The SIEA (superficial inferior epigastric artery) flap is even more anatomically dependent than other forms of autologous reconstruction. Again, skin and fat of the lower abdomen is used for microsurgical transfer to the mastectomy site, however these vessels do not come from under the abdominal muscles. Just as their name implies, these vessels are more superficial and, if present in adequate diameter, will make it so the muscles do not even need to be touched at all. When the vessels are of adequate size, this reconstruction is typically reserved when only half of the abdomen is needed to reconstruct the breast because these vessels may not adequately supply the tissue across the midline. The skin incision repair is no different than the other autologous reconstructions using abdominal tissues.
The S-GAP (superficial gluteal artery perforator) flap is a similar concept to the DIEP flap in that it uses skin and fat, but spares the muscle. A wedge of skin and fat from the upper part of the buttocks is removed and transferred to the mastectomy site using microsurgical techniques. This is typically an option for women who would like to avoid implant reconstruction (or are not a candidate for such) and do not have the option of abdominal tissues as a donor site.
Latissimus dorsi flap (back)
The use of the latissimus dorsi musculocutaneous flap was one of the first methods of breast reconstruction. The latissimus dorsi muscle (of the “lat”) is a broad, flat, roughly triangular muscle of the back. It extends from the thoracic spine and sweeps downward to the posterior iliac crest. It is used in motions such as pull-ups. When this muscle flap is used for reconstruction, it is typically tunneled from the back to the chest where the mastectomy defect is located. Because its volume alone is usually insufficient to reconstruct the breast, the latissimus dorsi flap is commonly used in conjunction with an implant. Although the latissimus dorsi muscle is often considered expendable, sacrificing this muscle may produce undesired weakness in patients who rely on upper body strength because of lower extremity disability or in patients with athletic professions or pastimes.