Suppressing unsteady flow in arterio-venous fistulae

Grechy, Lorenza; Iori, F.; Corbett, Richard; Shurey, Sandra; Gedroyc, W.; Duncan, Neill; G., C.; Vincent, Peter

doi:10.1063/1.5004190

Cited by 14 publications

(10 citation statements)

References 82 publications

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“…An alternative approach to observing the effect of geometry on the flow field and pathologic process is to define a geometry optimized for favorable flow conditions within a parameter space appropriate for AVFs and applying that in preclinical work to determine its effect on neointimal hyperplasia and fistula maturation. Preliminary work using this approach 42 has highlighted a potential geometry incorporating both arterial curvature and nonplanarity that is able to suppress potentially pathologic high-frequency flow unsteadiness.…”

Section: Discussionmentioning

confidence: 99%

Heterogeneity in the nonplanarity and arterial curvature of arteriovenous fistulas in vivo

Corbett

Grechy

Iori

et al. 2018

Journal of Vascular Surgery

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Section: Discussionmentioning

confidence: 99%

Heterogeneity in the nonplanarity and arterial curvature of arteriovenous fistulas in vivo

Corbett

Grechy

Iori

et al. 2018

Journal of Vascular Surgery

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“…Fulker et al [25] investigated the flow disturbance and turbulence induced by the dialysis needles in a patient specific fistula by computational fluid dynamics. Grechy et al [26] applied CFD and optimization to design a novel AVF configuration for the suppression of flow unsteadiness. However, direct measurement of these mechanical quantities in laboratory (in vivo or in vitro) are difficult and such data are not currently available in literature.…”

Section: Introductionmentioning

confidence: 99%

Simulation of blood flow past a distal arteriovenous-graft anastomosis at low Reynolds numbers

Bai

Zhu

2019

Physics of Fluids

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Patients with end-stage renal disease (ESRD) are usually treated by hemodialysis (HD) while waiting for kidney transplant. A common device for vascular access is arteriovenous graft (AVG). However, AVG failure induced by thrombosis has been plaguing dialysis practice for decades. Current studies indicate that the thrombosis is caused by intimal hyperplasia (IH) which is triggered by the abnormal flows and forces (e.g. wall shear stress) in the vein after AVG implant. Due to high level of complexity, in almost all of the existing works of modeling and simulation of the blood-flow vessel-AVG system the graft and blood-vessel are assumed to be rigid and immobile. Very recently we have found that the compliance of graft and vein can reduce flow disturbances and lower wall shear stress (WSS) (Z Bai and L Zhu, Computers & Fluids 181, pp. 403-415, 2019). In this paper, we apply the compliant model to investigate possible effects of several dimensionless parameters (AVG graft-vein diameter ratio R gv , AVG attaching angle θ, flow Reynolds numbers Re, and native vein speed V v ) on the flow and force fields near the distal AVG anastomosis at low Reynolds numbers (up to several hundreds). Our computational results indicate that the influences of the parameters R gv , θ, and Re lie largely on the graft and the influence of V v lies largely on the vein. In any case, the wall shear stress (WSS),

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“…While the agPCE‐based meta‐modelling approach used in this study could be used to efficiently propose a haemodynamically optimised graft design, other meta‐modelling approaches have also been suggested. For instance, in a study by Grechy et al 31 a Kriging‐based meta‐modelling approach was used to successfully optimise haemodynamics in an arteriovenous fistula model using a similar number of computationally expensive CFD simulations as were used in this study. However, it is unclear if the method used by Grechy et al also allows for a global sensitivity analysis prior to optimisation.…”

Section: Discussionmentioning

confidence: 99%

Haemodynamic optimisation of a dialysis graft design using a global optimisation approach

Quicken

Delhaas

Mees

et al. 2020

Numer Methods Biomed Eng

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Disturbed flow and the resulting non‐physiological wall shear stress (WSS) at the graft‐vein anastomosis play an important role in arteriovenous graft (AVG) patency loss. Modifying graft geometry with helical features is a popular approach to minimise the occurrence of detrimental haemodynamics and to potentially increase graft longevity. Haemodynamic optimisation of AVGs typically requires many computationally expensive computational fluid dynamics (CFD) simulations to evaluate haemodynamic performance of different graft designs. In this study, we aimed to develop a haemodynamically optimised AVG by using an efficient meta‐modelling approach. A training dataset containing CFD evaluations of 103 graft designs with helical features was used to develop computationally low‐cost meta‐models for haemodynamic metrics related to graft dysfunction. During optimisation, the meta‐models replaced CFD simulations that were otherwise needed to evaluate the haemodynamic performance of possible graft designs. After optimisation, haemodynamic performance of the optimised graft design was verified using a CFD simulation. The obtained optimised graft design contained both a helical graft centreline and helical ridge. Using the optimised design, the magnitude of flow disturbances and the size of the anastomotic areas exposed to non‐physiological WSS was successfully reduced compared to a regular straight graft. Our meta‐modelling approach allowed to reduce the total number of CFD model evaluations required for our design optimisation by approximately a factor 2000. The applied efficient meta‐modelling technique was successful in identifying an optimal, helical graft design at relatively low computational costs. Future studies should evaluate the in vivo benefits of the developed graft design.

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Suppressing unsteady flow in arterio-venous fistulae

Cited by 14 publications

References 82 publications

Heterogeneity in the nonplanarity and arterial curvature of arteriovenous fistulas in vivo

Heterogeneity in the nonplanarity and arterial curvature of arteriovenous fistulas in vivo

Simulation of blood flow past a distal arteriovenous-graft anastomosis at low Reynolds numbers

Haemodynamic optimisation of a dialysis graft design using a global optimisation approach

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