Mechanics-Oriented Coil Size Selection for an Internal Carotid Aneurysm With Fluid–Structure Interaction

Abstract

The coil intervention is a common aneurysm treatment strategy, but the effect of coil size on aneurysm hemodynamics and mechanics is not fully understood. In this paper, how different sizes of coils affect the hemodynamic and mechanical properties of a real internal carotid artery (ICA) aneurysm was investigated. A fluid–structure interaction (FSI) method based on the Arbitrary Lagrangian–Eulerian (ALE) approach was used to consider non-Newtonian blood flow, linear elastic arterial wall and simulations. It is indicated that with the increase of coil size, the hemodynamic parameters related to aneurysm such as wall shear stress (WSS), time-averaged WSS (TAWSS) and oscillatory shear index (OSI) decreased significantly. However, too large coils will compress the parent artery, produce high TAWSS areas in adjacent branches, and cause stress concentration on the aneurysm wall. Moreover, both the average displacement and von Mises stress of the aneurysm dome initially decrease and then increase with coil size. The appropriate size of the coil is beneficial to minimize displacement and stress by reducing blood flow velocity and vortices. The effects of different coil sizes were predicted by computational fluid dynamics (CFD), and the individualized treatment plan was adjusted according to the aneurysm morphology and hemodynamic characteristics. Our results provide a new theoretical basis for interventional therapy and help to promote the transformation of coil intervention from empirical filling to mechanics-oriented precision treatment.