Hemodynamics analysis and computational fluid dynamics simulations to identify potential location of rupture in abdominal aortic aneurysm

Abstract

Abstract Background Abdominal Aortic Aneurysm (AAA) rupture is the most severe consequence of aneurysmal disease, with an overall death rate of 80%. Early diagnosis and appropriate follow-up and management of AAA will significantly reduce the risk of rupture and mortality. Rupture risk assessment of AAA has a critical role for the early warning. Purpose To Predict of the course of an AAA and determine the rupture risk and location from a biomechanical point of view. AAA hemodynamics were investigated to clarify the relation between the hemodynamic parameters and the AAA rupture. Methods Computed tomography (CT) images of one healthy aorta and 23 patients’ aorta with aneurysms were analyzed. WSS-related hemodynamic parameters of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell activation potential (ECAP), and relative residence time (RRT) are investigated in patient-specific AAA geometries by performing computational fluid dynamics (CFD) simulations (Figure 1). Patient-specific AAA geometries are identified using medical imaging techniques and realistic boundary conditions are determined using Doppler ultrasonography. Results AAA rupture locations predicted by CFD simulations were in good agreement with the actual rupture locations of retrospective data. The rupture locations had relatively low TAWSS, high OSI, high ECAP, and high RTT levels. High risk of rupture is expected in regions with a local minimum of TAWSS, and a local maximum of OSI, ECAP, and RRT. Conclusions Examining the spatial distribution of the hemodynamic parameters was a powerful approach for rupture risk assessment of AAA. Predicting the rupture location using a single hemodynamic parameter is not feasible, and the accuracy of AAA rupture risk assessment can be improved by using multiple WSS-related parameters by identifying the common intersection regions of low TAWSS, high OSI, high ECAP, and high RRT.Figure 1