The utility of free abdominal flap without Zone 4 procedure for unilateral breast reconstruction

The perfusion concept of free abdominal flap for breast reconstruction shares the common perception. We believed that free abdominal flap without Zone 4 could be performed. The purpose of this study is to introduce the "without Zone 4 procedure" and compare with the conventional technique (without 4 vs. conventional groups).

The "without 4 group" included 61 patients, while the conventional group 55 patients. The inclusion criterion for the "without Zone 4 procedure" was defined as the thickest part of flap was more than half of the contralateral breast projection. The centerline of the skin island was adjusted to the position with the most medial side of the perforator. We compared basic characteristics (age, BMI, operation time, blood loss, contralateral breast size, smoking status, and history of laparotomy), the flaps' horizontal and vertical widths, thickness of the thickest part of the flap, elevated flap weight, and operative procedure.

The mean length of the flaps' horizontal width was significantly shorter (19.2 cm vs. 26.3 cm; p < .001) and the mean flap thickness was significantly greater in the without 4 group. The mean contralateral breast height and projection length were significantly longer in the conventional group. No significant differences were found with respect to the other characteristics.

Patients with a lower breast projection compared with the abdominal fat thickness could undergo reconstruction with a shorter flap horizontal width. Because of the esthetic outcome of the donor site, this procedure is more appropriate for low-BMI patients.