Transanal endoscopic microsurgery in the treatment of large rectal adenomas.

Abstract Transanal endoscopic microsurgery (TEM) is a minimally invasive technique allowing to excise large rectal adenomas by local approach. This study shows the feasibility and results of a long term experience of TEM applied in this field. A retrospective investigation was performed in patients affected by rectal adenomas (5-11 cm in diameter) who had undergone transanal endoscopic microsurgery from 1992 to 2015. A series of 207 patients met the inclusion criteria and were analyzed for characteristics, intraoperative and postoperative results and long-term follow-up. Median age was 71 years (52-83 years). Of the 207 total patients, 77 were women (37.2%) and 130 men (62.8%). Median distance from the anal verge was 8 cm (4-20 cm). Median size was 6 cm, with lesion ranging from 5 to 11 cm in diameter. Median operative time was 57 minutes (42-90 minutes). We observed 17 (8.2%) minor complications and 2 (0.9%) major complication according to the Clavien-Dindo classification. We did not observe any intraoperative or post-operative mortality. Histological examination showed preoperative undiagnosed cancer in 8 (3.8%) cases in which the pathologist revealed adenocarcinoma staged as T1 Sm1 according to the Kikuchi classification. The median follow-up was 115 months (12-288 months). Six recurrences (2.9%), we observed with a median time for recurrence of 14 months. TEM provides excellent oncological outcomes in the treatment of large benign rectal lesions, ensuring a minimal risk of resection margin infiltration at pathological examination, and is associated with low risk of complications.