Dual preconditioning: effects of pharmacological plus ischemic preconditioning on skin flap survival

To enhance skin flap viability, pharmacological and ischemic preconditioning methods were investigated intensively. This study was designed to determine whether combined local dexamethasone administration and pedicle clamping would result in an additive enhancement of skin flap survival in the rat model. Twenty-eight male Sprague-Dawley rats were included in dexamethasone injection, clamping, clamping plus dexamethasone injection, and control groups. A rectangular random skin flap (3 x 11 cm) was outlined as bipedicled on the back of the animals. The dexamethasone or saline injection points in the flap were standardized. In the dexamethasone injection group, after raising the flaps, a total of 2.5 mg/kg dexamethasone was injected into the flaps. In the ischemic preconditioning group, 1 hour after saline injection, the cranial pedicle was clamped for 20 minutes and then 40 minutes reperfusion was performed. The clamping-plus-dexamethasone injection group was the same as the clamping group except dexamethasone was injected instead of the saline. In the control group, saline was injected instead of dexamethasone. Regardless of the group, all flaps were cut at the cranial side at the end of the 2 hours and were sutured back. On day 7, the surviving area was significantly greater in all experimental groups compared with the control group (p<0.05). Furthermore, the clamping-plus-dexamethasone group demonstrated the highest flap viability.