An experimental and computational study of the inferior vena cava hemodynamics under respiratory-induced collapse of the infrarenal IVC

Tedaldi, Elisabetta; Montanari, C; Aycock, Kenneth I.; Sturla, Francesco; Redaelli, Alberto; Manning, Keefe B.

doi:10.1016/j.medengphy.2018.02.003

Cited by 17 publications

(13 citation statements)

References 39 publications

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“…In particular, f1 = 1:871 m/s, f2 = 1:849 m/s and f3 = 1:8209 m/s were found. The mesh sensitivity analysis revealed that the solution computed by the fine was relatively insensitive to further mesh refinement, and the grid chosen herein was the fine one, corresponding to a grid GCI1,2 of approximately 3.4%, which is in agreement with GCIs reported in recent studies (Craven et al, 2009;Tedaldi et al, 2018).…”

Section: Conflict Of Interest Statementsupporting

confidence: 81%

Evaluation of 4D flow MRI-based non-invasive pressure assessment in aortic coarctations

Saitta

Pirola

Piatti

et al. 2019

Journal of Biomechanics

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Severity of aortic coarctation (CoA) is currently assessed by estimating trans-coarctation pressure drops through cardiac catheterization or echocardiography. In principle, more detailed information could be obtained non-invasively based on space-and time-resolved magnetic resonance imaging (4D flow) data. Yet the limitations of this imaging technique require testing the accuracy of 4D flow-derived hemodynamic quantities against other methodologies. With the objective of assessing the feasibility and accuracy of this non-invasive method to support the clinical diagnosis of CoA, we developed an algorithm (4DF-FEPPE) to obtain relative pressure distributions from 4D flow data by solving the Poisson pressure equation. 4DF-FEPPE was tested against results from a patient-specific fluid-structure interaction (FSI) simulation, whose patient-specific boundary conditions were prescribed based on 4D flow data. Since numerical simulations provide noise-free pressure fields on fine spatial and temporal scales, our analysis allowed to assess the uncertainties related to 4D flow noise and limited resolution. 4DF-FEPPE and FSI results were compared on a series of cross-sections along the aorta. Bland-Altman analysis revealed very good agreement between the two methodologies in terms of instantaneous data at peak systole, end-diastole and time-averaged values: biases (means of differences) were +0.4 mmHg,-1.1 mmHg and +0.6 mmHg, respectively. Limits of agreement (2 SD) were ±0.978 mmHg, ±1.06 mmHg and ±1.97 mmHg, respectively. Peak-to-peak and maximum trans-coarctation pressure drops obtained with 4DF-FEPPE differed from FSI results by 0.75 mmHg and-1.34 mmHg respectively. The present study considers important validation aspects of non-invasive pressure difference estimation based on 4D flow MRI, showing the potential of this technology to be more broadly applied to the clinical practice.

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Section: Conflict Of Interest Statementsupporting

confidence: 81%

Evaluation of 4D flow MRI-based non-invasive pressure assessment in aortic coarctations

Saitta

Pirola

Piatti

et al. 2019

Journal of Biomechanics

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“…The mesh was refined until differences in these parameters between the chosen mesh and a finer mesh were less than 3.5%. The grid convergence index (CGI) was also calculated, and the chosen mesh had a CGI of < 5.5% for velocities and TAWSS at all selected planes, in line with previous studies (Craven et al 2009;Tedaldi et al 2018). Further details on the mesh sensitivity study can be found in the supplementary material.…”

Section: Methodsmentioning

confidence: 53%

The influence of inlet velocity profile on predicted flow in type B aortic dissection

Armour

Guo

Pirola

et al. 2020

Biomech Model Mechanobiol

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In order for computational fluid dynamics to provide quantitative parameters to aid in the clinical assessment of type B aortic dissection, the results must accurately mimic the hemodynamic environment within the aorta. The choice of inlet velocity profile (IVP) therefore is crucial; however, idealised profiles are often adopted, and the effect of IVP on hemodynamics in a dissected aorta is unclear. This study examined two scenarios with respect to the influence of IVP—using (a) patient-specific data in the form of a three-directional (3D), through-plane (TP) or flat IVP; and (b) non-patient-specific flow waveform. The results obtained from nine simulations using patient-specific data showed that all forms of IVP were able to reproduce global flow patterns as observed with 4D flow magnetic resonance imaging. Differences in maximum velocity and time-averaged wall shear stress near the primary entry tear were up to 3% and 6%, respectively, while pressure differences across the true and false lumen differed by up to 6%. More notable variations were found in regions of low wall shear stress when the primary entry tear was close to the left subclavian artery. The results obtained with non-patient-specific waveforms were markedly different. Throughout the aorta, a 25% reduction in stroke volume resulted in up to 28% and 35% reduction in velocity and wall shear stress, respectively, while the shape of flow waveform had a profound influence on the predicted pressure. The results of this study suggest that 3D, TP and flat IVPs all yield reasonably similar velocity and time-averaged wall shear stress results, but TP IVPs should be used where possible for better prediction of pressure. In the absence of patient-specific velocity data, effort should be made to acquire patient’s stroke volume and adjust the applied IVP accordingly.

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“…Considering the relatively low pulsatility of the IVC blood flow with low pressure, the IVC tube is assumed to be rigid, and the flow rate is constant, which is adequate for determining the main hemodynamic characteristics herein but only provides the first insight. However, the more actual factors including the eventual side branches, the IVC deformation and the respirationinduced IVC collapse that affect the simulation results of IVC blood flow greatly should be considered in the next step (Aycock et al, 2016;Tedaldi et al, 2018). Additionally, although the mean boundary conditions are used and acceptable for the present study, these conditions deviate from the reality (Craven et al, 2018) and should be further improved.…”

Section: Study Limitationsmentioning

confidence: 99%

“…This work focuses on comparing the flow features of the normal, reverse and different open states of the VTCF deployed in IVC using in silico CFD models. Complicated physiological factors, such as the eventual side branches, the IVC deformation and the respiration-induced IVC collapse (Aycock et al, 2016;Tedaldi et al, 2018), are temporarily neglected. Therefore, some primary assumptions need to be made for the CFD simulations.…”

Section: Cfd Modelsmentioning

confidence: 99%

Hemodynamic Analysis of VenaTech Convertible Vena Cava Filter Using Computational Fluid Dynamics

Wang

Huang

Zhou

et al. 2020

Front. Bioeng. Biotechnol.

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The VenaTech convertible filter (VTCF) has been widely used as an inferior vena cava (IVC) filter to prevent fatal pulmonary embolism in patients. However, its hemodynamics that greatly affect the filter efficacy and IVC patency are still unclear. This paper uses computational fluid dynamics with the Carreau model to simulate the non-Newtonian blood flows around the VTCF respectively deployed in the normal, reverse and three converted states in an IVC model. The results show that the prothrombotic stagnation zones are observed downstream from the normal, reverse and small open VTCFs, with the streamwise length is nearly eight times the IVC diameter. The no-slip boundary conditions of the thin-wire VTCF arms lead to the "viscous block" effect. The viscous block accelerates the blood flow by 5-15% inside the IVC and enhances the filter wall shear stress up to nearly 20 times that of the IVC only, which contributes to clot capture and thrombus lysis. The relative flow resistance is defined to evaluate the filter-induced resistance on the IVC blood flow that can be regarded as an index of IVC patency with the filter deployment. The flow resistance of the normal VTCF deployment increases dramatically by more than 60% compared with that of the IVC only and is a little higher (6%) than that of the reverse case. As the VTCF converts to a fully open configuration, the flow resistance gradually decreases to that of no filter. This work shows that even very thin VTCF arms can result in the viscous block effect and may cause significant hemodynamic impacts on clot capture, potential thrombosis and flow impedance inside the IVC. The present study also shows that CFD is a valuable and feasible in silico tool for analyzing the IVC filter hemodynamics to complement in vivo clinical and in vitro experimental studies.

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An experimental and computational study of the inferior vena cava hemodynamics under respiratory-induced collapse of the infrarenal IVC

Cited by 17 publications

References 39 publications

Evaluation of 4D flow MRI-based non-invasive pressure assessment in aortic coarctations

Evaluation of 4D flow MRI-based non-invasive pressure assessment in aortic coarctations

The influence of inlet velocity profile on predicted flow in type B aortic dissection

Hemodynamic Analysis of VenaTech Convertible Vena Cava Filter Using Computational Fluid Dynamics

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