An endoluminal graft which is both expandable and supportive is provided either in a longitudinal form or in a bifurcated form. The graft expands between a first diameter and a second, larger diameter. The support component is an expandable stent endoprosthesis. A cover, liner, or a liner, or both a cover and a liner are applied to the endoprosthesis in the form of a stretchable wall material that is porous, elastomeric and biocompatible in order to allow normal cellular invasion upon implantation, without stenosis, when the expandable and supportive graft is at its second diameter. Preferably, the elastomeric wall material is a polycarbonate urethane.