Effects of wall compliance on multiharmonic pulsatile flow in idealized cerebral aneurysm models: comparative PIV experiments

Abstract: The hemodynamics of intracranial aneurysm (IA) comprise complex phenomena that influence the IA’s growth and rupture risk. It has long been argued in in silico studies of IA hemodynamics that wall compliance could be neglected, because it does not alter the hemodynamic patterns. The purpose of this work is to investigate the effect of wall compliance on IA hemodynamic patterns and flow field variables. We conducted comparative in vitro laser PIV measurements on rigid silicone and elastic PVA-H models of side-wall IA. In the first study of its kind, the interaction between wall dynamics and IA hemodynamics is investigated experimentally at high spatio-temporal resolution. It is evidently shown that wall compliance affects the phase-shift, flow rate and pressure damping, velocity and vorticity fields inside the aneurysm in space and time. Near-wall velocity field, which affects vascular endothelial cells in reality, was found to have larger oscillations in the compliant model, leading to higher turbulent kinetic energy. Wall shear stress was also affected by wall compliance, with lower time average values but larger temporal variations. These differences emphasize the importance of modeling the compliance behavior of cerebral arteries in the study of aneurysms and their treatment. Graphic abstract: [Figure not available: see fulltext.]