Risk Stratification of Delayed Postpolypectomy Bleeding in Patients with and without Kidney Diseases: A Large, High-Dimensional Propensity Score-Matched Cohort Study

Background: The assessment of the risk of delayed bleeding following polypectomy in patients with chronic kidney disease (CKD), including those undergoing kidney failure with renal replacement therapy, has not been established. To address this issue, we conducted a high-dimensional propensity score-matched study to investigate whether CKD contributes to an increased risk of delayed post-polypectomy bleeding (PPB). Methods: A large cohort study and retrospective analysis of 20,052 patients who underwent colonoscopy and polypectomy, between 2005 and 2022 in Korea. Propensity score matching with adjustments for patient-related, polyp-related and procedure-related factors was used to account for differences between patients based on the stage of CKD. The primary end points were the risks of delayed PPB, and the secondary end points were the risks of bleeding depending on the stage of CKD. Results: A total of 16,895 patients were selected including 2,349 (13.9%) patients with CKD. Based on the estimated glomerular filtration rate (eGFR), 892 (38.0%) patients had CKD at stages 1 and 2, 1163 (49.5%) at stages 3 and 4, and 294 (12.5%) at stages 5 and ESRD. The prevalence of PPB in patient with CKD was 1.3 %. Adjusted propensity matching analysis, the risk of delayed PPB was significantly increased according to the stage of CKD (hazard ratio [HR] = 1.676, 95% confidence interval [CI] 1.100–2.552 for stage 1-2, HR 2.045, 95% CI 1.441–2.901 for stage 3-4, and HR 2.189, 95% CI 1.203–3.982 for stage 5 or ESRD, all p<0.05). Conclusion: CKD is an independent risk factor for delayed PPB, and it showed an association with a substantially increased risk of CKD stage. Consequently, greater caution should be treated when undergoing polypectomy on patients with CKD.