BASIC FIBROBLAST GROWTH FACTOR AND MYOINTIMAL HYPERPLASIA AFTER EXPERIMENTAL POLYTETRAFLUOROETHYLENE ARTERIAL GRAFTING

Objective: To assess the role of polyclonal antibodies to basic fibroblast growth factor (bFGF) in inhibiting myointimal hyperplasia after insertion of polytetrafluoroethylene (PTFE) grafts in rats. Design: Experimental study. Setting: University laboratory, Italy. Animals: 24 inbred Lewis rats. Interventions: A segment of PTFE 1 cm long was interposed in the abdominal aorta. The animals were randomised in two groups, n = 12 in each. The first were given polyclonal antibodies to bFGF at the time of operation, and for the first two postoperative days; and the second were given non- specific IgG at the same time periods. Main Outcome and Measures: Two animals died during the immediate postoperative period of anaesthetic complications. 12 animals (6 in each group) were killed 7 days postoperatively (24 hours after injection of 5-bromo-deoxyuridine BrdU) to assess smooth muscle cell proliferation. The remaining 10 animals (5 in each group) were killed after 1 month to assess the degree of anastomotic myointimal hyperplasia. Results: Antibodies to bFGF resulted in less smooth muscle cell proliferation at the anastomoses as well as anastomotic myointimal hyperplasia. Smooth muscle cell proliferation was reduced to about half in animals treated with anti-bFGF antibodies. Neointimal thickness was reduced in treated animals. Conclusions: We conclude that after PTFE arterial grafting there is increased production of bFGF at the anastomotic regions that leads to smooth muscle cell proliferation and formation of myointimal hyperplasia. Agents that reduce the production of bFGF may also reduce the development of myointimal hyperplasia after PTFE arterial grafting.

OBJECTIVE: To assess the role of polyclonal antibodies to basic fibroblast growth factor (bFGF) in inhibiting myointimal hyperplasia after insertion of polytetrafluoroethylene (PTFE) grafts in rats. DESIGN: Experimental study. SETTING: University laboratory, Italy. ANIMALS: 24 inbred Lewis rats. INTERVENTIONS: A segment of PTFE I cm long was interposed in the abdominal aorta. The animals were randomised in two groups, n = 12 in each. The first were given polyclonal antibodies to bFGF at the time of operation, and for the first two postoperative days; and the second were given non-specific IgG at the same time periods. MAIN OUTCOME AND MEASURES: Two animals died during the immediate postoperative period of anaesthetic complications. 12 animals (6 in each group) were killed 7 days postoperatively (24 hours after injection of 5-bromo-deoxyuridine BrdU) to assess smooth muscle cell proliferation. The remaining 10 animals (5 in each group) were killed after 1 month to assess the degree of anastomotic myointimal hyperplasia. RESULTS: Antibodies to bFGF resulted in less smooth muscle cell proliferation at the anastomoses as well as anastomotic myointimal hyperplasia. Smooth muscle cell proliferation was reduced to about half in animals treated with anti-bFGF antibodies. Neointimal thickness was reduced in treated animals. CONCLUSIONS: We conclude that after PTFE arterial grafting there is increased production of bFGF at the anastomotic regions that leads to smooth muscle cell proliferation and formation of myointimal hyperplasia. Agents that reduce the production of bFGF may also reduce the development of myointimal hyperplasia after PTFE arterial grafting.