Zolotarevsky, Eugene

Abstract Endoscopic mucosal resection (EMR) techniques for large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) have expanded with the introduction of ablation and cold EMR. This study assessed adverse events (AEs) for the newer EMR techniques, including cold EMR, compared with hot EMR. We conducted a secondary analysis of four prospective multicenter studies of consecutive patients with LNPCPs undergoing EMR from 2019 to 2024. The primary outcome was serious AEs (SAEs) with cold and hot EMR. Secondary outcomes included SAEs in the hot EMR subgroups (no ablation [hEMR], margin ablation [hEMR-m], margin and base ablation [hEMR-mb]). 1762 patients (mean age 65.8; 1890 LNPCPs) were included: 522 cold and 1368 hot EMRs (368 hEMR, 770 hEMR-m, 230 hEMR-mb). SAEs were higher with hot EMR (4.7%, 95%CI 3.6%–5.9%) vs. cold EMR (1.9%, 95%CI 0.9%–3.5%), also for the subgroups of hEMR (6.0%, 95%CI 3.8%–8.9%), hEMR-m (3.9%, 95%CI 2.6%–5.5%), and hEMR-mb (5.2%, 95%CI 2.7%–8.9%). Serious postendoscopic bleeding (PEB) was numerically higher with hot EMR (2.3%, 95%CI 1.6%–3.3%) vs. cold EMR (1.3%, 95%CI 0.5%–2.7%), also for the subgroups of hEMR (3.0%, 95%CI 1.5%–5.3%), hEMR-m (1.9%, 95%CI 1.1%–3.2%), and hEMR-mb (2.6%, 95%CI 1.0%–5.6%). Perforation, intraprocedural and post-procedural, was numerically higher with hot EMR (1.2%, 95%CI 0.7%–2.0%) vs. cold EMR (0.2%, 95%CI 0.0%–1.1%). hEMR-m and hEMR-mb with clipping had lower rates of serious and overall PEB than no clipping. Cold EMR demonstrated lower rates of SAEs, serious PEB, and perforation compared with hot EMR. Perforation and mortality occurred almost exclusively after hot EMR. Hot EMR with margin +/− base ablation did not increase SAEs compared with hot EMR without ablation.

Background Complications of endoscopic mucosal resection (EMR) of large colorectal polyps remain a concern. Objective We aimed to compare safety and efficacy of cold EMR (without electrocautery) to hot EMR (with electrocautery) of large colorectal polyps. Design In this multicentre randomised trial, patients with any large (≥20 mm) non-pedunculated colon polyp were assigned to cold or hot EMR (primary intervention), and to submucosal injection with a viscous or non-viscous solution (secondary intervention) following a 2×2 design. The primary outcome was the rate of severe adverse events (SAEs). The secondary outcome was polyp recurrence. In this study, we report results of the primary intervention. Results 660 patients were randomised and analysed. An SAE was observed in 2.1% of patients in the cold EMR group and in 4.3% in the hot EMR group (p=0.10) (per protocol analysis 1.4 vs 5.0%, p=0.017) with fewer perforations following cold EMR (0%) compared with hot EMR (1.6%, p=0.028). Postprocedure bleeding did not differ (1.5% vs 2.2%, p=0.57). The effect of cold resection was independent of the type of submucosal injection solution, polyp size or antithrombotic medications. Recurrence was detected in 27.6% and 13.6% in the cold and hot EMR groups, respectively (p<0.001). Recurrence was not significantly different for 20–29 mm polyps (18.6% vs 13.4%, p=0.24) and for sessile serrated polyps (14.1% vs 8.5%, p=0.33). Conclusion Universal application of cold EMR did not significantly lower SAEs (unless cold EMR could be completed) and doubled the recurrence rate compared with hot EMR. Trial registration details ClinicalTrials.gov, number: NCT03865537 .