Investigation of potential rupture locations for abdominal aortic aneurysms with patient-specific computational fluid dynamic analysis approach

Abstract

Background: About 18 million people die each year from cardiovascular disorders, accounting for 31% of all deaths worldwide. Abdominal Aortic Aneurysm (AAA) is a serious clinical condition manifested as dilation of the aorta beyond 50% of the normal vessel diameter. Current clinical practice is to surgically repair large AAAs with a diameter > 5.5 cm. However, the practice is questionable based on small AAA rupture and large AAA no rupture cases. Currently, there is no accepted technique to quantify the risk of rupture for individual AAAs. It is believed that rupture locations are where peak wall stresses act. Hemodynamic forces by the flowing blood such as shear stress are also thought to contribute to the formation of aneurysms leading to rupture. Aim: Our aim is to perform precise computational analysis for the assessment of rupture risk for AAA patients. Methods: In this IRCC funded project, we will develop a patient-specific computational modeling methodology to assess wall stresses acting on the diseased AAA, for reliable rupture risk assessment of the conditions. In the computational simulations, we will adapt the fluid-structure interaction approach to account for both tissue displacements and hemodynamic forces, for enhanced accuracy. We have recruited 20 AAA patients at HMC and collected CT scans and ultrasound images for these patients. Using these medical data, we are developing accurate 3D model geometries. Doppler ultrasound measurements are used as velocity boundary conditions in the simulations. Expected Results: Findings from this project will contribute significantly to understanding the biomechanics and mechanobiology of AAA rupture and will help to establish a computational modeling approach for rupture risk assessment of AAAs.