Cardiac & Resuscitation, Exclusives, Heart of America, Patient Care, Top Story

REBOA and SAAP: Aortic Interventions for Resuscitation

REBOA

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) involves the use of an aortic balloon catheter to limit blood loss caudal to the inflated balloon in patients with severe, uncontrolled truncal and junctional hemorrhage.

Initially described during the Korean War, aortic balloon occlusion for hemorrhage control in trauma was reported sporadically over the ensuing decades without general adoption into clinical practice.

This has changed in the past decade in response to injury patterns observed in the combat theaters of the Middle East. Preclinical studies in U.S. military research labs characterized the physiological effects and limitations associated with aortic balloon occlusion in laboratory models of severe non-compressible torso hemorrhage. This laid the scientific foundation for a 2011 report defining REBOA and the subsequent translation into clinical practice in recent years.1

Several aortic balloon catheters are now commercially available, and reports of clinical experience are increasing rapidly along with growing data reported to multi-institutional REBOA registries.

Aortic occlusion of the thoracic aorta (Zone I) for sub-diaphragmatic hemorrhage and infrarenal aorta (Zone III) for isolated pelvic and junctional hemorrhage have been reported in-hospital and in combat theaters. Prehospital Zone III REBOA has been reported and implementation of prehospital Zone I REBOA is forthcoming.

The use of REBOA for hemorrhage control in nontraumatic conditions, such as severe peripartum obstetrical hemorrhage, has also been increasing with favorable outcomes reported. Strategies for intermittent and graded partial aortic occlusion are maturing and offer the prospect of extending aortic balloon hemorrhage control while limiting distal ischemia.

The use of aortic balloon occlusion to augment coronary perfusion pressure during CPR chest compressions has been studied in laboratory models and evidence of increased coronary perfusion pressure has been reported. Clinical trials to investigate REBOA in medical cardiac arrest are being pursued.

Selective Aortic Arch Perfusion (SAAP)

Selective Aortic Arch Perfusion (SAAP) involves the use of a large-lumen thoracic aortic balloon catheter to provide relatively isolated perfusion to the heart and brain during cardiac arrest. The perfusate is initially an exogenous oxygen carrier, such as allogeneic blood or a hemoglobin-based oxygen carrier (HBOC), but autologous blood can subsequently be used, if needed, in a manner similar to extracorporeal life support (ECMO/ECLS).

SAAP was initially described in 1992 as a resuscitation technique for treating nontraumatic/medical cardiac arrest with the prehospital setting in mind.2 Preclinical studies in models of ventricular fibrillation demonstrated improved rates of return of spontaneous circulation (ROSC) compared to standard resuscitation therapies. The physiologic effects of SAAP were characterized and perfusion parameters were optimized.

The potential for SAAP balloon hemorrhage control in trauma and rapid volume repletion in hemorrhage-induced hypovolemia was also recognized. In a 2001 preclinical report, SAAP with oxygenated HBOC-201 showed consistent ROSC in a model of liver trauma with exsanguination-induced cardiac arrest.3 (See Figure 1.)

Subsequently, SAAP with allogeneic whole blood and red blood cells, have been studied given the lack of a commercially approved non-blood oxygen carrier. Translation into clinical use is presently being pursued with clinical trial preparations underway to investigate blood product and HBOC perfusates in both hemorrhage-induced traumatic cardiac arrest and non-traumatic/medical cardiac arrest.

At the current time, data are limited for the use of SAAP and REBOA in humans in cardiac arrest. In the future, this therapeutic approach may play a vital role in the treatment of traumatic and refractory cardiac arrest.

References

1. Stannard A, Eliason JL, Rasmussen TE. Resuscitative endovascular balloon occlusion of the aorta (REBOA) as an adjunct for hemorrhagic shock. J Trauma. 2011;71(6):1869-1872.

2. Manning JE, Murphy CA Jr, Hertz CM, et al. Selective aortic arch perfusion during cardiac arrest: A new resuscitation technique. Ann Emerg Med. 1992;21(9):1058–1065.

3. Manning JE, Katz LM, Pearce LB, et al. Selective aortic arch perfusion with hemoglobin-based oxygen carrier-201 for resuscitation from exsanguinating cardiac arrest in swine. Crit Care Med. 2001;29(11):2067–2074.