Selective adherence of stent-graft coverings

Abstract

An endoluminal prosthesis including a radially expandable support member having interior and exterior surfaces and a wall with openings, a first covering member including a biocompatible polymer material at least partially positioned against the interior surface, and a second covering member including a biocompatible polymer material at least partially positioned against the exterior surface. The first covering member attaches to the second covering member at predetermined bonding locations within less than all of the openings thereby leaving unbonded regions.

What is claimed is: 
     
         1 . A prosthesis comprising:
 an expandable support comprising plural openings;   a first covering inside of the support;   and   a second covering outside of the support,   wherein the first and second coverings have multiple connections that extend through openings in the support and the connections form a pattern of loose space around the support.   
     
     
         2 . The prosthesis of  claim 1  wherein the pattern of loose space includes a pocket around the support. 
     
     
         3 . The prosthesis of  claim 2  wherein the prosthesis further comprises a therapeutic agent. 
     
     
         4 . The prosthesis of  claim 3  wherein the pocket holds the therapeutic agent. 
     
     
         5 . The prosthesis of  claim 4  wherein the connections additionally form a predominantly circumferential pattern. 
     
     
         6 . The prosthesis of  claim 5  wherein the first covering is biocompatible. 
     
     
         7 . The prosthesis of  claim 6  wherein the second covering is biocompatible. 
     
     
         8 . The prosthesis of  claim 7  wherein the support and the first covering are unconnected. 
     
     
         9 . The prosthesis of  claim 4  wherein the connections additionally form a predominantly longitudinal pattern. 
     
     
         10 . The prosthesis of  claim 9  wherein the prosthesis length is greater than the first covering length and the second covering length. 
     
     
         11 . The prosthesis of  claim 10  wherein the first covering and the second covering are fully bonded at their ends. 
     
     
         12 . The prosthesis of  claim 11  wherein the second covering is biocompatible. 
     
     
         13 . The prosthesis of  claim 12  wherein the first covering is biocompatible. 
     
     
         14 . The prosthesis of  claim 13  wherein the support and the second covering are unconnected. 
     
     
         15 . The prosthesis of  claim 14  wherein the support is radially expandable. 
     
     
         16 . The prosthesis of  claim 15  wherein the support is cylindrical. 
     
     
         17 . The prosthesis of  claim 16  wherein the support is a stent. 
     
     
         18 . A prosthesis comprising:
 a radially expandable stent comprising a plurality of openings;   a first biocompatible covering inside of the stent;   and   a second biocompatible outside of the stent,   wherein   the first and second coverings are fully bonded at their ends, are unconnected to the stent, and have multiple connections that extend through openings in the stent, and the connections form a pattern of loose space defining a pocket around the stent,   the pocket contains a therapeutic agent,   and   the stent length is greater than the first covering length and the second covering length.