A Prospective, Multicenter Randomized Controlled Trial (RCT) of the da Vinci SP® Surgical System versus Open Surgery in Nipple-Sparing Mastectomy (NSM) Procedures for Patients with Breast Cancer

BACKGROUND: compared with open NSM in women with early stage breast cancer. PATIENTS AND METHODS: This Food and Drug Administration (FDA) investigational device exemption (IDE)-approved, two-arm, multicenter randomized controlled trial (RCT) randomized eligible women (clinical Tis-T2, N0) 1:1 to rNSM or open NSM with immediate implant-based reconstruction. Operations were performed at 14 US sites by 23 surgeons. Primary endpoints included conversion to open surgery, adverse events at 42 days, and positive surgical margin (PSM) rates. Secondary outcomes included operative time, estimated blood loss, nipple-areolar complex (NAC) and skin flap viability, final pathology, and patient-reported outcomes (BREAST-Q). RESULTS: Overall, 74 patients completed surgery, totaling 65 rNSM (38 therapeutic, 27 prophylactic) and 66 open NSM (38 therapeutic, 28 prophylactic). Operative time was longer for rNSM (141.6 versus 83.9 min) with no conversions to open surgery. Serious adverse events (SAEs) occurred in three rNSM and eight open NSM patients, with no device-related SAEs reported. NAC preservation at 42 days was 100% for rNSM and 98.5% for open NSM. PSM rates were identical (six patients each). Higher BREAST-Q scores favored rNSM in multiple domains. CONCLUSIONS: rNSM is feasible and has a safety profile comparable to open NSM for early stage breast cancer, with similar margin status and postoperative complications. Although SAEs and patient-reported outcomes were more favorable with rNSM, these differences were not statistically significant. rNSM was associated with longer operative times, which may in part reflect early experience with the technique.