Item Details

title

DEVELOPING COMPUTATIONAL FLUID DYNAMIC MODELS TO INVESTIGATE THE HEMODYNAMIC RESPONSE TO HEMORRHAGIC SHOCK AND RESUSCITATION WITH REBOA

author

Renaldo, Antonio

abstract

Abstract Hemorrhagic shock is the leading cause of preventable death after injury, accounting for 91% of military and 35% of civilian fatalities after trauma. More than half of these deaths occur pre-hospital, necessitating immediate lifesaving interventions. In response, Endovascular Hemorrhage Control (EHC) devices have been proposed as a more efficient and less invasive way to manage such injuries. Resuscitative Endovascular Balloon of the Aorta (REBOA) is the most popular EHC approach; it has become increasingly adopted as a less invasive intervention for the treatment of non-compressible torso hemorrhage (NCTH). REBOA involves temporary inflation of a balloon catheter in the aorta which restricts blood flow distal to the balloon and consequently minimizes bleeding. This technique is effective at restoring proximal perfusion, it can only be applied for short periods of time before the deleterious downstream effects of aortic occlusion (i.e., ischemia, organ failure, etc.) start to outweigh its initial benefit. In particular, the ischemia-reperfusion (I/R) injury following REBOA significantly impacts the kidneys and renal function. To address these concerns, many have proposed partial or time-varying occlusion methods. While partial REBOA methods attenuate the ischemic burden, there remains several questions over the optimal implementation of partial REBOA and other EHC devices. Part of the challenge is our limited ability to study the acute physiology during full vs. partial aortic occlusion in porcine models, the current gold standard for preclinical testing. Arguably, the lack of alternative tools to test EHC devices has hindered the growth and pace of innovation. The development of an in silico model as an adjunct platform to investigate REBOA and other EHC devices would significantly improve preclinical testing and optimization of these lifesaving interventions. In this dissertation, we aimed to develop a computational fluid dynamic (CFD) model to better understand the transient hemodynamic changes imposed during hemorrhagic shock and resuscitation with REBOA. These experiments were performed in three aims: • Aim 1. Develop and calibrate a 3D CFD model to investigate the hemodynamic impact of full vs. partial REBOA during hemorrhagic shock by leveraging in vivo data from a pre-established porcine hemorrhage model. • Aim 2. Quantify the impact of full vs. partial REBOA on vascular diameter changes across the aorta and main arterial branches. In this aim, we utilize contrast-enhanced CT imaging to measure changes in vascular diameters during hemorrhage and aortic occlusion. As a sub-aim, this information is then used to refine the CFD model using CRIMSON software. Here, the utilization of a three-dimensional (3D) vascular geometry coupled to a series of zero-dimensional (0D) 3-Element Windkessel elements as outflow boundary conditions, provides more insights into the acute resistance and compliance changes during hemorrhage and REBOA use. • Aim 3. Characterize the changes in clotting kinetics and coagulopathy associated with intermittent and partial REBOA, using thromboelastography (TEG). In this aim, we contextualize the hemodynamic changes with biological responses affecting platelets and the vascular endothelial function.

subject

CFD- computational fluid dynamics

Coagulopathy

Enodtheliopathy of Trauma

Hemorrhagic Shock

REBOA- resuscitative endovascular balloon occlusion of the aorta

Trauma

contributor

Rahbar, Elaheh (advisor)

Gayzik, F. Scott (committee member)

Jordan, James E. (committee member)

Neff, Lucas P. (committee member)

Richter, Jillian R. (committee member)

Williams, Timothy K. (committee member)

date

2024-02-13T09:36:08Z (accessioned)

2024 (issued)

degree

Biomedical Engineering (discipline)

embargo

2029-01-12 (terms)

2029-01-12 (liftdate)

identifier

http://hdl.handle.net/10339/102913 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation