VENA-CAVA REPLACEMENT WITH A PERITONEUM-LINED VASCULAR GRAFT

The use of the peritoneum as a venous conduit was analyzed because of the inherent fibrinolytic properties of the mesothelium. A canine mode l in which the infrarenal inferior vena cava was replaced with interpo sition grafts (2 cm) of either a peritoneal tube, polytetrafluoroethyl ene (PTFE), or PTFE lined with peritoneum (lined graft) was studied. V enograms were performed 1 and 6 weeks after graft implantation for the percent area reduction of the lumen. crafts were explanted at 6 weeks for light and scanning electron microscopy. The percent area reductio n at 1 week for all grafts was found to be predictive of graft clottin g by 6 weeks. At 6 weeks, one of three peritoneal tube grafts (33%), s ix of seven PTFE grafts (86%), and four of seven lined grafts (57%) we re patent. Histologic studies demonstrated that stenosis of PTFE graft s was due to intraluminal thrombus formation, whereas lined grafts ste nosed due to granulation tissue growth between the mesothelium and PTF E, A cellular circumferential intraluminal lining was found in four of four lined grafts, but in none of six PTFE grafts (p < 0.01). Further more, none of four lined grafts had intraluminal thrombus, but all of six PTFE grafts did (p < 0.01). Peritoneum-lined PTFE grafts maintain a continuous circumferential cellular lining, but have no improvement in short-term patency compared to PTFE alone.