Resuming Anticoagulation After Colonoscopic Polypectomy: Does It Increase the Risk of Delayed Post-Polypectomy Bleeding?

Background: Post-polypectomy bleeding is a rare but serious adverse event. Aim: To identify factors associated with the risk of delayed post-polypectomy bleeding. Methods: Case-control study: Cases were patients who developed hematochezia requiring medical evaluation 6 hours to 14 days after colonoscopic polypectomy. Controls were patients who underwent polypectomy without delayed bleeding, and were matched in approximately 3:1 ratio. The following risk factors were specified a priori: anticoagulation [within 1 week following polypectomy], aspirin use, hypertension, and polyp diameter. Unconditional logistic regression analysis was used to quantify the association between potential risk factors and post-polypectomy hemorrhage. Results: Of the 4592 patients who underwent colonoscopy with polypectomy, 41 patients [0.9%] developed delayed severe post-polypectomy bleeding [cases], and 132 patients were selected as controls. The mean age of cases was 64.3 years, and of controls was 65.4 years. Cases presented on average 6 days after polypectomy [range 1-14 days], and 48% required blood transfusion [average 4.2 units, range0-17]. Two patients required surgery. Table 1 shows the measures of association between the factors specified a priori and the risk of post-polypectomy bleeding. Anticoagulation was resumed following polypectomy in 34% of cases, compared with 9% of controls [OR 5.2; 95%CI 2.2-12.5, p < 0.001]. For every 1 mm increase in polyp diameter, the risk of hemorrhage increased by 9% [OR 1.09; 95%CI 1.0-1.2; p = 0.008]. Hypertension [OR 1.1] and aspirin use [OR 1.1] did not increase the risk of post-polypectomy bleeding. In exploratory analysis, diabetes [OR 2.5] and coronary artery disease [OR 3.0] were associated with post-polypectomy hemorrhage, but the association was no longer statistically significant once adjusted for the use of anticoagulation. Conclusions: Anticoagulation following polypectomy and polyp diameter were strongly associated with increased risk of delayed post-polypectomy bleeding. Hypertension and aspirin use were not. Table 1Risk factors (unadjusted) for post-polypectomy bleeding Cases n = 41 Controls n = 132 Odds Ratio 95% CI p value Anti-coagulation 14 (34%) 12 (9%) 5.2 2.2-12.5 0.0002 Aspirin 17 (41%) 51 (39%) 1.1 0.5-2.2 0.8 Hypertension 26 (63%) 81 (61%) 1.1 0.5-2.2 0.8 Polyp size (mm) 10.5 ± 7.1 6.7 ± 5.5 1.1 1.0-1.2 0.008 Anticoagulation = use of Warfarin or Heparin within 1 week after polypectomy. Aspirin use = use of at least one dose of aspirin within 5 days prior to polypectomy. Hypertension = systolic BP >140 mmHg or diastolic >90 mmHg, or use of anti-hypertensives. Open table in a new tab Anticoagulation = use of Warfarin or Heparin within 1 week after polypectomy. Aspirin use = use of at least one dose of aspirin within 5 days prior to polypectomy. Hypertension = systolic BP >140 mmHg or diastolic >90 mmHg, or use of anti-hypertensives.