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.

P3588The synergistic effect of NIRS-detected lipid-rich plaque and 5 different multidirectional wall shear stress metrics on human coronary plaque growth

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E M J Hartman ◽  
A M Kok ◽  
A Hoogendoorn ◽  
F J H Gijsen ◽  
A F W Steen ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Synergistic Effect ◽  
Coronary Arteries ◽  
Wall Thickness ◽  
Plaque Progression ◽  
Lipid Rich Plaque ◽  
Plaque Growth ◽  
Wall Shear ◽  
The Impact

Abstract Introduction Local wall shear stress (WSS) metrics, high local lipid levels (as detected by near-infrared spectroscopy (NIRS)), as well as systemic lipid levels, have been individually associated with atherosclerotic disease progression. However, a possible synergistic effect remains to be elucidated. This study is the first study to combine WSS metrics with NIRS-detected local lipid content to investigate a potential synergistic effect on plaque progression in human coronary arteries. Methods The IMPACT study is a prospective, single centre study investigating the relation between atherosclerotic plaque progression and WSS in human coronary arteries. Patients with ACS treated with PCI were included. At baseline and after 1-year follow-up, patients underwent near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging and intravascular doppler flow measurements of at least one non-culprit coronary artery. After one month, a CT angiography was made. CT derived centreline combined with IVUS lumen contours resulted in a 3D reconstruction of the vessel. The following WSS metrics were computed using computational fluid dynamics applying the vessel specific invasive flow measurements: time-average wall shear stress (TAWSS), relative residence time (RRT), cross-flow index, oscillatory shear index and transverse wall shear stress. Low TAWSS is known as pro atherogenic, in contrast to all the other shear stress metrics, at which a high magnitude is pro-atherogenic. The arteries were divided into 1.5mm/45° sectors. Based on NIRS-IVUS, wall thickness change over time was determined and NIRS positive sectors detected. Furthermore, per vessel the shear stress was divided into tertiles (low, intermediate, high). To investigate the synergistic effect of local lipids on shear stress related plaque growth, wall thickness change over time was related to the different shear stress metrics comparing the NIRS-positive with the NIRS-negative sectors. Results 15 non-culprit coronary arteries from the first 14 patients were analyzed (age 62±10 years old and 92.9% male). A total of 2219 sectors were studied (5.2%, N=130, NIRS-positive) for wall thickness changes. After studying all five shear stress metrics, we found for TAWSS and RRT that presence of lipids, as detected by NIRS, amplified the effect of shear stress on plaque progression (see figure). Sectors presenting with lipid-rich plaque, compared to NIRS-negative sectors, showed more progression when they were exposed to low TAWSS (p=0.07) or high RRT (p=0.012) and more regression in sectors exposed to high TAWSS (p=0.10) or low RRT (p=0.06). Delta wall thickness vs shear stress Conclusion We presented the first preliminary results of the IMPACT study, showing the synergistic effect of lipid rich plaque and shear stress on plaque progression. Therefore, intravascular lipid-rich plaque (NIRS) assessment has added value to shear stress profiling for the prediction of plaque growth, leading to improved risk stratification. Acknowledgement/Funding ERC starting grant 310457

Shear Stress Modulates Plaque Composition in Human Coronary Arteries In Vivo

2008 ◽  
Author(s):  
Frank Gijsen ◽  
Jolanda Wentzel ◽  
Johan Schuurbiers ◽  
Frits Mastik ◽  
Johannes Schaar ◽  
...  
Keyword(s):  
Shear Stress ◽  
Atherosclerotic Plaques ◽  
Plaque Composition ◽  
Low Shear Stress ◽  
Advanced Stages ◽  
Shear Stress And Strain ◽  
Stress Influences ◽  
The Relationship ◽  
Low Shear

It is well established that atherosclerotic plaques generally develop in low shear stress regions, including curved arterial segments and bifurcations1. Once these plaques intrude into the lumen, the shear stress they are exposed to alters with hitherto unknown consequences. We hypothesize that in the more advanced stages of the disease, shear stress has an important impact on plaque composition in such a way that high shear stress enhances plaque vulnerability through its biological impact on the endothelium2. We investigated this hypothesis previously by studying the relationship between shear stress and strain, a marker for plaque composition, in human coronary arteries3. In this study, we will extend that study by investigating how shear stress influences changes of strain, and thus plaque composition, over a period of 6 months.

Coronary Artery Stenting Affects Wall Shear Stress Topological Skeleton

2022 ◽  
Author(s):  
Claudio Chiastra ◽  
Valentina Mazzi ◽  
Maurizio Lodi Rizzini ◽  
Karol Calò ◽  
Anna Corti ◽  
...  
Keyword(s):  
Shear Stress ◽  
Coronary Artery ◽  
Wall Shear Stress ◽  
Vascular Diseases ◽  
Human Coronary Artery ◽  
Term Outcome ◽  
Clinical Images ◽  
Long Term Outcome ◽  
Wall Shear ◽  
The Impact

Abstract Despite the important advancements in the stent technology for the treatment of diseased coronary arteries, major complications still affect the post-operative long-term outcome. The stent-induced flow disturbances, and especially the altered wall shear stress (WSS) profile at the strut level, play an important role in the pathophysiological mechanisms leading to stent thrombosis (ST) and in-stent restenosis (ISR). In this context, the analysis of the WSS topological skeleton is gaining more and more interest by extending the current understanding of the association between local hemodynamics and vascular diseases. The present study aims to analyze the impact that a deployed coronary stent has on the WSS topological skeleton. Computational fluid dynamics simulations were performed in three stented human coronary artery geometries reconstructed from clinical images. The selected cases presented stents with different designs (i.e., two contemporary drug eluting stents and one bioresorbable scaffold) and included regions with stent malapposition or overlapping. A recently proposed Eulerian-based approach was applied to analyze the WSS topological skeleton features. The results highlighted that the presence of single or multiple stents within a coronary artery markedly impacts the WSS topological skeleton. In particular, repetitive patterns of WSS divergence were observed at the luminal surface, highlighting a WSS contraction action proximal to the struts and a WSS expansion action distal to the struts. This WSS action pattern was independent from the stent design. In conclusions, these findings could contribute to a deeper understanding of the hemodynamic-driven processes underlying ST and ISR.

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.

Strain Distribution Over Plaques in Human Coronary Arteries Relates to Shear Stress

2007 ◽  
Author(s):  
Frank J. H. Gijsen ◽  
Jolanda J. Wentzel ◽  
Johan C. H. Schuurbiers ◽  
Antonius F. W. van der Steen ◽  
Patrick W. Serruys
Keyword(s):  
Shear Stress ◽  
Coronary Arteries ◽  
Atherosclerotic Plaques ◽  
Plaque Composition ◽  
Biological Impact ◽  
Low Shear Stress ◽  
Advanced Stages ◽  
Shear Stress And Strain ◽  
The Relationship ◽  
Low Shear

It is well established that atherosclerotic plaques generally develop in low shear stress regions, including curved arterial segments and bifurcations. Once these plaques intrude into the lumen, the shear stress they are exposed to alters with hitherto unknown consequences. We hypothesize that in the more advanced stages of the disease, shear stress has an important impact on plaque composition in such a way that high shear stress enhances plaque vulnerability through its biological impact on the endothelium. We investigated this hypothesis by studying the relationship between shear stress and strain, a marker for plaque composition, in human coronary arteries.

Calculation of a Shear Strain Parameter for a Three-Dimensional Fung-Type Exponential Model of the Arterial Wall Under Torsion

2007 ◽  
Author(s):  
J. Scott VanEpps ◽  
David A. Vorp
Keyword(s):  
Coronary Arteries ◽  
Arterial Wall ◽  
Cardiac Cycle ◽  
Three Dimensional ◽  
Exponential Model ◽  
Atherosclerotic Plaques ◽  
Atherosclerotic Lesions ◽  
Epicardial Surface ◽  
Mechanical Deformations ◽  
Systemic Nature

The distribution of atherosclerotic lesions within the coronary arteries is highly localized, despite the fact that risk factors (e.g., dyslipidemia) are systemic nature. The biomechanical milieu of the coronary arteries is unique in that in addition to cyclic pressure, circumferential distension and shear stress, they experience mechanical deformations of twisting, bending, and longitudinal stretching due to their tethering to the dynamic epicardial surface [1]. Biplane cineangiographic reconstruction studies have demonstrated that the coronary arteries experience as much as 20° of torsion during a cardiac cycle [2]. Spatial variations in shear and mural stresses caused by this deformation could account for the heterogeneity of atherosclerotic plaques.

scholarly journals Examination of Fluid-Structure Interaction in Stent Grafts and its Hemodynamic Implications

2018 ◽  
Author(s):  
Eric M. Looyenga ◽  
Stephen P. Gent
Keyword(s):  
Risk Factors ◽  
Shear Stress ◽  
Arterial Wall ◽  
The United States ◽  
Plaque Formation ◽  
Peripheral Arteries ◽  
Stent Grafts ◽  
Structure Interaction ◽  
Aneurysm Formation ◽  
Abdominal Aortic

Every year in the United States, 4,500 deaths occur from abdominal aortic aneurysm (AAA) rupture. Aneurysms develop when the arterial wall weakens. Many risk factors can contribute to aneurysm formation, including age, sex, ethnicity, smoking and hypertension [1]. AAAs are the most common form of aneurysm because the aorta experiences the highest wall shear stress (WSS) of any vessels in the human body. These aneurysms are 5–6% prevalent in men and 1–2% in women, both over 65 years of age [2]. In the aorta, high WSS causes plaque formation, but in peripheral arteries where the flow rate is lower, atherosclerosis can also trigger aneurysm formation.

Abstract 412: Apelin-13 Enhances Atherosclerotic Plaque Stability in Apoe-Deficient Mice

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Rodrigo A Fraga-Silva ◽  
Hugo Seeman ◽  
Fabrizio Montecucco ◽  
Analina R da Silva ◽  
Fabienne Burger ◽  
...  
Keyword(s):  
Shear Stress ◽  
Atherosclerotic Plaque ◽  
Experimental Period ◽  
Serum Levels ◽  
Lesion Size ◽  
Plaque Formation ◽  
Atherosclerotic Plaques ◽  
Plaque Stability ◽  
Atherosclerosis Development

Introduction: Atherosclerosis remains one of the main cause of death worldwide and substantial efforts have been made to identify novel approaches to improve the management of this disorder. Apelin is an endogenous peptidergic family with essential role on the cardiovascular hemostasis and pathologies. Recent studies pointed out a fundamental contribution of Apelin system on atherosclerosis development; however, such reports revealed contradictory data, and to date, it is difficult to accurately define the beneficial or deleterious role of Apelin in atherosclerosis. Objective: To better understand the role of Apelin system on atherosclerosis, we aimed to investigate the actions of Apelin-13 treatment on atherosclerotic plaques composition, focusing on features of plaque vulnerability. Methods: Apolipoprotein E gene-deleted mice (n=40) were fed with western-type diet for 11 weeks. Atherosclerotic plaque formation was induced in the carotid artery by a shear stress modifier device, which exposed the vessel to distinct patterns of shear stress, resulting in plaque formation with different composition. The mice were treated with Apelin-13 (2 mg/Kg/day) or vehicle for the last 3 weeks of experimental period. Results: Apelin-13 treatment did not change atherosclerotic plaque size in the aorta, neither altered the lipid content of low shear stress and oscillatory shear stress-induced plaques in the carotid. However, Apelin-13 remarkably ameliorated plaque stability by increasing intraplaque collagen content, which was associated with a reduction of MMP-9 expression. Furthermore, Apelin decreased cell infiltration (neutrophil and macrophage) and intraplaque reactive oxygen species content. Interestingly, Apelin-13 treatment reduced total cholesterol, LDL levels and free fatty acids serum levels, while HDL, triglycerides serum levels were not significantly changed. Conclusion: Apelin-13 treatment for 3 weeks did not alter the lesion size, but significantly enhances the stable phenotype of atherosclerotic plaques and improved serum lipid profile. These results indicate that activation of Apelin system enhances plaque stability.

A Cytochemical Study of Glucose-6-Phosphatase (G-6-PASE) in Cells Participating in Atherogenesis of Rabbit Aorta

1975 ◽  
Vol 33 ◽  
pp. 460-461
Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks
Keyword(s):  
Lipid Metabolism ◽  
New Zealand ◽  
Aortic Wall ◽  
Rabbit Aorta ◽  
Plaque Formation ◽  
Metabolic Changes ◽  
Atherosclerotic Plaques ◽  
Cytochemical Study ◽  
Cellular Alteration ◽  
New Zealand White Rabbits

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.

scholarly journals Study for the Design of a Protocol to Assess the Impact of Stress in the Quality of Life of Workers

2021 ◽  
Vol 18 (4) ◽  
pp. 1413
Author(s):  
Patricia Concheiro-Moscoso ◽  
Betania Groba ◽  
Francisco José Martínez-Martínez ◽  
María del Carmen Miranda-Duro ◽  
Laura Nieto-Riveiro ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Occupational Stress ◽  
Categorical Variables ◽  
Complete Study ◽  
Stress Coping Strategies ◽  
Personal Level ◽  
Stress Influences ◽  
The Impact ◽  
Positive Effect

(1) Background: Work stress is one of the most relevant issues in public health. It has a significant impact on health, especially the development of mental disorders, causing occupational imbalance. There is a growing interest in the development of tools with a positive effect on workers. To this end, wearable technology is becoming increasingly popular, as it measures biometric variables like heartbeat, activity, and sleep. This information may be used to assess the stress a person is suffering, which could allow the development of stress coping strategies, both at a professional and personal level. (2) Methods: This paper describes an observational, analytical, and longitudinal study which will be set at a research center in A Coruña, Spain. Various scales and questionnaires will be filled in by the participants throughout the study. For the statistical analysis, specific methods will be used to evaluate the association between numerical and categorical variables. (3) Discussion: This study will lay the foundation for a bigger, more complete study to assess occupational stress in different work environments. This will allow us to begin to understand how occupational stress influences daily life activity and occupational balance, which could directly enhance the quality of life of workers if the necessary measures are taken.

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