Superior Gluteal Artery Perforator Free Flap for Breast Reconstruction

Robert J. Allen, M.D., and Charles Tucker, Jr., M.D.
New Orleans, LA

The purpose of this paper is to present a new method of breast reconstruction utilizing skin and fat from the buttock without muscle sacrifice. Cadaver dissections were done to study the musculocutaneous perforators of the superior gluteal artery and vein. Eleven breasts were reconstructed successfully with skin/fat flaps based on the superior gluteal artery with its proximal perforators. Long flap vascular pedicles allow the internal mammary or thoracodorsal vessels to be used as recipient vessels. This new technique has several advantages over the previously described gluteus maximus myocutaneous flaps, including long vascular pedicle and no muscle sacrifice. (Plast. Reconstr. Surg. 95: 1207, 1995.)

The free transverse rectus abdominis myocutaneous flap1,2 is the most commonly used free, flap for microsurgical breast reconstruction today. Frequently, the lower abdominal donor site is not a good choice because of prior operations or scarcity of lower abdominal tissue. The buttock site offers a good alternative. The gluteus maximus myocutaneous flap3 was the first free flap reported for microsurgical breast reconstruction and has been further developed and popularized by Shaw4 as the superior gluteal microvascular free flap. The inferior gluteal myocutaneous free flap was described by Paletta et al.5

The purpose of this paper is to present a new method of microsurgical breast reconstruction using a free skin/fat flap from the buttock with a long vascular pedicle without muscle sacrifice. The flap is based on the superior gluteal artery perforators and accordingly is called the S-GAP flap or superior gluteal artery perforator flap. The S-GAP flap differs from both previously described gluteal myocutaneous flaps by eliminating the muscle component and by providing a much longer vascular pedicle. We have used 11 flaps in 9 patients successfully.

Materials and Methods

The concept of basing skin/fat free flaps on arterial perforators has been studied by Allen and Treece6 and Koshima and Soeda.7 Gluteal perforator flaps for sacral wounds were reported by Koshima and associates.8 Cadaver dissections preceded surgical application to verify the feasibility of free flaps based on arterial perforators. In the cadaver, perforators were easily identified and were dissected down to the superior gluteal vascular pedicle, providing a vascular length of approximately 8cm.

In the operating room with the patient in the lateral decubitus position, a two-team approach is used. The superior gluteal vessels are marked out according to known anatomic landmarks.9 The Doppler probe is used to identify perforators and their axes.10 A fusiform skin island is then drawn out over the perforators (Fig. 1). The flap axis can be varied so that it can lie oblique or horizontal. Skin island size varies from 10 X 25 to 12 X 32 cm. The incision is made down through the skin and subcutaneous tissue to the muscle. Beginning distally, the flap is dissected off the muscle while proximal perforators are looked for. Once the perforators were found, loupe magnification and microsurgical technique are used to dissect the vessels. Selected perforators usually lie in a single muscle fiber cleavage plane so that very few muscle fibers, if any, are sacrificed. The muscle is split as needed in the direction of its fibers. Small muscular side branches of the perforator(s) are divided. One or two perforators are dissected down to the superior gluteal artery and vein deep to the muscle (Fig. 2). Dissection of the superior gluteal artery and vein for the final 2 or 3 cm is the most difficult part of the dissection.

FIG. 1. Skin island design over superior gluteal area.

FIG. 2. Intraoperative S-GAP flap dissection.

FIG. 3. Recipient vessels.

The S-GAP flap consists of only skin, fat, and a lengthy vascular pedicle. Flap weight ranged from 210 to 820 am. Internal mammary or the racodorsal vessels are selected as recipient vessels (Fig. 3). The third or fourth costar cartilage is removed to expose the internal mammary vessels. The thoracodorsal vessels are dissected thoroughly from the circumflex scapular branch to the serratus branch for maximum "swing" length. The donor area is closed with minimal undermining as needed. Following microvascular anastomoses, the flap is sutured to the pectoralis fascia and inset (Fig. 4).

FIG. 4. Insetting of flap after microvascular anastomoses.

FIG. 5. (Above, left) A 28-year-old woman after bilateral mastectomies. (Above, right) Right flap prior to transfer based on two perforators of the superior gluteal vessels. (Below, left) Results after bilateral breast reconstruction with S-GAP flaps. (Below, right) Donor sites.

Case Reports

Case 1
A 28-year-old woman developed a left breast carcinoma 7 years ago. She was treated with left modified radical mastectomy and immediate reconstruction with an expander/prosthesis. Two months later she underwent left nipple-areolar reconstruction and right subcutaneous mastectomy with insertion of an expander/prosthesis. Over the next 24 months, she underwent seven operations for implant-associated problems consisting of capsulotomies, implant exchanges, etc. She continued to have implant-associated problems consisting of breast pain, inability to sleep prone, and poor aesthetic results. For these reasons, the implants were removed. Physical examination revealed a small, white woman 5 ft 4 in height and 100 lb in weight. Abdominal tissue appeared limited and insufficient. The buttock donor sites were selected for bilateral breast reconstruction. On February 15, 1993, at Charity Hospital, the right breast was reconstructed with an ipsilateral superior gluteal artery perforator free flap. Two weeks later, left breast reconstruction was performed similarly. Both donor-flap vascular pedicles were of ample length for thoracodorsal anastomoses bilaterally. Left nipple-areolar reconstruction was performed subsequently. Aesthetic results in both breasts are good, and donor-site scars are acceptable (Fig. 5).

Case 2
A 50-year-old woman with fibrocystic disease of the breasts had multiple previous breast biopsies. Both her mother and grandmother had breast cancer. She had a right paramedian scar from a prior appendectomy. Bilateral prophylactic mastectomies with immediate reconstruction were recommended. A right mastectomy with a right superior gluteal artery perforator flap was done. The patient was discharged from the hospital on the fourth postoperative day and was readmitted 4 days later for left mastectomy and left superior gluteal artery perforator free-flap reconstruction. The postoperative course was uncomplicated. One month later, bilateral nipple-areolar reconstruction was performed (Fig. 6).

Case 3
A 33-year-old woman presented for reconstruction 1 year after a right modified radical mastectomy for ductal carcinoma. She was single with no excess lower abdominal tissue. Also, she had a midline abdominal scar from biliary pancreatic surgery. An S-GAP flap measuring 26 X 9 cm and weighing 494 gm was used to reconstruct the breast (Fig. 7). The internal mammary artery and vein were used as recipient vessels. The patient was discharged on the third postoperative day.

FIG. 6. (Above) A 50-year-old woman with fibrocystic disease and strong family history of breast cancer. ( Center) Donor site for right breast reconstruction. (Below) Postoperative appearance after bilateral breast reconstruction with S-GAP flaps.

FIG. 7. (Above) A 33-year-old woman 1 year after right modified radical mastectomy. (Center) Appearance after SGAP reconstruction. (Below) Donor site.

Case 4
This 34-year-old nulliparous woman was referred for immediate reconstruction following biopsy of carcinoma in the right breast. She was a Jehovah's Witness and could not receive blood products. Modified radical mastectomy with SGAP flap reconstruction was accomplished without complication. Internal mammary vessels were used as recipient vessels. The nipple was reconstructed 6 weeks postoperatively during her chemotherapy to complete her reconstruction (Fig. 8)

FIG. 8. (Above) A 34-year-old woman with carcinoma of the right breast. (Center) Appearance after S-GAP reconstruction. (Below) Donor site.

Discussion

It has been pointed out that in thin patients there is more abundant tissue in the inferior gluteal territory than in the superior gluteal territory.5 However, this has not been a problem in our patients. Our thin patients had small breasts, and breast tissue requirements were adequately met in the superior gluteal territory. Likewise, our patient with large breasts had abundant fat tissue availability in the superior gluteal territory. In other words, tissue availability in the superior gluteal territory corresponded well to the breast tissue requirements.

Disadvantages of the free TRAM flap include the following: loss of abdominal muscle strength, small incidence of postoperative herniation, tight closure and high scar in young, thin patients, flap unpredictability in patients with prior abdominal operations, and fat necrosis. The free gluteal myocutaneous flaps previously described avoid these disadvantages but are burdened by short pedicles that are difficult to dissect under a thick muscle. This creates a difficult recipient-vessel-site situation such as internal mammary vessels with size discrepancy and veins requiring mobilizing the external jugular or cephalic vein. Vein grafts to the thoracodorsal vessels may be required to position the flap properly.

The development of a buttock skin/fat based on the superior gluteal artery perforators provides a flap that results in a scar largely invisible to the patient, a flap of ample bulk even in young, thin patients, and a flap with a long vascular pedicle.

There is no muscle sacrifice, and usually no prior operations have been performed in the area. Donor-site morbidity is minimal, with patients ambulatory on the first postoperative day and discharged on the second or third day after reconstruction.

References

1. Holström, H. The free abdominoplasty flap and its use in breast reconstruction. Scand. J. Plast. Reconstr. Surg. 13: 423, 1979.

2. Friedman, R J., Argenta, L. C., and Anderson, R. Deep inferior epigastric free flap for breast reconstruction after radical mastectomy. Plast. Reconstr. Surg. 76: 455, 1985.

3. Fujino, T., Harashina, T., and Enomoto, K Primary breast reconstruction after a standard radical mastectomy by a free flap transfer (Case Report). Plast. Reconstr. Surg. 58: 371, 1976.

4. Shaw, W. W. Breast reconstruction by superior gluteal microvascular free flaps without silicone implants. Plast. Reconstr. Surg. 72: 490, 1983.

. Paletta, C. E., Bostwick, J., III, and Nahai, F. The inferior gluteal free flap in breast reconstruction. Plast. Reconstr. Surg. 84: 875, 1989.

6. Allen, R. J., and Treece, P. Deep inferior epigastric perforator flap for breast reconstruction. Ann. Plast. Surg. 32: 32, 1994.

7. Koshima, I., and Soeda, S. Inferior epigastric artery skin flaps without rectus abdominis muscle. Br. J. Plast. Surg. 42: 645, 1989.

8. Koshima, I., Moriguchi, T., Soeda, S., Kawata, S., Ohta, S., and Ikeda, A. The gluteal perforator-based flap for repair of sacral pressure sores. Plast. Reconstr. Surg. 91: 678, 1993.

9. Strauch, B., and Yu, H. L. Atlas of Microvascular Surgery. New York: Thieme Medical Publishers, 1993. P. 104.

10. Taylor, G. I., Doyle, M., and McCarten, G. The Doppler probe for planning flaps: Anatomical study and clinical applications. Br. J. Plast. Surg. 43: 1, 1990.