engleski

A computational study on the tortuosity of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) is focal dilatation of abdominal aorta with diameter larger than 30 mm, and a common cause of death among the elderly. Its pathogenesis is still not well understood, and our ability to predict whether a specific lesion will arrest, continue to enlarge, or ultimately rupture remains wanting. Apart from commonly proposed rupture risk factors (e.g., smoking, hypertension, female gender, etc.) Fillinger et al. [1] demonstrated that qualitative assessment of shape of three-dimensional aneurysm geometry predicts rupture potential more accurately than aneurysm diameter alone. One of the morphological parameters associated with rupture potential is tortuosity of aneurysmal aorta. Indeed, Pappu et al. [2] showed that significant increase in tortuosity leads to rupture. Additionally, blood vessel shape and tortuosity influence hemodynamic loads and peak wall stress, and are therefore important factors in AAA evolution. Despite increasing evidence that aneurysm tortuosity effects AAA evolution and rupture, current computational growth and remodeling models failed to model and study tortuous aneurysms. In this contribution we study causes and implications of tortuosity on axially non- symmetric aneurysms. It was suggested in Swedenborg et al. [3] that elongation and tortuosity are result of local elastin degradation. Our computational results confirm this hypothesis. However, based on irregular patient-specific AAA geometries, one can conclude that elastin loss is not the only parameter inducing bending. We aim to investigate the other factors that possibly cause tortuosity (e.g., position of spine in relation to location of elastin loss, heterogeneity of certain mechanical properties), as well as the consequences of tortuosity.

Abdominal aortic aneurysm, tortuosity, growth & remodeling

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