stabilizing portion comprises at least two primary struts, and each of the at least two primary struts has a first end and a second end, the first ends being commonly joined, and the second ends being splayed apart.
4 . The device of claim 3 , wherein the coaptation portion is configured to project inwardly with respect to a native annulus of the cardiac valve beyond a free end of the first native leaflet, and the first end of the stabilizing portion is configured to extend beyond a fixed end of the first native leaflet and superiorly along an atrial wall of the cardiac valve.
5 . The device of claim 1 , wherein the stabilizing portion and the fixation member clamp the first native leaflet without piercing into the first native leaflet such that the device can be repositioned and/or removed.
6 . The device of claim 1 , wherein the stabilizing portion comprises a lattice of the plurality of interconnected struts and openings interposed between adjacent ones of the plurality of interconnected struts.
7 . The device of claim 1 , wherein the fixation member comprises at least one primary strut, and the at least one primary strut is attached to the stabilizing portion.
8 . The device of claim 1 , wherein the fixation member comprises at least two primary struts spaced apart from one another.
9 . The device of claim 8 , wherein each of the at least two primary struts has a first end and a second end, the first ends are commonly joined, and the second ends are splayed apart.
10 . The device of claim 1 , wherein the fixation member comprises a plurality of primary struts and cross-struts between the plurality of primary struts and connected to the plurality of primary struts.
11 . The device of claim 1 , wherein at least one of the fixation member and the stabilizing portion further comprises frictional engagement elements.
12 . The device of claim 1 , wherein the cover encloses the hollow volume.
13 . The device of claim 12 , wherein the coaptation portion projects inwardly with respect to a native annulus beyond a free end of the first native leaflet and a first end of the stabilizing portion extends superiorly beyond a fixed end of the first native leaflet and along an atrial wall of the cardiac valve.
14 . The device of claim 1 wherein the coaptation portion is integrally formed with at least one of the stabilizing portion and the fixation member.
15 . The device of claim 1 , wherein the coaptation portion is orthogonal to each of the stabilizing portion and the fixation member, and the coaptation portion has a concave surface configured to face the first native leaflet and a convex surface configured to face the second native leaflet.
16 . The device of claim 1 , further comprising an atrial stabilizer attached to a first end of the stabilizing portion, the atrial stabilizer having a polygonal shape and includes a frictional engagement element and/or a second cover.
17 . The device of claim 1 , further comprising an atrial stabilizer attached to a first end of the stabilizing portion, the atrial stabilizer having a polygonal shape.
18 . The device of claim 1 , wherein the fixation member includes at least one strut integrally formed with the coaptation portion.
19 . The device of claim 1 , wherein the plurality of interconnected struts define a frame at the coaptation portion.
20 . The device of claim 1 wherein the coaptation portion is configured to project from the stabilizing portion and the fixation member inwardly with respect to the first native leaflet such that the coaptation portion is positioned to at least partially coapt with a plurality of leaflets of the cardiac valve including the second native leaflet.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a 35 U.S.C. 371 U.S. National Phase application of International Application No. PCT/US2018/061126, filed Nov. 14, 2018, which is incorporated herein by reference in its entirety. The present technology relates generally to implants for repairing a regurgitant or incompetent cardiac valve and for methods of implanting the same. The present technology is particularly useful for repairing a regurgitant mitral valve. BACKGROUND Conditions affecting the proper functioning of the mitral valve include, for example, mitral valve regurgitation, mitral valve prolapse and mitral valve stenosis. Mitral valve regurgitation is a disorder of the heart in which the leaflets of the mitral valve fail to coapt into apposition at peak contraction pressures, resulting in abnormal leaking of blood from the left ventricle into the left atrium. There are several structural factors that may affect the proper closure of the mitral valve leaflets. For example, many patients suffering from heart disease have an enlarged mitral annulus caused by dilation of heart muscle. Enlargement of the mitral annulus makes it difficult for the leaflets to coapt during systole. A stretch or tear in the chordae tendineae, the tendons connecting the papillary muscles to the inferior side of the mitral valve leaflets, may also affect proper closure of the mitral annulus. A ruptured chordae tendineae, for example, may cause a valve leaflet to prolapse into the left atrium due to inadequate tension on the leaflet. Abnormal backflow can also occur when the functioning of the papillary muscles is compromised, for example, due to ischemia. As the left ventricle contracts during systole, the affected papillary muscles do not contract sufficiently to effect proper closure. Mitral valve prolapse, or when the mitral leaflets bulge abnormally up in to the left atrium, causes irregular behavior of the mitral valve and may also lead to mitral valve regurgitation. Normal functioning of the mitral valve may also be affected by mitral valve stenosis, or a narrowing of the mitral valve orifice, which causes impedance of filling of the left ventricle in diastole. Mitral valve regurgitation is often treated using diuretics and/or vasodilators to reduce the amount of blood flowing back into the left atrium. Other treatment methods, such as surgical approaches (open and intravascular), have also been used for either the repair or replacement of the valve. For example, typical repair approaches have involved cinching or resecting portions of the dilated annulus. Cinching of the annulus has been accomplished by the implantation of annular or peri-annular rings which are generally secured to the annulus or surrounding tissue. Other repair procedures have also involved suturing or clipping of the valve leaflets into partial apposition with one another. Alternatively, more invasive procedures have involved the replacement of the entire valve itself where mechanical valves or biological tissue are implanted into the heart in place of the mitral valve. These invasive procedures are conventionally done through large open thoracotomies and are thus very painful, have significant morbidity, and require long recovery periods. However, with many repair and replacement procedures, the durability of the devices or improper sizing of annuloplasty rings or replacement valves may result in additional problems for the patient. Moreover, many of the repair procedures are highly dependent upon the skill of the cardiac surgeon where poorly or inaccurately placed sutures may affect the success of procedures. Compared to other cardiac valves, portions of the mitral valve annulus have limited radial support from surrounding tissue and the mitral valve has an irregular, unpredictable shape. For example, the inner wall of the mitral valve is bound by only a thin vessel wall separating the mitral valve annulus from the inferior portion of the aortic outflow tract. As a result, significant radial forces on the mitral annulus could lead to collapse of the inferior portion of the aortic tract with potentially fatal consequences. The chordae tendineae of the left ventricle are often an obstacle in deploying a mitral valve repair device. The maze of chordae in the left ventricle makes navigating and positioning a deployment catheter that much more difficult in mitral valve repair. Given the difficulties associated with current procedures, there remains the need for simple, effective, and less invasive devices and methods for treating dysfunctional heart valves. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a native mitral valve; FIGS. 2A-2C illustrate a leaflet extension device configured to be attached to a native cardiac leaflet according to the present technology; FIG. 3 is a side view of a frame-type expandable member according to the present technology; FIG. 4 illustrates a leaflet extension device implanted in a mitral