WO2008089044A2

WO2008089044A2 - Mitral valve repair device

Info

Publication number: WO2008089044A2
Application number: PCT/US2008/050771
Authority: WO
Inventors: Wilmo C. Orejola
Original assignee: The Trustees Of Columbia University
Priority date: 2007-01-12
Filing date: 2008-01-10
Publication date: 2008-07-24
Also published as: WO2008089044A3

Abstract

A mitral valve repair device includes substantially concentric outer and inner loop-like coils held in spaced relationship by radially directed spoke- like members. The outer coil is affixed to a selected circumferential area of the anterior and posterior annulus of the mitral valve, in the left atrium to locate the repair device in desired position against the mitral valve leaflets and thereby enable the repair device to eliminate mitral regurgitation due to valve flailing and/or dilation of the annulus.

Description

MITRAL VALVE REPAIR DEVICE

FIELD OF THE INVENTION

This invention relates to devices and methods for repairing a dysfunctional mitral valve without removing or replacing any constituents of the mitral valve. More specifically the invention relates to a support device positionable against the valve leaflets to reduce or eliminate valve flailing and improve coaptation of the valve leaflets thereby correcting regurgitation without unduly restricting the normal flow of blood through the valve orifice from the left atrium to the left ventricle.

BACKGROUND OF THE INVENTION

One type of abnormal functioning of the mitral valve, known as mitral regurgitation, results in backward flow or reflux of blood from the left ventricle into the left atrium. Mitral regurgitation is usually caused by flailing of the valve leaflets during systole or as a result of annular dilation of the left ventricle during systole, or a combination of valve flailing and annular dilation.

In a normal heart, during diastole or relaxation of the heart muscles, the mitral valve opens downwardly from the left atrium to the left ventricle to allow blood to flow downwardly from the left atrium into the left ventricle. When the left ventricle contracts, during systole or contraction of the heart muscles, the mitral valve snaps shut preventing any blood from flowing back up from the left ventricle into the left atrium.

In order for the heart to function efficiently, the mitral valve must be in a leak tight closed position during systole. Leakage of blood back through the mitral valve from the left ventricle into the left atrium during systole will cause the left atrium to enlarge because it must accommodate an abnormally large volume of blood. The increased blood volume from the left atrium will be forced into the lungs resulting in shortness of breath and, depending upon the extent of leakage or mitral regurgitation, congestive heart failure can result.

Mitral regurgitation thus occurs when there is incomplete closing and upward flailing of the valve leaflets during systole. Normally the valve leaflets move in an upward direction following diastole to a closed condition during systole. However in a dysfunctional mitral valve the valve leaflets continue to move in an upward direction beyond their normally closed position into an abnormally open or flailing condition in the left atrium following systole. This flailing condition allows blood to flow back or regurgitate into the left atrium through a mitral valve opening or orifice.

A well known surgical approach to treating mitral valve regurgitation is to suture an annuloplasty ring around the annulus of the mitral valve to reduce dilation of the left annulus and thereby enable the valve leaflets to more adequately coaptate or close at the appropriate time and thereby moderate the regurgitation.

However suturing of an annuluplasty ring around the annulus of a mitral valve will not always correct regurgitation, especially if the dysfunction of the mitral valve is due to defects in the tendons and muscles that control and stabilize movement of the mitral valve leaflets. For example, the mitral valve includes anterior and posterior leaflets that spread centrally from anterior and posterior portions of the mitral valve annulus (also referred to as the anterior annulus and the posterior annulus) that surrounds the leaflets. The valve leaflets are thin, pliable flaps, having margins that are tethered to papillary muscles by tendons known as chordae tendinae. Chordal or tendon rupture can occur because of congenital defects, or because of the aging process or as a result of a disease such as rheumatic fever, bacterial endocarditis or coronary artery disease, for example. Heart failure is likely to occur if mitral valve regurgitation is not resolved.

U.S. patent 7,070,618 to Streeter shows a mitral shield. Several embodiments of the shield are positioned only over the posterior leaflets of the mitral valve. The inventor suggests, with regard to at least one embodiment, that the posterior leaflets maybe excised or left in situ.

Two of the Streeter embodiments are positioned over both the anterior and posterior leaflets of the mitral valve. One of these shields includes a circular wire collar surrounding a series of spaced and parallel wires. The other shield is a disc-like structure that includes a solid portion and a portion with spaced openings. Although both of the shields appear to provide support for the valve leaflets the shield structure partially blocks the valve orifice and is thus likely to impede blood flow from the left atrium to the left ventricle. It is thus desirable to provide a mitral valve repair device that corrects flailing of the valve leaflets, does not unduly restrict blood flow through the valve orifice, does not require removal of any portion of the valve structure and can be installed via open heart surgery or percutaneously transluminally.

DESCRIPTION OF THE DRAWINGS

In the accompanying drawings,

Fig. 1 is a simplified schematic cross-sectional view of a mitral valve showing the direction of blood flow when there is regurgitation; Fig. 2 is a simplified cross-sectional view of a mitral valve repair device incorporating one embodiment of the invention, in an installed position against the mitral valve;

Fig. 3 is a simplified plan view of a mitral valve showing an anterior leaflet, a posterior leaflet and the valve orifice; Fig. 4 is a simplified plan view of the mitral valve repair device of

Fig. 2;

Fig. 5 is a simplified plan view of another embodiment of the mitral valve repair device;

Fig. 6 is a simplified profile view of a catheter for deploying the mitral valve repair device percutaneously; Fig. 7 is a simplified view of the catheter in an expanded condition prior to release of the mitral valve repair device from a locked position at the catheter tip;

Fig. 8 is a view similar to Fig. 7 showing the mitral valve repair device in an unbent condition and unlocked from the catheter tip prior to implantation of the repair device against the mitral valve as shown in Fig. 2; and,

Fig. 9 is a simplified schematic view showing the deployment catheter in perspective, and the unbending and expansion of the mitral valve repair device after release from the deployment catheter. Corresponding reference numbers indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, a mitral valve repair device incorporating a preferred embodiment of the invention is generally indicated by the reference number 10 in Fig. 5. The mitral valve repair device 10 is intended for implantation via an open heart procedure or by percutaneous deployment.

The mitral valve repair device 10 is positioned over a mitral valve 16 (Fig. 5), which is shown in simplified schematic form. The mitral valve 16 includes anterior leaflets 18 and posterior leaflets 20 surrounded by an annulus 26.

A mitral valve orifice 28 is shown in an open condition in Fig. 3 and in a closed condition in Figs. 2 and 5.

Referring to Fig. 5, the mitral valve repair device 10 includes an outer loop-like coil 34 of closed periphery. Unless otherwise indicated the mitral valve repair device 10 is formed of a non-thrombogenic material such as a biocompatible plastic and/or a bio-compatible metal such as titanium, nitinol wire, stainless steel wire and can be coated with an inert bio-compatible plastic material such as nylon or heparin. The outer loop-like 34 can, for example, be constructed in the same manner as a known annuloplasty ring. The mitral valve repair device 10 also includes an inner loop-like coil 36 of closed periphery, substantially concentric with the outer loop-like coil 34. The outer loop-like coil 34 and the inner loop-like coil 36 are held in a predetermined spaced relationship by spoke-like members 42 that are radially directed from a central axis of the coils 34 and 36.

The spoke-like members 42 have an outer end portion 44 connected to the outer coil 34 and an inner end portion 46 connected to the inner coil 36. Under this arrangement the outer coil 34, the inner coil 36 and the spoke-like members 42 are substantially co-planar. Except for the spoke-like members 42 there is completely open space between the outer and inner coils 34 and 36. In addition, there is completely open space within the area defined by the inner coil 36.

Preferably the inner coil 36 is approximately 1.5 centimeters in circumference. The inner coil 36 is also relatively infexible in comparison to the flexibility of the outer coil 34 and the spoke-like members 42.

In general the mitral valve repair device 10 is flexible and bendable such that the outer coil 34 and the spoke-like members 42 can be flexed, bent or deflected with respect to the inner coil 36 and then restored to the unbent shape. It should be noted that the mitral valve repair device 10 as shown in Fig. 5 is slightly elliptical as is dictated by the shape of the mitral valve that is undergoing repair by the repair device 10.

Thus the mitral valve repair device 10 is positioned against the anterior leaflet 18 and the posterior leaflet 20, and held in place by sutures 48 that secure the outer coil 34 to a circumferential area 50 (Fig. 5) of the anterior and posterior annulus of the mitral valve 16. It will be noted that the circumferential area 50 is a peripheral portion of the mitral valve 16 and for purposes of simplification is not demarked with boundaries. The sutures 48 are the only means for securing the mitral valve repair device 10 against the mitral valve 16 when the mitral valve repair device 10 is implanted through an open heart procedure. With the mitral valve repair device 10 in its installed position, as shown in Fig. 5, the inner coil 36, the spoke-like members 42 and the outer coil 34 provide support for the anterior and posterior leaflets 18 and 20 to prevent or moderate any flailing of the leaflets 18 and 20 into the left atrium as shown in Fig. 1.

The anterior and posterior leaflets 18 and 20 thus can be restored to a greater degree of functionality by remaining in situ and cooperating with the mitral valve repair device 10 to help prevent blood from the left ventricle 62 from being undesirably directed in the left atrium 60. It will also be noted from Fig. 5 that the inner coil 36 does not obstruct the opening of the valve orifice 28 and does not unduly impede the normal flow of blood from the left atrium 60 to the left ventricle 62.

The flexibility and bendability of the mitral valve repair device 10 facilitates installation and positioning of the device 10 against the mitral valve 16. Installation of the mitral valve repair device 10 can be accomplished with open heart surgery as well as percutaneously transluminally.

For example another embodiment of the mitral valve repair device that can be installed percutaneously is generally indicated by the reference number 70 in Figs. 2 and 4. The mitral valve repair device 70 includes an outer loop-like coil 74, an inner loop-like coil 76 and spoke-like members 82 joining the outer and inner coils 74 and 76. Thus the spoke-like members 82 include an outer end portion 84 connected to the outer coil 74 and an inner end portion 86 connected to the inner coil 76. Each of the spoke-like members 82 also include a barbed formation

92 that extends beyond the outer coil 74 and is bent at an angle of approximately 90° relative to the plane of the outer coil 74, as most clearly shown in Fig. 9.

The mitral valve repair device 70 is particularly suited for percutaneous transluminal deployment through the groin. Referring to Fig. 6 the mitral valve repair device 70 is supported in bent condition on a catheter 100. The outer coil 74 and the spoke-like members 82 are bent as folded against an umbrella-like support sleeve 102 having pivot members 104 (Fig. 7) for supporting and unbending the spoke-like members 82 of the repair device 70. A slidable sheath 108 maintains the bent condition of the mitral valve repair device 70 while it is being transported through the femoral artery and advanced intraluminally inside the heart, passing through the interatrial septum and positioned over the mitral valve orifice 28.

When the catheter 100 is positioned on the orifice 28 of the mitral valve 16, the sheath or sleeve 102 is pulled back out of the catheter.

Pivot members 104 upon which the mitral valve 70 is supported are pivoted to an expanded condition as shown in Fig. 7. A restraining member 110 bears against the inner coil 76 to hold it in a stable position on the catheter 100 until the barbed formations 92 are aligned with the selected circumferential area 50 of the mitral valve 16.

The restraining member 110 is partially retracted as shown in Fig. 8 to release the inner coil 76 and the mitral valve repair device 10 is pushed toward the mitral valve 16 to cause the barbed formations 92 to embed in the selected circumferential area of the mitral valve. Fig. 9 further shows the umbrella-like support 102 which includes the pivot members 104 that push the mounted mitral valve repair device 70 in place on the mitral orifice 28.

The mitral valve repair device 70 is thus affixed to the mitral valve 16 in a desired position without sutures. However if the mitral valve repair device 70 requires sutures a percutaneous transluminal suturing device (not shown) can be used for the suturing operation.

After the mitral repair device 70 is fixed in position on the mitral valve 16 the catheter 100 can be collapsed to the position of Fig. 6 and withdrawn from the patient. As various changes can be made in the above constructions and methods without departing from the scope of the invention it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

What is claimed is:

1. A mitral valve repair device for attachment to a selected circumferential area of the anterior and posterior annulus of the mitral valve comprising, a) an outer loop-like coil, having a first predetermined circumference and shape substantially corresponding to the size and shape of a selected circumferential area of the anterior and posterior annulus of a mitral valve, said outer loop-like coil being formed of a non-thrombogenic material, b) an inner loop-like coil having a second predetermined circumference of smaller magnitude than the first predetermined circumference of said outer loop-like coil, said inner loop-like coil being formed of a non-thrombogenic material, c) a plurality of spoke-like members having inner and outer end portions, the inner end portions being connected to the inner loop-like coil with predetermined spacing between neighboring inner end portions, the outer end portions being connected to the outer loop-like coil with predetermined spacing between neighboring outer end portions such that the spoke-like members extend radially from the inner loop-like coil to the outer loop-like coil and neighboring spoke-like members diverge from each other, from the inner loop-like coil to the outer loop-like coil, said spoke-like members being formed of a non- thrombogenic material, d) said outer loop-like coil, said inner loop-like coil and said spoke-like members are substantially coplanar, whereby said mitral valve repair device is positionable against the horizontal plane of the mitral valve in the left atrium, and is affixable to the mitral valve by attachment of the outer loop-like coil to the selected circumferential area of the anterior and posterior annulus, said outer loop-like coil thereby reinforcing the anterior and posterior annulus to moderate dilation of the anterior and posterior annulus, and fix the position of the spoke- like members and the inner loop-like coil against the mitral valve leaflets such that the inner loop-like coil, the outer loop-like coil and the spoke-like members form a substantially planar support for the anterior and posterior leaflets of the mitral valve to moderate any flailing of the leaflets and minimize regurgitation, whereby normal blood flow from the left atrium through the mitral valve to the left ventricle is substantially unobstructed by the round outer coil, the round inner coil and the spoke-like members.

2. A mitral valve repair device as claimed in claim 1 wherein the outer loop-like coil, the inner loop-like coil and the spoke-like members are formed of a metallic non-thrombogenic material.

3. The mitral valve repair device as claimed in claim 1 wherein the outer loop-like coil, the inner loop-like coil and the spoke-like members are relatively flexible and resilient, and the inner loop-like coil is relatively inflexible and stiff such that the outer loop-like coil and spoke-like members are bendable with respect to the inner loop-like coil and restorable to an unbent condition whereby the outer loop-like coil, the inner loop-like coil and the spoke-like members are substantially coplanar.

4. The mitral valve repair device as claimed in claim 2 wherein the outer loop-like coil, and the spoke-like members are formed of a metal selected from the group consisting of stainless steel and titanium, and are coated with an inert plastic coating.

5. The mitral valve repair device as claimed in claim 4 wherein the inert plastic coating is nylon.

6. The mitral valve repair device as claimed in claim 4 wherein the inert coating is bonded with a thrombolytic agent.

7. The mitral valve repair device as claimed in claim 1 wherein the outer loop-like coil is formed with spaced axially projecting barbs for embedment in the selected circumferential area of the anterior and posterior annulus of the mitral valve.

8. The mitral valve repair device as claimed in claim 1 wherein the outer loop-like coil is free of any axial protrusions and is suturable to the anterior and posterior annulus of the mitral valve.

9. The mitral valve repair device as claimed in claim 1 wherein the perimeter of the inner loop-like coil is approximately 1.5 centimeters.

10. A method of repairing the mitral valve to correct mitral regurgitation comprising, a) forming the mitral valve of claim 1 , affixing the outer loop- like coil to a selected circumferential area of the anterior and posterior annulus in the left atrium to correct remodeling of the left ventricle from dilation, b) aligning the loop-like inner coil with the orifice of the mitral valve and affixing the outer loop-like coil to the anterior and posterior annulus, and c) providing a selected number of spoke-like members to support the inner loop-like coil against the valve leaflets in a substantially coplanar relationship with the outer loop-like coil in the left atrium to resist flailing of the leaflets during systole and thereby correct regurgitation.

11. The method of claim 10 wherein the outer loop-like coil is affixed to the selected circumferential area of the anterior and posterior annulus by suturing.

12. The method of claim 10 including forming axially projecting barbs spaced around the outer loop-like coil, and embedding the barbs into the selected circumferential area of the anterior and posterior annulus to affix the outer loop-like coil to the selected circumferential area of the anterior and posterior annulus.

13. The method of claim 10 including affixing the mitral valve repair device to the mitral valve during open heart surgery.

14. The method of claim 10 including affixing the mitral valve repair device to the mitral valve percutaneously transluminally.

15. A mitral valve repair device comprising, a) a outer loop-like coil of closed periphery, and a substantially concentric inner loop-like coil of closed periphery, b) a plurality of spoke-like members connecting the outer and inner loop-like coils in substantially concentric relationship, c) the outer loop-like coil being of a predetermined size to permit affixation to the anterior and posterior annulus of a mitral valve, d) the outer and inner loop-like coils and the spoke-like members being formed of a non-thrombogenic material.

16. The mitral valve repair device as claimed in claim 15 wherein the inner loop-like coil has approximately a circumference of approximately 1.5 centimeters.

17. The mitral valve repair device as claimed in claim 15 wherein the outer loop-like coil, the inner loop-like coil and the spoke-like members are substantially coplanar.

18. The mitral valve repair device as claimed in claim 17 wherein the outer loop-like coil is free of any axial protrusions projecting beyond the plane of the inner and outer loop-like coils.

19. The mitral valve repair device as claimed in claim 17 wherein the outer loop-like coil includes spaced barbs projecting axially from the plane of the inner and outer loop-like coils for embedment in the anterior and posterior annulus of a mitral valve.

20. The mitral valve repair device as claimed in claim 15 wherein the outer loop-like coil, the inner loop-like coil and the spoke-like members are relatively flexible and resilient and the inner loop-like coil is relatively inflexible and stiff such that the outer loop-like coil and spoke-like members are bendable with respect to the inner loop-like coil and restorable to an unbent condition whereby the outer loop-like coil, the inner loop-like coil and the spoke-like members are substantially coplanar.