## 1 Introduction  
An abdominal aortic aneurysm is a degeneration of the aorta that progressively enlarges, usually assuming a swollen fusiform shape. It is a permanent dilatation, which is pathological when the diameter increases by 50% compared to the diameter of the vessel in physiological conditions [1, 2]. The risk of AAAs increases after 60 years of age with a major incidence in men (four to six times more common in men than in women [3]). The risk factors that affect the formation of the aneurysm are different. They can be divided into external factors and genetic factors. The external factors are smoking, obesity, existing heart disease, hypertension, and arteriosclerosis. Genetic factors, on the other hand, are linked to the heredity of the pathology, and more precisely to the internal arrangement and composition of the aortic tissue (collagen fibers). When the aneurysm exceeds 5 cm in diameter, surgical intervention becomes necessary. The walls of the aneurysm vessel are subject to failure due to progressive damage to the tissue in the area of the aneurysm. The aneurysm can rupture, or rather the dissection of the aorta occurs; consequently, an internal hemorrhage occurs in the patient, which in a few minutes leads to death [4] From a purely mechanical point of view, the rupture of an AAA occurs when the mechanical stresses (internal forces per unit area) acting on the aneurysm exceeds the ability of the wall tissue to withstand these stresses (i.e., the wall's failure strength). Among the innumerable parameters that can be considered and compared, wall shear stress is the one that has been used for the longest time and in the largest number of studies [2; 3; 4]. This indicator takes into account the combined effect of geometry, blood pressure, and the interaction between the fluid and solid domains. The surgical options for aneurysm treatment include the conventional Open Surgical Repair (OSR) and Endovascular Aneurysm Repair (EVAR). OSR is an invasive procedure that consists of a large incision at the site of the aneurysm, which is removed and replaced by a synthetic graft. Open repair is considered a good option for patients at a young age, with complications, severe co-morbidities, aortic dissection, or aneurysm rupture. It has limited use due to worse outcomes in terms of periand post-procedural mortalities and morbidities. On the other hand, EVAR is a minimally invasive procedure for the patient. It involves the release of a stent-graft introduced via a catheter into the patient's femoral artery at the site of the aneurysm. The limit of EVAR treatment is linked to the morphology of the patient's aorta, in particular the aspect linked to the curvature. Hostile behavior of the aortic neck is defined by its size, length, pulsatility, and thrombus and calcification lining. Generally speaking, the anatomical determinations that must be made in planning graft implantation are as follows:  
* Diameter and length of the infrarenal aorta and neck of the aorta,
* Diameter and length of the iliac attachments,
* Tortuosity and size of the access vessels, and
* Critical vessel anatomy. Criteria of eligibility for EVAR are as follows:  
* Neck length \(\geq\) 15 mm,
* Neck diameter \(<\) 30 mm,
* Neck angulation \(<\) 60-80 degrees, and
* Iliac diameter \(\leq\) 7 mm. The stent-grafts present on the market and produced by multinationals are standardized according to an array of measures that are adapted on the basis of the dimensions of the patient's aorta and are customized as regards the position of the lateral ramifications if involved by the aneurysm, and in this case, these are the most sophisticated and expensive that the vascular surgeon has at their disposal. Customized stents/grafts, i.e., made to measure for the patient in terms of size and shape (curvature, diameter of the attachment area, etc. ), are not currently produced and marketed.