Mechanism of blood flow energy loss in real healthy aorta using computational fluid-structure interaction framework

Abstract

Blood flow energy loss may correlate with the occurrence of vascular diseases. However, the mechanism of blood flow energy loss is still not fully explored. The objective of the present study is to reveal the mechanism of energy loss of blood flow in the healthy aorta. Two patients without aortic diseases are retrospectively screened from a clinical hospital. The computed tomography image is used to inversely reconstruct a three-dimensional geometric model of the healthy aorta. Non-invasive clinical measurements are applied to determine patient-specific boundary conditions. The fluid-structure interaction method is adopted to acquire high-resolution hemodynamics. A novel method is proposed to calculate the blood flow energy loss caused by aortic wall deformation. The distribution of blood flow validates the accuracy of the above computational framework, which could capture more than 90% of blood flow energy loss. Viscous friction of blood flow is the primary cause of energy loss, followed by aortic wall deformation, and finally turbulent dissipation. Energy loss due to viscous friction and wall deformation mainly occurs on the aortic vessel wall. The sum of these two energy losses approximates the total energy loss and may be associated with the initiation of aortic lesions. Besides, we find that the buffering efficiency of the real healthy aorta is about 80%. The mechanism of aortic blood flow energy loss is uncovered and these findings would inform the new hemodynamic markers and clinical assessment tool for the vascular wall.