Device And Method For Improving The Function Of A Heart Valve

Abstract

A device for improving the function of a heart valve comprises: a support member formed from a shape memory material, and a restraining member providing a restraining action on a course of the support member. The support member may abut one side of the valve conforming to the shape of the valve annulus upon said shape memory material assuming an activated shape while the restraining member restrains the course of the support member. The restraining action is removable for allowing the support member to assume a desired, altered course. The restraining member may be biodegradable to be degraded within a patient or may be detachable from the support member to be withdrawn. The support member according to another embodiment presents a shape change in that an increased cross-section is associated with a shortened length of the support member. The support member according to yet another embodiment has a first and a second activated shape.

What is claimed is: 
     
         1 . A method for improving the function of a heart valve comprised of valve tissue including an annulus and a plurality of leaflets, the method comprising:
 obtaining a support member at least partially formed from a shape memory material operable to assume an inactivated shape and an activated shape, wherein the support member is adapted to be brought into the activated shape by heating of the support member, the support member is adapted to assume a reduced radius of curvature for remodelling the annulus upon said shape memory material assuming the activated shape,   controlling the shape of the support member with a restraining member in the inactivated shape to position a first loop-shaped segment and a second loop-shaped segment of the support member at opposite sides of the heart valve and conforming to at least part of the annulus, and   withdrawing the restraining member to allow the support member to assume the activated shape by said heating.   
     
     
         2 . Method according to  1 , comprising heating selective portions of the support member to bring the selective portions to the activated shape. 
     
     
         3 . Method according to  claim 2 , comprising bringing a heating element of a catheter in contact with the selective portions. 
     
     
         4 . Method according to  claim 1 , comprising cooling the support member in a catheter to maintain the inactivated shape. 
     
     
         5 . Method according to  claim 3  or  4 , wherein the catheter controls the shape of the support member in the inactivated shape. 
     
     
         6 . Method according to  claim 3  or  4 , wherein the catheter is the restraining member. 
     
     
         7 . Method according to  claim 1 , wherein positioning the first loop-shaped segment and a second loop-shaped segment of the support member at opposite sides of the heart valve comprises introducing the second loop-shaped segment and the restraining member through an opening between the leaflets. 
     
     
         8 . Method according to  claim 7 , wherein an outer boundary of the second loop-shaped segment is greater than an outer boundary of the first loop-shaped segment. 
     
     
         9 . Method according to  claim 1 , wherein the restraining member provides a restraining action on the support member, wherein withdrawing the restraining member removes the restraining action. 
     
     
         10 . Method according to  claim 1 , wherein a portion of the tissue of the heart valve is trapped between the first loop-shaped segment and the second loop-shaped segment. 
     
     
         11 . A device for improving the function of a heart valve comprised of valve tissue including an annulus and a plurality of leaflets, the device comprising:
 a support member at least partially formed from a shape memory material operable to assume an inactivated shape and an activated shape,   wherein the support member is adapted to be brought into the activated shape by heating of the support member,   the support member comprises a first loop-shaped segment and a second loop-shaped segment, wherein the first and second loop-shaped segments are continuous to form a coil-shape adapted to be arranged on opposite sides of the heart valve,   the support member is adapted to assume a reduced radius of curvature for remodelling the annulus upon said shape memory material assuming the activated shape,   a restraining member being adapted to control the shape of the support member in the inactivated shape when the support member is positioned at the opposite sides of the heart valve and conforming to at least part of the annulus, and   wherein withdrawal of the restraining member allows the support member to assume the activated shape by said heating.   
     
     
         12 . A device according to  claim 11 , wherein the restraining member is adapted to provide a restraining action on the support member, wherein withdrawal of the restraining member removes the restraining action. 
     
     
         13 . A device according to  claim 11 , wherein the second loop-shaped segment and the restraining member are adapted to be introduced through an opening between the leaflets. 
     
     
         14 . A device according to  claim 11 , wherein the first and second loop-shaped segments are adapted to trap a portion of the tissue of the heart valve. 
     
     
         15 . A device according to  claim 11 , wherein support member is adapted to be cooled to maintain the inactivated shape.