Perfusion of free flaps with heparinized whole blood during ischemic storage

This study was designed to investigate the use of heparinized whole blood as a perfusate for extending the tolerable ischemic interval of free flaps. Unilateral free groin flaps stored at 20 degrees for 30 hr were used in four groups of 12 rats each. One group served as a control while a second involved systemic heparinization immediately prior to raising the flap for storage. The third and fourth groups underwent a brief perfusion (10-30 min) with anticoagulated whole blood midway through the ischemic interval (15 hr); one of these groups involved temporary revascularization to the arterial system of a donor heparinized rat. The fourth group received hand-perfused anticoagulated (with heparin and citrate) whole blood administered through a cannula placed in the flap artery. After the 30-hr interval, flaps were replanted to the original groin site with standard microvascular technique. Percentages of the numbers of surviving flaps were: 8 percent for controls, 58 percent for both preheparinized and donor-perfused flaps, and 92 percent for the hand-perfused group. The authors conclude that anticoagulated blood within the flap vasculature during ischemic storage can improve the chance for viable reperfusion after replantation, and may offer a safeguard against the no-reflow phenomenon after extended ischemia.