Cold versus hot snare endoscopic mucosal resection for 10–19-mm nonpedunculated colorectal polyps: a multicenter randomized trial

Evidence for cold snare endoscopic mucosal resection (CS-EMR) in 10–19-mm nonpedunculated colorectal polyps is scarce. We conducted a multicenter randomized controlled trial (RCT) to compare CS-EMR against hot snare EMR (HS-EMR) in this setting. We enrolled patients with 10–19-mm nonpedunculated colorectal polyps from 15 centers. Eligible polyps were individually randomized (1:1) to CS-EMR or HS-EMR. The primary outcome was histologic complete resection, analyzed in modified intention-to-treat (mITT) and per-protocol (PP) populations (noninferiority margin −10%). Secondary outcomes included en bloc resection, intraprocedural and delayed adverse events, and resection time. 216 patients with 233 eligible polyps were included (CS-EMR 116; HS-EMR 117). In the mITT analysis, complete resection was 90.4% in the CS-EMR group and 93.2% in the HS-EMR group (difference −2.7%, 95%CI −9.8 to 4.3), showing noninferiority of CS-EMR vs. HS-EMR. PP results were consistent (CS-EMR 93.3%; HS-EMR 93.2%; difference 0.2%, 95%CI −6.7 to 7.1). CS-EMR was noninferior for 10–14-mm polyps (94.3% vs. 94.0%; 95%CI −6.8 to 7.2) but not for 15–19-mm polyps (78.6% vs. 90.9%; 95%CI −30.4 to 5.8), although interaction was not significant. En bloc resection rates and resection time were similar between groups. Intraprocedural bleeding was more frequent with CS-EMR (19.1% vs. 3.4%), whereas delayed bleeding was rare (0.0% vs. 0.9%), and no perforation occurred in either group. CS-EMR was noninferior to HS-EMR for histologic complete resection of 10–19-mm nonpedunculated colorectal polyps, but its applicability to 15–19-mm lesions remains uncertain.