Computational fluid dynamic analysis to prevent aortic root and valve clots during left ventricular assist device...

Area of Science:

• Biomedical Engineering
• Cardiovascular Science
• Medical Device Design

Background:

• Aortic root and valve thrombosis are infrequent but serious complications in patients with left ventricular assist devices (LVADs).
• Understanding factors influencing clot formation in the aortic root is crucial for improving LVAD therapy.
• Maximal LVAD support can lead to altered hemodynamics in the aortic root.

Purpose of the Study:

• To theoretically analyze how left ventricular assist device (LVAD) inflow cannula design and orientation affect aortic root flow dynamics.
• To investigate the potential of specific cannula modifications to mitigate aortic root thrombosis.
• To evaluate the influence of inflow conduit angulation on aortic root hemodynamics.

Main Methods:

• Two-dimensional computational fluid dynamics (CFD) analysis using easy CFD-G software.
• Simulation of different inflow cannula designs: curved, straight, and curved with a hole.
• Analysis of the effect of inflow conduit angulation on the ascending aorta and aortic root flow.

Main Results:

• CFD analysis revealed stagnant blood flow in the aortic root during periods of minimal cardiac ejection.
• A hole on the aortic side of a curved inflow cannula was predicted to increase aortic root flow.
• Inflow conduit angulation significantly impacts aortic root blood stasis; a baffle may also be beneficial.

Conclusions:

• Inflow cannula design, orientation, and placement are critical factors influencing aortic root flow dynamics during LVAD support.
• Modifications such as incorporating a hole in a curved cannula may reduce the incidence of aortic root and valve thrombosis.
• Optimizing inflow cannula characteristics can potentially decrease the risk of thrombosis in LVAD patients with minimal cardiac output.