In a randomized trial, cold snare endoscopic mucosal resection demonstrated noninferior safety and efficacy compared with hot snare endoscopic mucosal resection in removing small (6 to 9 mm) colorectal polyps.
In a multicenter study, published in Scientific Reports, researchers compared the efficacy of cold snare endoscopic mucosal resection (CS-EMR) and hot snare endoscopic mucosal resection (HS-EMR) in treating small colorectal polyps in 99 patients with 138 eligible polyps treated at two South Korean hospitals.
The primary outcome of residual or recurrent adenoma (RAA) at 6-month follow-up occurred in 0% of the patients in the CS-EMR group and 1.5% of those in the HS-EMR group in the intention-to-treat analysis (risk difference [RD] = −1.47, 95% confidence interval [CI] = −4.34 to 1.39, P = .31). CS-EMR achieved an en bloc resection rate of 98.6%, similar to the 98.5% rate with HS-EMR (RD = −0.04, 95% CI = −4.12 to 4.02, P = .98). However, R0 resection, defined as microscopically negative margins, was significantly lower in the CS-EMR group at 55.7% compared with 82.4% in the HS-EMR group (RD = −27.80, 95% CI = −42.50 to −13.10, P < .001).
Median polyp size was 7 mm in both groups. Polyps were located in the right colon in 64.3% of CS-EMR patients and 58.8% of HS-EMR patients. Morphology was flat in 62.9% of CS-EMR polyps and 50.0% of HS-EMR polyps. Low-grade adenomas comprised 90.0% of CS-EMR polyps and 92.3% of HS-EMR polyps. The procedures were performed by expert endoscopists (> 2,000 prior HS-EMRs) for 91.4% of CS-EMRs and 80.9% of HS-EMRs.
Median total procedure time from submucosal injection to complete polyp removal was 172 seconds with CS-EMR and 186 seconds with HS-EMR (median difference = −14 seconds, 95% CI = −32 to 2 seconds, P = .40). Immediate bleeding requiring endoscopic hemostasis occurred in 11.4% of CS-EMRs and 7.4% of HS-EMRs (RD = 3.16, 95% CI = −6.68 to 13.00, P = .53). Delayed bleeding within 14 days occurred in 2.9% and 1.5% (RD = 1.37; 95% CI = −3.47 to 6.21, P = .58), respectively.
Prophylactic clipping was used in 1.4% of CS-EMRs and 2.9% of HS-EMRs. No perforations occurred in either group. One patient in the HS-EMR group developed postpolypectomy syndrome. Results were consistent in the per-protocol analysis.
The CS-EMR technique involved submucosal injection, snaring the polyp with ≥ 2 mm normal mucosal margins, and cold resection. HS-EMR followed the same steps using electrocautery. Resection sites were inspected with white light, narrow-band, and magnified imaging to assess for and snare any residual tissue.
The authors declared no competing interests.
