Development and Mechanical Evaluation of a Stent Graft for Endovascular Aneurysm Repair Using Finite Element Modeling

An abdominal aortic aneurysm (AAA) poses a significant risk of arterial wall rupture, which critically endangers the patient’s life. To address this condition, an endovascular aneurysm repair (EVAR) is required, involving the insertion and expansion of a stent-graft within the aorta, to support and isolate the weakened vessel wall. In this context, this article aims to approach the problem from a mechanical perspective and to simulate the expansion and deployment procedure realistically, utilizing the Finite Element Analysis (FEA). The process initiates with the computation evaluation of the aortic structure in order to identify critical regions of stress and strain in an aneurysmatic aortic region. Then, a customized 3D-designed stent graft model was developed for the aorta and positioned properly. Applying all the necessary boundary conditions, a complex nonlinear FEA was conducted until the stent-graft expanded radially, reaching a final diameter 25% larger than the aorta’s vessel wall while withstanding mean stress and strain values close to 400 MPa and 1.5%, respectively. Finally, the mechanical behavior of the stent-graft and its interaction with the internal aortic wall, during the expansion process, was evaluated, and the extracted results were analyzed.