TRANSGRAFT INFUSION OF HEPARIN TO PREVENT EARLY THROMBOSIS OF EXPANDED PTFE GRAFTS IN CANINE FEMORAL VEINS

Recently we designed an expanded polytetrafluoroethylene (ePTFE)-based local infusion device that delivers therapeutic agents directly throu gh the graft wall in the region adjacent to the upstream anastomosis, thereby achieving a high drug concentration downstream along the graft -blood interface. In this study we evaluated the effects of infusing h eparin by this method on graft patency and neointimal hyperplasia in a canine model of femoral vein replacement. Five dogs underwent bilater al femoral vein replacement with the device. In each case one graft wa s infused with continuous heparin (48 U/kg/day) while the contralatera l control graft received phosphate-buffered saline solution for 14 day s. AII heparin-treated grafts were patent and all control grafts were thrombosed at 14 days. There was no significant difference in systemic activated partial thromboplastin time among samples taken preoperativ ely, at 48 hours, and at 14 days of implantation (p > 0.5). There was no significant difference in neointimal hyperplasia between the upstre am and downstream anastomoses in heparin-treated grafts. These data de monstrate that the transgraft infusion of heparin preserved venous ePT FE graft patency without measurable systemic anticoagulation. Thus thi s approach may represent an attractive strategy for maintaining patenc y of synthetic venous grafts.