To explore the classification and harvesting strategy of free lower abdominal flap.

From September of 2015 to January of 2020, the data of breast cancer patients who underwent immediate or delayed breast reconstruction with free lower abdominal flap transplantation in Hu’nan Cancer Hospital and the Affiliated Hospital of Shandong University of Traditional Chinese Medicine were collected and analyzed retrospectively. According to the actual situation of perforating branch, four types of lower abdominal flap were prepared: (1) free full segment rectus abdominis flap; (2) free rectus abdominis flap with medial or lateral segment of rectus abdominis muscle; (3) free rectus abdominis flap with middle segment of rectus abdominis muscle; (4) free deep inferior epigastric artery perforator (DIEP) flap. The intraoperative conditions (flap weight, vascular pedicle length, harvesting time, etc.), appearance of reconstructed breast and complications of various lower abdominal flaps were statistically analyzed. Measurement data are expressed by Mean±SD.

A total of 181 patients with breast cancer were included, including 111 stage Ⅰ patients and 70 stage Ⅱ patients. The age of the patients was (38.5±4.8) years old (25-64 years old). A total of 197 free lower abdominal flaps were harvested. Twelve(6.1%) free full segment rectus abdominis flaps were harvested. The weight of the flap was (355.8±16.4) g, the average length of vascular pedicle was (5.7±0.8) cm, and the average harvesting time was (37.4±2.5) min. Forty-one (20.8%)rectus abdominis flaps with medial or lateral rectus abdominis muscle were harvested, the weight of the flap was (357.4±20.5) g, the average length of vascular pedicle was (6.9±0.6) cm, and the average harvesting time was (45.9±4.9) min. Sixty-eight(34.5%) rectus abdominis flaps with middle segment of rectus abdominis muscle were harvested, the weight of the flap was (362.6±24.7) g, the average length of vascular pedicle was (7.2±0.3) cm, the average harvesting time was (49.4±6.3) min. Seventy-six(38.6%) free deep inferior epigastric artery perforator flaps were harvested, the weight of the flap was (368.3±24.0) g, the average length of vascular pedicle was (9.8±0.4) cm, the average harvesting time was (49.7±3.1) min. Hematoma was noted in 3 cases after operation and removed by emergency operation. All the flaps survived completely. Twelve cases received fat lipofilling 6 to 24 months after operation. Patients were followed up for 14 to 60 months, with an average of 37.1 months, and no recurrence of breast cancer occurred. The reconstructed breasts had satisfactory appearance and texture without flap contracture and deformation. There was only linear scar left at the donor site, there was no significant functional deficit of the abdominal wall. Mild abdominal wall hernia occurred in one patient with full segment rectus abdominis flap and one patient with free DIEP flap, which was relieved by further strengthening the anterior sheath of rectus abdominis.

The location, size and source of perforating vessels in the lower abdomen and the anatomic variations of vascular pedicle are complex. The safest way of flap harvest must be adopted according to the actual situation. The DIEP flap is not the only choice of free lower abdominal flap.

Rectus abdominis myocutaneous flap; Deep inferior epigastric artery perforator flap; Breast reconstruction; Free flap