Spatial comparison between wall shear stress measures and porcine arterial endothelial permeability

Himburg, Heather A.; Grzybowski, Deborah M.; Hazel, Andrew L.; LaMack, Jeffrey A.; Li, Xue Mei; Friedman, Morton H.

doi:10.1152/ajpheart.00897.2003

Cited by 446 publications

(344 citation statements)

References 31 publications

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“…This is consistent with previous in vivo and experimental studies, which reported an inverse correlation between WSS and RT. 47,48 In the BTS, due to the unidirectional flow, there was a strong correlation between RT 1 and RT 2 , hence also between WSS and RT 2 . However, in the PA segment, there were many structures in the flow and the flow direction changed with the PDA/CS diameter.…”

Section: Discussionmentioning

confidence: 97%

A non-discrete method for computation of residence time in fluid mechanics simulations

2013

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Cardiovascular simulations provide a promising means to predict risk of thrombosis in grafts, devices, and surgical anatomies in adult and pediatric patients. Although the pathways for platelet activation and clot formation are not yet fully understood, recent findings suggest that thrombosis risk is increased in regions of flow recirculation and high residence time (RT). Current approaches for calculating RT are typically based on releasing a finite number of Lagrangian particles into the flow field and calculating RT by tracking their positions. However, special care must be taken to achieve temporal and spatial convergence, often requiring repeated simulations. In this work, we introduce a non-discrete method in which RT is calculated in an Eulerian framework using the advection-diffusion equation. We first present the formulation for calculating residence time in a given region of interest using two alternate definitions. The physical significance and sensitivity of the two measures of RT are discussed and their mathematical relation is established. An extension to a point-wise value is also presented. The methods presented here are then applied in a 2D cavity and two representative clinical scenarios, involving shunt placement for single ventricle heart defects and Kawasaki disease. In the second case study, we explored the relationship between RT and wall shear stress, a parameter of particular importance in cardiovascular disease. C 2013 AIP Publishing LLC. [http://dx

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Section: Discussionmentioning

confidence: 97%

A non-discrete method for computation of residence time in fluid mechanics simulations

2013

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“…High RRT values indicate regions of flow stagnation where endothelial dysfunction and high particle residence times are likely to be observed. 34 …”

Section: Analysis Of Balloon-expandable Coronary Stentsmentioning

confidence: 99%

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Martín¹,

Boyle²

2015

Cardiovasc Eng Tech

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Abstract-Several clinical studies have identified a strong correlation between neointimal hyperplasia following coronary stent deployment and both stent-induced arterial injury and altered vessel hemodynamics. As such, the sequential structural and fluid dynamics analysis of balloon-expandable stent deployment should provide a comprehensive indication of stent performance. Despite this observation, very few numerical studies of balloon-expandable coronary stents have considered both the mechanical and hemodynamic impact of stent deployment. Furthermore, in the few studies that have considered both phenomena, only a small number of stents have been considered. In this study, a sequential structural and fluid dynamics analysis methodology was employed to compare both the mechanical and hemodynamic impact of six balloon-expandable coronary stents. To investigate the relationship between stent design and performance, several common stent design properties were then identified and the dependence between these properties and both the mechanical and hemodynamic variables of interest was evaluated using statistical measures of correlation. Following the completion of the numerical analyses, stent strut thickness was identified as the only common design property that demonstrated a strong dependence with either the mean equivalent stress predicted in the artery wall or the mean relative residence time predicted on the luminal surface of the artery. These results corroborate the findings of the large-scale ISAR-STEREO clinical studies and highlight the crucial role of strut thickness in coronary stent design. The sequential structural and fluid dynamics analysis methodology and the multivariable statistical treatment of the results described in this study should prove useful in the design of future balloon-expandable coronary stents.

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“…In particular regions of low Wall Shear Stress (WSS), highly oscillatory flow, and low Lumen-to-Wall Oxygen Flux (LWOF), leading to wall hypoxia, are all implicated in the initiation of IH. [5][6][7][8][9][10][11][12][13][14][15][16][17] There have been various computational studies of blood flow within AVF and Arterio-Venous Grafts (AVG). In 2003, Loth et al 18 simulated blood flow within idealized AVG and compared results with those obtained in vivo.…”

Section: Introductionmentioning

confidence: 99%

Computational modelling of the interaction of shock waves with multiple gas-filled bubbles in a liquid

Betney

Tully²,

Hawker³

et al. 2015

Physics of Fluids

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This study presents a computational investigation of the interactions of a single shock wave with multiple gas-filled bubbles in a liquid medium. This work illustrates how multiple bubbles may be used in shock-bubble interactions to intensify the process on a local level. A high resolution front-tracking approach is used, which enables explicit tracking of the gas-liquid interface. The collapse of two identical bubbles, one placed behind the other is investigated in detail, demonstrating that peak pressures in a two bubble arrangement can exceed those seen in single bubble collapse. Additionally, a parametric investigation into the effect of bubble separation is presented. It is found that the separation distance has a significant effect on both the shape and velocity of the main transverse jet of the second bubble. Extending this analysis to effects of relative bubble size, we show that if the first bubble is sufficiently small relative to the second, it may become entirely entrained in the second bubble main transverse jet. In contrast, if the first bubble is substantially larger than the second, it may offer it significant protection from the incident shock. This protection is utilised in the study of a triangular array of three bubbles, with the central bubble being significantly smaller than the outer bubbles. It is demonstrated that, through shielding of bubbles until later in the collapse process, pressures over five times higher than the maximum pressure observed in the single bubble case may be achieved. This corresponds to a peak pressure that is approximately 40 times more intense than the incident shock wave. This work has applications in a number of different fields, including cavitation erosion, explosives, targeted drug delivery/intensification, and shock wave lithotripsy.

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Spatial comparison between wall shear stress measures and porcine arterial endothelial permeability

Cited by 446 publications

References 31 publications

A non-discrete method for computation of residence time in fluid mechanics simulations

A non-discrete method for computation of residence time in fluid mechanics simulations

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Computational modelling of the interaction of shock waves with multiple gas-filled bubbles in a liquid

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