Abstract 4367248: IJ Central Line Duration and Catheter Size-to-Weight Ratio are Thrombosis Risk Factors in Infants Undergoing Cardiothoracic Surgery

Introduction: Internal jugular (IJ) venous catheters placed for cardiothoracic (CT) surgery in infants are associated with an increased risk of thrombosis, contributing to significant morbidity and mortality. Complications from thrombosis include chylothorax, need for anticoagulation, and limited vascular access for future interventions. Despite the clinical impact, data summarizing thrombosis risk factors in this population is limited. This study aimed to determine the thrombosis rate at our center among infants undergoing cardiopulmonary bypass (CPB) and to identify associated risk factors. Methods: We conducted a retrospective cohort study of infants ≤ 6 months who underwent CPB for CT surgery at Primary Children’s Hospital from June 2023-December 2024. Exclusion criteria included preoperative thrombotic events or mechanical circulatory support. Variables collected included IJ catheter size (4Fr or 5Fr), patient weight at surgery, catheter duration, use of aspirin or low-dose heparin (10–15 units/kg/hr) prior to removal, intraoperative use of concentrated blood products, CPB duration, and surgical repair type. Outcomes assessed were IJ line-associated thrombosis, chylothorax, cardiac ICU and hospital length of stay (LOS), and mortality. Results: 244 patient surgeries were reviewed, of which 41 (16.8%) developed a thrombus. Chylothorax occurred in 46.3% of the thrombosis group vs. 7.8% in the non-thrombosis group. Mean CICU LOS was nearly doubled in the thrombosis group (24.9 vs. 12.3 days). Unadjusted odds ratios (OR) showed significant associations for line duration (OR 1.46, p<0.001) and line size-to-weight ratio (OR 4.60, p=0.001). Adjusted ORs remained significant for line duration (OR 1.32, p=0.006; 95% CI [1.09, 1.62]) and line size-to-weight ratio (OR 3.07, p=0.033; 95% CI [1.10, 8.84]). In the 5 Fr IJ line subgroup, lower weight was associated with increased thrombosis risk (OR 0.62, p=0.022; 95% CI [0.40, 0.90]). Use of aspirin, low-dose heparin, or concentrated blood products were not significant. Conclusion: Thrombosis following IJ catheter placement in infants undergoing CPB is associated with higher rates of chylothorax and prolonged CICU stay. Line duration and catheter size-to-weight ratio emerged as independent risk factors. Initiation of aspirin or low-dose heparin was not protective. These findings highlight the importance of individualized catheter selection and management duration to mitigate thrombotic risk in this vulnerable population.