A study of intersphincteric resection rate following robotic-assisted total mesorectal excision versus laparoscopic-assisted total mesorectal excision for patients with middle and low rectal cancer: study protocol for a multicenter randomized clinical trial.

Introduction: Robotic-assisted complete mesorectal excision (RATME) is increasingly being used by colorectal surgeons. Most surgeons consider RATME a safe method, and believe it can facilitate total mesorectal excision (TME) in rectal cancer, and may potentially have advantages over intersphincteric resection (ISR) and anus preservation. Therefore, this trial was designed to investigate whether RATME has technical advantages and can increase the ISR rate compared with laparoscopic-assisted TME (LATME) in patients with middle and low rectal cancer.

Methods and analysis: This is a multicenter, superiority, randomized controlled trial designed to compare RATME and LATME in middle and low rectal cancer. The primary endpoint is the ISR rate. The secondary endpoints are coloanal anastomosis (CAA) rate, conversion to open surgery, conversion to transanal TME (TaTME), abdominoperineal resection (APR) rate, postoperative morbidity and mortality within 30 days, pathological outcomes, long-term survival outcomes, functional outcomes, and quality of life. In addition, certain measurements will be conducted to ensure quality and safety, including centralized photography review and semiannual assessment.

Discussion: This trial will clarify if RATME improves ISR and promotes anus preservation in patients with mid- and low-rectal cancer. Furthermore, this trial will provide evidence on the optimal treatment strategies for RATME and LATME in patients with mid- and low-rectal cancer regarding improved operational safety.

Trial registration: ClinicalTrials.gov NCT06105203. Registered on October 27, 2023.