Left ventricular assist devices (LVAD), which facilitate blood flow from the left ventricle to the aorta, are a surgical option for patients with end-stage congestive heart failure, a condition that the heart fails to pump enough blood to meet the body’s need. LVAD can be surgically implanted through a left thoracotomy with outflow-graft anastomosis. Generally, the approach of LVAD should be considered when the left ventricle fails to provide more than 70% of blood flow. In this research, we investigated on three LVAD configuration positions: axial-flow and transversal-flow LVAD on ascending aorta and axial-flow LVAD on descending aorta. The position at which the graft is configured may have important clinical consequences depending on various severity of heart failure. We describe a computer-generated model to illustrate the flow dynamics in the aorta with respect to different outflow-graft configurations under various degrees of heart failure.
The simulation indicates that the location of the anastomosis has important effect on blood flow in the ascending aorta, the aortic arch and the descending aorta. Moreover, under the condition of 50% blockage of aortic root, LVAD is not generally recommended because the hazard associated with open heart surgery could outweigh its overall benefit. However, our simulation suggests that if LVAD is implanted under such condition, its configuration position does not make a significant impact to hemodynamics inside the aorta comparing to that of premorbid aorta. Under the condition of 70% blockage of aortic root, this is when LVAD implantation should be generally considered. The simulation indicates that under this scenario, axial-flow LVAD on descending aorta is the most optimal solution. The most extreme case of heart failure is 100% blockage of aortic root, meaning that the only source of blood supply is through LVAD. The simulation indicates that under this extreme case, transversal-flow LVAD on ascending aorta could be the most promising option. Results of this study provide insight on the importance of the anastomosis location on the hemodynamics in the aorta, systolic pressure on the aortic wall, velocity and vorticity of blood flow inside the aorta.
Table of Contents
Table of Contents
Geometrical Modeling 5
Physical Modeling (Navier-Stokes Fluid Dynamics) 8
Computer Simulation Results 19
About this Honors Thesis
|Committee Chair / Thesis Advisor|
|Numerical Simulation of Hemodynamics of Left Ventricular Assist Device for Surgical Planning ()||2019-04-08||