An improved prosthetic graft for the bypass, replacement or repair of vessels and organs that are in contact with blood flow is disclosed. The prosthetic graft includes a porous prosthetic implant and adherent cells adhered to the outer surface of the implant. The adherent cells are transfected with at least one recombinant nucleic acid molecule encoding at least one protein that enhances patency of the graft. The prosthetic graft has a long-term patency and success rate that is superior to other previously described prosthetic grafts designed for such use. Also disclosed are methods of making and using such a graft.