The surgical site should be sterilized using alcohol or betadine. It would be safer to perform the medial border incision first. From this incision the skin is raised and dissected laterally. This allows one to directly visualize the axial vessels from underneath. Medially and inferiorly dissection extends to include the groin fat pad. The incisions are then made along the remaining superior and lateral edges of the designed flap. The superior epigastric vessels usually need to be cauterized at the superior edge of the flap. Laterally, bleeding may occur from branches of the superficial epigastric vessels, which is easily controlled by a cautery. Inferiorly a plane should be created between the groin fat pad and overlying skin to protect the epigastric vessels diving into the fat pad. This is simply performed by careful dissection using a scissors. Then the inferior border of the flap is easily incised. The entire flap can be easily raised from cranial to caudal direction secondary to loose skin structure of the rat at a plane above the abdominal wall musculature. The femoral vessels should be identified to trace the superficial epigastric vessels. The entire flap is then freed from the wound bed and pedicled solely on the superficial epigastric vessels to create the axial pattern island groin flap model (Fig. 6.2). The flap can also be utilized as a free flap model revascularizing at the epigastric vessel level, which is technically challenging. For this purpose, in the groin region femoral vessels or in the neck the carotid artery and superficial jugular vein can be used for an end-to-side anastomosis. On the other hand, one may also utilize the entire groin flap using the larger caliber femoral vessels as the pedicle. In this way, not only one may increase the vessel size (femoral artery: 1.0 mm, femoral vein: 1.2–1.5 mm), but also a pedicle length of 2 cm or more can be obtained. This is easily achieved by meticulous dissection, isolation, and ligation or cauterization of various branches emerging with the femoral vessels both proximal and distal to the origin of the superficial epigastric vessels (Fig. 6.3).

First, the femoral vessels are ligated and divided distally. Dissection is then continued proximally. The vascular branches to the gracilis muscle and the superficial circumflex iliac vessels are next to ligate and divide. Maximum attention should be paid not to damage pudic epigastric trunk and or external pudental vein right at the inguinal ligament since bleeding from these veins may be quite difficult to control. These large venous branches do not need to be dissected. The entire flap now pedicled on the femoral vessels can be harvested for replantation or used as a transplantation model (Fig. 6.4). The femoral vessels can be used as recipient vessels for revascularization [7] (Figs. 6.5, 6.6, and 6.7). Six to eight stitches using 10–0 or 11–0 microsuture are sufficient for arterial and venous anastomoses. The carotid artery and superficial jugular vein can be used as recipient vessels if the flap is transferred to the neck. The size of the femoral vessels and these recipient vessels permits end-to-end anastomosis.

Torsion and kinking of the pedicle and undue tension on the anastomotic site should be avoided. After restoration of perfusion, the flap is sutured back to its place in case of orthotopic replantation and transplantation or at a heterotopic site. A few key stitches are placed in the right orientation using interrupted 5–0 monofilament suture. This is followed by a running stitch to finalize the skin closure. Placement of marks around the periphery of the flap prior to skin incisions allows proper positioning of the flap. Autocannibalization is very common among rats. Therefore, rats should be individually housed and protective rat vest should be employed postoperatively to avoid autocannibalization [8].