A vascular prosthesis and method are disclosed comprising a first flexible stent having a lattice structure with a compacted configuration and an expanded configuration, a second flexible stent inside the first flexible stent to form a tubular structure, a first film layer of graft material such as expanded polytetrafluoroethylene sandwiched between the first and second flexible stents, and a second film layer of expanded polytetrafluoroethylene sandwiched between the first and second flexible stents, the second layer having a higher rigidity and a lower plasticity than the first layer.