First Clinical Report of the International Single Port Robotic Rectal Cancer Registry.

Background: Rectal cancer surgery remains a significant technical challenge. Development and implementation of new technology offers hope for more accurate and precise surgery. To evaluate if single port robotic technology (SPR) helps achieve this goal we established an international SP robotic registry. This study reports short-term clinical and oncological outcomes from an international SPR registry for rectal cancer.

Methods: Review of a prospective international registry of SPR procedures approved for colorectal surgery under an investigational design exemption (IDE) was performed. Patients with rectal adenocarcinoma that had resection for curative intent using the SPR platform from 11/2018-9/2022 were included. Frequency statistics described patient and tumor characteristics and intraoperative, oncological and clinical outcome variables. The main outcome measure was the quality of the TME specimen. Secondary outcome measures were intraoperative conversions; 30-day postoperative morbidity and mortality.

Results: 113 SPR rectal cancer cases were performed at 2 centers by 4 colorectal surgeons. 9 local excisions were excluded, leaving 104 cases analyzed. The cohort was 50.96% men, mean age of 60.0years (SD 11.29) and BMI 25.8kg/m2 (SD 6.18). The most common T-stage was 3 (n=55, 52.8%), followed by 2 (n=19, 18.26%). Over 60% of patients had preoperative neoadjuvant chemoradiation. The cancers were a mean 2.9cm (SD 2.62) from the anorectal ring and 4.52cm (SD 1.82) in size. The procedures performed were a TATA/TaTME (n=52, 46%), low anterior resection (n=49, 43.3%), and abdominoperineal resections (n=3, 2.7%). The mean operating time was 168min (SD 56.9). There were no intraoperative complications and 2 (1.9%) conversions to laparoscopy. There was a median of 2 incisions, with a mean size of 2.3cm (SD 1.31). The TME specimen was complete in 97.1% (n=101) and near complete in 2.9% (n=3). R1 rate was 3.8% with 3 distal and 1 circumferential positive margins. Post-operatively, there were 15 total complications, 4 major and 11 minor. There were 2 readmissions (ileus and small bowel obstruction). There were no mortalities.

Conclusions: This early international experience with the SPR showed it was a safe and effective technique for distal rectal cancers, with excellent specimen quality. The complication and conversion rates seen with other techniques and platforms used in rectal cancer surgery were not demonstrated. With the use of an international registry, we hope to develop a better understanding of the opportunities and limitations of SPR in rectal cancer surgery as the technology is adopted and applied more widely. While structured training and controlled trials will be required to develop best practices and define the use of the SPR, initial international registry data is encouraging.