Incidence and Outcomes of Completion Mastectomy following Oncoplastic Reduction: A Case Series.

[BACKGROUND] Patients occasionally need completion mastectomy (CM) following oncoplastic reduction for various reasons necessitating definitive reconstructive techniques. The purpose of this study was to evaluate those patients who required CM following oncoplastic reduction and evaluate indications, technique, and outcomes.

[METHODS] Patients who underwent a completion mastectomy at some time point following the oncoplastic reduction were identified. Factors that influenced CM and additional reconstruction were analyzed. All statistical analysis was conducted using the IBM SPSS Statistics 27.0 (IBM Corp.).

[RESULTS] A total of 29 patients (5.3%) underwent CM during the study period with an average follow-up of 3 years since the original procedure. The most common reasons were positive margins (20/29, 69.0%) and recurrence (8/29, 27.6%). Twenty-two had reconstructive procedures (75.9%) and seven did not (24.1%). The patients who underwent CM and reconstruction were significantly younger (49.2 years) than those who had no reconstruction (64.3 years, = 0.004). The most common type of reconstruction was transverse rectus abdominis myocutaneous (TRAM)/deep inferior epigastric perforator (DIEP) flap (12/22, 54.5%), followed by latissimus (6/22, 27.3%) and tissue expander (3/22, 13.6%). The complication rate in the CM group was 24% (N = 7/29), which included two seromas (6.9%), followed by infection, fat necrosis, mastectomy skin necrosis, and donor site necrosis (3.4% each).

[CONCLUSIONS] Completion mastectomy is indicated typically for positive margins or recurrence. Reconstruction is performed more frequently in younger patients, with the TRAM/DIEP flap and latissimus dorsi reconstruction being the most common technique.