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In the current work, we present a descriptive fluid-structure interaction computational study of the end-to-side radio-cephalic arteriovenous fistula. This allows us to account for the different thicknesses and elastic properties of the radial artery and cephalic vein. The core of the work consists in simulating different arteriovenous fistula configurations obtained by virtually varying the anastomosis angle, i.e. the angle between the end of the cephalic vein and the side of the radial artery. Since the aim of the work is to understand the blood dynamics in the very first days after the surgical intervention, the radial artery is considered stiffer and thicker than the cephalic vein. Our results demonstrate that both the diameter of the cephalic vein and the anastomosis angle play a crucial role to obtain a blood dynamics without re-circulation regions that could prevent fistula failure. When an anastomosis angle close to the perpendicular direction with respect to the radial artery is combined with a large diameter of the cephalic vein, the recirculation regions and the low Wall Shear Stress (WSS) zones are reduced. Conversely, from a structural point of view, a low anastomosis angle with a large diameter of the cephalic vein reduces the mechanical stress acting on the vessel walls. • Fluid-structure interaction analysis for different configurations of the arteriovenous fistula. • Mismatch of the arterial and venous Young's moduli and different vessel thicknesses. • Real reconstruction of the shape of the anastomosis region. • The diameter of the cephalic vein drastically influences the hemodynamics. [ABSTRACT FROM AUTHOR]

Pulmonary valve replacement (PVR) consists of substituting a patient's original valve with a prosthetic one, primarily addressing pulmonary valve insufficiency, which is crucially relevant in Tetralogy of Fallot repairment. While extensive clinical and computational literature on aortic and mitral valve replacements is available, PVR's post‐procedural haemodynamics in the pulmonary artery and the impact of prosthetic valve dynamics remain significantly understudied. Addressing this gap, we introduce a reduced Fluid–Structure Interaction (rFSI) model, applied for the first time to the pulmonary valve. This model couples a three‐dimensional computational representation of pulmonary artery haemodynamics with a one‐degree‐of‐freedom model to account for valve structural mechanics. Through this approach, we analyse patient‐specific haemodynamics pre and post PVR. Patient‐specific geometries, reconstructed from CT scans, are virtually equipped with a template valve geometry. Boundary conditions for the model are established using a lumped‐parameter model, fine‐tuned based on clinical patient data. Our model accurately reproduces patient‐specific haemodynamic changes across different scenarios: pre‐PVR, six months post‐PVR, and a follow‐up condition after a decade. It effectively demonstrates the impact of valve implantation on sustaining the diastolic pressure gradient across the valve. The numerical results indicate that our valve model is able to reproduce overall physiological and/or pathological conditions, as preliminary assessed on two different patients. This promising approach provides insights into post‐PVR haemodynamics and prosthetic valve effects, shedding light on potential implications for patient‐specific outcomes. [ABSTRACT FROM AUTHOR]