Endoscopic resection of large rectal polyps involving the dentate line: experience from a UK tertiary referral centre

Aims The management of large rectal polyps involving the dentate line is particularly challenging. This study reviews techniques and clinical outcomes of endoscopic resection (ER) of these polyps at a UK tertiary referral centre.

Methods A retrospective study of ER of all rectal polyps>2cm involving the dentate line was performed between January 2015 and December 2023. Sedation requirements, resection technique, endoscopic success, complications and clinical outcomes were recorded.

Results Of 1103 attempted endoscopic resections of large colorectal polyps, 77 (7.0%) involved the dentate line. Median polyp size was 50mm (range 20-180mm). 14 (18.2%) were circumferential or near-circumferential. 18 (23.4%) were recurrent lesions. 53 (68.8%) were performed under general anaesthesia or propofol deep sedation. 42 (54.5%) were resected by endoscopic submucosal dissection (ESD), 5 (6.5%) by conventional endoscopic mucosal resection (EMR), 16 (20.8%) by knife-assisted EMR, and 14 (18.2%) by TASER (combined ESD+TAMIS) procedure. En bloc excision was achieved in 40/76 (52.6%) successful resections. All patients received prophylactic antibiotics. Intraprocedural bleeding requiring haemostatic forceps was frequent (63.6%) but successfully managed in all cases. Deep mural injury occurred in 6.5% but there were no perforations. 66.2% of patients were discharged on the day of the procedure. Those admitted had an average length of stay of 1.4 nights. Delayed bleeding requiring re-intervention or readmission occurred in 3.9%. There were no cases of post-polypectomy syndrome. Follow-up data was available for 60 resections (78.9%), with recurrence seen in 1/33 (3.0%) en bloc and 15/27 (55.6%) piecemeal resections. Recurrence was higher in circumferential vs non-circumferential polyps (50.0% vs 20.8%), and recurrent vs de novo polyps (43.8% vs 20.5%). Successful eradication for piecemeal resections improved to 66.7% and 74.1% at second and third follow-up, respectively. Overall, 8 cases were ultimately referred for surgery: 3 underwent proctectomy for cancer with high-risk features, 2 underwent proctectomy for non-endoscopically manageable benign recurrence, and 3 underwent transanal resection for non-endoscopically manageable benign recurrence.

Conclusions Endoscopic resection of large rectal polyps involving the dentate line is feasible in the majority of benign polyps, with a variety of techniques employed. En-bloc excision is preferrable and significantly reduces recurrence rate compared to piecemeal excisions.

Publication History

Article published online:
27 March 2025