Clinical application and refinement of the microdissected thin groin flap transfer operation.

A microdissected thin groin flap is a uniform thin flap with a long vascular pedicle prepared by microdissection of the deep branch of the superficial circumflex femoral system (SCIS). However, the safe dimensions of the flap are not known, and anatomical variations of the SCIS sometimes impede elevation of the flap based on the deep branch. Therefore, modifications of the operation and accumulation of empirical knowledge are required for safe preparation of the flap. Thirty cases of various types of tissue defects were reconstructed using microdissected thin groin flaps. Among these, large flaps exceeding 20 cm on the long axis were investigated to estimate the maximum dimensions of the flap. Additionally, new operative procedures were developed to overcome anatomical variations of the SCIS and to assist preparation of a thin flap. One flap was lost due to a venous thrombosis. A small distal area of three large flaps became necrotic. The perforators from the deep branches were absent in five cases, and three of these flaps were successfully elevated based on the superficial branch using the new method. The clinically deduced safe dimensions of the flap ranged from 5 x 2 cm to 25 x 12 cm. The microdissected thin groin flap was found to be useful for coverage of various types and sizes of skin defects. Through improved operative procedures, a large and extremely thin flap can be prepared safely even if the perforator from the SCIS is absent.