Blood flow and microcirculatory changes in an ischemia-reperfusion injury model: experimental study in the rabbit.

This is the first in a series of studies designed to investigate the simultaneous changes in blood flow and microcirculation in an island flap during ischemia, in an ischemia-reperfusion model in the rabbit. An island groin flap based on the inferior epigastric vessels was harvested in 17 rabbits. The flap was rendered ischemic for 4 (n = 4), 6 (n = 4), and 16 (n = 9) hr by applying a microvascular clamp to both the inferior epigastric artery and vein. The blood flow in the epigastric artery and the microcirculation of the flap were monitored for 1 hr before the ischemia and for 3 hr after the ischemia period, using a transonic Doppler and a laser Doppler, respectively. Both the blood flow and the microcirculation of the flap were found significantly increased immediately after the ischemia in the 4- and 6-hr ischemia groups, compared to the pre-ischemic values. In the same groups, blood flow and microcirculation remained elevated over pre-ischemic levels, indicating a hyperemic response. In the 16-hr ischemic group, blood flow and microcirculation values remained significantly lower than the pre-ischemic readings at all points in time, demonstrating ischemia-reperfusion injury.