A novel tool for case selection in Endoscopic Mucosal Resection training

Abstract

BACKGROUND AND STUDY AIMS: As Endoscopic mucosal resection (EMR) of large (20mm) adenomatous non-pedunculated colonic polyps (LNPCPs) becomes widely practiced outside expert centres, appropriate training is necessary to avoid failed resection and inappropriate surgical referral. No EMR-specific tool guides case selection for endoscopists learning EMR. This study aimed to develop an EMR case selection score (EMR-CSS) to identify potentially challenging lesions for "EMR-naive" endoscopists developing competency. PATIENTS AND METHODS: Consecutive EMRs were recruited from a single centre from September 2008-February 2022 Lesion characteristics, intra-procedural data and adverse events were recorded. Challenging lesions with intra-procedural bleeding (IPB), intra-procedural perforation (IPP) or unsuccessful resection were identified and predictive variables identified. Significant variables formed a numerical score and ROC curves generated cut-off values. RESULTS: Of 1993 LNPCPs, 286 (14.4%) were in challenging locations (anorectal junction, ileocaecal valve and appendiceal orifice), 368 (18.5%) encountered IPB and 77 (3.9%) IPP. 110 (5.5%) procedures were unsuccessful. The composite endpoint of IPB, IPP or unsuccessful EMR was present in 526 (26.4%) cases. Lesion size, challenging location, and sessile morphology were predictive of the composite outcome. A six-point score was generated with a cut-off of two demonstrating 81% sensitivity across training and validation cohorts. CONCLUSIONS: EMR-CSS is a novel case selection tool for conventional EMR training which identifies a subset of adenomatous LNPCPs that can be successfully and safely attempted in early EMR training.