A new flap model in the rat.

Abstract

Standardized skin flap models in the rat, such as the McFarlane and Finseth flaps, have suggested placement on the rat of only a single flap. The single flap, because of variations in skin vasculature among rats, may be problematic and require prohibitively large numbers of rats to obtain statistically significant results. In this study of 60 Sprague-Dawley rats, we have developed a flap model designed to be paired in a single rat and standardized to serve as the experimental flap and the control. At the level of the symphysis pubis, symmetrical, three-sided, caudally based, bilateral skin flaps, 2 cm in width, were extended to different bony landmarks. Only the length of the flaps was varied. The inferior epigastric pedicle was then divided. The flap length, which optimally produced predictable and persistent necrosis, was found midway between the xiphoid and the sternal notch. The model was pharmacologically manipulated with the injection of superoxide dismutase through the epigastric vein before division of the inferior epigastric pedicle; this scavenger did not effect the survival of the random pattern flaps.