SGAP Flap/Hip Flap
GAP stands for gluteal artery perforator, a blood vessel that runs through your buttocks. An SGAP flap (superior gluteal artery perforator), or gluteal perforator hip flap, uses this blood vessel, as well as a section of skin and fat from your upper buttocks/hip (the so-called “love handles”) to reconstruct the breast. Because no muscle is used, an SGAP flap is considered a muscle-sparing type of flap.
There is another type of GAP flap, the IGAP (inferior gluteal artery perforator) flap, which uses tissue from the bottom of your buttocks, near the buttock crease.
GAP flaps tend to make the most sense for women who are having both breasts reconstructed but can’t use tissue from the abdomen -- either because the abdomen is thin or has been damaged by other previous major surgeries there, such as a tummy tuck.
In the SGAP or hip flap surgery, fat, skin, and blood vessels are cut from your upper buttocks/hip and moved up to your chest to rebuild your breasts. Your surgeon carefully reattaches the blood vessels of the flap to blood vessels in your chest using microsurgery. Because skin and fat are moved from the buttocks to the chest, having the SGAP flap can mean your buttocks will be tighter -- as if you had a buttock lift. The SGAP flap leaves a scar near the top of your buttocks, but it's almost always covered by a bikini bottom or underwear.
The SGAP surgery removes tissue from high on the hip to avoid placing the surgical site in a potentially weight-bearing area, as the IGAP approach does. Also, tightening the buttock is more effective when pulling more above, much like “pulling up your pants.” The IGAP is less favorable because fat is removed from the area over your ischium, the large weight-bearing bone in your pelvis. This is where you bear your weight when you are sitting. It also produces some numbness around the incision site, which may be a concern for the formation of pressure-related wounds.
SGAP/hip flap surgery is more technically difficult than a TRAM, DIEP, or SIEA flap and usually takes more time to do. There are not many plastic surgeons who are trained to do it, so you may have to search for one if you’re interested in this procedure. An SGAP flap may be a good choice for thin women who don't have enough extra belly tissue for a TRAM, DIEP, or SIEA flap. If you've previously had liposuction on your buttocks, you may not be a good candidate for SGAP/hip flap reconstruction because you may not have enough extra tissue available. You can consult with your surgeon about your individual situation to determine whether or not you have enough tissue.
SGAP/hip flap reconstruction: What to expect
With an SGAP flap, an incision is made along the top of your buttocks and an oval section of skin, fat, and blood vessels is taken from your upper buttocks and moved up to your chest and formed into a breast shape. No muscle is moved. The tiny blood vessels that feed the tissue of your new breast are matched to blood vessels in your chest and carefully reattached under a microscope. Two new breasts would be created in this way (GAP flaps tend to make the most sense for women who are having both breasts reconstructed).
The SGAP flap procedure lasts about 9 to 12 hours. Many plastic surgeons prefer to do each breast separately, which means two different operations spaced a few months apart. You may wish to search for an experienced team that could do the surgery in one operation, with two surgeons working on different sides of the body at the same time.
After SGAP flap reconstruction surgery: You'll be moved to the recovery room after surgery, where hospital staff members will monitor your heart rate, body temperature, and blood pressure. If you're in pain or feel nauseated from the anesthesia, tell someone so you can be given medication.
You'll then be admitted to a hospital room. You usually stay in the hospital for about 4 days.
It can take about 6 to 8 weeks to recover from SGAP flap reconstruction surgery. Your doctor may recommend that you wear a compression girdle for up to 8 weeks after surgery. If you’re choosing immediate reconstruction, it’s important to keep in mind that since you’ve had surgery at multiple sites on your body (your chest and your hips/upper buttocks), depending on whether you had reconstruction on just one side or both sides at once, you might feel worse than someone who had only a mastectomy. It will likely take you longer to recover. You'll also have to take care of multiple incisions: on your breast(s) and your upper buttocks, and you'll probably have drains in your reconstructed breast(s) and in your buttock donor site(s). You may need to have help taking care of the incision on your upper buttocks and it may be uncomfortable for you to sit down for a week or more after surgery. If you had axillary node dissection at the same time, you may have incisions and drains to take care of under your arms.
It's important to take the time you need to heal. Follow your doctor's advice on when to start walking, stretching exercises, and your normal activities. You usually have to avoid strenuous sports, sexual activity, and lifting anything heavy for about 6 weeks after SGAP flap reconstruction.
It sometimes takes as long as a year or more for your tissue to completely heal and for your scars to fade.
SGAP/hip flap surgery risks
Like all surgery, SGAP/hip flap surgery has some risks. Many of the risks associated with SGAP flap surgery are the same as the risks for mastectomy. However, there are some risks that are unique to SGAP flap reconstruction.
Tissue breakdown: In rare instances, the tissue moved from your upper buttocks to your breast area won't get enough circulation and some of the tissue might die. Doctors call this tissue breakdown “necrosis.” Some symptoms of tissue necrosis include the skin turning dark blue or black, a cold or cool-to-the-touch feeling in the tissue, and even the eventual development of open wounds. You also may run a fever or feel sick if these symptoms are not addressed immediately. If a small area of necrosis is found, your surgeon can trim away the dead tissue. This is done in the operating room under general anesthesia or occasionally in a minor procedure setting. If most or all of the flap tissue develops necrosis, your doctor may call this a “complete flap failure,” which means the entire flap would need to be removed and replaced. Sometimes the flap can be replaced within a short timeframe, but in most cases the surgical team will remove all the dead tissue and allow the area to heal before identifying a new donor site to create a new flap.
Lumps in the reconstructed breast(s): If the blood supply to some of the fat used to rebuild your breast is cut off, the fat may be replaced by firm scar tissue that will feel like a lump. This is called fat necrosis. These fat necrosis lumps may or may not go away on their own. If they don't, it's best to have your surgeon remove them. After having mastectomy and reconstruction, it can be a little scary to find another lump in your rebuilt breast. Having it removed can give you greater peace of mind, as well as ease any discomfort you might have.
“Lopsided” buttock if you only had one breast reconstructed: If only one buttock was used as a donor site, your buttocks may look uneven after this surgery. This can be corrected with liposuction to the other side.
— Last updated on February 9, 2022, 8:32 PM