Risk factors for active bleeding from colonic angiodysplasia confirmed by colonoscopic observation

Colonic angiodysplasia is an important cause of lower gastrointestinal bleeding in the elderly. Here, we investigated the risk factors for bleeding from colonic angiodysplasia seen at endoscopy. We conducted a retrospective case-control study by reviewing records of 435 patients with angiodysplasia at colonoscopy from November 2006 to November 2015 in our hospital. To identify risk factors for active bleeding, the following were analyzed: age, sex, comorbidities, use of antithrombotic drugs and non-steroidal anti-inflammatory drugs, and the size and location of the lesions. Among the 435 patients, active bleeding from angiodysplasia was observed at endoscopy in 29 patients (6.7 %). Using multivariate analysis, we identified advanced age (odds ratio 5.15, 95 % confidence interval, 1.61-16.5), comorbidity of heart disease (6.88, 1.04-45.5), use of anticoagulant drug (4.22, 1.21-14.7), multiple lesions (6.67, 1.77-25.2), and small lesions (aecurrency sign5 mm) (17.7, 4.90-64.0) as independent and significant risk factors for active bleeding. Actively bleeding colonic angiodysplasia lesions were very small in most cases (1-2 mm, 24/29, 83 %) and predominantly located in the right-side colon (26/29, 90 %). All of the 29 patients with active bleeding were successfully and safely treated endoscopically, but re-bleeding occurred in nine patients (31 %, 9/29) during the follow-up period of 2-84 months. Multiple and small colonic angiodysplasia lesions in patients of advanced age, with heart disease, or receiving anticoagulants have increased risk for bleeding. We should be aware that small colonic angiodysplasia lesions in the right-side colon at colonoscopy in these patients may be a source of bleeding.