Anatomy and clinic application of reverse-flow island flaps on dorsal thumb web with dorsoulnar artery of thumb as a pedicle

Abstract

Objective To explore a surgical treatment of skin defects on the thumb by reverse-flow island flaps on dorsal thumb web with dorsoulnar artery of thumb as a pedicle.Methods The origin,courses and distribution of dorsoulnar artery of thumb from 70 adult cadaveric hand specimens perfused by red latex were explored.Skin defects on the thumb of 8 cases were repaired with reverse-flow island flaps on dorsal thumb web.The cut areas of flaps vary from 4.5 cm × 3.0 cm to 7.5 cm × 4.0 cm.Results There were 4 types of the dorsoulnar artery of thumb basing on the origin and courses.Type Ⅰ was outside the first dorsal interosseous muscle type,which was the dorsoulnar artery of thumb mainly originated from the first dorsal metacarpal artery and cross through the surface of the first dosal interosseous muscle(42.9％).Type Ⅱ was under the first dorsal interosseous muscle type,which was from the thumb principal artery or deep branch of radial artery and run under the first dorsal interosseous muscle(41.4％).Type Ⅲ was mixed type from the anastomose point of above two arteries at the level of the first metacarpophalangeal joint(11.4％).Type Ⅳ was absence type (4.3％).Eight flaps fully survived.Excellent texture and satisfying appearance of the flaps as well as normal thumb web function were verified after 8 months' follow-up.Conclusion It is significant to determine the type of dorsoulnar artery of thumb to decide different operations due to the artery's considerable variation.The reverse-flow island flap on dorsal thumb is an ideal method to repair soft tissue defect on the thumb for its convenient operating and little effect in the donor area. Key words: Thumb ; Dorsoulnar artery of thumb; Island flaps; Thumb web; Applied anatomy; Skin defect