Single-Port Robot-Assisted Nipple-Sparing Mastectomy: Main Analysis of a Retrospective Multicenter Study (SPROUT, KoREa-BSG 09).

[BACKGROUND] The emergence of single-port robotic systems has enabled their application in breast surgery, offering minimally invasive, cosmetically favorable options for mastectomy. This study aimed to evaluate surgical outcomes and operative efficiency of single-port robotic-assisted nipple-sparing mastectomy (SP-RNSM) across multiple institutions in Korea based on early experiences.

[METHODS] This multicenter retrospective study included the patients with primary breast cancer who underwent SP-RNSM with or without axillary surgery and immediate reconstruction between January 2018 and November 2023 at 12 institutions in Korea. Clinicopathologic characteristics, operative variables, including operative time, and postoperative outcomes were collected.

[RESULTS] A total of 428 patients were included in this study. Among them, 81.5% were diagnosed with invasive carcinoma, and 18.5% with ductal carcinoma in situ. The mean age was 45.7 years, and 78.5% were premenopausal. Direct-to-implant was the most common reconstruction method (66.1%). The mean breast surgeon's operative time, plastic surgeon's operative time, and total operative time were 160.5 ± 54.1, 167.1 ± 116.1, and 333.5 ± 132.6 minutes. Multivariable analysis identified lymph node metastasis, heavier breast weight, and absence of tumescent solution use as independent predictors of longer BS time, with breast weight showing the strongest association. Postoperatively, 80% of patients recovered without complications. The most common complication was seroma (10.5%), and the reoperation rate was 2.8%. In the learning curve analysis, no consistent or marked decrease in operative time was observed with increasing case numbers.

[CONCLUSIONS] The SP-RNSM is a feasible and safe approach for breast cancer surgery with favorable surgical outcomes and minimal complications.