The influence of systemic aspirin on rat small diameter vein grafts: a scanning electron microscopic study

Small diameter vein grafts have been shown previously to have a poor patency rate unmedicated rats. Oral aspirin administered to male and female rats for one week pre-operatively reduced the number of platelets laid down on the luminal surface of their grafts, and resulted in a greater number of grafts remaining patent up to one hour after the blood flow through them had been established. The patency rate of grafts examined one to 17 weeks after operation was significantly better in female rats than in males given aspirin pre- and post-operatively. The different effect of aspirin in preventing thrombosis of the vein grafts of the two sexes makes its clinical usefulness for this purpose suspect.