Computational Modeling and Simulation of Atherosclerotic Plaque Growth

2002 ◽  
Author(s):  
L. E. Breeher ◽  
Saikrishna Marella ◽  
H. S. Udaykumar ◽  
K. B. Chandran
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Atherosclerotic Plaque ◽  
Arterial Wall ◽  
Flow Characteristics ◽  
Plaque Formation ◽  
Constant Shear Stress ◽  
Plaque Growth ◽  
Serious Disease ◽  
Computational Modeling And Simulation

Research has been conducted by the authors with the objective to produce a computational model that will clearly display the coupled nature of the hemodynamics/fluid mechanics of blood flow and atherosclerotic plaque growth in the human carotid artery. The motivation for this investigation is the serious nature of atherosclerosis. Atherosclerosis is an inflammatory disease, which occurs in medium and large size arteries. Among the many effects stemming from the disease are heart attack, stroke, ischemia, and peripheral vascular disease. In healthy arteries, the collagen and elastin allow the artery to expand and contract with blood flow. This function enables the artery to maintain constant wall shear stress [1]. Plaque existence in the arterial wall results in decreased ductility of the wall, which inhibits the wall from maintaining constant shear stress. Plaque formations along the arterial wall then protrude into the artery, disturbing the blood flow. Characteristics of the fluid flow in the artery are also altered due to the presence of a plaque. Areas of low shear stress and recirculation move downstream from the plaque. These disturbances act not only to further the plaque formation at the site, but also to make the wall around the plaque formation more prone to lesions that could lead to new plaque initiation. Complex characteristics of the blood flow give areas of an artery such as bends and bifurcations a predisposition for the disease, whereas plaques affect blood flow, creating flow patterns that promote new plaque initiation. This interdependency makes atherosclerosis a very serious disease and one which is of great importance in research.

Abstract 249: Increased Vascular CCRL2 Expression by Disturbed Blood Flow Promotes Atherosclerotic Plaque Formation in ApoE Deficient Mice

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Shuhong Hu ◽  
Li Zhu
Keyword(s):  
Blood Flow ◽  
Atherosclerotic Plaque ◽  
Inflammatory Responses ◽  
Foam Cell ◽  
Cell Formation ◽  
Vascular Wall ◽  
Chronic Inflammatory Disease ◽  
Plaque Formation ◽  
Foam Cell Formation ◽  
Cell Trafficking

Atherosclerosis is a chronic inflammatory disease of the arterial wall elicited by accumulation of LDL and leucocytes in the subendothelium at predilection sites with disturbed laminar flow. Chemokines and their receptors appear to act as critical players in atherosclerosis as they not only direct atherogenic recruitment of leucocytes but also exert cell hemostatic functions by chemokine ligand-receptor axes and their specific or combined contributions. Atypical chemokine (C-C motif) receptor-like 2 (CCRL2) cooperates with its ligand chemerin and leukocyte-expressed chemerin receptor chemokine-like receptor 1 (CMKLR1) to regulate cell trafficking and inflammatory responses,but its role in atherosclerosis is not clear. To investigate whether CCRL2 contributes to the pathomechanism of atherogenesis, we generated CCRL2 -/- mice in hyperlipidemic atherosclerosis-prone ApoE -/- background and found that the atherosclerotic plaque area of the total aorta was significantly reduced compared with CCRL2 +/+ ApoE -/- mice on a high fat diet. The protective effect of CCRL2 deficiency was anatomically isolated primarily to the site of disturbed blood flow (D-flow) in the aortic arch but not in the descending aorta. Endothelial CCRL2 was upregulated in response to D-flow and either CCRL2 or CMKLR1 deletion reduced plaque formation. Further studies showed that CCRL2 co-localized with CMKLR1 and chemerin within the atherosclerotic aorta root. CCRL2 deficiency led to significantly less lipid deposition in aortic root, reduced CMKLR1 + leukocyte rolling on lesional vascular endothelium, diminished macrophage accumulation and foam cell formation, and polarized macrophage to an M2-like phenotype. These results demonstrate that D-flow induction of vascular CCRL2 is required for optimal formation of atherosclerotic plaques via coordinating the accumulation of CMKLR1 + monocytes/macrophages within the vascular wall, and thus identifies CCRL2 as a novel drug target to prevent or treat atherosclerosis. This work was supported by Natural Science Foundation of China (grant 81370373 to L.Z. and 31300781 to C.T.) Key Words: atherosclerosis, CCRL2, chemerin, macrophage

A New 3D Reconstruction Method for Human Coronary Bifurcations for Shear Stress Computations

2012 ◽  
Author(s):  
Frank Gijsen ◽  
Hans Schuurbiers ◽  
Michiel Schaap ◽  
Anton van der Steen ◽  
Jolanda Wentzel
Keyword(s):  
Shear Stress ◽  
Coronary Arteries ◽  
Arterial Wall ◽  
Plaque Formation ◽  
Atherosclerotic Plaques ◽  
Reconstruction Method ◽  
Human Coronary Artery ◽  
Multislice Computer Tomography ◽  
Stress Influences ◽  
The Impact

Atherosclerosis is characterized by lipid accumulation in the arterial wall, followed by an inflammatory response. Plaque formation is generally observed near bifurcations in coronary arteries. The composition of atherosclerotic plaques depends on the location, and it was hypothesized that blood flow induced shear stress influences plaque composition2. To study the impact of shear stress on atherosclerotic disease in human coronary arteries, we developed a technique that enables us to generate 3D lumen reconstruction based on multislice computer tomography (MSCT) and intravascular ultrasound (IVUS).We describe two approaches to generate 3D reconstructions of human coronary artery bifurcations and apply them to coronary segments with bifurcations. We will evaluate the effect on shear stress distribution and its relationship to wall thickness.

scholarly journals Investigation of blood flow through an artery in the presence of overlapping stenosis

2017 ◽  
Vol 14 (1) ◽  
pp. 39-46 ◽  
Author(s):  
K. Maruthi Prasad ◽  
S. Thulluri ◽  
M. V. Phanikumari
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Couple Stress ◽  
Flow Characteristics ◽  
Couple Stress Fluid ◽  
Flow Equations ◽  
Wall Shear ◽  
Fluid Parameters

The effects of an overlapping stenosis on blood flow characteristics in an artery have been studied. Blood has been represented by a couple stress fluid. The flow equations have been linearised and the expressions for pressure drop, resistance to the flow and wall shear stress have been derived. The results are shown graphically. It is observed that the resistance to the flow, pressure drop and wall shear stress increases with height and length of the stenosis. And it is noticed that the resistance to the flow and pressure drop decreases with couple stress fluid parameters. But wall shear stress increases with couple stress fluid parameters.

scholarly journals INDUCTION OF PERTURBED SHEAR STRESS LEADS TO FOCAL ADVANCED ATHEROSCLEROTIC PLAQUE FORMATION IN TRANSGENIC MINIPIGS WITH HYPERCHOLESTEROLEMIA

2015 ◽  
Vol 65 (10) ◽  
pp. A1927
Author(s):  
Christian Bo Poulsen ◽  
Ryan M. Pedrigi ◽  
Vikram V. Mehta ◽  
Anouk Post ◽  
Nilesh Pareek ◽  
...  
Keyword(s):  
Shear Stress ◽  
Atherosclerotic Plaque ◽  
Plaque Formation ◽  
Atherosclerotic Plaque Formation

EFFECT OF PROGRESSIVE DEGREES OF SIDE-BRANCH BIFURCATION ANGLES ON FLOW IN ARTERY USING NUMERICAL SIMULATION

2016 ◽  
Vol 16 (04) ◽  
pp. 1650043
Author(s):  
HUIRONG WANG ◽  
XIAORAN WANG ◽  
YILUN JIN ◽  
GUIYING LIU ◽  
XINYUE LI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Numerical Models ◽  
Human Life ◽  
Flow Characteristics ◽  
Side Branch ◽  
Computational Framework ◽  
Abdominal Aortic ◽  
Invasive Method ◽  
Serious Disease ◽  
Major Factors

Malfunction of the cardiovascular system is a serious disease affecting human life around the world that is caused by several factors. One of the major factors is atherosclerosis that is a disease of the artery. Atherosclerosis is a serious vascular condition, which always occurs in branch vessels such as the abdominal aortic bifurcation and the carotid artery bifurcation. Wall shear stress (WSS) and wall pressure gradient (WPG) pertaining to these vessels will dramatically change when the geometry of these vessels is varied. Computational hemodynamics, as an invasive method, can be employed to understand the blood flow characteristics. In this paper, blood flow through arteries with variable side branches is presented using a computational framework. Numerical models pertaining to the different side-branch bifurcation angles are simulated to verify this. The side-branch bifurcation angle correlates positively to the maximum WSS experienced by the artery and this has an effect on atherogenesis. The low WPG regions are found to decrease with increased values of the angles, while the high WPG regions concentrate in the same region with larger values. Such hemodynamics information can be used to understand the effect of arterial geometrical variation on hemodynamics and the causes of atherosclerosis.

scholarly journals Analysis of Flow Characteristics of the Blood Flowing through an Inclined Tapered Porous Artery with Mild Stenosis under the Influence of an Inclined Magnetic Field

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Neetu Srivastava
Keyword(s):  
Magnetic Field ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Volumetric Flow Rate ◽  
Mhd Equations ◽  
Inclined Magnetic Field ◽  
Wall Shear

Analytical investigation of MHD blood flow in a porous inclined stenotic artery under the influence of the inclined magnetic field has been done. Blood is considered as an electrically conducting Newtonian fluid. The physics of the problem is described by the usual MHD equations along with appropriate boundary conditions. The flow governing equations are finally transformed to nonhomogeneous second-order ordinary differential equations. This model is consistent with the principles of magnetohydrodynamics. Analytical expressions for the velocity profile, volumetric flow rate, wall shear stress, and pressure gradient have been derived. Blood flow characteristics are computed for a specific set of values of the different parameters involved in the model analysis and are presented graphically. Some of the obtained results show that the flow patterns in converging region (ξ<0), diverging region (ξ>0), and nontapered region (ξ=0) are effectively influenced by the presence of magnetic field and change in inclination of artery as well as magnetic field. There is also a significant effect of permeability on the wall shear stress as well as volumetric flow rate.

Numerical Analysis of the Cooling Effect of Blood Over Inflamed Atherosclerotic Plaque

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Taehong Kim ◽  
Obdulia Ley
Keyword(s):  
Blood Flow ◽  
Atherosclerotic Plaque ◽  
Wall Temperature ◽  
Temperature Increase ◽  
Arterial Wall ◽  
Stokes Equations ◽  
Inflammatory Cells ◽  
Cooling Effect ◽  
Flow Reduction ◽  
Blood Flow Reduction

Atherosclerotic plaques with high likelihood of rupture often show local temperature increase with respect to the surrounding arterial wall temperature. In this work, atherosclerotic plaque temperature was numerically determined during the different levels of blood flow reduction produced by the introduction of catheters at the vessel lumen. The temperature was calculated by solving the energy equation and the Navier–Stokes equations in 2D idealized arterial models. Arterial wall temperature depends on three basic factors: metabolic activity of the inflammatory cells embedded in the plaque, heat convection due to luminal blood flow, and heat conduction through the arterial wall and plaque. The calculations performed serve to simulate transient blood flow reduction produced by the presence of thermography catheters used to measure arterial wall temperature. The calculations estimate the spatial and temporal alterations in the cooling effect of blood flow and plaque temperature during the measurement process. The mathematical model developed provides a tool for analyzing the contribution of factors known to affect heat transfer at the plaque surface. Blood flow reduction leads to a nonuniform temperature increase ranging from 0.1°Cto0.25°Celsius in the plaque/lumen interface of the arterial geometries considered in this study. The temperature variation as well as the Nusselt number calculated along the plaque surface strongly depended on the arterial geometry and distribution of inflammatory cells. The calculations indicate that the minimum required time to obtain a steady temperature profile after arterial occlusion is 6s. It was seen that in arteries with geometries involving bends, the temperature profiles appear asymmetrical and lean toward the downstream edge of the plaque.

scholarly journals Mathematical Modeling of Atherosclerotic Plaque Formation Coupled with a Non-Newtonian Model of Blood Flow

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Telma Silva ◽  
Adélia Sequeira ◽  
Rafael F. Santos ◽  
Jorge Tiago
Keyword(s):  
Shear Stress ◽  
Atherosclerotic Plaque ◽  
Reaction Diffusion ◽  
Plaque Formation ◽  
Reaction Diffusion Equations ◽  
Lower Shear ◽  
Atherosclerotic Lesions ◽  
Atherosclerotic Plaque Formation ◽  
Before And After ◽  
Lesion Growth

We deal with a mathematical model of atherosclerosis plaque formation, which describes the early formation of atherosclerotic lesions. The model assumes that the inflammatory process starts with the penetration of low-density lipoproteins cholesterol in the intima, and that penetration will occur in the area of lower shear stress. Using a system of reaction-diffusion equations, we first provide a one-dimensional model of lesion growth. Then we perform numerical simulations on an idealized two-dimensional geometry of the carotid artery bifurcation before and after the formation of the atherosclerotic plaque. For that purpose, we consider the blood as an incompressible non-Newtonian fluid with shear-thinning viscosity. We also present a study of the wall shear stress and blood velocity behavior in a geometry with one plaque and also with two plaques in different positions.

scholarly journals Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure

2021 ◽  
Author(s):  
Aurelio Secinaro ◽  
Elena Giulia Milano ◽  
Paolo Ciancarella ◽  
Matteo Trezzi ◽  
Claudio Capelli ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Magnetic Resonance ◽  
Aortic Valve ◽  
Wall Shear Stress ◽  
Aortic Root ◽  
Flow Characteristics ◽  
Ascending Aorta ◽  
Ross Procedure ◽  
4D Flow

Abstract Aims The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients. Methods and results Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9–16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity. Conclusion Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.

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