Wall expansion assessment of an intracranial aneurysm model by a 3D Digital Image Correlation System

• A polymeric aneurysm model with features close to us blood vessels is presented.
• A 3D DIC technique is proposed to assess the wall expansion of a 3D aneurysm.
• Thinner wall zones of the model are particularly prone to experience higher strains.
• The wall thickness may play an important role in the initiation, growth and rupture of aneurysms.

Intracranial aneurysm is a local dilatation of an intracranial artery with high risk of rupture and death. Although it is generally accepted that the weakening of the arterial wall is the main cause for the rupture of an aneurysm, it still no consensus about the reasons for its creation, expansion and rupture. In particular, what is the role played by the blood flow in these phenomena. In this way, the aim of this work is the in vitro mechanical assessment of the wall expansion, namely the displacements, deformations and strains occurring in a saccular intracranial aneurysm model, when subjected to different flow rates. To obtain new insights into the mechanisms involved in the aneurysm rupture, a 3D-Vic™ Digital Image Correlation System was used and validated with a finite element analysis. The wall expansion results have revealed that the displacements, deformations and principal strains are directly related to the internal pressure caused by the fluid on the wall of the aneurism. These findings were especially observed in the weakened areas of the aneurysm model, where the wall was thinner. Furthermore, the technique used in this study has shown to be a potential method to validate numerical simulations of aneurysms, allowing the future performance of more complex and realistic haemodynamic studies.