Impact of Contralateral Implant Placement in Unilateral Implant-Based Postmastectomy Breast Reconstruction: A Single Center Retrospective Cohort Study

<b>Background/Objectives</b>: Investigating how placement of a contralateral breast implant in the context of unilateral implant-based breast reconstruction influences aesthetic and patient-reported outcomes. <b>Methods</b>: A retrospective analysis was performed on a single-center prospectively maintained database (January 2021-March 2025) including patients who underwent unilateral implant-based breast reconstruction in association with a contralateral implant placement or not. Exclusion criteria were bilateral implant-based reconstruction or autologous reconstruction, follow-up of less than 6 months and missing data. Demographics and complications were analyzed. Aesthetic outcomes were evaluated by independent blinded surgeons using the Kroll Scale, patient satisfaction was investigated with the BREAST-Q Reconstruction Module v2.0. Statistical analysis used the Student's <i>t</i>-test, Multivariate regression analysis and Mann-Whitney U test with significance set at <i>p</i> < 0.05. <b>Results</b>: The study group included 21 patients (40.4%) who received a contralateral implant, while the control group included 31 patients (59.6%) who did not receive a contralateral implant. Patients who received contralateral implants showed a significant improvement in cosmetic outcomes evaluated with the Kroll Scale and a raw increment, without statistical significance, in BREAST-Q scores in all subsections investigated (Psychosocial well-being, Sexual well-being and Satisfaction with breasts). <b>Conclusions</b>: Placing a contralateral breast implant in the context of unilateral implant-based breast reconstruction significantly improves aesthetic outcomes and correlates with higher patient satisfaction scores for the reconstructed breast, compared to placing no contralateral implant, without increasing the overall complication rate.