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Updated: Jun 19, 2026
In Vitro Model of Physiological and Pathological Blood Flow with Application to Investigations of Vascular Cell Remodeling
Published on: November 3, 2015
Investigation of pulsatile flowfield in healthy thoracic aorta models
Chih-Yung Wen1, An-Shik Yang, Li-Yu Tseng
1Department of Aeronautics and Astronautics, National Cheng-Kung University, No. 1 University Road, Tainan City 701, Taiwan, R.O.C. cywen@mail.ncku.edu.tw
Insights
This study used advanced imaging and computational fluid dynamics to analyze blood flow in the aorta. Findings link complex hemodynamics, wall shear stress, and pressure patterns to aortic dissection and atherosclerosis development.
Area of Science:
- Cardiovascular Science
- Biomedical Engineering
- Fluid Mechanics
Background:
- Cardiovascular diseases are a leading cause of death globally.
- Complex blood flow dynamics (hemodynamics) are implicated in aortic disorders like dissection and atherosclerosis.
- Understanding blood flow mechanics is crucial for cardiovascular health.
Purpose of the Study:
- To investigate the relationship between hemodynamics, wall shear stress (WSS), and pressure in the human thoracic aorta.
- To correlate these factors with the development of aortic dissection and atherosclerosis.
- To analyze the oscillatory shear index (OSI) and its role in aortic wall changes.
Main Methods:
- Acquired thoracic aorta geometry using Phase-Contrast Magnetic Resonance Imaging (PC-MRI).
- Created a transparent aorta model for in vitro experiments and rapid prototyping (RP).
- Employed Computational Fluid Dynamics (CFD) with ACE+((R)) for simulating pulsatile, incompressible blood flow.
- Validated CFD results against PC-MRI data for axial velocity.
Main Results:
- Detailed analysis of thoracic aorta flow characteristics, WSS, OSI, and wall pressures.
- Identified correlations between high WSS/pressure locations and thoracic aorta dissection sites.
- Observed low WSS and high OSI associated with wall thickening in specific aortic regions.
Conclusions:
- The study provides insights into the biomechanical factors contributing to aortic dissection.
- Hemodynamic parameters like WSS and OSI are significant indicators for predicting aortic disorders.
- Findings support the link between altered blood flow and pathological changes in the aorta.
Abstract:
Cardiovascular disease is the primary cause of morbidity and mortality in the western world. Complex hemodynamics plays a critical role in the development of aortic dissection and atherosclerosis, as well as many other diseases. Since fundamental fluid mechanics are important for the understanding of the blood flow in the cardiovascular circulatory system of the human body aspects, a joint experimental and numerical study was conducted in this study to determine the distributions of wall shear stress and pressure and oscillatory WSS index, and to examine their correlation with the aortic disorders, especially dissection. Experimentally, the Phase-Contrast Magnetic Resonance Imaging (PC-MRI) method was used to acquire the true geometry of a normal human thoracic aorta, which was readily converted into a transparent thoracic aorta model by the rapid prototyping (RP) technique. The thoracic aorta model was then used in the in vitro experiments and computations. Simulations were performed using the computational fluid dynamic (CFD) code ACE+((R)) to determine flow characteristics of the three-dimensional, pulsatile, incompressible, and Newtonian fluid in the thoracic aorta model. The unsteady boundary conditions at the inlet and the outlet of the aortic flow were specified from the measured flowrate and pressure results during in vitro experiments. For the code validation, the predicted axial velocity reasonably agrees with the PC-MRI experimental data in the oblique sagittal plane of the thoracic aorta model. The thorough analyses of the thoracic aorta flow, WSSs, WSS index (OSI), and wall pressures are presented. The predicted locations of the maxima of WSS and the wall pressure can be then correlated with that of the thoracic aorta dissection, and thereby may lead to a useful biological significance. The numerical results also suggest that the effects of low WSS and high OSI tend to cause wall thickening occurred along the inferior wall of the aortic arch and the anterior wall of the brachiocephalic artery, similar implication reported in a number of previous studies.
