['Noncompressible torso hemorrhage is the leading cause of potentially preventable death on the modern battlefield. The objective of this study is to characterize resuscitative aortic balloon occlusion (BO) compared to thoracotomy with aortic clamping in a model of hemorrhagic shock.', 'A total of 18 swine (3 groups; 6 animals/group) were used in this study. Swine in class IV shock underwent no aortic occlusion (NO), thoracotomy and clamp occlusion (CO), or endovascular BO. Animals in the NO group underwent direct placement of a temporary vascular shunt (TVS) at the injury site, whereas animals in the CO and BO groups underwent aortic occlusion before TVS placement. Hemodynamic and physiologic measures were collected.', 'The central aortic pressure, carotid blood flow and brain oxygenation as measured by oximetry increased in the CO and BO groups compared to the NO group (P < .05). During resuscitation, the BO group was less acidotic than the CO group (pH,7.35 vs 7.24; P < .05) with a lower serum lactate level (4.27 vs 6.55; P < .05) and pCO2 level (43.5 vs 49.9; P < .05). During resuscitation, the BO group required less fluid (667 mL vs 2,166 mL; P < .05) and norepinephrine (0 mcg vs 52.1 mcg; P < .05) than the CO group.'] Is endovascular balloon occlusion of the aorta superior to resuscitative thoracotomy with aortic clamping in a porcine model of hemorrhagic shock?