Robotic transanal excision of rectal lesions: expert perspective and literature review

Abstract

Transanal excision of benign lesions, moderately or well-differentiated rectal T1 adenocarcinomas is typically completed via transanal endoscopic microsurgery (TEM) or laparoscopic transanal minimally invasive surgery (TAMIS). Robotic platforms provide ergonomic comfort in an enclosed space, enhanced range of motion, and superior 3D visualization. This study sought to perform a literature review of robotic TAMIS (R-TAMIS) and provide expert commentary on the technique. A Pubmed literature search was performed. Study design, robot type, indication, techniques compared, surgical margins, conversion, complications, operative time, estimated blood loss, patient positioning, and defect closure were collected from included articles. Expert opinion on pre-operative planning, technical details, and possible pitfalls was provided, with an accompanying video. Twelve articles published between 2013 and 2022 were included. Five were case reports, three case series, two prospective cohort studies, one retrospective cohort study, and one Phase II trial. The Da Vinci Si (n = 3), Xi (n = 2), single port (n = 3) and flex robotic system (n = 2) were used. Five studies reported negative surgical margins, one reported positive margins, and six did not comment. Operating room time ranged from 45 to 552 min and EBL ranged from 0 to 100 mL. Patient positioning varied based on lesion location but included supine, prone, modified lithotomy, and prone jackknife positions. 11/12 studies reported defect closure, most commonly with V-Loc absorbable suture. We recommend pre-operative MRI abdomen/pelvis, digital rectal exam, and rigid proctoscopy; prone jackknife patient positioning to avoid collisions with robotic arms; and defect closure of full-thickness excisions with backhanded running V-Loc suture.