Background/Objective: Implant-based breast reconstruction is a common plastic surgery procedure with well-documented clinical outcomes. Despite this, the natural history and timing of key complication endpoints are not well described. The goal of this study is to determine when patients are most likely to experience specific adverse events after implant-based reconstruction. Methods: Retrospective consecutive series of patients who received mastectomy and implant-based reconstruction over a 6-year period were included. Complications and unfavorable outcomes including hematoma, seroma, wound infection, skin flap necrosis, capsular contracture, implant rippling, and implant loss were identified. A time-to-event analysis was performed and Cox regression models identified patient and treatment characteristics associated with each outcome. Results: Of 1473 patients and 2434 total reconstructed breasts, 785 complications/unfavorable outcomes were identified. The 12-month cumulative incidence of hematoma was 1.4%, seroma: 4.3%, infection: 3.2%, skin flap necrosis: 3.9%, capsular contracture: 5.7%, implant rippling: 7.1%, and implant loss: 3.9%. In the analysis, 332/785 (42.3%) complications occurred within 60 days of surgery; 94% of hematomas, 85% of skin necrosis events, and 75% of seromas occurred during this period. Half of all infections and implant losses also occurred within 60 days. Of the remaining complications, 94% of capsular contractures and 93% of implant rippling occurred >60 days from surgery. Conclusions: Complications following mastectomy and implant-based reconstruction exhibit a discrete temporal distribution. These data represent the first comprehensive study of the timing of adverse events following implant-based reconstruction. These findings are immediately useful to guide postoperative care, follow-up, and clinical trial design.

With improvement in mastectomy skin flap viability and increasing recognition of animation deformity following sub-pectoral implant placement, there has been a transition toward pre-pectoral breast reconstruction. While studies have explored the cost effectiveness of implant-based breast reconstruction, few investigations have evaluated cost with respect to pre-pectoral versus sub-pectoral breast reconstruction. A retrospective review of 548 patients who underwent mastectomy and implant-based breast reconstruction was performed from 2017 to 2020. The demographic and surgical characteristics of the pre-pectoral and sub-pectoral cohorts were well matched, except for reconstructive staging, as patients who underwent pre-pectoral reconstruction were more likely to undergo single-stage instead of two-stage reconstruction. Comparison of institutional cost ratios by reconstructive technique revealed that the sub-pectoral approach was more costly (1.70 ± 0.44 vs 1.58 ± 0.31, p < 0.01). However, further stratification by laterality and reconstructive staging failed to demonstrate difference in cost by reconstructive technique. These results were confirmed by multivariable linear regression, which did not reveal reconstructive technique to be an independent variable for cost. This study suggests that pre-pectoral breast reconstruction is a cost-effective alternative to sub-pectoral breast reconstruction and may confer cost benefit, as it is more strongly associated with direct-to-implant breast reconstruction.