The combined gracilis and semitendinosus free flap in the rat.

A free-flap model in rats is presented, that consists of gracilis and semitendinosus muscles pedicled on the femoral vessels, in continuation with deep femoral and saphenous vessels. This flap was transferred to the contralateral side in 40 rats and yielded a 95 percent survival rate. The weight of the flaps averaged 1.65 gm, and the mean pedicle length was 20 mm. The flap is reliable, versatile, and may be used as a muscular, musculocutaneous, or osteomusculocutaneous free flap. The gracilis and semitendinosus muscles may be innervated independently as functioning muscle units. In the musculocutaneous flap, each pedicle may be monitored separately by raising two independently vascularized skin islands. The statistical distribution of the origins of the deep femoral vessels was established in 164 groin dissections; two origins of the vessels not previously described are reported here. The volume of the transferable tissue-about three times more than described in previous studies-and the reliability of the flap make it an ideal microsurgical, experimental model.