Impact of mechanical properties of aneurysms and intraluminal thrombus on abdominal aortic aneurysm outcomes

Abstract This study aims to examine how changes in material coefficients impact the mechanical responses of AAA models, including both cases with and without the ILT. The main focus will be on identifying the material coefficients that most significantly influence strain and stress fields, using the GHO model, which is widely regarded as the most popular hyperelastic model. The findings of this study reveal that compliant AAAs are particularly sensitive to fiber dispersion, which exerts a substantial influence on stress distribution and deformation patterns. In stiffer AAAs, however, matrix stiffness emerges as the key player. Notably, the study of interactions among all GHO parameters demonstrate that even minor adjustments can dramatically shift model behavior, emphasizing the importance of finely fitted parameter combinations for accurate predictions. The impact of ILT material properties on AAA mechanical behavior was found to be relatively minor, indicating that precise fitting of ILT coefficients may not be essential. However, the inclusion of the ILT itself was important, as it played a crucial role in shielding the AAA wall by reducing stress. This study offers valuable insights into the material modeling of AAA tissue and the significance of the ILT. The findings can be instrumental in optimizing patient-specific computational models, enhancing the accuracy of AAA wall material behavior, while also incorporating the ILT’s effects.