First clinical report of the international single-port robotic rectal cancer registry

Background: Rectal cancer surgery remains a significant technical challenge. The development and implementation of a new technology offer hope for more accurate and precise surgery. To evaluate whether single-port robotic (SPr) technology helps achieve this goal, an international SPr registry was established. This study reported short-term clinical and oncologic outcomes from an international SPr registry for rectal cancer.

Methods: A review of a prospective international registry of SPr technology approved for colorectal surgery with an investigational design exemption was conducted. Patients with rectal adenocarcinoma who had resection for curative intent using the SPr platform between November 2018 and September 2022 were included. Frequency statistics described patient and tumor characteristics and intraoperative, oncologic, and clinical outcome variables. The main outcome measure was the quality of the total mesorectal excision (TME) specimen. The secondary outcome measures were intraoperative conversion and 30-day postoperative morbidity and mortality.

Results: A total of 113 SPr procedures for rectal cancer were performed at 2 centers by 4 colorectal surgeons. Of note, 9 local excisions were excluded, leaving 104 cases analyzed. The cohort consisted of 53 men (50.96%), had a mean age of 60.00 years (SD, 11.29), and had a body mass index of 25.80 kg/m² (SD, 6.18). The most common T stage was 3 (55 [52.8%]), followed by 2 (19 [18.26%]). More than 60% of patients had preoperative neoadjuvant chemoradiation. The mean tumor distance from the anorectal ring was 2.90 cm (SD, 2.62), and the mean tumor size was 4.52 cm (SD, 1.82). The procedures performed included transanal abdominal transanal/transanal TME (52 [46%]), low anterior resection (49 [43.3%]), and abdominoperineal resection (3 [2.7%]). The mean operating time was 168.0 min (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 2.30 cm (SD, 1.31). The TME specimens were complete in 101 cases (97.1%) and near complete in 3 cases (2.9%). The R1 rate was 3.8%, with 3 positive distal margins and 1 positive circumferential margin. Postoperatively, there were 15 total complications, of which 4 were major complications and 11 were minor complications. There were 2 readmissions (ileus and small bowel obstruction). There were no mortalities.

Conclusion: This early international experience with the SPr procedure showed that it is a safe and effective technique for distal rectal cancers, with excellent specimen quality. The complication and conversion rates observed with other techniques and platforms used in rectal cancer surgery were not demonstrated. An international registry was used to better understand the opportunities and limitations of SPr technology in rectal cancer surgery as the technology is adopted and applied more widely. Although structured training and controlled trials will be required to develop best practices and define the use of the SPr technology, initial international registry data are encouraging.