A previous study reported that cold snare polypectomy (CSP) was superior to cold forceps polypectomy (CFP) for the removal of diminutive colorectal polyps (DCPs) (≤5 mm) when the techniques were assessed for completeness of resection. However, completeness is expected to be greater with CFP when strict investigation of the remnant polyp is performed. The aim of this study was to assess the efficacy of CFP with narrow-band imaging (NBI) evaluation of polypectomy sites for removal of DCPs, compared with CSP.

This was a randomized, controlled, noninferiority trial at a tertiary-care referral hospital. Of the 380 patients screened, 146 patients with 231 DCPs were enrolled. CFP was used to resect DCPs until no remnant polyp was visible by NBI endoscopy. The primary noninferiority endpoint was histologic eradication of polyps, with a noninferiority margin of -10%.

A size of >3 mm was seen in 129 polyps (55.8%). The overall rates of histologic eradication were 90.5% in the CFP group and 93.0% in the CSP group (difference, 2.5%; 95% confidence interval [CI], -9.67 to 4.62). However, when confined to the polyps >3 mm, the histologic eradication rate was 86.8% and 93.4% (95% CI, -17.2 to 3.6), respectively. Polyp size, histology, location, and time taken for polypectomy did not differ between the groups. The failure rate of tissue retrieval was higher in the CSP than in the CFP group (7.8% vs 0.0%, respectively; P =.001).

In this study, >90% of all DCPs were completely resected by using CFP with NBI evaluation of polypectomy sites, showing noninferiority compared with CSP. However, in polyps measuring >3 mm, CFP failed to show noninferiority versus CSP. CFP appears to be the proper method for resection of DCPs 1 to 3 mm in size if no remnant polyp is visible by NBI endoscopy, but CFP is likely to be insufficient for larger polyps. (Clinical trial registration number: NCT02201147.)