Sample size and statistical analysis This study is an ambispective cohort study. According to the previous retrospective research data of the center, the breast satisfaction score is the main research object. The standard deviation was 2.6, the non-inferiority margin was 0.15, the test level was α=0.05, β=0.2, and a one-sided test was performed. Eighty patients will be needed for two cohorts in a 1:1 ratio. Considering the 10% loss to follow-up rate, 44 patients will be required to be enrolled in each group.
There are controversies about breast implant-based reconstruction techniques. Our center pioneered single-port insufflation endoscopic nipple-sparing mastectomy (SIE-NSM) combined with stage I prosthesis reconstruction. The study's primary objective is to compare single-port endoscopic NSM combined with pre-pectoral breast reconstruction to the subpectoral breast reconstruction group regarding breast satisfaction.~This study is an ambispective cohort study. The study will be conducted at Beijing Friendship Hospital, affiliated with Capital Medical University. Patients will be enrolled retrospectively from January 2014 to March 2022 by reviewing the medical records and recruited prospectively from March 2022 to March 2025. The two cohorts are the pre-pectoral breast reconstruction cohort and the subpectoral breast reconstruction cohort, both following single-port insufflation endoscopic nipple-sparing mastectomy. The primary outcome of this study is postoperative breast satisfaction, which the BREAST-Q score will measure. The different variables will be compared using the Χ2 test for categorical variables and the Mann-Whitney test for continuous variables.