Flexible heart valve leaflets with concave free edges

Abstract

A flexible prosthetic tissue-type heart valve having commissures that are substantially decoupled from a cusp support structure. The valve includes three leaflets having arcuate cusp edges and opposed concave shaped free edges, with outwardly-directed attachment tabs therebetween. A cusp support structure in either one or more pieces attaches to the leaflet cusp edges. Three commissures are each formed partly with an axially-extending insert member to which two adjacent leaflet tabs attach. An inverted V-shaped clip maintains close contact between the adjacent leaflet tabs and provides a stress-relieving clamping action in conjunction with the insert member. The insert member attaches about its lower end to base sections of the cusp support structure, or to an intermediate sewing ring, so that the commissures may pivot about the cusp support structure. The sewing band is scalloped and enables attachment of the valve along the scalloped aortic root so as to couple the valve to the natural motion of the aorta. Increased vibrational damping results from this biomechanical coupling.

What is claimed is:  
     
         1 . A tissue-type heart valve adapted to have reduced stress risers in the leaflets, comprising: 
 three leaflets each having arcuate cusp edges on their inflow ends, free edges on the outflow ends, and two side tabs, the free edges extending between the side tabs in a concave fashion.    
     
     
         2 . The heart valve of  claim 1 , further including commissure posts to which adjacent leaflet tabs attach, each post including an insert around which the leaflet tabs wrap, the valve further including a cusp support structure attached to the cusps of each leaflet, wherein the insert is pivotally coupled to the cusp support structure.  
     
     
         3 . The heart valve of  claim 2 , further a sewing band for attachment to a valve annulus that surrounds the cusp support structure and is truncated in the region of the inserts to permit direct attachment of the commissure posts to an anatomical wall structure adjacent the annulus.  
     
     
         4 . The heart valve of  claim 1 , wherein each leaflet free edge further includes a region that is above a line extending between the middle of the free edge and the side tabs so that the region is not placed in direct tension during closure of the valve.  
     
     
         5 . The heart valve of  claim 4 , wherein the region is generally triangular and culminates in an apex.  
     
     
         6 . The heart valve of  claim 5 , wherein a concave filet exists between the apex and the side tab.