LEUKOCYTE-DEPLETING EFFECT OF HYPOTHERMIA ON MUSCLE FLAP MICROCIRCULATION FOLLOWING ISCHEMIA-REPERFUSION INJURY

The aim of this study was to determine the effect of leukocyte-endothe lial interaction and capillary perfusion on the microcirculation of mu scle flaps submitted to ischemia in normothermic and hypothermic condi tions. The cremaster muscle flap model was employed. Sixty rats were s tudied in six groups: normothermic and hypothermic control groups and groups that underwent reperfusion after 4 and 6 hours of ischemia in b oth normothermic and hypothermic conditions. In each group the followi ng measurements were made: main vessel diameters, red blood cell veloc ities, the number of perfused capillaries, and the number of leukocyte s rolling and sticking in the postcapillary venules. Hypothermia decre ased the flow rate significantly and eliminated leukocytes from the mi crocirculation. Six hours of ischemia under normothermic conditions pr oved to be lethal for these muscle flaps, whereas hypothermia preserve d flap viability.