Endolumenal vascular prosthesis with neointima inhibiting polymeric sleeve

Abstract

The present invention is related to a low profile endolumenal prosthesis. The prosthesis comprises a radially expandable tubular wire support and an expanded PTFE membrane. The density, wall thickness and intranodal distance of the ePTFE are selected to inhibit the formation and nourishment of a viable neointima on the inner surface of the prosthesis, through the ePTFE membrane.

What is claimed is: 
     
         1 . An endolumenal prosthesis having a lumenal surface and an ablumenal surface, comprising:
 a tubular wire support with proximal and distal ends and a central lumen extending therebetween, the wire support comprising at least two axially adjacent tubular segments, each segment comprising a series of proximal and distal bends connected by a length of wire, wherein the wire support is radially compressible into a first, reduced cross sectional configuration for translumenal navigation to a treatment site in a body lumen and self-expandable to a second, enlarged cross sectional configuration for deployment at the treatment site in the body lumen; and   a uniform porous tubular ePTFE sheath on the wire support, the tubular sheath having a sheath proximal end region and a sheath distal end region, wherein the sheath is porous and configured to inhibit sufficient cellular ingrowth through the wall of the sheath that would permit the formation of a viable neointimal layer on the lumenal surface of the sheath at the sheath proximal and distal end regions without a coating on the sheath that would inhibit cellular ingrowth.   
     
     
         2 . The endolumenal prosthesis of  claim 1 , wherein the ePTFE sheath wall thickness is no greater than about 0.2 mm. 
     
     
         3 . The endolumenal prosthesis of  claim 1 , wherein the ePTFE sheath has a density of at least about 0.75 grams per milliliter. 
     
     
         4 . The endolumenal prosthesis of  claim 3 , wherein the ePTFE sheath has a plurality of nodes, and the average distance between nodes is within the range of from about 6 microns to about 80 microns. 
     
     
         5 . The endolumenal prosthesis of  claim 1 , wherein the ePTFE sheath has a density of at least about 0.5 grams per milliliter. 
     
     
         6 . The endolumenal prosthesis of  claim 1 , wherein the ePTFE sheath has a plurality of nodes, and the average distance between nodes is within the range of from about 6 microns to about 80 microns. 
     
     
         7 . The endolumenal prosthesis of  claim 1 , wherein the ePTFE sheath has a water entry pressure in the range of from about 10 psi to about 24 psi. 
     
     
         8 . A prosthetic vascular graft, comprising:
 an expandable tubular wire support;   a uniform porous, tubular ePTFE layer carried by the support, the ePTFE layer having:
 a wall thickness less than about 0.15 millimeters; 
 an average density of greater than about 0.75 grams per milliliter; and 
 an average distance between nodes in the range of between about 6 to about 80 microns; 
   so that the uniform porous ePTFE layer prevents the formation and nourishment of a viable neointimal layer therethrough along portions of the tubular ePTFE layer's axial length, which are in contact with a vessel wall.   
     
     
         9 . The prosthetic vascular graft of  claim 8 , wherein the ePTFE layer has a density within the range of from about 1.1 to about 1.5 grams per milliliter. 
     
     
         10 . The prosthetic vascular graft of  claim 8 , wherein the ePTFE layer has a water entry pressure in the range of from about 10 psi to about 24 psi. 
     
     
         11 . The prosthetic vascular graft of  claim 8 , wherein the ePTFE layer is further configured to inhibit the formation of a viable neointimal layer on the lumenal surface of the ePTFE layer at the prosthetic vascular graft's distal end. 
     
     
         12 . The prosthetic vascular graft of  claim 8 , wherein a proximal end of the prosthetic vascular graft comprises a single opening and a distal end of the prosthetic vascular graft comprises two openings, such that the prosthetic vascular graft is configured for implantation at a vascular bifurcation. 
     
     
         13 . An artificial vascular prosthesis comprising an enlargeable support structure having a uniform, porous, expanded polytetrafluoroethylene (ePTFE) layer thereon, the layer having a microstructure consisting of nodes interconnected by fibrils which prevents tissue ingrowth through portions of the layer that contact a vessel wall when the prosthesis is implanted to span an aneurysm, in which either the ePTFE layer's density is greater than about 1 gram per milliliter or the ePTFE layer's wall thickness is less than about 0.2 millimeters, or both. 
     
     
         14 . The artificial vascular prosthesis of  claim 13 , wherein the ePTFE layer's wall thickness is about 0.1 mm. 
     
     
         15 . The artificial vascular prosthesis of  claim 13 , wherein the ePTFE layer's wall thickness is within a range of from about 0.05 mm to about 0.15 mm. 
     
     
         16 . The artificial vascular prosthesis of  claim 15 , wherein the ePTFE layer has a density within a range of from about 1.1 to about 1.5 grams per milliliter. 
     
     
         17 . The artificial vascular prosthesis of  claim 15 , wherein the ePTFE layer has a plurality of nodes, and an average distance between nodes is within a range of from about 6 microns to about 80 microns. 
     
     
         18 . The artificial vascular prosthesis of  claim 13 , wherein the ePTFE layer is further configured to inhibit the formation of a viable neointimal layer on a lumenal surface of the ePTFE layer at the artificial vascular prosthesis's distal end. 
     
     
         19 . The artificial vascular prosthesis of  claim 13 , wherein a proximal end of the artificial vascular prosthesis comprises a single opening and a distal end of the artificial vascular prosthesis comprises two openings, such that the artificial vascular prosthesis is configured for implantation at a vascular bifurcation. 
     
     
         20 . The artificial vascular prosthesis of  claim 13 , wherein the ePTFE sheath has a water entry pressure in a range of from about 10 psi to about 24 psi.