Influence of morphological parameters on hemodynamics in internal carotid artery bifurcation aneurysms

Abstract

Recent advancements in medical imaging techniques have enabled the accurate identification of unruptured intracranial aneurysms. To facilitate a proper patient management strategy, it is important to develop suitable mathematical models for their rupture prediction. To this end, the development of high-fidelity computational fluid dynamics (CFD) simulations with patient-specific boundary conditions will be useful in providing reliable hemodynamic parameters. In recent review articles, researchers have pointed out that, among several clinical and image-based indicators, morphological parameters, such as aspect ratio (AR) and size ratio (SR) of the aneurysm, correlated consistently with the rupture mechanism. However, it is not clear how these morphological indicators influence the hemodynamics-based CFD predictions. In the present work, the effect of these top-ranked morphological parameters on aneurysm hemodynamics and rupture prediction is investigated. Three patient-specific models have been used for analysis with the patient-specific inlet boundary conditions. We found that with an increase in AR and SR, the maximum value of wall shear stress (WSS) near the aneurysm neck is increased. Oscillatory shear index and relative residence time values are also increased with an increase in AR and SR. Furthermore, it was observed that an aneurysm with a multilobed structure shows complex flow, low WSS, and higher residence time over the secondary lobe. The turbulent kinetic energy and vorticity near the aneurysm neck are also increased with an increase in AR and SR.