Left Ventricular Assist Devices: Impact of Flow Ratios on the Localisation of Cardiovascular Diseases Using Computational Fluid Dynamics

McElroy, Michael; Ruiz-Soler, Andres; Keshmiri, Amir

doi:10.1016/j.procir.2015.11.008

Cited by 12 publications

(8 citation statements)

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“…These resistance and capacitance values are based on measured blood pressure and flow rates, however, acquiring these model parameters can be a difficult task, often due to practical difficulties in the acquisition of pressure and flow data of all required sites, or the measurement data available is insufficient for accurately estimating these model parameters 14 . Hence, despite more reliable methods existing, it is still common amongst the cardiovascular research community to use simpler outlet BCs such as zero pressure [15][16][17][18][19][20][21][22] , flow ratios based on Murray's Law (ML) 20 and the combination of flow ratios based on ML and in vivo data 23,24 . To put this into some perspective, during the 2013 intracranial aneurysm rupture challenge, 46% of 26 participating CFD groups defined zero pressure at all outlets, 46% applied flow splits (either arbitrary values or based on ML), whilst 8% implemented a 3-Element Windkessel model 20 .…”

Section: Introductionmentioning

confidence: 99%

Impact of Using Conventional Inlet/Outlet Boundary Conditions on Haemodynamic Metrics in a Subject-Specific Rabbit Aorta

McElroy

Keshmiri

2017

Proc Inst Mech Eng H

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Computational fluid dynamics is a tool capable of accurately measuring metrics currently used to predict the behaviour of cardiovascular diseases. This study quantifies the impact various commonly used inlet and outlet boundary conditions have on various shear rate-based haemodynamic metrics currently used for predicting the localisation of cardiovascular diseases. Simulations are conducted on an accurately represented rabbit aorta configuration and comparison has been made against available in vivo data. The boundary conditions studied include two different inlet profiles, three outlet boundary conditions, and steady-state versus pulsatile flow cases. Large variations were found in the results, particularly when using different outlet boundary conditions, and the discrepancies were evaluated both quantitatively and qualitatively. The results clearly highlight the importance of the type of boundary condition used when simulating complex cardiovascular models. By restricting the attention to the flow within the aorta and the intercostal branches, the results suggest that prescribing transient simulation and fully developed flow at the inlet are not required. Furthermore, assuming the widely accepted low wall shear stress theory of Caro, it was found that Murray's law-based outlet boundary condition returns the most physiologically accurate results when compared to in vivo data.

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Section: Introductionmentioning

confidence: 99%

Impact of Using Conventional Inlet/Outlet Boundary Conditions on Haemodynamic Metrics in a Subject-Specific Rabbit Aorta

McElroy

Keshmiri

2017

Proc Inst Mech Eng H

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“…The localization of various lesions including atherosclerosis and thrombosis has been extensively studied and have shown to be related to different local haemodynamic metrics including some of the work of the present authors (Deyranlou et al 2020;Kabinejadian et al 2016;Keshmiri et al 2016;McElroy et al 2016a;McElroy and Keshmiri 2018;Ruiz-Soler et al 2017;Swanson et al 2020). These haemodynamic parameters can be directly derived from the flow velocity fields obtained by CFD-based simulation tools.…”

Section: Haemodynamic Parametersmentioning

confidence: 99%

“…Despite more reliable methods existing, it is still common amongst the cardiovascular research community to use simpler outlet BCs such as zero-pressure (Cheng et al 2014;Deyranlou et al 2020;Janiga et al 2015;Kabinejadian et al 2016;Karmonik et al 2014Karmonik et al , 2012bMcElroy et al 2016b;Moon et al 2014;Ruiz-Soler et al 2017;Shang et al 2015). Running 'Tests 0-6' using a conventional zero-pressure BC for all outlets produces significantly different results and misleading conclusions when compared against using a threeelement Windkessel model.…”

Section: Effects Of Using Conventional Zero-pressure Boundary Conditionmentioning

confidence: 99%

Impact of heart failure severity on ventricular assist device haemodynamics: a computational study

2020

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Purpose This computational fluid dynamics study investigates the necessity of incorporating heart failure severity in the preoperative planning of left ventricular assist device (LVAD) configurations, as it is often omitted from studies on LVAD performance. Methods A parametric study was conducted examining a common range of LVAD to aortic root flow ratios (LVAD/AR-FR). A normal aortic root waveform was scaled by 5-30% in increments of 5% to represent the common range of flow pumped by the left ventricle for different levels of heart failure. A constant flow rate from the cannula compensated for the severity of heart failure in order to maintain normal total aortic flow rate. Results The results show that LVAD/AR-FR can have a significant but irregular impact on the perfusion and shear stress-related haemodynamic parameters of the subclavian and carotid arteries. Furthermore, it is found that a larger portion of the flow is directed towards the thoracic aorta at the expense of the carotid and subclavian arteries, regardless of LVAD/AR-FR. Conclusion The irregular behaviour found in the subclavian and carotid arteries highlights the necessity of including the LVAD/ AR-FR in the preoperative planning of an LVAD configuration, in order to accurately improve the effects on the cardiovascular system post implantation.

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“…It is the number one cause of disease-related deaths, causing 17.3 million deaths across the World, and this number is expected to rise to a 23.6 million by the year 2030 [1,2]. While cardiovascular diseases paint such a picture in the globe, the Europe is also subject to a similar situation as they are the leading cause of death every year [3]. Among the cardiovascular diseases, particularly atherosclerosis is the leading cause of death in developed countries [4,5].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Effects of Arterial Geometries in Different Severities of Symmetrical Stenosis on Pressure Drop and Pump Power

Sonmez

Yildirim

Karagöz

et al. 2021

Preprint

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Biomedical studies is among the multidisciplinary studies attracting most interest in recent years. Blood and vessel interactions and consequent hemodynamic effects cause cardiovascular diseases. A testing setup constituted by a peristaltic pump (similar to the heart mechanism) system was installed. The purpose of the experimental study presented is to investigate the effect, pressure drop, peristaltic pump inlet and outlet pressure and most importantly, the amount of power consumed by the peristaltic pump regarding arterial stenosis severity with varying areal stenosis percentages. The tests were performed for the pulse values from 54 to 168 bpm by setting up models with 0%, 60%, 70% and 80% symmetrical stenosis severities. In the study, the pressure difference in the test area increased concomitantly with elevated pulse value and increased stenosis severity. This situation revealed that as the intensity of narrowing increases in vessels, the narrowing space differential pressure increases, and this amount increases even more with increased exertion. The pressure at the peristaltic pump outlet increased concomitantly with elevated pulse value and increased stenosis severity. The peristaltic pump overworked to overcome the increased differential pressure related to the increased pulse value and stenosis severity. This result of the experimental data reveals the necessity to avoid activities requiring high pulse in human arteries similarly with a high percentage of stenosis.

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Left Ventricular Assist Devices: Impact of Flow Ratios on the Localisation of Cardiovascular Diseases Using Computational Fluid Dynamics

Cited by 12 publications

References 0 publications

Impact of Using Conventional Inlet/Outlet Boundary Conditions on Haemodynamic Metrics in a Subject-Specific Rabbit Aorta

Impact of Using Conventional Inlet/Outlet Boundary Conditions on Haemodynamic Metrics in a Subject-Specific Rabbit Aorta

Impact of heart failure severity on ventricular assist device haemodynamics: a computational study

Experimental Investigation of the Effects of Arterial Geometries in Different Severities of Symmetrical Stenosis on Pressure Drop and Pump Power

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