**1. Introduction**

150 Aneurysm

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Endovascular Treatment (EVAR) is considered the treatment of choice for the majority of Abdominal Aortic Aneurysms (AAA) nowadays, since it demonstrates improved perioperative morbidity and aneurysm-related mortality, comparing to conventional open repair. However, despite the initial technical success and early discharge of the patient, this technique is amenable to early and late complications, the most important of which are the endoleaks (ie. recurrence of blood flow detection within the aneurysm sac) accompanied sometimes with variable degrees of intrasac pressurization (Georgakarakos et al, 2012a). Furthermore, the hemodynamic changes that the endograft sustains during the follow-up period make it prone to positional changes with subsequent risk for endograft migration and loss of sealing between the endograft and either the aneurysm neck or the iliac fixation sites.

Computer-enhanced geometric modeling and Finite Volume Analysis have been used to study the biomechanical behavior of the aortic aneurysms before and after the insertion of the endograft device (Georgakarakos et al, 2012b). Numerical modeling of endovasculartreated AAA is used to determine the stresses and forces developed on AAA sac and stent-graft materials in-vivo, estimating hemodynamic parameters, such as the pressure and stress distribution over the main body, the bifurcation, the limbs of a stent-graft or the drag and displacement forces predisposing to graft migration. Consequently, the study of flow dynamics within aortic endografts holds a fundamental role in the delineation of the endograft behavior under pulsatile flow, providing useful information for developing and modifying the endograft design and surgical techniques. This chapter discusses the aforementioned changes, by using three-dimensional (3D) reconstructed endograft model.

© 2012 Georgakarakos et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
