Related Experiment Video
Updated: Jun 14, 2026
11:00
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
Published on: July 19, 2016
11.9K
Effect of intimal flap motion on flow in acute type B aortic dissection by using fluid-structure interaction
Mei Yan Chong1,2, Boram Gu2, Bee Ting Chan3
1Department of Biomedical Engineering, University of Malaya, Kuala Lumpur, Malaysia.
Summary
Fluid-structure interaction (FSI) modeling reveals that dissection flap motion in acute type B aortic dissection significantly alters blood flow dynamics. This motion impacts true and false lumen flow distribution and increases disturbed flow and wall shear stress, offering new insights into disease progression.
Area of Science:
- Cardiovascular Mechanics
- Computational Fluid Dynamics
- Medical Imaging and Simulation
Background:
- Acute type B aortic dissection (TBAD) involves a tear in the aorta, leading to a secondary channel (false lumen) alongside the true lumen.
- Understanding the impact of intimal flap motion on hemodynamics is crucial for predicting TBAD progression and complications.
- Existing computational models often simplify aortic wall behavior, potentially missing key biomechanical interactions.
Purpose of the Study:
- To develop and validate a monolithic, fully coupled fluid-structure interaction (FSI) computational framework for simulating dissection flap motion in TBAD.
- To analyze the effects of flap motion on intimal flap deformation, lumen compression, and hemodynamic parameters including pressure, flow, and wall shear stress (WSS).
- To compare hemodynamic conditions between rigid-wall and FSI models to quantify the influence of physiological flap movement.
Main Methods:
- Development of a monolithic, fully coupled FSI computational framework.
- Simulation of blood flow and aortic wall deformation in a TBAD model.
- Analysis of key hemodynamic parameters: wall deformation, pressure, flow split, flow disturbance (λ₂-criterion), and wall shear stress (WSS).
- Comparison of results from the FSI model against a rigid-wall model.
Main Results:
- The FSI model accurately reproduced realistic flap deformation, causing up to 21.4% compression of the distal true lumen.
- Flap motion shifted the true lumen to false lumen flow split from 88:12 (rigid) to 83:17 (FSI) at peak systole.
- Disturbed flow increased in the false lumen (13.5% in FSI vs. 9.8% in rigid during diastole), and local WSS increased by up to 70.0% near tears.
- Low time-averaged WSS regions in the false lumen were significantly reduced in the FSI model (113.11 cm² vs. 177.44 cm²).
- The FSI model predicted dampened pulse pressure, with lower systolic and higher diastolic pressures compared to the rigid model.
Conclusions:
- The developed FSI framework provides novel insights into the biomechanical consequences of flap motion in acute TBAD.
- Physiological flap movement significantly alters intra-aortic hemodynamics, increasing flow resistance in the true lumen and promoting turbulent flow in the false lumen.
- Hemodynamic changes induced by flap motion, such as altered pressure and WSS, may serve as potential prognostic indicators for TBAD complications.
