Anatomic study of the island flaps on the dorsum of the first metacarpal

Objective To investigate the anatomical basis for four types of island flaps from the dorsum of the first metacarpal. Methods32 hands of fresh adult cadavers were studied. Vascular perfusion with dye,angiography,and specimen transparency were performed before microsurgical anatomy study was carried out. Distribution of the blood vessels and the concomitant cutaneous nerves were observed. Results 1. At the dorsal aspect of the first metacarpal, a vascular network in the fascial layer is formed by the vessels as follows:(1) the dorsal carpal branch of the radial artery;(2) the radial dorsal digital artery of the thumb;(3) the ulnar branch of the first dorsal metacarpal artery to the thumb;(4) the collateral branch of the radial palmar artery of the thumb distributing to the MP joint;(5) the ulnar dorsal digital artery of the thumb arising from principal pollicis artery. The vascular network had segmental concomitance of the dorsal superficial nerves of the thumb. 2. In this area, there were two accompanying superficial veins with venous valves. Conclusions Four types of island flaps,based on the radial dorsal digital artery of the thumb, the fascial vascular pedicle of the radial aspect of the thumb, the ulnar branch of the first dorsal metacarpal artery of the thumb, or the neurovascular pedicle from the dorsum of the thumb, can be harvested from the dorsum of the first metacarpal for coverage of tissue loss.