\u3cp\u3eNovel methods for determining rupture risk in abdominal aortic aneurysms (AAAs) have focused primarily on CT-based wall stress analysis using finite element models (FEMs). Recent studies have demonstrated ultrasound (US) based FEM, and the possibility of using inverse FEM analysis: matching displacements between the models and US to find patient specific aortic stiffness. This requires an accurate representation of deformation of the FEM-based aorta, which could be highly influenced by the presence of surrounding tissue. Typically, these methods solely include the vessel, fixed on both ends. The abdominal aorta (AA) however is surrounded by other tissue including the spine, which acts as a stiff boundary. In this study, AA(A) models based on 4D US were constructed with increasing complexity. The importance of modelling surrounding tissues was investigated by comparing mechanical parameters.\u3c/p\u3