The effect of cold ischemia on the patency of microvascular repair following arterial avulsion injury.

Unlabelled: Avulsion injuries have a poor prognosis for survival in clinical replantation surgery. Arterial thrombosis is the most significant factor contributing to avulsion replant failure, and severe arterial damage has been observed with this injury. However, patency rates of experimentally avulsed arteries repaired immediately are much higher than in the clinical situation. This paper evaluates the effect of an added component--ischemia--on the patency of experimentally avulsed arteries. All avulsions seen clinically are subject to some degree of ischemia prior to replantation. Ninety rabbits had both femoral arteries avulsed under general anesthesia. A 6.5-cm graft was harvested from the left distal femoral artery. In 20 rabbits (group 1: 0 hours of ischemia) the graft was immediately inserted into the defect in the right femoral artery. Sixty rabbits (20 grafts per group) had their grafts stored at 4 degrees C for either 10 hours (group 2), 18 hours (group 3), or 24 hours (group 4) and reinserted into the right femoral artery in a second operation. Patency was assessed 3 weeks after reinsertion. Groups 1 and 2 maintained high patency rates (85 percent); however, group 3 (70 percent) and group 4 (45 percent) had lower patency rates than group 1, with a significant difference between groups 1 and 4 (p < 0.01). In a fifth group (10 grafts), avulsed 24-hour ischemic grafts were hydrodilated prior to reinsertion. The patency rate of this group increased significantly (90 percent) compared with group 4 (p < 0.005).
Conclusion: These experiments suggest that a combination of avulsion injury and ischemia time is responsible for the poor clinical results of avulsion replantations.