Background: Prepectoral direct-to-implant reconstruction with acellular dermal matrix (ADM) represents a safe, fast, and successful option in breast reconstruction in a selected cohort of patients. Nowadays, this procedure is considered challenging in thin. Meanwhile, his cohort has not been accurately analyzed yet. Methods: A single institution retrospective cohort study was performed between January 2019 and March 2023 in all women who underwent mastectomy. Biometrical and clinical data were recorded. Also, surgical technique, operating room (OR) time, mastectomy weights, implant choice, and acellular dermal matrix (ADM) types were properly noted. Postoperative complications represented the main topic: these were classified into early and late ones based on onset time. At least 12-month follow-up was required. A comparison between thin and ideal body mass index (BMI) populations was performed. Results: Early complications did not seem to differ between the 2 groups with 37.8% and 38.9% of women having at least 1 early complication in thin and ideal-weight women, respectively (P = .919). In univariable regression analysis, compared with women with a BMI of 22.1 to 25.0, women with a BMI ≤ 22.0 were associated with an increased risk of late complications of 2.84 (1.13-7.14). Specifically, thin women appeared to have a 3-fold increased risk (OR = 2.97, 95% CI 1.08-8.18) of ripples/wrinkles compared with women with ideal weight. Conclusions: Prepectoral reconstruction with ADM in thin patients may be considered as safe as in standard BMI patients. Rippling may be more frequent, but, whenever needed, easy to correct with a few sessions of lipo-grafts. Level of Evidence: III.
