Hemodynamic and pathological Effects of aortic occlusion during Resuscitation: An ex vivo circulatory platform and in vivo animal study.

Aortic occlusion serves as a critical life-saving intervention by simultaneously controlling hemorrhage and restoring perfusion pressure. However, its clinical efficacy remains debated due to the difficulty of assessing real-time hemodynamic responses during emergencies and the absence of pathological validation. Here, we present an integrated biomechanical-pathological framework combining a biomimetic circulatory platform with in vivo animal validation. The platform, which couples a pulsatile pump-motor system with a 3D-printed aortic model, faithfully replicates physiologic flow and enables systematic mapping of pressure and cerebral perfusion across occlusion sites under graded cardiac outputs. We found that proximal occlusion progressively restores pressure with greater output loss (from iliac to thoracic levels: <22% to < 64%), yet under relatively mild reductions (<5%-55%), it may induce supraphysiologic pressures, imposing vascular wall injury. Cardiac output reductions within intermediate ranges mitigate this trade-off, balancing inadequate perfusion against pressure-induced vascular damage. Complementary animal studies revealed that an occlusion lasting longer than 30 min triggered vascular wall inflammation under hypertension and induced hepatic and renal ischemia-reperfusion injury. Collectively, these findings define the competing risks of inadequate pressure restoration, vascular overload, and distal ischemia, providing a biomechanical basis to complement established anatomy-driven decision-making.