Robotic transanal minimally invasive surgery: a case series.

Introduction: This study describes the experience with robot-assisted transanal minimally invasive surgery (rTAMIS) at a single institution. TAMIS has become a popular minimally invasive technique for local excision of well-selected rectal lesions. rTAMIS has been proposed as another option as it improves the ergonomics of conventional laparoscopic techniques.

Methods: Retrospective case series of patients with rectal lesions who underwent rTAMIS. Patient demographics, final pathology, surgical and admission details, and clinical outcomes were recorded. Successful procedures were defined as having negative margins on final pathology.

Results: A total of 16 patients underwent rTAMIS by a single surgeon between April 2018 and December 2019. Mean age of patients was 63 years. Final pathologies were negative for tumor (n = 4), tubulovillous adenoma (n = 4), tubulovillous adenoma with high-grade dysplasia (n = 4), and invasive rectal adenocarcinoma (n = 4). 43% were located in the middle rectum and 56% were located in the distal rectum. Mean maximum diameter was 4.1 cm (IQR 2-3.1 cm). Negative margins were seen in 100% of the excision cases, and 100% were intact. Mean operative time was 87 min (IQR 54.8-97.3 min), and median length of stay was 0 days (IQR 0-1 days). Postoperative complications included incontinence (n = 1) and abscess formation (n = 2). rTAMIS provided curative treatment for 12/16 patients, and the remaining 4 patients received the appropriate standard of care for their respective pathologies.

Conclusions: Robot-assisted TAMIS is a safe alternative to laparoscopic TAMIS for resection of appropriate rectal polyps and early rectal cancers. rTAMIS may provide a modality for resecting larger or more proximal rectal lesions due to the wristed instruments and superior visualization with the robotic camera. Future studies should focus on comparing outcomes between robotic and laparoscopic TAMIS, and whether rTAMIS allows for the removal of larger, more complex lesions, which may save patients from a more morbid radical proctectomy.