Anatomically the aorta is divided in several parts, depending on the zone of the body that the vessel covers. The aorta is first called thoracic aorta as it leaves the heart, ascends, arches, and descends through the chest until it reaches the diaphragm when takes the name of abdominal aorta and continues down the abdomen. The abdominal aorta ends where it splits to form the two iliac arteries that go to the legs. Aorta is subject of aneurysm and it can develop anywhere along the length of the aorta.

The majority, however, are located along the abdominal zone. Most (about 90%) of abdominal aneurysms (AAA) are located below the level of the renal arteries, the vessels that leave the aorta to go to the kidneys. About two‐thirds of abdominal aneurysms are not limited to just the aorta but extend from the aorta into one or both of the iliac arteries. Normally aortic aneurysms take a fusiform shape. Nowadays, it is recognized that current clinical criteria for assessment of the abdominal aortic aneurysm rupture risk can be considered insufficient because they have not a physically theoretical basis [1], despite they are based on a wide empirical evidence. Hence, in last many years, researchers and physicians have had the challenge to identify a more reliable criterion associated with the actual rupture risk of the patient‐specific aneurysm. The literature begins to reflect the existence of a consensus that, rather than empirical criteria, the biomechanical approach, based on the material failure, could facilitate a better method to assess the AAA rupture risk. One of these AAA rupture criteria are based on the evaluation of the hemodynamic stresses inside the AAA.

To estimate the AAA rupture risk, from biomechanical point of view (material failure), an aneurysm ruptures when the stresses acting on the arterial wall exceed its failure strength.

According to the Laplace's law, the wall stress on an ideal cylinder is directly proportional to its radius and intraluminal pressure.  Even though, the AAA is not ideal cylinder, Laplace's law said that with a large diameter, the internal pressure increases, and therefore increases the risk of rupture. Due to the increasing of the internal pressure, against the aortic walls, the AAA diameter grows progressively, and eventually, it could be able to overcome the resistance of the aortic wall with its breakup. In turn, further increase of the AAA diameters produces internal flow recirculation producing ILT formation in the AAA sac. This phenomenon provokes AAA stabilization and starting a vicious circle inside the AAA. It is well documented [1], that the aneurysm shape has a strong influence on flow patterns and consequently on wall stress distribution (peak values and locations). It is reflected by the interaction between the arterial wall structural remodeling and the forces generated by blood flow within the AAA. Therefore, the AAA morphology has a significant influence in its potential rupture.

The study is focused on the behavior of the blood fluid, inside the aneurism and how this illness will change the normal path of the fluid. Vortices and abnormal fluid paths will affect the normal and physiological pressure field and also produce alterations in the Wall Shear Stress (WSS) on the vessel walls.

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[1] D.A. Vorp, “Biomechanics of abdominal aortic aneurysm”. J. Biomech., 40(2007), 1887–1902.

[2] E. Soudah, J. Pennecot, J.S. Perez, M. Bordone, E. Oñate, Chapter 10: “Medical‐GiD: 381 From medical images to simulations, MRI Flow Analysis”. Book: Computational Vision and Medical Image Processing: Recent Trends. ISSN 1871‐3033 383 Ed. Springer.

[3] E. Soudah, M. Bordone, J.S. Perez, ”Gmed: a platform for images treatment inside GiD system”. 5th Conference On Advances And Applications Of GiD. Barcelona 2010. www.gidhome.com GiD ‐ The personal pre and postprocessor.

[4] A. Paul, P.A. Yushkevich, J. Piven, H.C. Hazlett, R.G. Smith, S. Ho, et al., “User‐ 413 guided 3D active contour segmentation of anatomical structures: Significantly 414 improved efficiency and reliability”, Neuroimage 31 (2006) 1116–1128.

[5] W.E. Lorensen, H. E. Cline, Marching cubes: A high resolution 3d surface construction algorithm. In Proceedings of SIGGRAPH, pages 163–169 (1987).

[6] M. Bordone, C.García, J.García, E.Soudah, Biodyn User Manual. TDYN: theoretical Background: www.compassis.com/compassis. COMPASSIS (2012)

[7] E. A. Finol, K. Keyhani, C. H. Amon. “The Effect of Asymmetry in Abdominal Aortic Aneurysms Under Physiologically Realistic Pulsatile Flow Conditions”. Journal of Biomechanical Engineering APRIL 2003, Vol. 125, 207‐ 217. DOI: 10.1115/1.1543991

[8] J. Biasetti, F. Hussain, T.C. Gasser, “Blood flow and coherent vortices in the normal and aneurysmatic aortas: a fluid dynamical approach to intra‐luminal thrombus formation”. J.R. Soc. Interface, Doi:10.1098/rsif.2011.0041.

[9] E. Oñate, S. Idelsohn, O.C. Zienkiewicz, R.L. Taylor, “A finite point method in computational mechanics. Applications to convective transport and fluid flow”, Int. Journal for Numerical Methods in Engineering 39 (1996) 3839–3866.

[10] J. García, E. Oñate, H. Sierra, C. Sacco, and S. Idelsohn, “A Stabilised Numerical Method for Analysis of Ship Hydrodynamics”. Proceedings Eccomas Conference on CFD, 7‐11 September 1998, Athens, John Wiley, 1998.

[11] Y. Papaharilaou, J.A Ekaterinaris, E. Manousaki, et al: “A decoupled fluid structure approach for estimating wall stress in abdominal aortic aneurysm”. J. Biomech. 40 (2007), 464‐475.

[12] A. Borghia, N.B. Wooda, R.H. Mohiaddinb, X.Y. Xua. “Fluid–solid interaction simulation of flow and stress pattern in thoraco abdominal aneurysms: A patient‐specific study”. Journal of Fluids and Structures 24 (2008) 270–280.

[13] R. Barrett et al., Templates for the Solution of Linear Systems: Building Blocks for Iterative Methods, 2nd Edition, Philadelphia, PA: SIAM, 1994.

[14] C.M. Scotti, E.A. Fino, “Compliant biomechanics of abdominal aortic aneurysm: A fluidstructural interaction study”. Computer and Structures, 85 (2007), 1097‐1113.

[15] A.V. Salsac, S.R. Sparks, J.M. Chomaz, J.C. Lasheras, “Evolution of the wall shear stresses during the progressive enlargement of symmetric abdominal aortic aneurysms”. J. Fluid Mech, 560 (2006), 19‐51.

[16] D. Bluestein, E. Rambod, M. Gharib, “Vortex shedding as a mechanism for free emboli formation in mechanical heart valves”. ASME Journal of Biomechanical Engineering 122,2 (2000), 125–134.

[17] A. Sheidaei, S.C. Hunley, S. Zeinali‐Davarani, L.G. Raguin, S. Baek, “Simulation of abdominal aortic aneurysm growth with updating hemodynamic loads using a realistic geometry”. Medical Engineering & Physics 33 (2011) 80–88.

[18] D.A. Vorp, P.C. Lee, D.H.J. Wang, M.S. Makaroun, E.M. Nemoto, S. Ogawa, et al. “Association of intraluminal thrombus in abdominal aortic aneurysm with local hypoxia and wall weakening”. Journal of Vascular Surgery 2001; 34: 291–9.

[19] C. Kleinstreuer and Z. Li, “Analysis and computer program for rupture‐risk prediction of abdominal aortic aneurysms”. BioMedical Engineering OnLine 2006, 5:19.

[20] Judy Shum,Giampaolo Martufi, Elena Di Martino,Christopher B. Washington, Joseph Grisafi, Satish C. Muluk, and Ender A. Finol. Quantitative Assessment of Abdominal Aortic Aneurysm Geometry. Ann Biomed Eng. 2011 January; 39(1): 277–286.

[21] W.A. Cappeller, H. Engelmann, S. Blechschmidt, M. Wild, L. Lauterjung, “Possible objectification of a critical maximum diameter for elective surgery in abdominal aortic aneurysms based on one‐and three‐dimensional ratios”. Journal of Cardiovascular Surgery 1997, 38:623‐628.

[22] K. Ouriel, R.M. Green, C. Donayre, C.K. Shortell, J. Elliott, J.A. Deweese, “An evaluation of new methods of expressing aortic aneurysm size: Relationship to rupture”. Journal of Vascular Surgery 1992, 15:12‐20.

[23] D.A. Vorp, M.L. Raghavan, M.W. Webster (April 1998). "Mechanical wall stress in abdominal aortic aneurysm: influence of diameter and asymmetry". Journal of Vascular Surgery 27 (4): 632–9. doi:10.1016/S0741‐5214(98)70227‐7.

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