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Updated: Apr 10, 2026

Complete and Partial Resuscitative Endovascular Balloon Occlusion of the Aorta for Hemorrhagic Shock
Published on: May 19, 2022
Is the COBRA-OS 4 French Aortic Occlusion Device Feasible for Partial REBOA?
Adam Power1, Asha Parekh2, Samuel Jessula1
1Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
Background:
Noncompressible torso hemorrhage is a leading cause of preventable death. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to control hemorrhage but full aortic occlusion is limited by distal ischemia. Partial REBOA (pREBOA) allows some distal perfusion to prolong occlusion, but precise balloon titration is difficult with standard devices. The COBRA-OS 4 French (Fr) aortic occlusion catheter was evaluated in vitro and in vivo for partial REBOA.
Methods:
Bench-top (in vitro) and porcine (in vivo) models were used. The titration window of the device was evaluated in a non-hemorrhage porcine model and in a pulsatile aortic model. The ability of the device to maintain a targeted distal aortic pressure (20 mmHg) for an extended period (3 h) was tested in a porcine model of hemorrhagic shock (40% blood volume), with a corresponding in vitro experiment using a pulsatile aortic model.
Results:
The COBRA-OS demonstrated a 3-4 mL linear titration window with 1-1.5 mL deflation volume to reach a target distal aortic pressure of 20 mm Hg in vitro and in vivo. During 3 h of prolonged partial REBOA, the device maintained a stable distal target with a set-and-forget strategy (21 +/- 2 mmHg in vitro and 22 +/-7 mmHg in vivo).
Conclusions:
The COBRA-OS 4 Fr device enabled precise, stable partial aortic occlusion in this preclinical model. This is the first demonstration of a 4 Fr REBOA catheter achieving prolonged, controlled partial occlusion in a large-animal hemorrhagic shock model, supporting the feasibility of this device for pREBOA.
Level Of Evidence:
Basic Science, Animal study.

