MODIFICATION IN FLAP DESIGN OF THE EPIGASTRIC ARTERY FLAP IN RATS - ANEW EXPERIMENTAL FLAP MODEL

The standard rat epigastric artery flap has been a very reliable model for flap research. The purpose of this study was to describe a modifi ed design of this flap that included only the medial branch of the epi gastric artery. Axial-pattern epigastric island skin flaps, measuring 8 x 8 cm, were raised in two groups of Sprague-Dawley male rats. In gr oup A (N = 20) the vascular pedicle consisted of the main trunk of the epigastric vessel and both medial and lateral branches. In group B (N = 20) the flap was based solely on the medial branch of the epigastri c artery, excluding the large lateral branch. The flaps were elevated and then sutured back to their beds. Flap survival was studied and the amount of viable skin in both groups was compared 1 week later. The r ats were photographed using a digital camera and the images were analy zed using imaging software. The mean percentage surviving flap area in group A was 86.24% and in group B it was 69.72%, which is statistical ly significant (p < 0.001). We believe that this flap model, with its new modified design that includes a larger flap and inclusion of only the medial branch, will broaden its application to microsurgery. The m ain advantage of this flap over the conventional epigastric flap is th at in this model it is possible to achieve predictable and consistent necrosis in the random extension of the flap.