Incidence and risk factors of delayed postpolypectomy bleeding a retrospective cohort study

Background/Aim: Delayed bleeding is a serious complication that occurs after polypectomy. Many risk factors for delayed bleeding have been suggested, but there is little analysis of procedure-related risk factors. The purpose of this study is to identify a wide range of risk factors for delayed postpolypectomy bleeding (DPPB) and analyze the correlations of those potential DPPB risk factors. Materials and Methods: In this retrospective cohort study, 5981 polypectomies in 3788 patients were evaluated between January 2010 and February 2012. Patient-related, polyp-related, and procedure- related factors were evaluated as potential DPPB risk factors. Results: Delayed bleeding occurred in 42 patients (1.1%). Multivariate analysis revealed that polyp size >10mm [odds ratio (OR), 2.785; 95% confidence interval (CI), 1.406-5.513; P=0.003], location in the right hemi-colon (OR, 2.289; 95% CI, 1.117-4.693; P=0.024), and endoscopist's experience (<300 total cases of colonoscopy performed; OR, 4.803; 95% CI, 2.631-8.766; P=0.001) were significant risk factors for DPPB. Especially protruded type polyps (Ip, Isp) larger than 1 cm in the right-side colon were associated with increased risk. Right-side polypectomy by a nonexpert endoscopist was a significant risk factor for DPPB, especially with procedures in the cecum area. Taking the 1.5% DPPB incidence as cutoff value, the learning curve of colonoscopic polypectomy may be estimated as 400 cases of polypectomy. Conclusions: Polyp size, endoscopist's experience, and right hemicolon location were identified as potential risk factors for DPPB development.