Intermittent thoracic resuscitative endovascular balloon occlusion of the aorta improves renal function compared to 60 min continuous application after porcine class III hemorrhage

Background Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) may be considered for stabilization of patients with hemorrhage from below the diaphragm. Occluding the aorta is a powerful means of hemorrhagic control but is also associated with acute kidney injury, which increases mortality in trauma patients. Allowing for intermittent distal blood flow during REBOA application (iREBOA) could decrease this risk, but circulatory consequences have not been sufficiently elucidated. Therefore, we investigated circulatory effects and the renal artery blood flow (RBF) in iREBOA versus continuous, complete aortic occlusion (cREBOA). Methods In a porcine model of uncontrolled class III hemorrhage (34% estimated total blood volume, mean 1360 mL), swine (n = 12, mean weight 60.3 kg) were randomly assigned to iREBOA: 3-min full deflation every 10 min (n = 6), or cREBOA (n = 6), for 60 min of thoracic (zone I) application. The animals then underwent 60 min of reperfusion (critical care phase). Results Survival was 100% in iREBOA and 83% in cREBOA. The intermittent balloon deflation protocol was hemodynamically tolerable in 63% of reperfusion intervals. Systolic blood pressure decreased during the reperfusion intervals in iREBOA animals (mean 108 mm Hg versus 169 mm Hg; p < 0.005). No differences were detected in heart rate, cardiac output or stroke volume between methods. Troponin I increased in cREBOA after 60 min (mean 666-187 ng/L, p < 0.05). The norepinephrine requirement increased in cREBOA during reperfusion (mean infusion time 12.5-5.5 min; p < 0.05). Total ischemic time decreased in iREBOA (60.0-48.6 min; p < 0.001). RBF increased in iREBOA during balloon deflations and after 60 min reperfusion (61%-39% of baseline RBF; p < 0.05). Urine output increased in iREBOA (mean 135-17 mL; p < 0.001). Nephronal osteopontin, a marker of ischemic injury, increased in cREBOA (p < 0.05). Conclusion iREBOA was survivable, did not cause rebleeding, dec