scholarly journals Human coronary plaque wall thickness correlated positively with flow shear stress and negatively with plaque wall stress: an IVUS-based fluid-structure interaction multi-patient study

2014 ◽  
Vol 13 (1) ◽  
pp. 32 ◽  
Author(s):  
Rui Fan ◽  
Dalin Tang ◽  
Chun Yang ◽  
Jie Zheng ◽  
Richard Bach ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Thickness ◽  
Fluid Structure Interaction ◽  
Wall Stress ◽  
Coronary Plaque ◽  
Flow Shear ◽  
Fluid Structure ◽  
Patient Study ◽  
Structure Interaction ◽  
Flow Shear Stress

Advanced Human Coronary Plaque Wall Thickness Correlates Positively With Flow Shear Stress and Negatively With Plaque Wall Stress: An IVUS-Based FSI Study

2013 ◽  
Author(s):  
Dalin Tang ◽  
Chun Yang ◽  
Joseph D. Petruccelli ◽  
Jie Zheng ◽  
Richard Bach ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Thickness ◽  
Wall Stress ◽  
Coronary Plaque ◽  
Stress Conditions ◽  
Patient Specific ◽  
Plaque Progression ◽  
Flow Shear ◽  
Flow Shear Stress

Atherosclerotic plaque progression is believed to be associated with low and oscillating flow shear stress conditions [1–3]. In vivo image-based coronary plaque modeling papers are relatively rare because clinical recognition of vulnerable coronary plaques has remained challenging [3–4]. Samady et al. [3] published their seminal patient follow-up coronary plaque progression study and indicated that flow shear stress (FSS) was associated with plaque progression and remodeling. We have published results based on follow-up studies showing that advanced carotid plaque had positive correlation with flow shear stress and negative correlation with plaque wall stress (PWS) [4]. In this paper, patient-specific intravascular ultrasound (IVUS)-based coronary plaque models with fluid-structure interaction (FSI), on-site pressure and ex vivo biaxial mechanical testing of human coronary plaque material properties were constructed to obtain flow shear stress and plaque wall stress data from six patients to investigate possible associations between vessel wall thickness and both flow shear stress and plaque wall stress conditions.

Fluid-structure interaction in abdominal aortic aneurysms: Structural and geometrical considerations

2015 ◽  
Vol 26 (04) ◽  
pp. 1550038 ◽  
Author(s):  
Yaser Mesri ◽  
Hamid Niazmand ◽  
Amin Deyranlou ◽  
Mahmood Reza Sadeghi
Keyword(s):  
Wall Thickness ◽  
Arterial Wall ◽  
Fluid Structure Interaction ◽  
Wall Stress ◽  
Aortic Aneurysms ◽  
Material Behavior ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Abdominal Aortic ◽  
Iliac Bifurcation

Rupture of the abdominal aortic aneurysm (AAA) is the result of the relatively complex interaction of blood hemodynamics and material behavior of arterial walls. In the present study, the cumulative effects of physiological parameters such as the directional growth, arterial wall properties (isotropy and anisotropy), iliac bifurcation and arterial wall thickness on prediction of wall stress in fully coupled fluid-structure interaction (FSI) analysis of five idealized AAA models have been investigated. In particular, the numerical model considers the heterogeneity of arterial wall and the iliac bifurcation, which allows the study of the geometric asymmetry due to the growth of the aneurysm into different directions. Results demonstrate that the blood pulsatile nature is responsible for emerging a time-dependent recirculation zone inside the aneurysm, which directly affects the stress distribution in aneurismal wall. Therefore, aneurysm deviation from the arterial axis, especially, in the lateral direction increases the wall stress in a relatively nonlinear fashion. Among the models analyzed in this investigation, the anisotropic material model that considers the wall thickness variations, greatly affects the wall stress values, while the stress distributions are less affected as compared to the uniform wall thickness models. In this regard, it is confirmed that wall stress predictions are more influenced by the appropriate structural model than the geometrical considerations such as the level of asymmetry and its curvature, growth direction and its extent.

scholarly journals Numerical modeling in arterial hemodynamics incorporating fluid-structure interaction and microcirculation

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Fan He ◽  
Lu Hua ◽  
Tingting Guo
Keyword(s):  
Numerical Modeling ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Fluid Structure Interaction ◽  
Rigid Wall ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Arterial Hemodynamics ◽  
Wall Compliance ◽  
Wall Shear

Abstract Background The effects of arterial wall compliance on blood flow have been revealed using fluid-structure interaction in last decades. However, microcirculation is not considered in previous researches. In fact, microcirculation plays a key role in regulating blood flow. Therefore, it is very necessary to involve microcirculation in arterial hemodynamics. Objective The main purpose of the present study is to investigate how wall compliance affects the flow characteristics and to establish the comparisons of these flow variables with rigid wall when microcirculation is considered. Methods We present numerical modeling in arterial hemodynamics incorporating fluid-structure interaction and microcirculation. A novel outlet boundary condition is employed to prescribe microcirculation in an idealised model. Results The novel finding in this work is that wall compliance under the consideration of microcirculation leads to the increase of wall shear stress in contrast to rigid wall, contrary to the traditional result that wall compliance makes wall shear stress decrease when a constant or time dependent pressure is specified at an outlet. Conclusions This work provides the valuable study of hemodynamics under physiological and realistic boundary conditions and proves that wall compliance may have a positive impact on wall shear stress based on this model. This methodology in this paper could be used in real model simulations.

Numerical CFD / FSI Study of Teflon and Dacron for Use in the Femoral Artery Graft Procedure

2019 ◽  
Author(s):  
Sukwinder Sandhu ◽  
Kevin R. Anderson
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Femoral Artery ◽  
Hoop Stress ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Implant Materials ◽  
Artery Graft ◽  
Wall Shear

Abstract This paper presents Fluid Structure Interaction modeling of candidate implant materials used in the femoral artery graft medical procedure. Two candidate implant materials, namely Teflon and Dacron are considered and modeled using Computational Fluid Dynamics (CFD) and structural Finite Element Analysis (FEA) to obtain Fluid Structure Interaction (FSI) developed stresses within the candidate materials as a result of non-Newtonian blood flowing in a pulsatile unsteady fashion into the femoral artery implant tube. The pertinent findings for a pulsatile velocity maximum magnitude of 0.3 m/s and period of oscillation of 2.75 sec are as follows. For the biological tissue the wall shear stress is found to be 2.15 × 104 Pa, the hoop stress is found to be 1.6 × 104 Pa. For the Teflon implant material, the wall shear stress is found to be 1.177 × 104 Pa, the hoop stress is found to be 2.2 × 104 Pa. For the Dacron implant material the wall shear stress is found to by 3.9 × 104 Pa, the hoop stress is found to be 2.17 × 104 Pa. Based upon the analysis herein the PTFE material would be recommended.

A New Hypothesis for Human Atherosclerotic Plaque Progression Based on Serial In Vivo MRI and Computational Modeling Method

2007 ◽  
Author(s):  
Sayan Mondal ◽  
Chun Yang ◽  
Joseph D. Petruccelli ◽  
Chun Yuan ◽  
Fei Liu ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Thickness ◽  
Computational Models ◽  
Ex Vivo ◽  
Maximum Principal Stress ◽  
Magnetic Resonance Images ◽  
Shear Stresses ◽  
Flow Shear ◽  
Flow Shear Stress

It has been well-accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses. However, this shear stress mechanism cannot fully explain why advanced plaques continue to grow under elevated flow shear stress conditions. Our previous investigations using 3D computational models with fluid-structure interactions (FSI) based on in vivo/ex vivo magnetic resonance images (MRI) of human carotid atherosclerotic plaques indicated that there is a negative correlation between advanced plaque wall thickness and structural maximum principal stress (Stress-P1) in the plaque and a positive correlation between plaque wall thickness and flow shear stress [3].

Reversed Correlations Between Atherosclerotic Carotid Plaque Progression and Flow Shear Stress/Plaque Wall Stress Based on Past and Current Scan Data: In Vivo MRI-Based 3D FSI Studies

2010 ◽  
Author(s):  
Chun Yang ◽  
Gador Canton ◽  
Chun Yuan ◽  
Thomas Hatsukami ◽  
Dalin Tang
Keyword(s):  
Shear Stress ◽  
Wall Stress ◽  
Significant Negative Correlation ◽  
Shear Stresses ◽  
Plaque Progression ◽  
Flow Shear ◽  
Carotid Plaques ◽  
Flow Shear Stress ◽  
The Difference

It has been well accepted that low and oscillating blood flow shear stresses (LFSS) correlate positively with intimal thickening and atherosclerosis initiation [1,2]. However, the LFSS hypothesis cannot explain why advanced plaques continue to grow under elevated high flow shear stress conditions [3]. For patient tracking studies, plaque progression is often measured by the difference of plaque geometries between two scans (“past” and “current” scans) when medical imaging is used. Mechanical flow shear stress (FSS) and plaque wall stress (PWS) conditions from the two scans may have different correlations with plaque progression. Using 2D structure models based on in vivo magnetic resonance imaging (MRI) human carotid plaques, Tang et al. showed that 18 out of 21 patients had significant negative correlation between plaque progression measured by wall thickness increase (WTI) and plaque wall stress from current scan [3]. The correlation was reversed when plaque wall stress from past scan was used. In this paper, 3D fluid-structure interactions (FSI) models for 32 matched “past-current” scan pairs of human atherosclerotic carotid plaques based on in vivo MRI data were solved and plaque wall stress (PWS) and flow shear stress (FSS) data were obtained to quantify their correlations with plaque progression measured by WTI.

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