Optimizing venous anastomosis angle for arteriovenous graft with intimal hyperplasia using computational fluid dynamics

Abstract Vascular access (VA), a renal failure therapy, is often performed using an arteriovenous (AV) graft for patients with veins and arteries that cannot be connected with autologous blood vessels. However, VA using AV grafts changes blood flow in the vein and damages vessels, leading to failure due to intimal hyperplasia (IH). The change in blood flow due to AV graft depends on various conditions, such as the anastomosis angle, IH shape, and position. In our study, we simulated the blood flow near the anastomosis between the vein and AV graft and investigated the effect of the anastomosis angleon blood vessel damage under various IH formation conditions. Blood vessel damage was quantitatively evaluated using hemodynamic factors, such as wall shear stress (WSS) and oscillatory shear index (OSI). We considered the flow rate decrease owing to IH formation in the vein for a realistic simulation. Our results show that a smaller anastomosis angle reduces damage to blood vessels and prevents IH formation and growth. This result is valid regardless of IH progression, shape, and position. These results can contribute to the optimization of the anastomosis angle during VA surgery to improve a patient’s prognosis.