Fluid Flow Analysis of Pulmonary Hypertension in End-Stage Renal Disease: A Novel Alternative Methods-Driven Case Study

Pulmonary hypertension (PH) is a serious condition affecting patients with end-stage renal disease (ESRD), yet the hemodynamic mechanisms underlying development remain poorly understood. Novel alternative methods (NAMs), such as computational fluid dynamics (CFD), provide a powerful and ethical approach to investigate vascular physiology using patient-specific data. We developed a CFD model of the pulmonary artery (PA) informed by noninvasive magnetic resonance imaging (MRI) from an ESRD patient to characterize flow dynamics and wall shear metrics relevant to PH. Simulations were performed using image-based geometry, and velocity fields, wall shear stress (WSS), time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) were quantified. Results demonstrated physiologically consistent flow distributions, with higher velocities localized near outlet regions and lower velocities in branches. Spatially averaged TAWSS was approximately 9 dyn/cm2, in agreement with previously reported ranges. OSI values were low across the pulmonary vasculature, suggesting limited flow reversal. Together, these results highlight the feasibility of using patient-specific CFD to capture PA hemodynamics in ESRD and demonstrate consistency with published physiological values. This framework demonstrates the utility of NAMs to provide insight into complex biomechanical systems and a foundation for future studies seeking to clarify mechanistic links between ESRD development, arteriovenous fistula (AVF) creation, and eventual PH development, ultimately informing development of patient-specific diagnostic and therapeutic strategies. As NAMs gain regulatory and scientific traction, approaches like this will play an important role in reducing reliance on animal models while enabling ethically responsible, patient-specific discovery in cardiovascular research.