Cold Snare Endoscopic Mucosal Resection (EMR) vs Cold EMR With Margin Snare Tip Soft Coagulation (STSC)

Randomised controlled trial comparing cold snare endoscopic mucosal resection (EMR) with cold snare EMR and adjuvant margin STSC in the complete resection of 15-40mm lateral-spreading adenomas

Rationale: Conventional EMR is well-established for the resection of lateral-spreading adenomas and has been shown to be highly efficacious with adjuvant STSC. Cauterisation-related complications occur relatively frequently and while endoscopically treatable, still carry morbidity not seen in current cold snare polypectomy data. Cold snare polypectomy has an excellent safety profile for smaller polyps, without cauterisation-related adverse events. Limited data on cold EMR for large adenomatous laterally-spreading lesions shows minimal complications. Efficacy, however, is yet to be evaluated in prospective randomised trials. Observational data demonstrates recurrence rates exceeding conventional EMR. Since STSC causes significant reduction in recurrence in conventional EMR, the safety and efficacy of this adjuvant technique, when compared to isolated cold snare EMR, has theoretical advantages in both safety and efficacy. The safety and efficacy of these two techniques will therefore be compared in a randomised controlled trial. Hypothesis: Cold snare EMR of 15-40mm lateral-spreading adenomas with adjuvant STSC is expected to be superior regarding complete resection and adenoma recurrence rates as compared to cold snare EMR.

Inclusion Criteria: * Any patient undergoing colonoscopy who is older than 18 years of age, has a written consent for trial participation and has at least one laterally spreading lesion meeting the following description: * Localisation in the colon or rectum * Benign adenomatous surface features (Kudo III / IV, Japan NBI Expert Team (JNET) 2a) * Granular or non-granular topography * Paris classification 0-IIa/IIb +/- Is * If present, sessile component may be no greater than 10mm in size. * Polyp size ranging from 15 to 40mm Exclusion Criteria: * Current use of antiplatelet (excluding aspirin) or anticoagulants which have not appropriately been interrupted according to the guidelines. * Known bleeding disorder or coagulopathy. * Pregnancy * History of inflammatory bowel disease * Previously attempted or otherwise non-lifting lesions * Endoscopic features suggestive of submucosal invasion (Kudo Vi/n, JNET 2b / 3) or concurrent colorectal cancer * Lesions involving the ileocaecal valve (ICV), appendiceal oriface or anorectal junction (ARJ)