Swirlgraft versus conventional straight graft as vascular access: a full CFD-analysis

Two 3D models of an arterio-venous graft, a connection between an artery and a vein as vascular access for hemodialysis, were studied. One model of a conventional straight loop graft, the other of a graft with helical configuration (e.g. SwirlGraft (Veryan Medical, London, UK)). The statement that the helical design reduces Intimal Hyperplasia (IH) formation was studied by evaluating low wall shear stress and high oscillatory shear stress zones next to the helicity flow index. The IH-inducing zones were reduced but were not eliminated and the helicity of the flow was increased. The statement that the SwirlGraft avoids stenosis should however be considered with care in clinical practice

A Novel Hydraulic Thick-walled Phantom for the Assessment of Left Ventricular Function

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A Novel Multiplane Scanning Stereo PIV Setup to Investigate Left Ventricular Flow

The spatiotemporal characteristics of the intraventricular flow field, and their evolution with time, are of (patho)physiological and clinical interest. This is shown in several recent in vivo studies, using modern medical imaging techniques. Intraventricular flow is also topic of biofluid mechanic research, in silico and in vitro. Particle image velocimetry (PIV) studies have been performed in hydraulic bench models to investigate the flow field inside a left ventricle (LV) replica in a two-dimensions. However, as the intraventricular flow has a complex 3D and unsteady structure. In this study therefore we present a novel experimental setup which allows 3D volume reconstruction of the flow field in a transparent pulsatile LV membrane model, in different controllable and repeatable physiological relevant hydrodynamic conditions. The setup was primarily designed and developed to facilitate consecutive stereoscopic measurements without repeating the complex and time consuming stereo calibration