Heart valve having tissue alignment with anchors and an outer sheath

Abstract

An apparatus and a method for constructing a heart valve prepared from autologous tissue is disclosed. Three tissue leaflets are held in place with tissue anchors on a tissue mounting frame having an annular base and a plurality of commissure posts extending from the base. An elastomeric sheath rests gently on the tissue leaflets to prevent the leaflets from coming off of the anchor hooks and encloses the leaflets to form valve cusps. The leaflets touch each other on a coaptation line with an angle of approximately 65° C. relative to the commissure post. The heart valves can be constructed intraoperatively in a short time, typically ten minutes. The low coaptation angle and the fact that the leaflets are held in place without being clamped between two unyielding members minimize stress on the tissue.

What is claimed is:  
     
         1 . A heart valve comprising: 
 a frame comprising an annular base and a plurality of posts extending from said base;    a plurality of tissue anchors attached to said frame;    a plurality of tissue leaflets retained by said tissue anchors; and    a flexible elastomeric sheath, wherein said sheath fits around said frame and said tissue leaflets and retains said tissue leaflets on said tissue anchors.    
     
     
         2 . The heart valve of  claim 1 , wherein said elastomeric sheath self adjusts to apply substantially equal force to said tissue leaflets on said frame.  
     
     
         3 . The heart valve of  claim 1 , wherein the tissue leaflets are supported and retained by the combination of (i) said tissue anchors and (ii) said elastomeric sheath engaging a peripheral portion of said tissue leaflets between said elastomeric sheath and said frame, without clamping said tissue between two unyielding members.  
     
     
         4 . The heart valve of  claim 1 , comprising  3  tissue leaflets retained by said tissue anchors.  
     
     
         5 . The heart valve of  claim 1 , wherein said tissue leaflets comprise partially fixed autologous tissue.  
     
     
         6 . The heart valve of  claim 1 , wherein said tissue leaflets comprise partially fixed autologous pericardial tissue.  
     
     
         7 . The heart valve of  claim 1 , wherein said frame is covered with a fabric.  
     
     
         8 . The heart valve of  claim 1 , wherein said elastomeric sheath is covered with a fabric.  
     
     
         9 . The heart valve of  claim 1 , additionally comprising a flexible annular sewing ring.  
     
     
         10 . The heart valve of  claim 9 , wherein said elastomeric sheath and said annular sewing ring are attached to said frame.  
     
     
         11 . The heart valve of  claim 1 , wherein said tissue leaflets are assembled to said frame intraoperatively during a valve replacement operation.