Evaluation of postoperative complications and adjuvant treatments following immediate prepectoral versus subpectoral direct-to-implant breast reconstruction without acellular dermal matrix.

Background In immediate breast reconstruction (IBR), it remains unclear whether there is any difference in complication rates between prepectoral versus subpectoral implant placement without acellular dermal matrix (ADM). Aim To compare rate of early post-operative complications and time to initiation of adjuvant treatment in patients undergoing IBR between prepectoral and subpectoral implant placement without ADM for the two surgical procedure. Methods We retrospectively retrieved data for patients undergoing IBR with prepectoral vs subpectoral implant placement between 1st January 2020 and 31th December 2022 in a large cancer center in France. Results We included 192 patients: 119 in the prepectoral and 73 in the subpectoral group. The clinical characteristics were similar. Thirty patients (15.6%) had adjuvant chemotherapy, of whom 27 (14.1%) within 12 weeks; there was no difference between groups (p=0.12). In the prepectoral group, 39 patients (32.8%) had adjuvant radiotherapy, vs 5 (6.8%) in the subpectoral group (p<0.001), but there was no significant different in time to treatment commencement. Overall, 35 patients (29.4%) in the prepectoral group and 17 (23.3%) in the subpectoral group experienced post-operative complications (p=0.44). By multivariable analysis, the only factor associated with post-operative complications was mastectomy weight [odds ratio 1.98 (1.10-3.59) for weight ≥500g, p=0.02]. Conclusion Prepectoral implant placement without ADM can be proposed to patients undergoing IBR and with an indication for adjuvant treatment. However, in our study, the reoperation rate with this technique was slightly higher (p = 0,008). This is partly due to the learning curve for surgeons using this new technique.