Experimental and numerical analyses of the hemodynamics impact on real intracranial aneurysms: A particle tracking approach

• Vortical structures in an aneurysm are studied using particle tracking velocimetry. • The onset of vortex appearance is determined in a real intracranial aneurysm. • Flow structures and impingement areas are identified for physiological flow rates. • Hemodynamical analysis is numerically extended for transient flow in three patients. • PTV and numerics combination provides additional insight for medical treatment. This study investigates the impact of hemodynamics on real intracranial aneurysms (IAs) using experiments and computational fluid dynamics (CFD) simulations. A particle tracking velocimetry (PTV) approach was used to study the vortical structures inside a real aneurysm and validate numerical simulations performed at a steady regime for different flow rates. Moreover, this and two additional patient-specific cases have been numerically analyzed, focusing on flow patterns, wall shear stress (WSS), relative residence time (RRT), and oscillatory shear index (OSI) for transient studies. For the transient simulations, vorticity profiles indicated significant rotation of fluid particles in the neck and outlet arteries. TAWSS analysis revealed high WSS values in the bifurcation zone, neck, and middle cerebral artery (MCA), with variations among the patients. OSI and RRT plots provided insights into disturbed flow patterns, low or oscillatory WSS areas, and regions with prolonged residence time. This study shows great potential for combining PTV and CFD to obtain detailed insights into flow structures in aneurysms, which are crucial to developing effective treatments and interventions for IA management.