Human umbilical vein grafts as infrainguinal bypasses: long-term clinical follow-up and pathological investigation of explanted grafts.

This retrospective study examines 105 consecutive infrainguinal bypasses using human umbilical vein (HUV) grafts as blood conduits over a 9 year period. In addition, 39 segments of these grafts were harvested at reoperation and submitted for morphologic, histologic, and scanning electron microscopy examinations. Fifty-two below-knee femoro-popliteal and 53 femoro-distal bypasses were performed in 93 patients. Sixty-seven per cent of these bypasses were performed for either rest pain (18%) or gangrene (49%) and 29% were performed for acute ischemia. Primary and secondary patency rates were not statistically different and were 38% and 29% at 1 and 3 years respectively. Factors found to have a significant effect on patency were site of distal anastomosis, state of distal run-off, and indication for operation. Other complications requiring reoperation included aneurysm formation (8 cases), infection (6 cases), mural thrombus (2 cases), and stenosis (2 cases). Pathologic examination revealed a damaged luminal surface in 22 grafts, deep folds in 8 grafts and delamination of the graft wall in 16 cases. Bacteria were seen in the folds of the grafts and, in addition, the presence of bacteria was documented in 7 out of 26 clinically non-infected grafts. The combination of poor patency rates and pathologic evidence of biodegradative phenomena have led us to discontinue HUV as an arterial substitute.