Blood flow numerical modeling in catheterized arteries with mild stenosis

Stenosis, characterized by the narrowing of blood vessels due to plaque accumulation, significantly impacts blood flow dynamics and poses risks such as blood clot formation. This study investigates blood flow in a mildly stenosed, catheterized artery, modeled as a two-dimensional axisymmetric tube, utilizing the incompressible viscous Navier–Stokes equations. Blood is treated as a non-Newtonian fluid, with the Carreau model applied to capture its rheological properties. The Semi-Implicit Method for Pressure-Linked Equations method, renowned for its computational efficiency in solving incompressible flow equations, is employed alongside the finite volume method to ensure local conservation of mass, momentum, and energy. Validation through a planar Poiseuille flow simulation and experimental data demonstrated concordance between numerical and analytical/experimental results, affirming the accuracy of the velocity profile for laminar flow. Subsequent real-case analysis involved a bifurcating artery in a 60-year-old male with atherosclerosis. Findings revealed that the presence of plaques increased wall shear stress (up to 5.5 Pa) at the throat of the stenosis, accompanied by low wall shear stress regions (approximately 0.5 Pa) downstream. A sharp pressure gradient was observed, with upstream pressure reaching 20 Pa and dropping significantly downstream of the stenosis. Velocity distribution showed peak values of approximately 0.2 m/s in the stenosed artery compared to 0.12 m/s in the non-stenosed case. Flow disturbances, including vortex formation and recirculation zones, were identified downstream of the stenosis, contributing to potential vessel wall corrosion and plaque instability. The study concludes that plaques induce significant hemodynamic changes, including low flow velocity regions, altered wall shear stress, and pressure gradients, which can precipitate plaque rupture and atherosclerosis.