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. 1 shows a transverse cross
 section of the left ventricle 10 of a failing heart taken from FIG. 2. The
 papillary muscles 12 are shown in cross section. FIG. 2 is a vertical
 cross section of human heart 10. A mitral valve is disposed near the top
 of left ventricle 10. Mitral valve 14 includes two leaflets or cusps 16.
 Chordae 18 extend between leaflets 16 and papillary muscles 12.
 FIG. 3 is a cross section of heart 10 modified from that shown in FIG. 1 by
 placement of valve repair device 20 in accordance with the present
 invention as shown in FIG. 4. FIG. 4 is a vertical cross section of left
 ventricle 10 with geometry modified by device 20. In this embodiment of
 the invention, device 20 includes a basal anchor 22 such as an
 annuloplasty or suture ring sewn proximate the annulus of valve 14.
 Extending from basal anchor 22 are elongate tension members 24. Each have
 a first end connected to basal anchor 22 and a second end anchored to
 papillary muscles 12 or the heart wall.
 As can be seen in FIGS. 3 and 4, both the transverse radius and vertical
 dimension of left ventricle 10 has been reduced in comparison to that of
 FIGS. 1 and 2 by drawing papillary muscles 12 toward valve 14 with tension
 members 24. 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 to FIGS. 5 and 6.
 FIG. 5 is 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 muscle 12 has been drawn away from
 mitral valve 14. The chordae connections between papillary muscles 12 and
 valve 14 in turn draws leaflets 16 apart such that during the normal
 cardiac cycle, leaflets 16 may not completely close. Thus, an opening 26
 is left between leaflets 16 throughout the cardiac cycle. Opening 26 will
 allow blood to leak, reducing chamber efficiency.
 FIG. 6 is a view of the mitral valve 14 of FIG. 5 which has been modified
 by placement of valve repair device 20 as shown. Suture ring 22 is sewn
 proximate the annulus of valve 14, as known to those skilled in the use of
 suture rings. The annulus of valve 14 can be decreased in size by drawing
 the annulus toward the suture ring by the sutures used to connect ring 22
 to the valve. Drawing the annulus of valve 14 toward suture ring 22 will
 help to eliminate opening 26. Tension member 24 is then anchored to
 papillary muscle 12 such that papillary muscle 12 is drawn toward valve
 14. Whether or not the suture ring alone is sufficient to eliminate
 opening 26, drawing papillary muscle 12 toward valve 14 will provide
 additional stress relief on leaflet 16 promoting complete closure of valve
 14. Drawing papillary muscle 12 toward valve 14 also reduces heart wall
 stress and increases chamber efficiency as discussed previously.
 FIG. 7 is a highly simplified view of left ventricle 10 and valve repair
 device 20 as shown in FIG. 4. It can be noted that tension members 24
 extend from basal anchor 22 to an adjacent papillary muscle 12. In
 contrast, FIG. 8 is a similar cross sectional view of left ventricle 10,
 but a valve repair device 120 is placed such that its tension members 124
 extend between a basal anchor 122 and a papillary muscle 12 transversely
 opposite the point at which tension member 124 is connected to basal
 anchor 122. This arrangement, as opposed to that shown in FIG. 7, can
 increase the transverse component of the tension force in tension members
 124 relative to the vertical component of that tensile force.
 FIG. 9 shows yet another embodiment of the valve repair device in
 accordance with the present invention referred to by numeral 220. In this
 embodiment, device 220 is disposed in left ventricle 10 in a manner
 similar to that of device 20 shown in FIG. 7 in that tension members 224
 of device 220 extend from a basal anchor 222 to an adjacent secondary
 anchor point. The secondary anchor point is established by transverse
 extension of a tension member 225 across left ventricle 10. Tension member
 225 is anchored transmurally to the heart wall at its opposite ends by
 pads 227. In turn, tension members 224 are anchored or connected to
 tension member 225.
 Tension member 225 can be used to further alter the geometry of left
 ventricle 10 in a manner disclosed in U.S. patent application Ser. No.
 08/933,456, entitled "HEART WALL TENSION REDUCTION APATUS AND METHOD",
 which was filed on Sep. 18, 1997 and is incorporated herein by reference.
 FIG. 10 shows yet another embodiment of a valve repair device in accordance
 with the present invention referred to by numeral 320. This embodiment
 includes a basal anchor 322 and tension members 324 and a transverse
 tension member 325 having anchor pads 327 similar to those of device 220.
 With respect to device 320, however, tension members 324 are crossed
 similar to those of device 120 of FIG. 8 to increase the horizontal
 component relative to the vertical component of the tensile force in
 tension member 324.
 FIG. 11 is a yet another embodiment 420 of the valve repair device of the
 present method. Valve repair device 420 includes a basal anchor 422 and
 tension members 424. Tension members 424 are disposed in an arrangement
 similar to tension members 24 of device 20 shown in FIG. 7 except that
 tension members 424 are anchored transmurally by pads 427 rather than into
 papillary muscles 12. The relatively greater thickness of tension members
 424 shown in FIG. 11, as compared to tension members 24 shown in FIG. 7,
 merely illustrates that the tension members can be substantially rigid or
 in the case of tension members 24, 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. 12 is a top or posterior view of valve 14. In this embodiment, the
 basal anchor for the valve repair device is shown as discrete pads 28
 which can be sewn to the posterior side of valve 14. Tension members 24
 are shown extending from respective pads 28 into the left ventricle.
 FIG. 13 is the same view of valve 14 as FIG. 12. In FIG. 13, however, the
 basal anchor 22 is shown as a crescent-shaped suture ring. Tension members
 24 extends from basal anchor 22 through valve 14 into the left ventricle.
 FIG. 14 is a side view of an artificial heart valve 30. If it is necessary
 to replace the valve rather than merely repair it, artificial valve 30 can
 be used as a basal anchor for tension members 24.
 FIG. 15 is a top view of an alternate embodiment of a suture ring basal
 anchor 32. Ring 32 has a crescent shape and a pylon 34 extending through
 the mitral valve. FIG. 16 is a side view of suture ring 32 showing tension
 members 24 attached to pylon 34.
 Tension members 24 preferably extend through the tissue of valve 14 rather
 than through the valve opening. It can be appreciated, however, that
 tension members 24 could be disposed through the valve opening. In the
 case of the embodiment of FIGS. 15 and 16, however, pylon 34 would be
 disposed through the valve opening. Tension members 24 associated with
 pylon 34 would be disposed on the opposite side of valve 14 from suture
 ring 32. Pylon 34 would preferably be disposed through the valve opening
 rather than the tissue forming valve 14.
 FIGS. 17 and 18 are 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 valve 14, 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 members 24 can 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. 19-21 show various configurations of anchoring devices shown at the
 second end of tension member 24. It can be appreciated that these
 anchoring devices could be used with each of the tension members described
 above. In FIG. 19, the second end of tension member 24 includes a
 secondary anchor 40 formed as screw which is shown augured into papillary
 muscle 12. FIG. 20 shows a secondary anchor 42 including a loop sewn
 through papillary muscle 12. FIG. 21 shows a tension member 24 extending
 transmurally to an exterior pad 44 to which it is connected. Tension
 member 24 could be sewn to pad 44 or 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.