[Replacement of portal vein with E-PTFE vascular graft; experimental study on process of the endothelialization]

Expanded polytetrafluoroethylene (E-PTFE) vascular graft was been exposed to intestinal content and evaluated the process of endothelialization and as to whether or not the material was feasible for its use under condition similar to clinical pancreatic surgery. In group A, E-PTFE tubular graft was inserted into the portal vein defect. In group B, choledochojejunostomy was also performed combined with the E-PTFE graft interposition. In other groups, bile (group C) or suspension of Escherichia Coli (group D) was put on graft implanted in the portal vein. The grafts were removed from the dogs for histological and scanning electronmicroscopic evaluation at intervals varying from 12 hours to 4 years and 8 months after surgery. Thirty one of 38 grafts were patent (patency rate; 82%). Complete formation of the inner capsule of the graft was essential to endothelialization. Direct extension of the endothelium was seen from the anastomotic site. Sporadic endothelialization was observed, however, communications among islet formed endothelialized portions. It were remarkable and endothelium derived from the host vein. These results demonstrated the feasibleness of clinical application of the E-PTFE graft to portal vein reconstruction with combination of the digestive surgery.