comscoreStacked/"Hybrid" GAP Flap

Stacked/"Hybrid" GAP Flap

Stacked/"hybrid" GAP flap reconstruction is a newer approach to GAP that can be used to reconstruct one breast in women who don’t have a lot of extra tissue in their buttocks.

Stacked/"hybrid" GAP flap reconstruction is a newer approach to GAP that can be used to reconstruct one breast in women who don’t have a lot of extra tissue in their buttocks and therefore aren’t eligible for standard GAP flap surgery.

GAP stands for the 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.

Your plastic surgeon may recommend GAP flap reconstruction if you don’t have enough belly tissue to reconstruct your breasts, you’ve had multiple abdominal surgeries, or you’ve had previous reconstruction that already used tissue from your belly. If your buttocks are fairly small and your breasts are larger, there may not be enough tissue to reconstruct both breasts using GAP flap reconstruction. However, if you only need one breast reconstructed, stacked GAP reconstruction may be a solution for you. This approach typically uses the SGAP flaps, also called hip flaps, from the upper buttocks.

In standard SGAP or hip flap surgery, a flap of fat, skin, and blood vessels is cut from each side of 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. In stacked GAP flap surgery, the surgeon takes a flap of skin from each upper buttock and stacks them, one on top of the other, to recreate a single breast. 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.

Like the standard SGAP/hip flap surgery, stacked GAP 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. If you've previously had liposuction on your buttocks, you may not be a good candidate for stacked GAP 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.


Stacked/"hybrid" GAP flap reconstruction: What to expect

With a stacked GAP flap reconstruction, an incision is made along the top of each buttocks and an oval section of skin, fat, and blood vessels is removed from each side. The surgeon then takes the two flaps and moves them up to your chest area to create one breast shape. 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.

The stacked GAP flap procedure typically lasts 5-6 hours.

After stacked GAP 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 3-4 days.

It can take about 6 to 8 weeks to recover from stacked GAP reconstruction surgery. Your doctor may recommend that you wear a compression girdle for up to 8 weeks after surgery. Keep in mind that if you had immediate reconstruction, you’ve had surgery at three sites on your body (one side of your chest and your hips/upper buttocks), and 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 three incisions: on your breast(s) and your upper buttocks, and you'll probably have drains in your reconstructed breast and in your buttock donor sites. 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 stacked GAP reconstruction.

It sometimes takes as long as a year or more for your tissue to completely heal and for your scars to fade.


Stacked/"hybrid" GAP flap surgery risks

Like all surgery, stacked GAP reconstruction has some risks. Many of the risks associated with stacked GAP reconstruction are the same as the risks for mastectomy. However, there are some risks that are unique to stacked GAP 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.

If the tissue isn’t getting enough blood supply, you’ll know it within a few days after surgery based on the appearance of these symptoms. Otherwise, you know the tissue is getting enough blood supply and long-term problems with tissue breakdown are not a concern.

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.

Center for Restorative Breast Surgery

This information made possible in part through the generous support of

— Last updated on July 26, 2022, 5:58 PM