Background 

• Hemorrhage continues to be a leading cause of preventable death on the battlefield. It can be broadly categorized as compressible or non-compressible, depending on its location. Non-compressible Torso Hemorrhage (NCTH) arises from trauma to the torso vessels, pulmonary parenchyma, solid abdominal organs, or the bony pelvis.² Because NCTH is not amenable to control by direct pressure or extremity tourniquet application, it is particularly lethal.³
• Resuscitative Aortic Occlusion (RAO) affords distal hemorrhage control while increasing cardiac afterload and thereby maintaining coronary and cerebral perfusion pressure until (or while) hemorrhage control is achieved.⁴ RAO has traditionally required a left thoracotomy or laparotomy for aortic exposure.^5-8 Resuscitative thoracotomy has a high mortality rate, due largely to the nature of the injuries and because this technique is not typically employed until after arrest.^9-11 Nonetheless, data from combat theaters indicate that there is a reasonable probability of long-term survival and recovery following RAO in appropriately selected casualties as described in the JTS Emergent Resuscitative Thoracotomy (ERT) CPG.^12-14
• REBOA is an alternative form of RAO for patients at risk of imminent cardiovascular collapse. It is performed through a common femoral artery approach without the need for thoracotomy. REBOA is best applied prior to cardiovascular collapse when the site of hemorrhage is below the diaphragm and no open thoracic intervention is otherwise indicated.¹⁵
• ERT allows management of thoracic injuries and manual cardiac compression and thus remains the procedure of choice for patients with significant thoracic or cardiac injury. However, REBOA has been used in combination with open thoracotomy and/or sternotomy as a resuscitative bridge to open surgical control of hemorrhage to treat thoracic great vessel injury.¹⁶
• ERT may improve cardiac index as well as coronary and cerebral perfusion pressure compared to closed chest compression.¹⁷ However, when closed chest compressions are combined with REBOA, cardiopulmonary resuscitation is more effective allowing for higher end-tidal carbon dioxide (EtCO2) and cardiac compression fraction compared to open cardiac massage and aortic cross clamping.¹⁸
• RAO poses a significant risk of life-threatening and limb-threatening complications. RAO is a time-critical intervention that should never be undertaken without expedient access to definitive surgical hemorrhage control and without adequate vascular access for simultaneous resuscitation with blood. ^{2–20,8-17,19-30,19,22,25}