Tubular prothesis having a composite structure

Abstract From the Canadian patent

A tubular prosthesis having a composite structure comprising (i) tubular polytetrafluoroethylene having a microfibrous structure comprising small nodes interconnected with fibrils and (ii) materials which can be absorbed by a living body wherein (a) said polytetrafluoroethylene has a greater average fibril length on the outer surface than on the inner surface and, the fibrous structure of said polytetrafluoroethylene varies continuously across the thickness of the tube wall wherein said inner surface has said fibrous structure being predominantly oriented along the axial direction and said outer surface has said fibrous structure being predominantly oriented along the concentric direction; …