Abstract No. 123 Predictors of Active Extravasation During Catheter Angiography in Patients with Suspected Acute Lower Gastrointestinal Bleeding

To identify clinical and pre-procedural imaging predictors of active extravasation and subsequent outcomes in patients undergoing catheter angiography for suspected acute lower gastrointestinal bleeding (LGIB). Retrospective analysis of 96 patients who underwent catheter angiography for LGIB at a single health system between 2017-2023. Data was collected on demographics, hemodynamic parameters, laboratory data, procedural details, and outcomes. Additionally, extravasated contrast on pre-procedure, multiphase CT angiography (CTA) was quantified using specialized software (Vitrea, Canon Medical Systems), and standardized by time between arterial and venous phases to derive an extravasation rate. Clinical success was defined as absence of rebleeding within 30 days. Significance was determined using t-test or Chi-squared analyses. 42 (43.8%) of the 96 patients exhibited active extravasation on catheter angiography. Significant predictors of active extravasation included max heart rate and units of blood transfused within the 24 hours preceding the procedure (Table 123.1). Pressor requirements, blood pressure, pre-procedure hemoglobin, INR, and platelet counts showed no significant difference between groups. A multiphase CTA was performed before catheter angiography in 49 patients (51.0%). The overall mean extravasation rate was 15.7 ± 23.7 uL/s, with 20.1 ± 30.6 uL/s in the positive catheter angiogram group, and 10.6 ± 10.3 uL/s in the negative group (P=0.19). The median time from a positive CTA result to the catheter angiogram was 6.2 ± 4.1 hours, with no significant time difference between groups (P=0.21). Technical and clinical success rates for embolization attempts were 97.5% and 95.0%, respectively. 17 (17.7%) patients required a repeat procedure (e.g., embolization, endoscopy, surgery) to address recurrent bleeding during their admission. Maximum heart rate within 24 hours prior to angiography and blood transfusion requirements were significant predictors of extravasation on catheter angiography. Though there was an observable trend indicating a higher extravasation rate on pre-procedure CTA in the positive catheter angiogram group, this did not achieve statistical significance.