Bilateral Implant-based Breast Reconstruction with Unilateral Radiotherapy: A Matched Cohort Study Comparing Nipple-sparing Mastectomy and Skin-sparing Mastectomy

Background: Nipple-sparing mastectomy (NSM) preserves the natural nipple-areola complex and entire native breast skin, with the goal of better cosmetic outcomes in breast reconstruction. In bilateral TE/implant-based reconstruction requiring unilateral postmastectomy radiotherapy (PMRT), progressive radiation-induced fibrosis can lead to increasing nipple asymmetry with cosmetic dissatisfaction. Thus, PMRT may ultimately negate the intended positive cosmetic value of NSM compared with skin-sparing mastectomy (SSM). This study compares (1) surgical complications, (2) patient satisfaction, and (3) aesthetic outcomes between NSM versus SSM in bilateral implant-based reconstruction with unilateral PMRT. Methods: This retrospective matched cohort study included consecutive NSM patients with bilateral TE/implant breast reconstruction + unilateral PMRT matched 1:2 to SSM group. Patients completed PMRT and TE exchange to implants. Demographics, oncologic stage, comorbidities, and complications were collected. Patient satisfaction was evaluated by BREAST-Q. Aesthetic outcomes were assessed by blinded reviewers with a five-point Likert scale. Results: Among 58 patients who underwent bilateral TE/implant reconstruction with unilateral PMRT, 17 NSM patients were matched to 41 SSM patients by age, body mass index, and comorbidities. No significant differences existed in overall surgical complications and individual BREAST-Q questionnaire scores between cohorts. However, aesthetic outcomes scores were higher in SSM compared with NSM. Conclusions: Although NSM is generally associated with superior cosmetic outcomes compared with SSM, it has far less impact in bilateral implant-based breast reconstruction with unilateral PMRT due to the negative postradiotherapy effect on nipple symmetry.