Patients who are not candidates for an abdominal flap may be candidates for a flap utilizing tissue from the buttocks. The SGAP flap takes tissue from the upper buttocks based on blood vessels that “perforate” through the gluteus maximus muscle. During this procedure, the perforator vessels are gently dissected by splitting the fibers of the muscle, which is thereby preserved. This tissue is then transferred to the chest, where it is sculpted into a breast mound and reattached to blood vessels using a microscope. Bilateral breast reconstruction using the SGAP flap is usually performed in two separate operations.