Vascularization of the thumb. Anatomy and surgical applications

Microsurgical procedures require rapid and atraumatic dissection of vessels. The authors have tried to schematize the most common variations of the palmar arteries, dividing the thumb into three segments, delimited from the MCP and interphalangeal flexion crease. If a vascular anastomosis has to be carried out in the first segment, the arteries that intersect the palmar surface of such a region do not generally hold much interest for the surgeon as far as size and constancy are concerned. One therefore can avoid frustration while searching in vain for such an artery by starting dissection in the dorsal compartment, where there is a much better chance of finding an artery suitable in every aspect. In replanting a thumb in the second segment, the ulnar collateral artery should be the artery that is looked for first, because it is usually the biggest, the most superficial, and nearly always is composed of a single trunk (Fig. [figure: see text] 18). Let us not forget, however, that the contralateral artery can frequently have all the necessary requirements for an adequate anastomosis. In the third segment, the layout of the vessels is rather difficult to schematize; if it is true that the inverted Y or H shape can make a microanastomosis easier in cases of distal reimplantation (Fig. 19), it is also true that such a pattern is impossible to foresee, and, therefore, the interest of such classification is more academic than practical. Skin loss coverage at the thumb level greatly differs from the that of fingers. In the past few years, a multitude of useful new flaps has been presented by different authors. Their accomplishment (especially those of the last generation, who base their survival on extremely fine vascular axes) presupposes an adequate knowledge of surgical and microsurgical anatomy. Surgeons dealing with this type of pathology should be capable of performing all of the possible flaps because each may be indicated in specific situations.