Summary/Key Points

Patient Selection

Breast reconstruction using autologous tissue has been performed for several decades and has become a safe and reliable technique.¹ Abdominal flaps, either pedicled or free, remain the first choice for breast reconstruction using autologous tissue. However, in patients who are very thin or who had previously undergone abdominoplasty or prior breast reconstruction with an abdominal flap, a gluteal flap can be an excellent alternative.^2–5

The reconstructed breast mound using gluteal flaps may have more projection, but not be as soft or mobile as when using abdominal flaps. Patient selection should be based on the patient’s individual characteristics, such as the volume of tissue required to achieve symmetry with the contralateral breast, the donor flap size, the pedicle length and caliber, and the relative advantages and disadvantages of each flap (Table 11.1). In patients with inadequate abdominal tissue or in whom an abdominal flap had been used before, gluteal flaps present an alternative for autologous breast reconstruction.^6–8 Selection between the SGAP or IGAP flap depends on the patient’s desired scar position, distribution of adiposity, and where sizable perforators can be found (Table 11.1). In patients with a sagging buttock, the IGAP flap is usually preferred. We prefer to harvest a perforator flap rather than a myocutaneous flap to obtain a longer pedicle and to avoid sacrifice of the gluteus maximus muscle.

Indications

Adequate volume of skin and subcutaneous tissue is usually available in the gluteal region. Even in very thin patients, there is frequently excess subcutaneous adipose tissue available in the gluteal region, making it a good substitute in breast reconstruction. It provides a flap with good projection that is very suitable for breast reconstruction, especially in young patients with a projecting contralateral breast. The donor site can be closed primarily if the width is less than 6–8 cm and can be hidden in the gluteal crease with the IGAP flap and under clothes with the SGAP flap. Closure of the donor site also provides aesthetic lifting of the buttock, which is sometimes desirable for the patient. However, mild buttock asymmetry could be noted after unilateral gluteal flap harvesting. An advantage over abdominal flaps is that gluteal flaps spare the morbidity of the abdominal wall. The main disadvantage in free GAP flaps, inferior or superior, is the technical difficulty in dissection of the perforator(s). If the perforator dissection is avoided by performing a musculocutaneous flap, the pedicle is often prohibitively short. Furthermore, flap dissection is performed when patient is in the prone or lateral decubitus position, which limits simultaneous work at the recipient site. Because of these potential problems, gluteal flaps are usually reserved as an alternative to abdominal flaps in breast reconstruction.

Indications for using gluteal flaps for breast reconstruction include:

Contraindications include previous buttock surgery, buttock liposuction or buttock lift, and heavy tobacco use. Dissection of the SGAP or IGAP flap is technically demanding and is better done by an experienced reconstructive microsurgeon. It is especially difficult in Asian women, who are relatively thin and have tiny perforators.^6–8

Operative Technique

Preoperative marking and flap dissection

Superior gluteal artery perforator flap

Preoperative marking

Preoperative marking is done with the patient in the prone or lateral decubitus position. A line is marked from the posterior superior iliac spine to the greater trochanter. The superior gluteal artery is located at the medial one third of this line.^3,4 Two or three audible perforators are usually detectible by hand-held pencil Doppler. An elliptical skin paddle is designed around the perforators and its axis can be oriented transversely or obliquely (Fig. 11.1).

Fig. 11.1 The perforators of the superior gluteal artery are located at the medial third of a line drawn from the posterior superior iliac spine to the greater trochanter. An elliptical skin paddle encompassing these perforators is designed.

Flap dissection

Flap dissection is started from the superior and lateral border. An incision is made down to the subfascial plane. Superior and inferior beveling can be done to include more subcutaneous adipose tissue, 3 cm wider than the skin paddle in each direction.

After reaching the subfascial plane, dissection is carried out from lateral to medial to identify the perforators. One large perforator is usually enough to supply the entire flap. After choosing the largest perforator, dissection is continued by splitting the gluteus maximus muscle along the direction of its fibers. A self-retaining retractor is used to spread the fibers of the gluteus maximus muscle. When proceeding to the deeper layer, good exposure of the surgical field by retracting the piriformis muscle is crucial to allow a clear visualization and to prevent any vascular damage. During dissection, any side branches or sacrificed perforators should be adequately coagulated or clamped with hemoclips to prevent postoperative hematoma or seroma accumulation. The perforator is traced to its proximal origin to gain as long a pedicle as possible. A longer pedicle can be obtained by using a perforator located more laterally in the flap. A pedicle averaging 8–12 cm in length can be dissected (Table 11.1). During the procedure, dissection requires an assistant to hold the flap gently and without traction on the pedicle to prevent avulsion or vasospasm. Intermittent irrigation of the pedicle with lidocaine or papaverine and keeping the pedicle moist also prevent vasospasm. Care should be taken to check the pulsation frequently during dissection to ensure that the perforator is intact and is not under too much tension.

After finishing flap elevation, the wound is closed primarily with 2-0 Vicryl and by undermining the upper and lower skin flaps and followed by the subcuticular suture with 3-0 Monocryl. A suction drain is inserted for adequate drainage. The patient is then turned to the supine position for microvascular anastomosis and insetting of the flap.

Inferior gluteal artery perforator flap

Preoperative marking

The patient’s position is the same as in harvesting the SGAP flap. The inferior gluteal artery travels inferior to the piriformis muscle and gives branches to the gluteus maximus muscle. The point of entrance into the gluteus maximus is halfway between the posterior superior iliac spine and the ischial tuberosity. Deeply, the inferior gluteal artery travels with the internal pudendal vessels, which lie medial to it, and the sciatic nerve, which lies lateral. In the distal course, the posterior cutaneous nerve of the thigh runs with the inferior gluteal artery and should be preserved during dissection.

Before flap dissection, a hand-held pencil Doppler is used to locate the perforators. The flap is designed as a transverse ellipse that includes the audible perforators (Fig. 11.2). The lower margin of the flap is situated in the gluteal crease to hide the scar (the so-called ‘in-the- crease’ flap).¹¹

Fig. 11.2 The perforators of the inferior gluteal artery are located around the midpoint of a line drawn between the posterior superior iliac spine and the ischial tuberosity. The flap is designed as the donor site scar is hidden in the gluteal crease.

Flap dissection

Incisions are made along the markings. A beveling technique can be applied in the superior and inferior margin to include more subcutaneous tissue, 3 cm wider than the skin paddle in each direction. This provides more flap volume and better breast shaping. The flap is elevated in the subfascial plane. When approaching the ischial tuberosity, the important cushion-providing adipose tissue, light brown in color, should be carefully preserved to minimize donor site morbidity. The intramuscular course of the inferior gluteal artery tends to be more tortuous and transverse than that of the superior gluteal artery (Fig. 11.3), and the dissection is more technically demanding. However, a longer pedicle can be obtained with the inferior gluteal artery than the superior gluteal artery (Fig. 11.4). Perforators supplying the lateral gluteal region have a slightly longer intramuscular course than those supplying the medial gluteal region; thus, usage of a lateral perforator can yield a pedicle 1–2 cm longer in length. The posterior cutaneous nerve of the thigh accompanies the inferior gluteal vessels and should be carefully preserved to prevent postoperative numbness of the posterior thigh. When approaching the origin of the perforator, the sciatic nerve may be encountered and must obviously be protected (Fig. 11.5). The surrounding muscle should be kept in place as much as possible to provide adequate coverage of the sciatic nerve after flap elevation. After the intramuscular dissection is finished, the pedicle is divided and the flap transferred. The donor site is closed primarily in layers with 2-0 Vicryl and 3-0 Monocryl, and the patient is turned to the supine position for the remainder of the procedure (Fig. 11.6).

Fig. 11.3 The intramuscular course of inferior gluteal artery perforator tends to be more tortuous and requires more tedious dissection than that of superior gluteal artery.

Fig. 11.4 A 10-cm in length pedicle can be dissected with a perforator of the inferior gluteal artery.

Fig. 11.5 The sciatic nerve could be exposed and must be carefully protected during dissection of the inferior gluteal artery near its origin (arrow).

Fig. 11.6 The donor site is primarily closed and the scar is hidden in the gluteal crease.

Preparation of the recipient site

The recipient site is prepared under loupe magnification when the patient is in the supine position. In a delayed reconstruction, exposure is gained through the previous scar, which is excised and sent for pathologic review. Extensive release of scar tissue is performed to create an adequate breast pocket, especially in the axillary region. The authors prefer to use the internal mammary artery (IMA) and vein (IMV) as the recipient vessels.¹⁴ A 1 × 1 cm section of the third costal cartilage is excised, preserving the superior aspect of the perichondrium. The small piece of cartilage is preserved and at the end of the case will be banked in the subcutaneous layer of the lower breast flap for the strut in nipple reconstruction later. The remaining third costal cartilage is removed in the direction of the sternal junction in piecemeal fashion with a rongeur until the recipient vessels are seen. The perichondrium is removed carefully with bipolar electrocautery. Dissection then proceeds under the microscope to prevent damage to the recipient vessels, especially the thin-walled vein. Dissection of the IMA and IMV is performed with two microforceps, gently shearing the adventitia (Fig. 11.7). After the dissection is finished, the wound is closed temporarily and the patient is turned to the prone position for flap elevation.

Fig. 11.7 The dissection of the internal mammary vessels is gently performed under the microscope to protect the thin wall of the vein.

In addition to the internal mammary vessels, the thoracodorsal vessels are the other commonly used recipients. However, dissection of these vessels in delayed reconstructions, when the tissue is scarred or radiated, can be very difficult. Moreover, the thoracodorsal vessels serve as the main pedicle for the latissimus dorsi myocutaneous flap, a potential backup for breast reconstruction. Finally, when using a gluteal flap with a relatively short pedicle, the thoracodorsal vessels do not easily allow medial positioning of the flap as do the internal mammary vessels.

Donor site closure and morbidity

With careful preoperative design, the gluteal flap donor site can always be closed primarily. The wound should be sutured in layers with a closed suction drain in place. The drain is removed when the daily output is less than 30 ml and the fluid becomes serous.

The morbidity of the gluteal donor site is minimal. Splitting the muscle fibers and preserving the motor nerve to the gluteus maximus muscle during pedicle dissection may effectively reduce donor site morbidity. The postoperative ambulation is not restricted in most cases. The most significant morbidities are numbness of the surrounding skin, contour deformity, and minor asymmetry of the buttocks (Figs 11.8 and 11.9).

Fig. 11.8 A 62-year-old woman underwent a right superior gluteal artery perforator (SGAP) flap for left breast immediate reconstruction. The donor site of SGAP flap developed a sunken appearance.

Fig. 11.9 The same patient underwent a left inferior gluteal artery perforator (IGAP) flap for right breast immediate reconstruction 2 years later. The donor site of the left IGAP flap was much better than that of the right SGAP flap.

More donor site morbidities are reported in harvesting the IGAP flap. The inferior gluteal artery accompanies the sciatic nerve when traversing the greater sciatic foramen. Unpreventable exposure of the sciatic nerve during IGAP dissection may result in dysesthesia that persists for several months after surgery. Gentle dissection and preservation of the gluteal muscles minimize this complication. Another important step is to preserve the adipose tissue around the ischial tuberosity when dissecting the IGAP flap to prevent postoperative discomfort with sitting (Box 11.1).

Box 11.1 Summary of the operative steps

Step 1 Mark the origin of the superior or inferior gluteal artery

Step 2 Detect the perforators using hand-held pencil Doppler

Step 3 Design the flap as an ellipse around the largest perforator, with a maximum width of 6 cm

Step 4 Prepare the internal mammary vessels on the third intercostal space, dissect the IMV under the microscope to avoid injury of the vein simultaneously with the flap dissection in lateral decubitus position, or before flap dissection in supine position

Step 5 Skin incision with beveling of the subcutaneous fat 3 cm beyond the skin paddle superiorly and inferiorly

Step 6 Dissect the flap from lateral to medial, with careful intramuscular dissection of the perforator until adequate pedicle size and length are obtained. Frequently check for pulsation of the perforator during dissection to ensure that it is intact and not under too much tension

Step 7 Close the donor site primarily

Step 8 Transfer the flap and perform the anastomoses in the supine position

Step 9 Inset the flap with the patient in the seated position to achieve symmetry with the contralateral breast

Pitfalls and How to Correct

The IGAP flap holds several advantages over the SGAP flap. Usually the inferior gluteal region provides more tissue than the superior gluteal region, and removal of the excess inferior fat is sometimes of benefit to the patient. Flaps harvested from the superior gluteal region leave a scar in the aesthetic unit of the buttock while those from the inferior region leave the scar hidden ‘in- the-crease.’ Figures 11.8–11.12 show a patient who twice underwent immediate breast reconstruction with a gluteal flap each time. In the first reconstruction, the right SGAP flap was used since there was adequate tissue in the superior gluteal area. However, the selection was shifted to the left IGAP flap in the second reconstruction because the patient was concerned about the contour deformity and visible scar left at the right superior gluteal site. The selection should be based on each patient’s individual situation. Figures 11.13–11.16 demonstrate another happy patient receiving breast reconstruction with the SGAP flap. The early concern of sciatic nerve palsy is not a problem with recent approaches. The inferior gluteal area is now considered a better donor site than the superior gluteal area in most situations.¹¹ However, the dissection of tiny perforators of the IGAP flap is extremely difficult and requires a more experienced surgeon to perform. Preoperative Doppler study mapping of the perforators may be helpful in flap design and dissection. However, the benefit of preoperative duplex mapping seems uncertain due to the thicker subcutaneous fat tissue.

Fig. 11.10 At a 4-month follow-up, the right reconstructed breast using the left IGAP flap was smaller than that of the left reconstructed breast using right SGAP flap. A-P view.

Fig. 11.11 Same patient as in Figure 11.10, right lateral view.

Fig. 11.12 Same patient as in Figure 11.10, left lateral view.

Fig. 11.13 A 28-year-old female underwent modified radical mastectomy for right breast cancer, stage 1.

Fig. 11.14 A left SGAP flap measuring 28 × 10 × 5.5 cm was transferred using the right internal mammary vessels as a recipient site for right breast delayed reconstruction.

Fig. 11.15 At a 5-year follow-up, the patient was satisfied with the symmetry of the reconstructed breast mound. A-P view.

Fig. 11.16 Same patient as in Figure 11.15, lateral view.

Breast reconstruction using autologous tissue is a challenge for a thin patient presenting with a breast defect post mastectomy with an implant in the submuscular plane. The gluteal region provides adequate soft tissue for symmetric and projecting breast reconstruction (Figs 11.17–11.20).

Fig. 11.17 A 45-year-old female with augmentation mammaplasty underwent mastectomy for right breast cancer. She was very thin, with insufficient abdominal tissue for right breast reconstruction.

Fig. 11.18 Same patient as in Figure 11.17. There was adequate soft tissue at the inferior gluteal region to provide breast reconstruction with satisfactory volume.

Fig. 11.19 Same patient as in Figure 11.17. At 4-month follow-up, the patient was pleased with the symmetric and natural appearance of the reconstructed breast with IGAP flap.

Fig. 11.20 Postoperative appearance of the patient in Figure 11.17 after nipple reconstruction.

Breast reconstruction using gluteal flaps can be done with a two-team approach when patients are placed in lateral decubitus position. However, because of the difficulty in flap dissection and the limited surgical field at the recipient site, the two-team approach requires two well-experienced surgeons to achieve a smooth and safe operation.

The interpretation of beauty varies with time and among different cultures and races. Patients benefit from abdominoplasty when receiving breast reconstruction with abdominal tissue. This is appreciated throughout the world. However, the use of gluteal flaps can be resisted in specific situations. Many people in South America and Spain consider round, full buttocks to be an attractive feature. In these cultures it is even more important to have full buttocks than full breasts. If adequate abdominal tissue is not available, these patients would rather undergo reconstruction with implants than gluteal flaps.

Postoperative Care

The patient is kept warm and well perfused in the ICU for a few days. The flap is monitored by observing the color, skin turgor, temperature, and capillary refilling, and a hand-held pencil Doppler is used to check the perforator. The implantable Doppler for monitoring the venous outflow is also very helpful. Care should be taken to avoid compression of the perforators, tight wound closure, and hip joint flexion posture. Medications such as low molecular weight dextran and low dose heparin are not routinely given unless the flap develops any vascular compromise. Patients are encouraged to wear a supportive brassiere beginning on the third postoperative day to maintain the position of the breast mound.