Breast Reconstruction Using Combined Unilateral Hemiabdominal DIEP Flap with Lipofilling from the Contralateral Abdomen

Summary:

The deep inferior epigastric perforator (DIEP) flap is the gold standard breast reconstruction procedure for patients with adequate lower abdominal tissue and is often elevated, including the unilateral DIEP. In patients with a lower midline abdominal surgical scar, the volume of the DIEP flap used for breast reconstruction may be limited because of the cessation of blood perfusion over the scar. Several options have been used for increasing the flap volume using bipedicled flaps; however, they are more invasive for the abdominal donor site and require longer operation time for complex vascular anastomoses. To overcome these disadvantages, we propose immediate breast reconstruction with simultaneous fat grafting combined with a DIEP flap, which can achieve an adequate breast volume. The patient was a 46-year-old woman with left-sided invasive ductal carcinoma. She underwent a left nipple-sparing mastectomy, sentinel lymph node biopsy, and one-stage immediate DIEP flap breast reconstruction. Indocyanine green angiography was used to evaluate the blood supply to the DIEP flap, and lipofilling was performed from the unstained flap area. The fat was injected into and under the pectoralis major muscle, and the total volume of the fat graft was 66 mL. The advantages of immediate lipofilling harvested from the unstained flap area include minimal sacrifice, the expectation of simultaneous restoration of the overall appearance of the breast with a minimal number of operations, the simplicity of the procedure, and the best use of viable tissues. Therefore, breast reconstruction combined with fat grafting is effective for volume augmentation.

The deep inferior epigastric perforator (DIEP) flap is the gold standard breast reconstruction procedure for patients with adequate lower abdominal tissues.¹ The DIEP flap is often elevated, including the unilateral DIEP. In patients with a complete lower midline abdominal scar, the blood supply is often interrupted, and contralateral areas of zones II and IV are usually excised.² A concern about insufficient breast volume was also reported with a unipedicled DIEP flap alone. Several options increased the flap volume using bipedicled flaps, such as a stacked DIEP flap, a stacked DIEP and transverse rectus abdominis myocutaneous flap, a superficial inferior epigastric artery flap, or a superficial circumflex iliac artery perforator flap.^2–4 However, these are more invasive for the abdominal donor site and require longer operation time to perform complex vascular anastomoses. To overcome these disadvantages, we propose immediate DIEP flap breast reconstruction with simultaneous fat grafting for patients with a lower midabdominal scar to achieve adequate breast volume.

CASE REPORT

The patient was a 46-year-old woman with left-sided invasive ductal carcinoma, luminal HER2 type, cT1cN0M0, stage I. Left nipple-sparing mastectomy, sentinel lymph node biopsy (SLNB), and one-stage immediate DIEP flap breast reconstruction were performed. Because she had a history of a lower midline abdominal cesarean scar just below the umbilicus to the upper border of the pubic symphysis, measuring approximately 13 cm, we were concerned about insufficient donor site volume using only a unipedicled DIEP flap. We then planned fat grafting harvested from the unstable blood flow area of the DIEP flap.

Preoperatively, the patient underwent computed tomography angiography to identify the deep inferior epigastric artery, superficial inferior epigastric artery, and superficial circumflex iliac artery patterns. In addition, Doppler flowmetry was used to detect the DIEP. The abdominal flap was designed between the umbilicus and the superior border of the pubic symphysis with a height of 12 cm, and the bilateral midaxillary lines over the anterior superior iliac spines with a width of 43.5 cm (Fig. 1).

Fig. 1.

Preoperative image of the patient. She had a lower midline abdominal cesarean scar from just below the umbilicus to the upper border of the pubic symphysis, about 13 cm in length. The abdominal flap was designed between the umbilicus and the upper border of the pubic symphysis with a height of 12 cm, and the bilateral midaxillary lines over the anterior superior iliac spines with a width of 43.5 cm.

The DIEP flap was elevated and thereby dissected while breast surgeons performed nipple-sparing mastectomy and SLNB. Mastectomy weight was 267 g, and SLNB was negative. Intraoperative indocyanine green (ICG) angiography was performed to evaluate blood perfusion in the DIEP flap, which revealed that the left flap area was perfused early and homogeneously, zone II was perfused late and heterogeneously, zone IV was not perfused, and the borders of each area were marked (Fig. 2).

Fig. 2.

Intraoperative image of the flap elevation and markings after ICG angiography. The DIEP flap was elevated, and the left deep inferior epigastric artery was dissected. ICG angiography revealed that the left flap area (*) was stained early and homogeneously, zone Ⅱ (†) was stained late and heterogeneously, zone Ⅳ (‡) was unstained, and the borders for each zone were marked.

After dissecting the internal mammary vessels, fat was harvested from zone IV (Fig. 3). First, the elevated flap was fixed to the abdominal skin for stability during liposuction. Then, fat was injected into and under the pectoralis major muscle while being careful not to inject too much volume to avoid flap complications, and the total volume of the fat graft was 66 mL. (See figure, Supplemental Digital Content 1, which displays intraoperative images of fat grafting. http://links.lww.com/PRSGO/D561.) The patient was aware of the breast volume difference. Thus, the total volume that we transplanted was larger than the mastectomy breast volume to achieve symmetrical breasts. (See figure, Supplemental Digital Content 2, which displays statistical details of the breast. http://links.lww.com/PRSGO/D562.)

Fig. 3.

Intraoperative image of fat grafting. The fat was harvested from the unstained area of the flap. The liposuction volume was 130 mL.

The DIEP flap pedicle was resected, and the weight of the left area, which was considered sufficiently perfused, was 406 g. The left internal mammary vessel was used as the recipient vessel for the end-to-end anastomosis. The flap ischemic time was 1 hour and 12 minutes. After completing the microsurgery, the flap was placed on the lipografted pectoralis major muscle to create a breast mound. The final weight of the transplanted flap was 374 g. The unnecessary flap skin, except for the monitoring of the skin paddle, was de-epithelialized, and all wounds, including the abdominal donor site, were sutured.

The patient had no flap or donor site complications, and she was discharged on the eighth day postoperatively. At 1-year postoperative follow-up, no significant difference was observed in thickness from the skin surface to just above the fifth costal bone between the affected and the healthy breast, and no oil cysts were found in the left-sided pectoralis major muscle on ultrasound sonography, indicating that no fat necrosis had occurred. The monitoring skin paddle was removed approximately 1 year and 7 months postoperatively. The size and shape of the affected breast were almost symmetrical; however, a depression on the upper pole was observed, which was considered to be caused by partially removing the third costal cartilage to anastomose the vessels. Therefore, it was corrected with a secondary fat graft taken from the upper abdomen approximately 1 year and 10 months after breast reconstruction. The abdominal dog ear was corrected simultaneously (Fig. 4).

Fig. 4.

Two-year and 4-month postoperative image of the patient after the DIEP flap breast reconstruction. The size and shape of the affected and unaffected breasts were almost symmetrical.

DISCUSSION

When a patient has a lower midline abdominal surgery scar, the volume of the DIEP flap used for breast reconstruction is limited due to the cessation of blood perfusion over the scar based on the scar length.² Recent studies demonstrated some operative methods to achieve sufficient breast volume, such as a stacked DIEP flap.^2–4 However, these methods are invasive for the abdominal donor site and require a considerable operation time due to their complexity. In our case, to achieve a minimally invasive and simpler procedure and avoid additional wounds, fat grafting was chosen for breast volume augmentation, combined with the DIEP flap simultaneously.

In breast reconstruction using the latissimus dorsi flap, fat grafting is performed simultaneously to supplement the flap volume.⁵ Fat is often injected not only into the latissimus dorsi flap but also into the pectoralis major muscle and mastectomy flaps. This method is similar to our immediate fat grafting with DIEP flap breast reconstruction and indicates that immediate fat grafting is a versatile and safe method of adding volume. However, fat grafting has the potential risk of cyst formation and induration caused by fat necrosis. Therefore, follow-up with imaging is necessary 1 year postoperatively.^4,6

Regarding the use of fat tissue in zone IV in a DIEP flap, which is usually discarded, Sowa et al⁷ reported that fat grafting with harvesting from zone IV in a DIEP flap is suitable for dent or step-off augmentation in the décolletage area. The advantages of immediate lipofilling with fat harvested from zone IV are minimal scarring, the expectation of simultaneously restoring the overall appearance of the breast with a minimal number of operations, the simplicity of the procedure, and making the best use of viable tissues. Lipofilling into and under the pectoralis major muscle is suitable to augment basal breast volume and adjust the breast shape easily because the understructure becomes thick and fat can be injected little by little where needed, rather than using a stacked flap or folding the transferred flap. Therefore, breast reconstruction combined with fat grafting is effective for adding volume or improving aesthetics in the cases that are estimated over augmentation if a bipedicled DIEP flap is used.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.