Comment on "Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis".

This is a comment on a meta-analysis of published studies comparing cold vs hot polypectomy. We believe that the conclusion of this meta-analysis that "cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy" needs more rigorous evidence.

Core tip: This is a comment on a meta-analysis of published studies comparing cold vs hot polypectomy. We believe that the conclusion of this meta-analysis needs more rigorous evidence.

TO THE EDITOR

We read with interest the article by Fujiya et al[1] entitled “Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis”, which compared cold and hot polypectomy with respect to efficacy and adverse events. The authors attempted to perform a systematic review and meta-analysis of the “randomized controlled trials (RCTs)” from several databases, one of which is actually a retrospective study[2]. In addition, among the six included studies, two (one article[3] and one abstract[4]) actually utilized the same data, which is another serious issue.

Colorectal polyps can be divided into three groups based on size: diminutive (≤ 5 mm), small (6-9 mm), and large (≥ 10 mm). The American Society for Gastrointestinal Endoscopy recommends that cold snare polypectomy should be the primary modality used for resection of diminutive polyps. However, polyps that are 6 to 9 mm in size can be resected by cold snare polypectomy or hot snare polypectomy because the optimum technique is not defined[5]. In this meta-analysis, the authors demonstrated that cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy. However, among the six included studies, one compared hot snare, cold snare and cold forceps polypectomy for diminutive colorectal polyps[6], and the other five studies compared hot snare with cold snare polypectomy for small polyps (10 mm or less in diameter, and most were 8 mm or less)[2-4,7,8]. Hence, we believe that the conclusion is not sufficient.

All six included studies reported the rate of adverse events, including bleeding. The study by Horiuchi et al[8], however, focused on small colorectal polyps in patients receiving anticoagulation therapy. Thus, it should be excluded from this meta-analysis, or sensitivity analysis should be done to explore whether it was biased.