The Effects of Geometric Variation from OCT-Derived 3D Reconstructions on Wall Shear Stress in a Patient-Specific Coronary Artery

2017 ◽  
pp. 1-13 ◽  
Author(s):  
Lachlan J. Kelsey ◽  
Carl Schultz ◽  
Karol Miller ◽  
Barry J. Doyle
Keyword(s):  
Shear Stress ◽  
Coronary Artery ◽  
Wall Shear Stress ◽  
Patient Specific ◽  
3D Reconstructions ◽  
Wall Shear ◽  
Geometric Variation

scholarly journals Wall shear stress gradient is independently associated with middle cerebral artery aneurysm development: a case-control CFD patient-specific study based on 77 patients

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mikołaj Zimny ◽  
Edyta Kawlewska ◽  
Anna Hebda ◽  
Wojciech Wolański ◽  
Piotr Ładziński ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Case Control ◽  
Independent Effect ◽  
Patient Specific ◽  
Aneurysm Formation ◽  
Wall Shear ◽  
Mca Aneurysm

Abstract Background Previously published computational fluid dynamics (CFD) studies regarding intracranial aneurysm (IA) formation present conflicting results. Our study analysed the involvement of the combination of high wall shear stress (WSS) and a positive WSS gradient (WSSG) in IA formation. Methods We designed a case-control study with a selection of 38 patients with an unruptured middle cerebral artery (MCA) aneurysm and 39 non-aneurysmal controls to determine the involvement of WSS, oscillatory shear index (OSI), the WSSG and its absolute value (absWSSG) in aneurysm formation based on patient-specific CFD simulations using velocity profiles obtained from transcranial colour-coded sonography. Results Among the analysed parameters, only the WSSG had significantly higher values compared to the controls (11.05 vs − 14.76 [Pa/mm], P = 0.020). The WSS, absWSSG and OSI values were not significantly different between the analysed groups. Logistic regression analysis identified WSS and WSSG as significant co-predictors for MCA aneurysm formation, but only the WSSG turned out to be a significant independent prognosticator (OR: 1.009; 95% CI: 1.001–1.017; P = 0.025). Significantly more patients (23/38) in the case group had haemodynamic regions of high WSS combined with a positive WSSG near the bifurcation apex, while in the control group, high WSS was usually accompanied by a negative WSSG (14/39). From the analysis of the ROC curve for WSSG, the area under the curve (AUC) was 0.654, with the optimal cut-off value −0.37 Pa/mm. The largest AUC was recognised for combined WSS and WSSG (AUC = 0.671). Our data confirmed that aneurysms tend to form near the bifurcation apices in regions of high WSS values accompanied by positive WSSG. Conclusions The development of IAs is determined by an independent effect of haemodynamic factors. High WSS impacts MCA aneurysm formation, while a positive WSSG mainly promotes this process.

scholarly journals Wall Shear Stress in Intracranial Self-Expanding Stents Studied Using Ultra-High-Resolution 3D Reconstructions

2008 ◽  
Vol 30 (3) ◽  
pp. 479-486 ◽  
Author(s):  
G. Benndorf ◽  
M. Ionescu ◽  
M.V. y Alvarado ◽  
J. Hipp ◽  
R. Metcalfe
Keyword(s):  
Shear Stress ◽  
High Resolution ◽  
Wall Shear Stress ◽  
3D Reconstructions ◽  
Wall Shear

scholarly journals Genetic correlates of wall shear stress in a patient-specific 3D-printed cerebral aneurysm model

2019 ◽  
Vol 11 (10) ◽  
pp. 999-1003 ◽  
Author(s):  
Michael R Levitt ◽  
Christian Mandrycky ◽  
Ashley Abel ◽  
Cory M Kelly ◽  
Samuel Levy ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Aneurysm ◽  
Cell Morphology ◽  
Patient Specific ◽  
Parent Vessel ◽  
3D Printed ◽  
Wall Shear ◽  
Dynamics Simulations

ObjectivesTo study the correlation between wall shear stress and endothelial cell expression in a patient-specific, three-dimensional (3D)-printed model of a cerebral aneurysm.Materials and methodsA 3D-printed model of a cerebral aneurysm was created from a patient’s angiogram. After populating the model with human endothelial cells, it was exposed to media under flow for 24 hours. Endothelial cell morphology was characterized in five regions of the 3D-printed model using confocal microscopy. Endothelial cells were then harvested from distinct regions of the 3D-printed model for mRNA collection and gene analysis via quantitative polymerase chain reaction (qPCR.) Cell morphology and mRNA measurement were correlated with computational fluid dynamics simulations.ResultsThe model was successfully populated with endothelial cells, which survived under flow for 24 hours. Endothelial morphology showed alignment with flow in the proximal and distal parent vessel and aneurysm neck, but disorganization in the aneurysm dome. Genetic analysis of endothelial mRNA expression in the aneurysm dome and distal parent vessel was compared with the proximal parent vessels. ADAMTS-1 and NOS3 were downregulated in the aneurysm dome, while GJA4 was upregulated in the distal parent vessel. Disorganized morphology and decreased ADAMTS-1 and NOS3 expression correlated with areas of substantially lower wall shear stress and wall shear stress gradient in computational fluid dynamics simulations.ConclusionsCreating 3D-printed models of patient-specific cerebral aneurysms populated with human endothelial cells is feasible. Analysis of these cells after exposure to flow demonstrates differences in both cell morphology and genetic expression, which correlate with areas of differential hemodynamic stress.

scholarly journals Effects of a Short-Term Left Ventricular Assist Device on Hemodynamics in a Heart Failure Patient-Specific Aorta Model: A CFD Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Wang ◽  
Junwei Wang ◽  
Jing Peng ◽  
Mingming Huo ◽  
Zhiqiang Yang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pressure Difference ◽  
Left Ventricular ◽  
Patient Specific ◽  
Short Term ◽  
Ventricular Assist ◽  
Left Ventricular Assist ◽  
Wall Shear ◽  
Hemodynamic Performance

Patients with heart failure (HF) or undergoing cardiogenic shock and percutaneous coronary intervention require short-term cardiac support. Short-term cardiac support using a left ventricular assist device (LVAD) alters the pressure and flows of the vasculature by enhancing perfusion and improving the hemodynamic performance for the HF patients. However, due to the position of the inflow and outflow of the LVAD, the local hemodynamics within the aorta is altered with the LVAD support. Specifically, blood velocity, wall shear stress, and pressure difference are altered within the aorta. In this study, computational fluid dynamics (CFD) was used to elucidate the effects of a short-term LVAD for hemodynamic performance in a patient-specific aorta model. The three-dimensional (3D) geometric models of a patient-specific aorta and a short-term LVAD, Impella CP, were created. Velocity, wall shear stress, and pressure difference in the patient-specific aorta model with the Impella CP assistance were calculated and compared with the baseline values of the aorta without Impella CP support. Impella CP support augmented cardiac output, blood velocity, wall shear stress, and pressure difference in the aorta. The proposed CFD study could analyze the quantitative changes in the important hemodynamic parameters while considering the effects of Impella CP, and provide a scientific basis for further predicting and assessing the effects of these hemodynamic signals on the aorta.

scholarly journals An MRI-based method to register patient-specific wall shear stress data to histology

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0217271 ◽  
Author(s):  
A. M. Moerman ◽  
K. Dilba ◽  
S. Korteland ◽  
D. H. J. Poot ◽  
S. Klein ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Patient Specific ◽  
Wall Shear
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