Cold snare endoscopic mucosal resection versus standard hot technique for large flat nonpedunculated colonic lesions: a randomized controlled trial.

Backgrounds:  Cold snare EMR (CS-EMR) in large flat nonpedunculated colonic lesions (LFNPCLs) is an alternative to the standard EMR procedure with a better safety profile, but scientific evidence on its efficacy is unavailable. This study aimed to compare the recurrence rate between the two techniques at 6 months. Secondary aims were comparison of the safety profile and procedure-related outcomes.

Methods:  This was a noninferiority, multicenter, open-label, randomized controlled trial of consecutive large (≥ 20 mm) LFNPCLs without suspicious features of submucosal invasion.

Results:  229 patients were randomized to receive CS-EMR (n = 115) or EMR (n = 114). The median lesion size was 25 mm and 74.6 % were adenomas. The trial was stopped early by clinical consensus according to a safety monitoring board. At first surveillance colonoscopy (n = 220) the recurrence rate was significantly greater in the CS-EMR group than in the EMR group: 33.0 % vs. 16.2 % ( = 0.004) and 34.7 % vs. 14.8 % ( = 0.001) in the intention-to-treat and per-protocol analyses, respectively. According to the subgroup analysis, the recurrence rate was significantly greater after CS-EMR for LFNPCLs ≥ 30 mm (43.1 % vs. 18.2 %). There was no difference in the rate of adverse events. The use of clips was more common in the EMR group (52.6 % vs. 27.8 %).

Conclusions:  The recurrence rate of LFNPCLs after CS-EMR was significantly greater than after the standard hot technique. A similar safety profile was found between groups.