Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction

Primary soft-tissue covrage for large palmar defects of the fingers is a difficult problem for Cases ill Which homodigital or heterodigital flaps cannot be used. The aim of this study, was to explore the muscular and a neutral anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mill) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalanar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 min). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in all oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 nim) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 X 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches front the palmar digital nerve. supplying the midpalmar at-ea. From this study, two different reverse flaps were proposed. First, a 5 X 2 cm flap from the distal midpalmar region was elevated oil the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal The second flap candidate was that front the radial aspect of the midpalm, Which was by the terminal branch of, the superficial palmar. arch. In studio's with cadaver hands, connection of (his artery with the deep) arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft-tissue loss of fingers.