Is the dorsal vascular system sufficient to vascularize the entire teguments of the thumb?

Purpose: Simultaneous lesions of both proper digital arteries of the thumb are common in hand trauma surgery. The purpose of this anatomical study was to determine if the dorsal arterial network could be sufficient to ensure the vascularization of the thumb skin sheath.
Methods: We carried out a cadaveric study on 22 hands. The ulnar and radial proper digital arteries of the thumb were ligated at the base of the first phalanx. Red dye was injected into the radial artery and blue dye into the ulnar artery at the wrist level. Visual evaluation of skin staining and systematic photographs was done at 1, 3 and 10 min after injection of dyes.
Results: Staining of the thumb sheath was obtained in 100% of the dissections and complete in 91.91% of cases. Staining originated from mixed radial and ulnar artery origins in 81.82% of cases. It was incomplete in 9.09% of cases with a missing on the dorsoradial edge of the proximal phalanx. In one dissection, the whole hand skin was only stained red, and in another dissection only stained blue.
Conclusion: The dorsal vascular network ensures the substitution of the skin vascularization in more than 90% of cases when ligating the proper digital arteries of the thumb. A clinical impression of good skin vascularization after injury of both proper digital arteries might lead the surgeon not to perform systematic revascularization, but the risk of variable damages of adjacent tissues due to an interruption of one major arterial system requires a palmar arterial anastomosis whenever possible.