Extended split superior gluteus maximus musculocutaneous flap and reconstruction after resection of perianal and lower gluteal hidradenitis suppurativa.

Various modifications of the gluteus maximus musculocutaneous flap have been reported. Among them, the split gluteus maximus musculocutaneous flap is easy to prepare and does not leave ambulatory insufficiency. However, the safety of extending the skin portion beyond the margin of the muscle has not yet been clarified. Angiography was performed systemically on 11 fresh cadavers, and the distance the margin of the gluteus maximus muscle could be extended was observed. Based on these anatomical data, reconstruction after total skin resection of perianal and lower gluteal hidradenitis suppurativa was performed with an extended split superior gluteal maximus musculocutaneous flap. Surgery was performed on three sides of two patients. From the anatomical results, we found that it is possible to extend the flap beyond the iliac crest several centimetres superiorly, and to the gluteal fold inferiorly, and several centimetres laterally. We designed the flap such that the extended area is situated in these areas. All flaps took well and did not show any congestion or necrosis. There were no recurrences at least 1 year after surgery. When reconstructing the lower part of the buttock, an extended split superior gluteus maximus musculocutaneous flap is easy to raise and leaves aesthetically satisfactory results. Thus it may be the first choice for reconstruction of the lower buttock.