Recurrence after transanal endoscopic microsurgery for benign and malignant rectal tumours: experience of a single New Zealand centre.

BACKGROUND: Transanal endoscopic microsurgery (TEM) is an established technique for the resection of rectal adenomas and selected malignant tumours. It avoids the morbidity of radical resection for tumours not amenable to endoscopic resection. An important marker of quality is the local recurrence rate. The primary objective was to determine local recurrence rates for benign and malignant rectal tumours.

METHODS: We identified index TEM excisions of rectal adenomas and adenocarcinomas in patients age 18 and over at Dunedin Hospital, New Zealand, between 2000 and 2020, from a prospective database. Surveillance data were collected via chart review. The primary outcome was recurrence rate for adenomas and adenocarcinomas. Secondary outcomes included time to recurrence, association of recurrence with recognized risk factors, and adverse event rates.

RESULTS: We identified 100 patients for analysis. Of 75 benign cases, 11 (14.7%) developed local recurrence, with 63.6% identified within 1 year. Of the 25 malignant cases (19 T1, 5 T2, 1 T3), 9 (36%) developed recurrence, with 77.8% identified within 2 years. Adverse events occurred in 26% of patients, with no reoperations or deaths.

CONCLUSION: Our adenoma recurrence rate was at the higher end of the reported range of 2.4-16%. Minor complications were common, but not major morbidity. The propensity for rectal tumours to recur commonly and early reinforces the importance of regular standardized endoscopic surveillance.