E-selectin and L-selectin blockade in pure skin flaps exposed to ischaemia and reperfusion injury

The inflammatory recruitment of leucocytes is a main cause of tissue damage in ischaemia/reperfusion (I/R) injury. Under appropriate flow conditions, E-selectin and L-selectin participate in the initial deceleration of neutrophils (PMNs) on inflamed endothelial cells before transmigration of PMNs into the surrounding tissue. Previous work from our lab showed increased survival of I/R injured myocutaneous flaps after treatment with anti-E/L-selectin. In this study, we have evaluated a combined antibody to E-selectin and L-selectin (EL-246) in porcine pure skin flaps exposed to I/R injury. Buttock skin flaps were exposed to eight hours of ischaemia and 20 hours of reperfusion. EL-246 or saline was given intra-arterially into the flaps. Estimated surviving area was not improved in the treated group. The lack of effect of EL-246 supports our suspicion that different mechanisms are involved in I/R injury in myocutaneous flaps compared with pure skin flaps. As a certain shear stress must be present for the selectins to exert their effect, a possible explanation for the diverse results in muscle and skin might be different reflow patterns.