Refinement of robot-assisted nipple-sparing mastectomy utilizing the da Vinci SP system and SP access port device: the RASPB-1 Pilot Trial

The most updated version of the da Vinci single-port (SP) system features a single robotic arm and a balloon-shaped access port for stable entry and efficient multi-jointed instrument use in tight spaces. We conducted a prospective trial in a single-arm design to evaluate its effectiveness for robot-assisted nipple-sparing mastectomy (R-NSM). Patients with stage 0-III breast cancer (without skin/nipple invasion) underwent unilateral R-NSM and immediate reconstruction. The main outcome was R-NSM completion without extra ports or conversion; the secondary outcomes included surgical results, complications, margin status, patient feedback, and recurrence. Thirty R-NSMs were performed via mid-axillary incisions. Median docking and console times were 2.5 and 107 min, respectively. All margins were negative. Mastectomy-related complications (all grade 1) included skin necrosis (3 cases), blistering (7 cases), partial nipple-areolar necrosis (8 cases), and one nipple loss. Reconstruction used 25 free flaps and 5 implants, with 4 flap vessel issues and 1 implant loss. Serial BREAST Q scores showed quick recovery of satisfaction and physical well-being by the 3rd month. At 36-month follow-up, there was no locoregional recurrence and one distant metastasis. The SP system is efficient and safe for R-NSM in Asian patients, resolving prior limitations with the multi-arm (Xi) system. Further studies are needed to compare its clinical benefits with other systems. Trial registration : NCT05448963, ClinicalTrials.gov (Date of registration 18/06/2022).