ADM-Assisted Direct-to-Implant Prepectoral Breast Reconstruction in Postmastectomy Radiation Therapy Setting: Long-Term Results

•Prepectoral breast reconstruction is safe with postmastectomy radiotherapy.•Preserving an optimal mastectomy flap decreases complication rates.•Capsular contracture is the only complication significantly increased with PMRT.•Minimal need of revisional surgery in the long-term for radiotreated PPBR. Postmastectomy radiotherapy (PMRT) on immediate breast reconstruction historically involved a marked increase in complication rate (up to 50%). Prepectoral breast reconstruction (PPBR) has shown promising early postoperative results. This study aims to evaluate PPBR long-term results in PMRT setting. This is a retrospective monocentric analysis of 485 PPBR (439 patients) undergoing Acellular-Dermal-Matrix assisted direct-to-implant reconstruction (46 bilateral procedures) between January 2015 and December 2020 (mean FU:35.6 months). Group 1 comprised 401 PPBR not submitted to PMRT, and 84 reconstructions receiving PMRT in Group 2. Patients’ characteristics, postoperative complication and revisional surgery rate were examined. PMRT characteristics and subcutaneous tissue thickness, measured in Group 2 by CT scan, were also evaluated. Long-term complication rate was 11.2% in Group 1 vs. 21.4% in Group 2 (P-value = .019). Capsular contracture represented the only complication associated to a statistically significant difference between the 2 groups (P-value < .001). In Group 2, only 4.8% implant loss and 8.3% severe capsular contracture rate was found. In patients who underwent PMRT, 38.9% of complications settled with no consequences, and only 4.8% of patients needed revisional surgery in the long-term FU. According to multivariate analysis, drug intake and PMRT were significantly associated with postoperative complications. In Group 2, a thinner subcutaneous tissue was linked to a higher complication risk. In our series, patients treated with PPBR who underwent PMRT, presented a low complication rate and minimal need for revisional surgery in the long-term follow-up, suggesting that this technique is feasible and safe also in PMRT context. Postmastectomy radiotherapy (PMRT) applied on breast reconstruction usually involves a marked increase in complication rate. This study analyses 485 prepectoral reconstructions (84 radiotreated), performed with Acellular-dermal-matrix assisted direct-to-implant technique. Low complication rate and minimal need for revisional surgery were reported in the long-term (mean FU 35.6 months). Therefore, this technique seems safe and