Functional outcome after resuscitative endovascular balloon occlusion of the aorta of the proximal and distal thoracic aorta in a swine model of controlled hemorrhage

Background: Noncompressible torso hemorrhage remains an ongoing problem for both military and civilian trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been characterized as a potentially life-saving maneuver. The objective of this study was to determine the functional outcomes, paraplegia rates, and survival of 60-min balloon occlusion in the proximal and distal thoracic aorta in a porcine model of controlled hemorrhage. Methods: Swine (Sus scrofa, 70-110 kg) were subjected to class IV hemorrhagic shock and underwent 60 min of REBOA. Devices were introduced from the left carotid artery and positioned in the thoracic aorta in either the proximal location (pREBOA [n = 8]; just past takeoff of left subclavian artery) or distal location (dREBOA [n = 8]; just above diaphragm). After REBOA, animals were resuscitated with whole blood, crystalloid, and vasopressors before a 4-day postoperative period. End points included evidence of spinal cord ischemia (clinical examination, Tarlov gait score, bowel and bladder dysfunction, and histopathology), gross ischemiareperfusion injury (clinical examination and histopathology), and mortality. Results: The overall mortality was similar between pREBOA and dREBOA groups at 37.5% (n = 3). Spinal corderelated mortality was 12.5% for both pREBOA and dREBOA groups. Spinal cord symptoms without death were present in 12.5% of pREBOA and dREBOA groups. Average gait scores improved throughout the postoperative period. Conclusions: REBOA placement in the proximal or distal thoracic aorta does not alter mortality or paraplegia rates as compared with controlled hemorrhage alone. Functional recovery improves in the presence or the absence of REBOA, although at a slower rate after REBOA as compared with negative controls. Additional research is required to determine the ideal placement of REBOA in an uncontrolled hemorrhage model to achieve use compatible with survival outcomes and quality of life.