The beneficial effect of heparin in preischemic perfusion solutions for cold-stored skin flaps

Storage of skin flaps in the cold before replantation increases their tolerance to ischemic damage. Rat epigastric skin flaps were perfused immediately before 2 days of cold ischemia with 3 ml of normal saline containing either 10 U per milliliter of heparin (group 1, N = 11) or normal saline (group 2, N = 10), or stored without perfusion (group 3, N = 6), and replanted. Flap viability was assessed 7 days later. The mean flap survival in groups 1, 2, and 3 was 73% (p<0.01 compared with group 2), 10%, and 33% respectively. Intravascular fibrin deposits were detected histochemically 5 minutes before reperfusion in nonperfused flaps and 5 minutes after reperfusion in saline-perfused flaps, but not in flaps perfused with heparinized saline. Angiography revealed evidence of no reflow in the first 5 minutes of reperfusion in saline-perfused flaps, but normal blood flow in heparinized saline-perfused flaps. Tissue water content, myeloperoxidase activity, and hydroperoxide levels after 1 and 24 hours of reperfusion were not significantly different in flaps perfused with heparinized saline and normal saline. These findings indicate that in skin flaps perfused before ischemia, flaps perfused with heparinized saline survive significantly better than flaps perfused with normal saline. They also survive better than nonperfused flaps but the improvement is not significant.