Microsurgical second dorsal metacarpal artery cutaneous and tenocutaneous flap for distal finger reconstruction: anatomic study and clinical application

In this paper, we report on the anatomical study of 34 cadaveric forearms with red latex injection and the clinical application of this study to 11 cases of microsurgical second dorsal metacarpal artery (SDMA) flaps. There were 8 cutaneous cases and 3 tenocutaneous cases using SDMA flaps for distal finger reconstruction. The SDMA was classified into 2 types and 4 subtypes according to its anatomical origin and course. Type I (76.5%) originated from the dorsal branch of the radial artery at the snuffbox. Type II (23.5%) originated from the perforating branch of the deep palmar arch at the bases of second and third metacarpal bones. Diameter of the SDMA was 1.2 +/- 0.2 mm at its snuffbox origin, and 1.0 +/- 0.1 mm at the base of the second and third metacarpal bones. Clinically, microsurgical SDMA free flaps were raised and transferred for repair of finger injuries. Ten flaps survived completely. One flap failed due to thrombosis of vascular anastomosis. In conclusion, the second dorsal metacarpal artery is a constant and reliable vessel for microvascular anastomosis in microsurgical SDMA flap transfer. This flap can be used as an alternative for hand and finger reconstruction, and especially repair of a distal phalanx, when either an orthograde or retrograde island SDMA flap is unable to reach the defect.