End-stage renal disease (ESRD) is a life-threatening condition that affects over 10%
of the global population, necessitating hemodialysis (HD) for patients awaiting a
kidney transplant. The arteriovenous fistula (AVF) is the preferred access for HD
treatment, but it is often prone to complications that jeopardize its effectiveness and
pose serious risks like thrombosis. AVF failure primarily stems from non-maturation
of the AVF and post-maturation stenosis. Previous in-silico studies have suggested
that ...
End-stage renal disease (ESRD) is a life-threatening condition that affects over 10%
of the global population, necessitating hemodialysis (HD) for patients awaiting a
kidney transplant. The arteriovenous fistula (AVF) is the preferred access for HD
treatment, but it is often prone to complications that jeopardize its effectiveness and
pose serious risks like thrombosis. AVF failure primarily stems from non-maturation
of the AVF and post-maturation stenosis. Previous in-silico studies have suggested
that these events are influenced by changes in the vascular lumen cross-sectional area
and the degree of the anastomotic angle, which could be correlated with the patient’s
inflammatory state. However, literature on this subject is limited, focusing solely on
individual patient-specific models in Computational Fluid Dynamics (CFD) simulations, neglecting specific boundary conditions and the patients’ health status. This
study aims to establish a foundation for constructing an advanced numerical model
that accounts for the clinical, hemodynamic, and morphological characteristics of
patients. It includes nine patient-specific geometries, with CFD simulation results
presented for three of them while the others are still being analyzed. The models
were created based on Magnetic Resonance Imaging (MRI) obtained at three time
periods (1 week, 1 month, and 6 months) after surgery, which are critical for understanding the development and temporal evolution of the AVF. Boundary conditions
were derived from ultrasound scans taken at these specific time points. Additionally,
a mathematical 3-element Windkessel model was utilized, taking into account the
patient’s classification as normotensive or hypertensive to estimate its parameters.
No previous study has examined such a large number of patients or conducted a
comprehensive temporal follow-up while also considering the patients’ health status. Specific AVF geometries and their evolution over time were found to impact
the flow characteristics in patients. The juxta-anastomotic section was identified
as the area most affected by flow in cases where the angle of the anastomosis was
not tortuous describing a ’U-shape’, exhibiting higher magnitude and distribution
of Wall Shear Stress (WSS) and greater velocity magnitude.
+
