A Quadrant-based Algorithm for Oncoplastic Breast Reduction: The Use of Mirror Flaps for Filling Superior Pole Lumpectomy Defects.

[BACKGROUND] Reconstructing upper-quadrant defects in oncoplastic breast reduction (OBR) can be challenging due to upper-pole concavity after tumor resection. To address this, we adopted a dual-component technique using 2 separate flaps: (1) a superiorly based flap for the nipple-areola complex (NAC) and (2) an inferior advancement flap from the quadrant ipsilateral to the lumpectomy defect, "mirroring" the laterality of the defect. This study evaluates outcomes using this algorithm for superior pole reconstruction in OBR.

[METHODS] A retrospective review was conducted of OBR cases performed by a single surgeon from September 2022 to November 2024. All were performed for oncologic indications and used an inferior flap for upper-quadrant volume displacement according to the senior author's algorithm demonstrated in Figure 1.

[RESULTS] A total of 47 patients (51 breasts) underwent lumpectomy and immediate OBR. Most tumors were located in the upper outer quadrant (UOQ; 70.6%), followed by the upper inner quadrant (UIQ; 29.4%). Superomedial NAC pedicles were used for UOQ defects, and superolateral pedicles for UIQ. All UOQ defects were filled with inferolateral advancement flaps, and all UIQ defects with inferomedial flaps. Over 13.2 ± 7.5 months of follow-up, 15.7% of breasts experienced complications. One breast (2.0%) had upper-pole concavity not requiring revision. Six breasts (11.8%) underwent revision secondary to complications related to radiation (5/6) or dehiscence (1/6).

[CONCLUSIONS] The proposed dual-component mirror flap technique reliably reconstructs superior quadrant defects with low rates of contour deformity.