Evaluation of post-operative 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 is unclear whether there is any difference in the complication rates between prepectoral versus subpectoral implant placement without acellular dermal matrix (ADM).

Aim: To compare the rates 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 of patients who underwent IBR with prepectoral versus subpectoral implant placement between January 1, 2020 and December 31, 2022 in a large cancer center in France.

Results: We included 192 patients: 119 in the prepectoral and 73 in the subpectoral group. Their clinical characteristics were similar. Thirty patients (15.6%) received adjuvant chemotherapy, among them 27 (14.1%) received it within 12 weeks, and there was no difference between the groups (p = 0.12). In the prepectoral group, 39 patients (32.8%) received adjuvant radiotherapy versus 5 (6.8%) in the subpectoral group (p < 0.001), but there was no significant difference 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). Using multivariable analysis, the only factor associated with post-operative complications was determined to be mastectomy weight (odds ratio 1.98 (1.10-3.59) for weight ≥500 g; p = 0.02).

Conclusion: Prepectoral implant placement without ADM can be proposed to patients undergoing IBR 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.