Valve to myocardium tension members device and method

A device for heart valve repair including at least one tension member having a first end and second end. A basal anchor is disposed at the first end of the tension member and a secondary anchor at the second end. The method includes the steps of anchoring the basal anchor proximate a heart valve and anchoring the secondary anchor at a location spaced from the valve such that the chamber geometry is altered to reduce heart wall tension and/or stress on the valve leaflets.

BACKGROUND OF THE INVENTION

The present invention pertains generally to the field of heart valve repair. More specifically, the present invention pertains to a device and method for the reduction of myocardial wall tension and the repair of mitral valve insufficiency.

Dilated cardiomyopathy is often accompanied by mitral valve insufficiency. There are several reasons for the presence of mitral valve insufficiency associated with a dilated heart. First, chamber dilation and associated high wall stresses increase the diameter of the mitral valve annulus. Additionally, as the heart dilates, the positioning of the papillary muscles is altered. Papillary muscles and chordae in a dilated heart will have moved both radially away and down from the mitral valve. This rearrangement of the vascular apparatus and enlargement of the annulus prevent the valve from closing properly.

Currently mitral valve insufficiency is treated by either repairing or replacing the valve. Surgical procedures used to repair the valve including ring posterior annuloplasty which consists of sewing a C or D-shaped ring around the posterior leaflet of the mitral valve and drawing in the annulus, reducing its previously enlarged diameter. Another method is to approximate the anterior and posterior mitral leaflets (Alfieri repair) by placing one suture through the center of both leaflets. This gives the valve a figure 8-shaped appearance when the valve is opened. When the mitral valve is replaced, the original leaflets are removed and the chordae are cut. An artificial valve consists of mechanical or tissue leaflets suspended on struts attached to a metal stent, and is sutured into place on the mitral annulus.

It has been argued that valve repair is preferable to valve replacement if the leaflet-chordae-papillary connections can be maintained. Heart wall stress will increase if the chordae are cut during valve replacement. It has been shown that by severing the chordae there can be 30 percent (30%) reduction in chamber function. Mitral valve replacement has high mortality in very sick, chronic heart failure patients.

SUMMARY OF THE INVENTION

The present invention pertains to a device and method for mitral valve repair. The mitral valve is generally defined as its leaflets or cusps, but in reality, it actually consists of the entire left ventricle chamber. By creating an improved chamber geometry, both chamber and valve function will be improved. The device of the present invention and method for valve repair/replacement can include treatment for chronic heart failure by reducing left ventricular wall tension.

In one embodiment of the present invention, the valve repair device includes an elongate tension member having a first end and second end. The basal anchor is disposed at the first end and the secondary anchor is disposed at the second end.

The basal anchor could include a pad and annuloplasty ring or the like. Alternately an artificial heart valve could serve as the basal anchor.

Tension members can be substantially rigid or substantially flexible. The secondary anchor can include a hook-shaped papillary muscle tissue loop, screw-shaped tissue anchor or transmural anchor pad.

The method of the present invention providing a tension member having a first end and a second end. The tension member has a basal anchor at the first end and a secondary anchor at the second end. The basal anchor is anchored proximate to the valve such that the tension member is disposed in the chamber. The secondary anchor is anchored to a portion of the heart spaced from the basal anchor such that the tension member is under tension and the geometry of the chamber has been altered by placement of the tension member.

The basal anchor can include an artificial heart valve, annuloplasty ring or the like. The secondary anchor can be anchored to a papillary muscle or transmurally anchored.

More than one tension member can be used. Additionally, a transverse tension member can be placed across the chamber generally perpendicular to the other tension members to further alter the geometry of the heart, reducing wall stress and improving chamber performance.

DETAILED DESCRIPTION OF THE INVENTION

Referring now the drawings wherein like reference numerals refer to like elements throughout the several views,FIG. 1shows a transverse cross section of the left ventricle10of a failing heart taken fromFIG. 2. The papillary muscles12are shown in cross section.FIG. 2is a vertical cross section of human heart10. A mitral valve is disposed near the top of left ventricle10. Mitral valve14includes two leaflets or cusps16. Chordae18extend between leaflets16and papillary muscles12.

FIG. 3is a cross section of heart10modified from that shown inFIG. 1by placement of valve repair device20in accordance with the present invention as shown inFIG. 4.FIG. 4is a vertical cross section of left ventricle10with geometry modified by device20. In this embodiment of the invention, device20includes a basal anchor22such as an annuloplasty or suture ring sewn proximate the annulus of valve14. Extending from basal anchor22are elongate tension members24. Each have a first end connected to basal anchor22and a second end anchored to papillary muscles12or the heart wall.

As can be seen inFIGS. 3 and 4, both the transverse radius and vertical dimension of left ventricle10has been reduced in comparison to that ofFIGS. 1 and 2by drawing papillary muscles12toward valve14with tension members24. This change in geometry reduces heart wall stress and consequently increasing chamber function. Valve function is also improved as explained in more detail by reference toFIGS. 5 and 6.

FIG. 5is a generally vertical cross section of an insufficient mitral valve of a heart suffering from chronic heart failure. In this case as the failing heart has dilated, papillary muscle12has been drawn away from mitral valve14. The chordae connections between papillary muscles12and valve14in turn draws leaflets16apart such that during the normal cardiac cycle, leaflets16may not completely close. Thus, an opening26is left between leaflets16throughout the cardiac cycle. Opening26will allow blood to leak, reducing chamber efficiency.

FIG. 6is a view of the mitral valve14ofFIG. 5which has been modified by placement of valve repair device20as shown. Suture ring22is sewn proximate the annulus of valve14, as known to those skilled in the use of suture rings. The annulus of valve14can be decreased in size by drawing the annulus toward the suture ring by the sutures used to connect ring22to the valve. Drawing the annulus of valve14toward suture ring22will help to eliminate opening26. Tension member24is then anchored to papillary muscle12such that papillary muscle12is drawn toward valve14. Whether or not the suture ring alone is sufficient to eliminate opening26, drawing papillary muscle12toward valve14will provide additional stress relief on leaflet16promoting complete closure of valve14. Drawing papillary muscle12toward14also reduces heart wall stress and increases chamber efficiency as discussed previously.

FIG. 7is a highly simplified view of left ventricle10and valve repair device20as shown inFIG. 4. It can be noted that tension members24extend from basal anchor22to an adjacent papillary muscle12. In contrast,FIG. 8is a similar cross sectional view of left ventricle10, but a valve repair device120is placed such that its tension members124extend between a basal anchor122and a papillary muscle12transversely opposite the point at which tension member124is connected to basal anchor122. This arrangement, as opposed to that shown inFIG. 7, can increase the transverse component of the tension force in tension members124relative to the vertical component of that tensile force.

FIG. 9shows yet another embodiment of the valve repair device in accordance with the present invention referred to by numeral220. In this embodiment, device220is disposed in left ventricle10in a manner similar to that of device20shown inFIG. 7in that tension members224of device220extend from a basal anchor222to an adjacent secondary anchor point. The secondary anchor point is established by transverse extension of a tension member225across left ventricle10. Tension member225is anchored transmurally to the heart wall at its opposite ends by pads227. In turn, tension members224are anchored or connected to tension member225.

Tension member225can be used to further alter the geometry of left ventricle10in a manner disclosed in U.S. Pat. No. 5,961,440, entitled “HEART WALL TENSION REDUCTION APPARATUS AND METHOD”, which was filed on Sep. 18, 1997 and is incorporated herein by reference.

FIG. 10shows yet another embodiment of a valve repair device in accordance with the present invention referred to by numeral320. This embodiment includes a basal anchor322and tension members324and a transverse tension member325having anchor pads327similar to those of device220. With respect to device320, however, tension members324are crossed similar to those of device120ofFIG. 8to increase the horizontal component relative to the vertical component of the tensile force in tension member324.

FIG. 11is a yet another embodiment420of the valve repair device of the present method. Valve repair device420includes a basal anchor422and tension members424. Tension members424are disposed in an arrangement similar to tension members24of device20shown inFIG. 7except that tension members424are anchored transmurally by pads427rather than into papillary muscles12. The relatively greater thickness of tension members424shown inFIG. 11, as compared to tension members24shown inFIG. 7, merely illustrates that the tension members can be substantially rigid or in the case of tension members24, substantially flexible. It should be understood, however, that in any of the embodiments shown herein, the tension members could be advantageously formed to be substantially flexible or substantially rigid.

FIG. 12is a top or posterior view of valve14. In this embodiment, the basal anchor for the valve repair device is shown as discrete pads28which can be sewn to the posterior side of valve14. Tension members24are shown extending from respective pads28into the left ventricle.

FIG. 13is the same view of valve14asFIG. 12. InFIG. 13, however, the basal anchor22is shown as a crescent-shaped suture ring. Tension members24extends from basal anchor22through valve14into the left ventricle.

FIG. 14is a side view of an artificial heart valve30. If it is necessary to replace the valve rather than merely repair it, artificial valve30can be used as a basal anchor for tension members24.

FIG. 15is a top view of an alternate embodiment of a suture ring basal anchor32. Ring32has a crescent shape and a pylon34extending through the mitral valve.FIG. 16is a side view of suture ring32showing tension members24attached to pylon34.

Tension members24preferably extend through the tissue of valve14rather than through the valve opening. It can be appreciated, however, that tension members24could be disposed through the valve opening. In the case of the embodiment ofFIGS. 15 and 16, however, pylon34would be disposed through the valve opening. Tension members24associated with pylon34would be disposed on the opposite side of valve14from suture ring32. Pylon34would preferably be disposed through the valve opening rather than the tissue forming valve14.

FIGS. 17 and 18are yet additional alternate embodiments of suture rings which can be used as basal anchors in accordance with the present invention. The shape of the rings is selected such that as they are sewn into place on valve14, the sutures can be used to draw tissue toward the inside of the ring, thus reducing the transverse and/or vertical cross sectional area of the associated heart chamber. This will advantageously reduce heart wall stress which is of particular benefit if the patient has a failing heart.

It can be appreciated that tension members24can be fixably or releasably attached to the basal anchor. Preferably, the tension members are fixably attached to the basal anchor during the valve repair procedure.

FIGS. 19-21show various configurations of anchoring devices shown at the second end of tension member24. It can be appreciated that these anchoring devices could be used with each of the tension members described above. InFIG. 19, the second end of tension member24includes a secondary anchor40formed as screw which is shown augured into papillary muscle12.FIG. 20shows a secondary anchor42including a loop sewn through papillary muscle12.FIG. 21shows a tension member24extending transmurally to an exterior pad44to which it is connected. Tension member24could be sewn to pad44or otherwise mechanically connected thereto.

It can be appreciated that various biocompatible materials can be advantageously used to form the various components of the device of the present invention. It is anticipated that the present device will usually be chronically implanted. Thus, when selecting materials to form each of the components consideration should be given to the consequences of long term exposure of the device to tissue and tissue to the device.

Numerous characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The inventions's scope is, of course, defined in the language in which the appended claims are expressed.