Rates of Incomplete Resection of 1- to 20-mm Colorectal Polyps: A Systematic Review and Meta-Analysis

Background & Aims Incomplete resection of neoplastic colorectal polyps can result in postcolonoscopy colorectal cancer. We performed a systematic review and meta-analysis to determine the incomplete resection rate (IRR) of colorectal polyps and associated factors. Methods We searched MEDLINE, EMBASE, EBM Reviews, and CINAHL to identify full-text articles that reported IRRs of polyps 1 to 20 mm, published until March 2019. Exclusion criteria were studies of inflammatory bowel disease cohorts, referrals for difficult polypectomy, polyp sizes larger than 20 mm, and endoscopic submucosal resection and/or dissection as polypectomy approaches. IRRs were calculated based on findings from biopsies taken at polypectomy sites or assessments of margins of resected polyps. The primary outcome was IRR for snare removal of polyps 1 to 20 mm. Secondary outcomes included IRR for polyps 1 to 10 mm and 10 to 20 mm, IRR for hot and cold snare removal of polyps 1 to 10 mm and 10 to 20 mm, IRR of snare removal with or without submucosal injection, and IRR for forceps and cold snare removal of polyps 1 to 5 mm. Results We identified 6148 reports and used 32 studies, with a total of 9282 polyps, in our quantitative analysis. The IRR for snare removal of polyps 1 to 20 mm was 13.8% (95% confidence interval [CI] 10.3–17.3; 13 studies, 5128 polypectomies). IRRs were 15.9% for snare removal of polyps 1 to 10 mm (95% CI 9.6–22.1; 9 studies, 2531 polypectomies) and 20.8% for snare removal of polyps 10 to 20 mm (95% CI 12.9–28.8; 6 studies, 412 polypectomies). The IRR for hot snare removal of polyps 1 to 10 mm was 14.2% (95% CI 5.2–23.2) vs 17.3% for cold snare polypectomy (95% CI 14.3‒20.3). The IRR for forceps removal of polyps 1 to 5 mm was 9.9% (95% CI 7.1–13.0) vs 4.4% for snare polypectomy (95% CI 2.9–6.1). Conclusions In a systematic review and meta-analysis, we found that colorectal polyps 1 to 20 mm are frequently incompletely resected, and that risk increases for polyps 10 mm or larger. There is no difference in IRRs of cold vs hot snares for polyps 1 to 10 mm. Snare polypectomy should be used over forceps for polyps 1 to 5 mm.