Surgical outcomes of robot-assisted rectal cancer surgery using the da Vinci Surgical System: a multi-center pilot Phase II study.

Introduction: We conducted a multi-center pilot Phase II study to examine the safety of robotic rectal cancer surgery performed using the da Vinci Surgical System during the introduction period of robotic rectal surgery at two institutes based on surgical outcomes.

Methods: This study was conducted with a prospective, multi-center, single-arm, open-label design to assess the safety and feasibility of robotic surgery for rectal cancer (da Vinci Surgical System). The primary endpoint was the rate of adverse events during and after robotic surgery. The secondary endpoint was the completion rate of robotic surgery.

Results: Between April 2014 and July 2016, 50 patients were enrolled in this study. Of these, 10 (20%) had rectosigmoid cancer, 17 (34%) had upper rectal cancer, and 23 (46%) had lower rectal cancer; six underwent high anterior resection, 32 underwent low anterior resection, 11 underwent intersphincteric resection, and one underwent abdominoperineal resection. Pathological stages were Stage 0 in 1 patient, Stage I in 28 patients, Stage II in 7 patients and Stage III in 14 patients. Pathologically complete resection was achieved in all patients. There was no intraoperative organ damage or postoperative mortality. Eight (16%) patients developed complications of all grades, of which 2 (4%) were Grade 3 or higher, including anastomotic leakage (2%) and conversion to open surgery (2%).

Conclusion: The present study demonstrates the feasibility and safety of robotic rectal cancer surgery, as reflected by low morbidity and low conversion rates, during the introduction period.