THE EFFECT OF COLD ISCHEMIA ON THE PATENCY OF MICROVASCULAR REPAIR FOLLOWING ARTERIAL AVULSION INJURY

Avulsion injuries have a poor prognosis for survival in clinical repla ntation surgery. Arterial thrombosis is the most significant factor co ntributing to avulsion replant failure, and severe arterial damage has been observed with this injury. However, patency rates of experimenta lly avulsed arteries repaired immediately are much higher than in the clinical situation. This paper evaluates the effect of an added compon ent-ischemia- on the patency of experimentally avulsed arteries. All a vulsions seen clinically are subject to some degree of ischemia prior to replantation. Ninety rabbits had both femoral arteries avulsed unde r general anesthesia. A 6.5-cm graft was harvested from the left dista l femoral artery. In 20 rabbits (group 1: 0 hours of ischemia) the gra ft was immediately inserted into the defect in the right femoral arter y. Sixty rabbits (20 grafts per group) had their grafts stored at 4 de grees 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 op eration. Patency was assessed 3 weeks after reinsertion. Groups 1 and 2 maintained high patency rates (85 percent); however, group 3 (70 per cent) and group 4 (45 percent) had lower patency rates than group 1, w ith a significant difference between groups 1 and 4 (p < 0.01). In a f ifth group (10 grafts), avulsed 24-hour ischemic grafts were hydrodila ted prior to reinsertion. The patency rate of this group increased sig nificantly (90 percent) compared with group 4 (P < 0.005). Conclusion: These experiments suggest that a combination of avulsion injury and i schemia time is responsible for the poor clinical results of avulsion replantations.