Effect of dome size on flow dynamics in saccular aneurysms – A numerical study

Image-based Computational Fluid Dynamic (CFD) simulations of anatomical models of human arteries are gaining clinical relevance in present days. In this study, CFD is used to study flow behaviour and hemodynamic parameters in aneurysms, with a focus on the effect of geometric variations in the aneurysm models on the flow dynamics. A computational phantom was created using a 3D modelling software to mimic a spherical aneurysm. Hemodynamic parameters were obtained and compared with the available literature to validate. Further, flow dynamics is studied by varying the dome size of the aneurysm from 3.75 mm to 6.25 mm with an increment of 0.625 mm keeping the neck size constant. The aneurysm is assumed to be located at a bend in the arterial system. Computational analysis of the flow field is performed by using Navier – Stokes equation for laminar flow of incompressible, Newtonian fluid. Parameters such as velocity, pressure, wall shear stress (WSS), vortex structure are studied. It was observed that the location of the flow separation and WSS vary significantly with the geometry of the aneurysm. The reduction of WSS inside the aneurysm is higher at the larger dome sizes for constant neck size.