Comparative Analysis of the Risk of Rebleeding between Catheter Angiography and Colonoscopy Following a Positive Computed Tomography Angiography Results in Patients with Severe Lower Gastrointestinal Bleeding

Abstract

Background/Aims: Few studies have compared the outcomes of catheter angiography and colonoscopy after positive computed tomography angiography (CTA) results in patients with severe lower gastrointestinal bleeding. This study aimed to evaluate differences in clinical outcomes between these approaches. Methods: We analyzed data from 254 patients with positive CTA results of the lower gastrointestinal tract at Severance Hospital, South Korea (2014-2024). Clinical outcomes were compared between the catheter angiography group (n=108) and the colonoscopy group (n=146), and the predictive risk factors for rebleeding were examined. Results: There were no significant differences in the confirmation yield (59.3% vs 47.9%), therapeutic yield (64.8% vs 56.2%), and mean hospitalization duration (20.1 days vs 21.3 days) between groups. However, the mean time to procedure (12.3 hours vs 19.2 hours) and rebleeding rate (36.1% vs 48.6%) were lower in the catheter angiography group. Logistic regression revealed that time to procedure predicted higher confirmation and therapeutic yields. Multivariate Cox regression showed that risk factors for rebleeding included receiving >5 units of packed red blood cells (hazard ratio [HR], 1.711; 95% confidence interval [CI], 1.025 to 2.857, p=0.040) and undergoing colonoscopy instead of catheter angiography (HR, 1.922; 95% CI, 1.242 to 2.974, p=0.003). Conclusions: Following a positive CTA result, colonoscopy (compared to catheter angiography) and the need for more than 5 units of packed red blood cell transfusion were significant risk factors for rebleeding.