USE OF UROKINASE DURING SECONDARY ISCHEMIA IN EXPERIMENTAL SKIN FLAPS

The ability of urokinase to salvage experimental flaps after a seconda ry ischemic insult was investigated in a rat model. Unilateral abdomin al island skin flaps based on the superficial inferior epigastric vess els were raised and subjected to either 4 or 6 hours of primary ischem ia followed by 12 hours of reperfusion and varying lengths of secondar y ischemia. At the conclusion of secondary ischemia, the flaps were pe rfused with either lactated Ringer's solution or urokinase. One group of flaps served as a control and received no postischemic perfusion wa shout. The secondary critical ischemia time at which 50% of the flaps failed clinically was greater for flaps perfused with urokinase. Furth ermore, the survival rates for all flaps perfused with urokinase were significantly greater than either control flaps or flaps perfused with lactated Ringer's solution (p < 0.05). Flap survival decreased signif icantly in all groups with increasing primary and/or secondary ischemi a time (p < 0.05).