Prosthetic replacement of the superior vena cava treated with antiplatelet agents.

The effects of cepharanthin and dipyridamole depot capsules (RAD) on the fate of Teflon fluorocarbon resin grafts used for replacement of the canine superior vena cava were studied. After short-term observation of 11 implanted grafts, 57 adult mongrel dogs underwent superior vena caval replacement with these Teflon grafts. Cepharanthin (2 mg/kg daily) and RAD (10 mg/kg daily) were administered after surgery to 28 and 14 animals, respectively. Dogs were killed at 12 days to 6 months after graft implantation. Fifteen dogs served as controls. In the cepharanthin-treated group, three grafts exhibited luminal obstruction with severe intimal hyperplasia, but smooth, semitransparent thin neointima was recognized in 25. The endothelial cell lining of the neointima exhibited excellent spread 2 months after implantation. Although one graft was obstructed with hyperproliferative fibrosis in the RAD-treated group, a well-developed neointima with complete coverage of endothelial cells was confirmed in 14 dogs. With regard to the rate of occurrence of luminal obstruction, these data were significantly different from those of the control group, which suggests that intimal hyperplasia can be reduced by treatment with antiplatelet agents.