Experimental and Computational Analysis of a Typical Arterio-Venous Fistula

摘要

End Stage Renal Disease (ESRD) is the final stage of kidneyfailure where the kidneys are no longer able to perform theirregulatory functions. Haemodialysis is the primary form oftreatment for ESRD. Treatment requires vascular access to theblood stream with a sufficient increase in blood flow rates foreffective dialysis. This is often achieved through the surgicalanastomosis between the radial artery and cephalic vein knownas an arteriovenous fistula (AVF). Complications arise from thisincluding stenosis and thrombosis. To gain insight and understandingof these complications, an idealised AVF geometry hasbeen modelled in CFD and also studied experimentally usingparticle imaging velocimetry (PIV). Results obtained showedsignificant flow disturbances with abnormally high and low valuesof wall shear stress (WSS). Correlation of trends in thesehaemodynamic factors at sites prone to failure supports hypothesessuggesting low WSS is the key factor in triggeringcomplications leading to access failure. Other trends such asWSS gradients and oscillations were noted; however these characteristicsrequire further quantification for investigation.