Role of the cold biopsy technique in diminutive and small colonic polyp removal: a systematic review and meta-analysis

Background and aims: The most commonly detected polyps during screening colonoscopy are diminutive and small polyps, and therefore endoscopic treatment of those polyps is a daily routine for every colonoscopist. The primary aim of this study was to compare the complete eradication rate of diminutive and small colorectal polyps using cold biopsy versus other techniques, because randomized controlled trials have shown conflicting results.

Methods: In March 2015 we searched for randomized controlled trials in Medline, EMBASE, and ISI the Web of Science, starting with their dates of inception, and abstracts of pertinent scientific meetings (eg, American College of Gastroenterology, Digestive Disease Week). The primary outcome was complete removal of diminutive and small polyps (≤7 mm) by histologic eradication rates. The secondary outcome was total procedure time. Using RevMan (Cochrane), we used the Mantel-Haenszel random effects model for binary endpoints and the inverse variance method for continuous outcomes. Grading of Recommendations Assessment, Development and Evaluation was used to rate the quality of evidence for each outcome.

Results: Five randomized controlled trials included a total of 668 patients and 721 polyps. Removal techniques included cold biopsy, jumbo biopsy, and cold snare polypectomy. Based on histologic criteria, incomplete polyp removal was significantly lower with cold snare/jumbo forceps biopsy technique than with the cold biopsy technique (relative risk, .40; 95% CI, .26-.62), with no heterogeneity (I(2), 0%). Total procedure time was an average of 2.66 minutes shorter for the cold snare/jumbo forceps biopsy techniques compared with the cold biopsy technique (95% CI, -5.14 to -.18). The quality of evidence was rated moderate.

Conclusions: There is moderate quality evidence that cold snare or jumbo biopsy techniques reduce the risk of incomplete diminutive polyp removal by 60% without increasing the total procedure time. Adequately powered randomized clinical trials are warranted to confirm these findings.