The primary mechanically related problems of endovascular aneurysm repair are migration and type la endoleaks. They occur when there is no effective seal between the proximal end of the stent-graft and the vessel. In this work, we have developed several deployment simulations of parameterized stents using the finite element method (FEM) to investigate the contact stiffness of a nitinol stent in a realistic Thoracic Aortic Aneurysm (TAA). Therefore, we evaluated the following factors associated with these complications: (1) Proximal Attachment Site Length (PASL), (2) stent over-sizing value (0%), (3) different friction conditions of the stent/aorta contact, and (4) proximal neck angulation alpha. The simulation results show that PASL > 18 mm is a crucial factor to prevent migration at a neck angle of 60 degrees, and the smoothest contact condition with low friction coefficient (mu = 0.05). The increase in 0% ranging from 10% to 20% improved the fixation strength. However, 0% >= 25% at 60 degrees caused eccentric deformation and stent collapse. Higher coefficient of friction mu >0.01 considerably increased the migration risk when PASL= 18 mm. No migration was found in an idealized aorta model with a neck angle of 0 degrees, PASL= 18 mm and mu = 0.05. Our results suggest carefully considering the stent length and oversizing value in this neck morphology to strengthen the contact and prevent migration. (C) 2014 IPEM. Published by Elsevier Ltd. All rights reserved.