Transanal Minimally Invasive Surgery Versus Endoscopic Submucosal Dissection for Rectal Lesions: A Community Hospital Experience.

Background: To compare tumor margins and surgical outcomes between transanal minimally invasive surgery (TAMIS) and endoscopic submucosal dissection (ESD) for large or malignant rectal adenomatous polyps. Methods: Single institution retrospective analysis of patients who underwent TAMIS or ESD surgery. Results: In total, 30 consecutive patients with similar demographics who underwent either TAMIS (n = 19) or ESD (n = 11) were included. The median (interquartile range, IQR) tumor distances from the anal verge for TAMIS and ESD were 5 cm (3.5-8) and 3 cm (2-4.25) (P = 0.016). Four in TAMIS and two in ESD occupied more than half of the circumference of the bowel lumen. Five (four in situ and one stage 1) in TAMIS and two (one in situ and one stage 1) in ESD were malignant. The median specimen length, width, and height were 3.2 cm, 2.6 cm, and 1.0 cm and 3.5 cm, 2.0 cm, and 0.3 cm for TAMIS and ESD, respectively. There were no statistically significant differences in tumor circumference, malignant ratios, or specimen sizes. Resection margins were involved in two of the ESD, while none of the TAMIS were involved (P = 0.041). The median (IQR) operative time was 72 (62-89) minutes and 120 (90-180) minutes for TAMIS and ESD (P = 0.005). The median (IQR) follow-up time was 3.3 (0.3-11.7) and 0.9 (0.3-15.4) months for TAMIS and ESD. There were no morbidities, no mortalities, or local recurrences among the two groups. Conclusions: Both TAMIS and ESD were found to be feasible and safe in community hospital practice. Operative time was shorter, and there were no involved margins in TAMIS (versus ESD).