Numerical Simulation of Blood Flow to Predict Risk of Aneurysm Rupture in Brain Vessel
Hemodynamic parameters played an important role in rupture risk prediction brain aneurysms. Relative residence time (RRT) is an important hemodynamic parameter to investigate the rupture risk. The prediction was performed through numerical simulation of two-phase blood flow solved by discrete phase model (DPM).
A brain aneurysm is a bulging of an area in the wall of blood vessels in the brain. Such conditions result in abnormal widening, ballooning, or bleb. Consequently, the aneurysm wall is weakening, and there is a risk for rupture or bursting of the aneurysm. The rupture causes bleeding in the brain or known as hemorrhagic stroke. An understanding of the mechanism of brain aneurysm rupture has played a critical role in finding the treatment to avoid the possibly fatal event. The development of aneurysms occurs due to the artery wall thinning and it is often difficult to diagnose before it ruptures and leads to several fatal diseases, including brain damage, stroke, behavioral inconsistency, and eye movement disturbances. The factors of aneurysm rupture can be divided into biomechanical and biological factors.
The research focuses on biomechanical factors where the hemodynamics of blood flow was taken into consideration. The medical image segmentation and computational fluid dynamics (CFD) simulation has been performed using Materialise and ANSYS Fluent software respectively to predict the risk of aneurysm rupture in brain vessel with aneurysms. Two-phase blood considered as plasma with red blood cells solved with DPM and the validation was performed.
CFD simulation were performed to four patient-specific brain artery with aneurysm to analyze the rupture risk. RRT is an important hemodynamic parameter used to calculate the residence time of blood flow circulation inside the aneurysm. RRT indicate the forces that impacted the vessel wall that could stimulate the receptors and trigger biological reactions. The reactions could lead to the aneurysm growth and rupture. Figure shows the RRT changes of aneurysm geometries under investigation. Geometry one, two, and four indicates may have a high risk of rupture compare to geometry three may has a low risk of rupture based on RRT.