New prostheses for venous substitution

In 81 Beagle dogs, 6 cm long segments of the inferior vena cava were replaced end-to-end by artificial vascular grafts (10 mm in diameter) without an av-fistula and anticoagulant drugs. Different graft materials have been used, such as various e-PTFE (30-90 microns fiber length) and polyurethane with low and increased microporosity. e-PTFE with 75 microns fiber length and polyurethane with increased porosity showed the best tissue incorporation, complete endothelialization of the whole length and a high patency rate of 80-85% after a follow-up of 12 months. In contrast to other commercially available vascular grafts (textile woven or knitted, e-PTFE 30 microns) tested in previous series, polyurethane and e-PTFE with increased microporosity had already achieved complete endothelialization after 6-12 weeks. Therefore, these optimized prostheses should be introduced into clinical practice for large venous substitution. Thereafter, an adjunctive av-fistula as protection is probably no longer necessary.