A Novel Automated Endovascular Variable Aortic Control Device to Expand Function of Standard REBOA Catheters

Abstract

Abstract
 Background
 Endovascular methods for hemorrhage control, including Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA), are evolving and are increasingly being applied clinically. Partial flow strategies to mitigate the consequences of complete aortic occlusion have been demonstrated in pre-clinical models to enhance REBOA and expand its application to various shock states. Initial studies demonstrated that controlled partial flow requires precision beyond the capabilities of manual balloon volume adjustment, therefore automation is required. Our group previously developed a proof-of-concept computer-controlled extracorporeal flow circuit capable of precision aortic flow regulation, but it was not clinically applicable. To bring this concept closer to clinical applicability, we have developed the first endovascular strategy to achieve precision aortic flow regulation, termed Endovascular Variable Aortic Control (EVAC).
 Methods
 Following instrumentation, 5 Yorkshire-cross swine were subjected to controlled 25% hemorrhage, followed by precision low volume aortic flow regulation using a commercially available compliant balloon catheter pre-positioned in the descending thoracic aorta, connected to a custom, wireless syringe pump. Closed-loop feedback algorithms based on streaming physiologic data were used to determine balloon volume changes.
 Results
 The EVAC syringe pump was highly effective at maintaining precise aortic flow throughout the 45-minute intervention period during steady state conditions as well as during rapid fluid administration. Aortic flow and distal mean arterial pressure remained stable during EVAC, despite changing proximal hemodynamics. Balloon volume was dynamic, averaging over 500 changes during intervention, with a mean volume change of 6.7 uL and a maximal change of 100 uL.
 Conclusion
 The EVAC syringe pump is capable of achieving aortic flow regulation with high precision, beyond what is achievable with manual control. This serves as a model for future device design, enabling as-of-yet unachievable clinical therapies for hemorrhage and shock states. Future technological development is required to fully translate this into clinical use.
 Level of Evidence – Level V
 Study Type – Translational Science
 Keywords – EVAC, P-REBOA, REBOA, automation, hemorrhage
 
 
 

Partial Resuscitative Endovascular Balloon Occlusion of the Aorta: A Systematic Review of the Preclinical and Clinical Literature

“…Others focus on the comparison between balloon inflation volume or pressure and distal flow or pressure, 17,22,25,34 use of computerized controllers to achieve precision control, 23,28,29 or the use of partial REBOA as a technique to enable contrast-enhanced computerized tomography diagnostic imaging. 35 It is worth noting that many of the dependent variables in these articles are relevant only to the device used, and care is warranted when considering the generalizability of this work.…”

Targeted Regional Optimization: Increasing the Therapeutic Window for Endovascular Aortic Occlusion In Traumatic Hemorrhage

“…Central aortic and cerebral pressures are maintained to achieve physiologic levels perfusion while targeted distal perfusion mitigates distal ischemia (16)(17)(18)(19). This strategy usually incorporates intermittent REBOA (iREBOA) (20)(21)(22), partial REBOA (pREBOA) (17,18,(23)(24)(25), or automated occlusive devices (16)(17)(18)26). These endoluminal resuscitative strategies offer a potential solution to the limitations and morbidities of complete aortic occlusion.…”

Advanced partial occlusion controller allows for increased precision during targeted regional optimization in a porcine model of hemorrhagic shock

“…The effectiveness of automated systems for partial aortic occlusion has been demonstrated elsewhere. An endovascular variable aortic control device was studied by Williams et al 19 in a porcine model of hemorrhagic shock. This group implemented variable aortic control over a 45-minute period targeting distal flow rates of approximately 10% of baseline distal aortic flow.…”