the present invention relates to a support structure / membrane composite device which includes a support structure , such as a radially expandable stent , a porous non - textile polymeric membrane adjacent to said stent and a thermoplastic anchor means attaching said stent to said porous non - textile polymeric membrane . the porous non - textile polymeric membrane is preferably made from expandable fluoropolymer materials . the anchoring means is a thermoplastic material which is dissolvable at the interface between the support structure and membrane by a suitable solvent which wets the membrane surface and deposits the thermoplastic material within the pores of the membrane . methods of preparing the device are also disclosed .