Numerical simulation of the fluid structure interactions in a compliant patient‐specific arteriovenous fistula

Abstract

The objective of the study is to investigate numerically the fluid-structure interactions (FSI) in a patient-specific arteriovenous fistula (AVF) and analyze the degree of complexity that such a numerical simulation requires to provide clinically relevant information. The reference FSI simulation takes into account the non-Newtonian behavior of blood, as well as the variation in mechanical properties of the vascular walls along the AVF. We have explored whether less comprehensive versions of the simulation could still provide relevant results. The non-Newtonian blood model is necessary to predict the hemodynamics in the AVF because of the predominance of low shear rates in the vein. An uncoupled fluid simulation provides informative qualitative maps of the hemodynamic conditions in the AVF; quantitatively, the hemodynamic parameters are accurate within 20% maximum. Conversely, an uncoupled structural simulation with non-uniform wall properties along the vasculature provides the accurate distribution of internal wall stresses, but only at one instant of time within the cardiac cycle. The FSI simulation advantageously provides the time-evolution of both the hemodynamic and structural stresses. However, the higher computational cost renders a clinical use still difficult in routine.

Review of Experimental Modelling in Vascular Access for Hemodialysis

“…A similar study was done by researchers from the same group in 2014, to validate numerical simulations of non-Newtonian flow in a compliant, patient specific AVF (reported by Decorato et al [12]). In this case, a rigid, directly 3D-printed PMMA model was used for PIV measurements in a steady, Newtonian flow (waterglycerol mixture, 1.1 l/min).…”

“…Principle Quantity Measurement type pressure sensor [37,17,18,4,6,39,38,11,10,26] various pressure bulk, instantaneous, ≥ kHz flow sensor [35,37,17,18,6,39,38,11,10,26] various flow rate bulk, instantaneous, ≥ kHz LDV [35] optical velocity point, instantaneous, ≥ kHz VDUS [22,21] acoustic velocity point, average * , O(10) Hz PIV [4,19,12,2,27,15,28,3] optical velocity grid of points, instantaneous, O(10) Hz UIV [20] acoustic velocity grid of points, instantaneous, O(10 − 1000) Hz PLIF [3] optical concentration 2D plane, instantaneous, O(10) Hz CDUS [22,21] acoustic velocity 2D plane, average * , O(10) Hz Different methods exist to measure bulk pressure and flow rate, including Pitot tube-type and piezo-electric pressure sensors, and paddle wheel or ultrasoundbased flow rate sensors (for more information, see e.g. [36]).…”

“…Geometry Stiffness Sivanesan et al [35] Idealised Rigid Van Canneyt et al [37] Idealised, based on patient data Compliant Huberts et al [17,18] Idealised, based on patient data Compliant Botti et al [4] Patient-specific -Kharboutly et al [19] Patient-specific Rigid Decorato et al [12] Patient-specific Rigid Barber et al [2] Rigid Lwin et al [27] Idealised Rigid Browne et al [6] Idealised Rigid -Data not available Table 3 Hemodynamic conditions of AVF experiments reviewed (in order of discussion).…”

“…Water-glycerol (62-38%) -500-1300 [17,18] Water -5000 [4] Water-glycerol 550, 1000 220, 400 [19] Water-glycerol (60-40%) -1840, 2000, 2450 [12] Water-glycerol (70-30%) -1000…”

Finite element analysis of uncommonly large renal arteriovenous malformation—Adjacent renal cyst complex

“…More importantly, it was not possible to experimentally estimate its material characteristics. Knowing these parameters could provide more insight into the RAVM rupture by performing Fluid Solid Interaction simulations [31]. Thus, the focus of this study was restricted to the hemodynamics quantities which preceded the RAVM complications.…”