Applied anatomied study in bilobed micro-flap of second dorsal metacarpal artery and dorsal digital artery

Objective To observe the location and the distribution of distal 1/3 segment of the second dorsal metacarpal artery, the finger web artery and the dorsal digital artery, and to provide anatomical data for repairing the soft tissue defect on the hand with bilobed or multi-lobed micro-flap with second metacarpal dorsal artery-dorsal digital artery. Methods From June, 2018 to March, 2019, 34 fresh adult upper limb specimens were selected. The radial and ulnar arteries were perfused with red latex in 24 specimens. The radial and ulnar arteries were infused with cast materials to make cast specimens in 10 specimens. The location and distribution of the distal 1/3 segment of the second dorsal metacarpal artery, the finger web and the dorsal digital artery were observed. Results The distal 1/3 segment of second dorsal metacarpal artery extended (4±1) cutaneous branches, and continued to become the finger web artery at the plane of the articular surface. The length of the finger web artery was (2.5±0.6) cm, and there were 4 types anastomic methods of communication with arteries. The second dorsal metacarpal artery extended 2 finger dorsal artery to the proximal dorsal skin of the middle finger and index finger. The length of dorsal digital artery was 2.6±0.4 cm and the diameter was 0.2±0.1 mm. Four to 6 micro-cutaneous branches were extended and consistent with the nearby skin cutaneous branches. Conclusion The distal segment of the second dorsal metacarpal artery and the dorsal digital artery is anatomically constant. The distal segment of the second dorsal metacarpal artery and dorsal digital artery are the pedicle for the design of the bilobed flap of middle finger and index finger to repair small soft tissue defect on the thumb and purlicue. Key words: Second dorsal metacarpal artery; Finger web artery; Dorsal digital artery; Bilobed flap; Applied anatomy