[Free sensory or retrograde pedicled fasciocutaneous thenar flap: anatomic study and clinical application]

In 1993, Kamei et al. presented the "free thenar flap" based on the superficial palmar branch of the radial artery. In light of the microsurgical importance of this vessel, we decided to perform an anatomic study. 20 fresh upper extremity specimens were injected with 30 cc colored latex and examined. The superficial palmar branch of the radial artery was constantly found, originating on an average 23 mm proximal to the scaphoid tubercle with an average diameter of 0.8 mm. Normally, five cutaneous branches to the thenar skin and a branch of the antebrachial nerve, securing the sensibility of the flap, have been found. Based on this neurovascular pedicle, a thin sensory, fasciocutaneous flap can be tailored to reconstruct large palmar defects of the fingers. Primary wound closure is possible, provided the flap is not broader than 15 mm. In about half of the cases, the superficial palmar branch of the radial artery anastomoses with the superficial palmar branch of the ulnar artery, forming the superficial palmar arch. In these cases, the flap can be raised as a reversed pedicle thenar flap. To our knowledge, this flap has not yet been reported in the literature.