Experimental microvascular autogenous vein grafts for arterial defects: a study of anastomotic sites

Autogenous femoral vein grafts with an average external diameter of 1.5 mm and an average length of 2.87 cm have been used to bridge defects in the contralateral femoral artery of 15 adult New Zealand white rabbits. An experimental microvascular technique to minimise trauma to the graft was performed, by which clamps were never applied to the graft itself. Patency was assessed over a 12-week period, and the overall graft success rate, excluding one technical failure, was 86%. Each of the three failures resulted from thrombosis. Histologic examination of the patent anastomoses showed marked medial damage at 1 week, complicated by fibrosis and calcification by 4 weeks; thereafter the intima developed prominent fibroelastic thickening. This led to a degree of luminal narrowing by 12 weeks. However, the underlying medial damage, attributable to operative trauma, did not seem to diminish luminal patency.