Circulatory and metabolic events in pig island skin flaps after arterial or venous occlusion

After 1 hour of arterial or venous occlusion, the circulatory and metabolic events in island skin flaps of the pig were studied. Both occlusion types showed significant but transient increases in glucose uptake and a parallel release of lactate, hypoxanthine, and potassium. Oxygen uptake and noradrenaline release were not significantly affected. No significant difference between the arterial and venous occlusions was seen in the metabolic parameters. The flap blood flow, measured by total venous outflow and laser Doppler flowmetry, was significantly lower after venous than after arterial occlusion. This long-lasting difference in flow response may help to explain the observation that venous occlusion is more deleterious to skin flaps than arterial occlusion. A mechanism underlying these results may be more pronounced microthrombotization and/or edema formation after venous occlusion than after arterial occlusion.