Computational Biomechanics of Abdominal Aortic Aneurysms

Ender Finol, Institute for Complex Engineered Systems & Biomedical Engineering

Abdominal aortic aneurysms (AAAs) are localized balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. Abdominal aortic aneurysm rupture is the 13th leading cause of death in the United States, affecting patients over 55 years of age, typically 2-4% of elderly males. Factors that are known to affect the risk of rupture are: AAA expansion rate, maximum transverse dimension of the aneurysm, relative aneurysm size compared to the patient’s body size, smoking, and family history. Typical treatment consisting of conservative or surgical management is based on the surgeon’s estimation of the risk of rupture vs. mortality and morbidity during surgery combined with the patient’s life expectancy.

The purpose of this project is to utilize computational fluid dynamics (CFD), finite element analysis (FEA) and fluid-structure interaction (FSI) techniques for the assessment of rupture potential of individual (patient-specific) AAAs. To achieve this goal we will use large-scale numerical simulations and modeling based on physiologically realistic measurements obtained during patient diagnosis. The concepts of image-based numerical modeling and in vivo measured blood flow characteristics will be incorporated and tested for the computational predictions. Patient-specific data is obtained retrospectively and prospectively from a Pittsburgh area hospital. The work will be performed in Dr. Finol’s Computational and Experimental Fluid Mechanics Laboratory (CEFML) and at the Pittsburgh Supercomputing Center (PSC). It is expected that this work will improve the accuracy of the computational predictions utilized for the assessment of risk of rupture in individual AAAs.