Preconditioning of the distal portion of a rat random-pattern skin flap.

It has been shown that preconditioning either by proximal pedicle clamping or by pedicle intravascular drug administration, for example with adenosine, can improve flap survival. These methods, however, are not well suited to random-pattern flap transfer in the clinical setting. The aim of this study was to evaluate clinically applicable preconditioning methods for random-pattern flaps. Eighteen male Sprague-Dawley rats were used. Bipedicled dorsal skin flaps (2 x 8cm) containing panniculus carnosus were elevated. In the ischaemic preconditioning group the cranial pedicle was clamped for 20min, followed by 40min reperfusion before the cranial pedicle was cut, producing a caudally based random-pattern flap. In the pharmacologic preconditioning group adenosine was locally injected in the cranial half of the flap before the cranial pedicle was cut. In the control group saline was locally injected instead of adenosine and the pedicle was cut in the same manner. Flap survival area was evaluated at day 7. Flap survival area in both preconditioning groups was significantly higher than in the control group (P<0.05). Both preconditioning methods can improve random-pattern flap survival in rats. These methods may prove useful in the clinical setting.