Combined use of ischemic preconditioning and postconditioning in a skin flap model in rats

Purpose: Reperfusion injury (RI) by abrupt restoration of circulation after prolonged ischemia remains an unsolved problem in reconstructive microsurgery. We hypothesized that the combination of ischemic preconditioning (IPreC) and ischemic postconditioning (IPostC) would result in additional preservation of epigastric skin flaps in rats after the ischemic period. Materials and Methods: We used epigastric artery skin flaps measuring 6 cm x 3 cm in 40 Wistar rats. The animals were allocated randomly into four groups: (1) Control, (2) IPreC, (3) IPostC, and (4) IPreC + IPostC group. Flap viability was assessed 1 week after the surgical procedure, and surviving flap area was recorded as a percentage of the whole flap area.Results: Animals in the IPreC, IPostC, and IPreC + IPostC groups showed significantly smaller areas of flap necrosis than those in the control group (P = 0.001). Statistical analyses indicated significant differences between the IPreC group and IPostC group (P = 0.008). However, there were no significant differences between the IPreC group and IPreC + IPostC group (P = 0.453) or between the IPostC group and the IPreC + IPostC group (P = 0.141). Conclusions: IPreC and IPostC showed protective effects against ischemia-reperfusion injury in the epigastric skin flap model. IPostC showed a greater protective effect than IPostC. The combination of preconditioning and postconditioning provided no additional benefit over either intervention performed alone in the skin flap model.