VARIATIONS IN THE VASCULAR PEDICLE OF THE RAT GRACILIS MUSCLE FLAP

The rat gracilis muscle is a reliable model for microsurgical research . Exploration of 364 inguinal regions and preparation of 80 free graci lis muscle flaps in Sprague-Dawley and Lewis rats revealed six distinc t origins of the dominant arterial pedicle and lour Variations of the venous pedicle. Popliteal, external iliac, and truncus pudendoepigastr icus associations are described for the first time in this study. The total incidence of atypical variation of arterial pedicle origin is 20 .7 percent. The most common origin of muscular branch arteries are the superficial epigastric artery (53.3 percent), femoral artery (22.0 pe rcent), popliteal artery (14.6 percent), and the external iliac arteri es (5.5 percent). Muscular branch Veins drain most frequently into the femoral vein (79.1 percent). Gracilis muscle Flaps prepared from rats weighing 329 +/- 45 g weighed an average of 0.64 +/- 0.13 g, and thei r Volume averaged 0.87 +/- 0.12 mi. Muscular branch artery and vein di ameters (external) averaged 0.21 +/- 0.05 mm and 0.54 +/- 0.06 mm, res pectively. This new anatomic information is essential for reproducible microsurgery research using the rat gracilis muscle.