A Morphometric Model for Endovascular Occlusion of The Retrohepatic Vena Cava in Pediatric Trauma

The resuscitative endovascular balloon occlusion of the aorta (REBOA) device has been adapted for inferior vena cava (IVC) use in both animal models and adult case reports. The aim of this study is to examine the feasibility for use of the REBOA device for pediatric IVC injuries and create a potential framework for implementation.

A simulated venous system was designed with modeled IVC components based on 290 abdominal computed tomography scans of pediatric trauma patients. These patients were randomly selected to represent the ten Broselow categories. These IVC segments were selected to represent the posthepatic and prehepatic diameters for the five largest Broselow categories. A closed circulatory model was created with steady-state flow designed to model the venous system. The REBOA device was inserted into the system with the balloon in the IVC segment. Pressure monitors were placed distally and in the closed system, replicating the capacitance of the venous system. A flow meter was placed distally to the segment and balloon. Flow and pressure readings were recorded as the REBOA device was inflated and total occlusion was achieved.

Suprahepatic IVC diameters ranged from 1.14 to 2.71 cm, while infrahepatic IVC diameters ranged from 0.76 to 2.39 cm. There was significant overlap in the measurements of the IVC, allowing five modeled segments to represent ten different IVCs. The venous model demonstrated a significant delay between balloon inflation and vessel occlusion. Approximately 80%-90% of the REBOA inflation volume results in approximately an initial 10% reduction in flow. Flow was completely obstructed which corresponded with a small increase in pressure difference between the proximal and distal pressure monitors, reflecting the capacitance in the venous system with inflation.

Pediatric IVC injuries with significant hemorrhage should be amenable to endovascular occlusion as an adjunct to resuscitation and operative management.