Split gluteus maximus muscle flap in the reconstruction of the external anal sphincter and levator ani.

We treated 52 patients with anal and low rectal carcinomas by orthotopic reconstruction of the anus, using an unilateral split gluteus maximum (GM) muscle flap to form the external anal sphincter and levator ani together with invagination of the colon to form the internal sphincter after radical resection of carcinoma. Among the 36 patients who were followed up for over 6 months, 34 (94.4%) exhibited good to excellent continence.