GROWTH-FACTOR PRODUCTION AFTER POLYTETRAFLUOROETHYLENE AND VEIN ARTERIAL GRAFTING - AN EXPERIMENTAL-STUDY

Purpose: Occlusion caused by myointimal hyperplasia appears to be the main reason of late failure of polytetrafluoroethylene (PTFE) arterial bypass grafts. Evidence exists that growth factors are involved in th e genesis of myointimal hyperplasia. The aim of this study was to asse ss the release of platelet-derived growth factor (PDGF) and basic fibr oblastic growth factor (bFGF) by PTFE arterial grafts. Methods: In 15 inbred Lewis rats a 1 cm long segment of PTFE was interposed at the le vel of the abdominal aorta. In a control group of another 15 Lewis rat s a vein graft was implanted at the level of the abdominal aorta. Anim als were killed 4 weeks after implantation and the tissue was studied in organ culture for release of PDGF AA, PDGF BE, and bFGF. Results: P TFE grafts released a greater quantity of PDGF AA than did control vei n grafts (28 +/- 4 ng/cm(2)/72 hr vs 7 +/- 2 ng/cm(2)/72 hr). Similarl y, PTFE grafts released a greater quantity of bFGF than did arterial v ein grafts (308 +/- 22 ng/cm(2)/72 hr vs 204 +/- 20 ng/cm(2)/72 hr). C onclusions: We conclude that PTFE arterial grafts release a high quant ity of growth factor, which could explain, in part, the occurrence of distal anastomotic myointimal hyperplasia.