Safety and Efficacy of Cold compared to Hot Endoscopic Mucosal Resection of Large Non-Pedunculated Colorectal Polyps: Systematic Review and Meta-Analysis

Introduction: Endoscopic mucosal resection (EMR) is traditionally performed using electrosurgical cautery (hot snare) to resect premalignant colorectal polyps. Recent data have suggested the superior safety of cold EMR (c-EMR), even for polyps > 20 mm in size. We aimed to perform a systematic review and meta-analysis to assess the safety and efficacy of cold EMR compared with traditional (hot) EMR. Methods: We performed a comprehensive systematic review ending in December 2024. The primary outcome of interest was the odds of delayed bleeding for c-EMR compared with h-EMR of nonpedunculated colorectal polyps > 20 mm in size. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported. The secondary outcomes included early bleeding, perforation, and polyp recurrence. Publication bias was assessed using the classic fail-safe test. Forest plots were used to report the pooled effect estimates. Heterogeneity was assessed using I 2 . Results: Our systematic review identified 1,632 unique citations, a total of 3 RCTs and four non-randomized comparative studies were identified and included in the primary analyses. Four additional cohort studies were included in the secondary analyses. On random effects modeling, c-EMR was associated with a significantly lower risk of delayed bleeding (OR, 0.25 [95%CI:0.11 - 0.57], p=0.001, I 2 =0%), early bleeding (OR, 0.34 [95%: 0.2 – 0.6], p<0.001, I 2 =0%), and perforation (OR 0.14 [95%CI:0.04 – 0.51], p=0.003, I 2 = 0%) than h-EMR. C-EMR was associated with a higher rate of recurrence (OR, 1.81 [95%CI: 1.01 – 3.25], p=0.045, I 2 = 72%). Conclusions: c-EMR has a superior safety profile to h-EMR for non-pedunculated colorectal polyps > 20 mm in size, but strategies to manage the higher odds of recurrence remain essential.