scholarly journals High Wall Shear Stress Is Related to Atherosclerotic Plaque Rupture in the Aortic Arch of Patients with Cardiovascular Disease: A Study with Computational Fluid Dynamics Model and Non-Obstructive General Angioscopy

2020 ◽  
Author(s):  
Keisuke Kojima ◽  
Takafumi Hiro ◽  
Yutaka Koyama ◽  
Akihito Ohgaku ◽  
Hidesato Fujito ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Cardiovascular Disease ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Atherosclerotic Plaque ◽  
Plaque Rupture ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Atherosclerotic Plaque Rupture

scholarly journals Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model

2016 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Ozkan Adiguzel ◽  
Mehmet Gokhan Gokcen ◽  
Ali Bahadir Olcay
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Root Canal ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Tilting Angle ◽  
Wall Shear

Aim: The Irrigant flow dynamics has strong influence on the root canal cleaning effectiveness. The aim of this study was to evaluate the effect of needle tilting angle on irrigant flow inside a prepared root canal during final irrigation with a side-vented needle using a validated Computational Fluid Dynamics (CFD) model. Methodology: To analyze the irrigant flow a CFD model with tilting angles of 0 and 2 degrees was created. The irrigant flow in the apical root canal was simulated. Computations were carried out for two selected flow rates of 0.26 and 0.78 mL/s to evaluate the velocity and turbulence quantities along the solution domain. Results: In addition to velocity and pressure distribution at the apex, wall shear stress distribution, vorticity and turbulent intensity results were obtained for needle tilting angle of 0 and 2 degrees. In the case of turbulent flows where the flow rate was higher, irrigation is better; however, higher apical pressures were observed for both tilting angles. Although the effect of tilting angle of two degrees for laminar flow was slightly better than zero degrees, the effect of tilting was significant for the turbulent flow case. Wall shear stress distribution, vorticity and turbulent intensity results were consistent with each other. Conclusions: A small tilting angle of 2 degrees had an effect on irrigation effectiveness which could be clearly observed from the wall shear stress, vorticity and velocity distribution results. The velocity distribution results obtained at the symmetry plane should be evaluated with the wall shear stress values together to observe the complete fluid dynamics structure inside the root canal.  How to cite this article: Adiguzel O, Gokcen MG, Olcay AB. Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model. Int Dent Res 2016;6:1-8.  Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Relation Between Wall Shear Stress and Plaque Necrotic Core in the Left Coronary Arteries of Patients Using Intravascular Ultrasound and Computational Fluid Dynamics

2008 ◽  
Author(s):  
Jin Suo ◽  
Michael McDaniel ◽  
Habib Samady ◽  
Don Giddens
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Intravascular Ultrasound ◽  
Coronary Arteries ◽  
Plaque Rupture ◽  
Necrotic Core ◽  
Elastic Membrane ◽  
Wall Shear

Atherosclerosis is a disease characterized by arterial plaques that include several components of which the necrotic core has been recognized as an important indicator of the likelihood of plaque rupture [1]. In the present study, the relation of hemodynamic wall shear stress (WSS) to necrotic core localization in the left coronary artery of patients was investigated using intravascular ultrasound (IVUS) and computational fluid dynamics (CFD). An innovative 3D measuring technique was developed and was successfully used to reconstruct coronary arteries in patients based on angiographic images and echo ultrasound slices from IVUS. The reconstruction includes lumen, external elastic membrane (EEM) and spatial distribution of plaque components such as fibrous tissue, necrotic core and calcium. WSS distribution in the vessel segment was computed by CFD, and the relative locations of necrotic core and WSS were determined. Results to date support the hypothesis that a greater necrotic core in coronary plaques is associated with areas of low WSS. The methodology developed has implications for the study of plaque progression and the prediction of likelihood of plaque rupture.

6125High wall shear stress predicts plaque rupture of the aortic arch: computational fluid dynamics model and non-obstructive general angioscopy study

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Kojima ◽  
T Hiro ◽  
Y Ebuchi ◽  
T Morikawa ◽  
S Migita ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Aortic Arch ◽  
Plaque Rupture ◽  
Aortic Atherosclerosis ◽  
3D Ct ◽  
Significant Difference ◽  
Wall Shear

Abstract Background Wall shear stress (WSS) has been considered as a major determinant of aortic atherosclerosis. Recently, non-obstructive general angioscopy (NOGA) was developed to be able to visualize a variety of its atherosclerotic pathology, including in vivo ruptured plaque (RP) in the aorta. We, therefore, investigated the relationship between NOGA derived RP in the aortic arch and the stereographic distribution of WSS by using computational fluid dynamics modeling (CFD) on three-dimensional CT angiography (3D-CT). Methods We investigated 30 consecutive patients who underwent 3D-CT before and NOGA during coronary angiography. WSS in the aortic arch was measured with an application of CFD based on finite element method by using uniform inlet and outlet flow conditions. Aortic RP was detected by NOGA. Results The maximum and mean values of WSS were 67.2±29.2 Pa and 2.4±0.6 Pa. A total of 18 RPs was detected by NOGA. The patients with a distinct RP showed a significantly higher maximum WSS in the whole aortic arch, and the greater and lesser curvature of the aortic arch than those without it (73.3±29.0 Pa vs 50.4±15.2 Pa, p=0.035, 95.0±27.5 Pa vs 42.8±25.2 Pa, p=0.003, 70.8±29.3 Pa vs 46.1±11.9 Pa, p=0.013, respectively), whereas there was no significant difference in the mean WSS between those with and without it. In a multivariate analysis, the maximum value of WSS was an independent predictor of RP in the aortic arch (odds ratio 1.05, 95% confidence interval 1.01–1.13, p=0.019). Representative picture of WSS and NOGA Conclusions Aortic RP detected by NOGA was strongly associated with the higher maximum WSS in the aortic arch derived by CFD using 3D-CT. Maximum WSS may explain the underlying mechanism of not only aortic atherosclerosis, but also aortic RP.

scholarly journals Potential relationship between high wall shear stress and plaque rupture causing acute coronary syndrome

2021 ◽  
Author(s):  
Yusuke Fukuyama ◽  
Hiromasa Otake ◽  
Fumiyasu Seike ◽  
Hiroyuki Kawamori ◽  
Takayoshi Toba ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Acute Coronary Syndrome ◽  
Multivariate Analysis ◽  
Wall Shear Stress ◽  
Plaque Rupture ◽  
High Wall Shear Stress ◽  
Coronary Syndrome ◽  
Fibrous Cap

Abstract Purpose: To investigate the detailed relationship between high wall shear stress (WSS) and plaque rupture (PR) in longitudinal and circumferential locations.Methods: Overall, 100 acute coronary syndrome (ACS) patients whose culprit lesions had PR documented by optical coherence tomography (OCT) were enrolled. Lesion-specific three-dimensional coronary artery models were created using OCT data. At the ruptured portion, tracing of the luminal edge of the residual fibrous cap was smoothly extrapolated to reconstruct the luminal contour before PR. Then, WSS was computed from computational fluid dynamics analysis. PR was classified into central-PR and lateral-PR according to the disrupted fibrous cap location.Results: In the longitudinal 3-mm segmental analysis, multivariate analysis demonstrated that higher WSS in the upstream segment was independently associated with Upstream-PR and a thinner fibrous cap was independently associated with Downstream-PR. In PR cross-sections, PR region had a significantly higher average WSS than the non-PR region. In the cross-sectional analysis, peak WSS was most frequently observed in the lateral region (66.7%) in lateral-PR, whereas that in central-PR was most frequently observed in the central region (70%). Multivariate analysis demonstrated that the presence of peak WSS at the lateral region, thinner broken fibrous cap, and larger lumen area were independently associated with lateral-PR, while the presence of peak WSS at the central region and thicker broken fibrous cap were independently associated with central-PR.Conclusions: A combined approach with computational fluid dynamics simulation and morphological plaque evaluation by OCT might help predict future PR-induced ACS events.

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