Realistic virtual intracranial stenting and computational fluid dynamics for treatment analysis

In order to support the decisions of medical experts and to develop better stent designs, the availability of a simulation tool for virtual stenting would be extremely useful. An innovative virtual stenting technique is described in this work, which is directly applicable for complex patient-specific geometries. A basilar tip aneurysm provided for the Virtual Intracranial Stenting Challenge 2010 is considered to demonstrate the advantages of this approach. A free-form deformation is introduced for a wall-tight stent deployment. Numerical flow simulations on sufficiently fine computational meshes are performed for different configurations in order to characterize the inflow rate into the aneurysm and the corresponding residence time in the aneurysm sac. A Neuroform and a SILK stent have been deployed at various locations and the computed residence times have been evaluated and compared, demonstrating the advantage associated with a lower stent porosity. It has been found that the SILK stent leads to a large increase in the residence time and to a significant reduction in the maximum wall shear stress in the aneurysm sac. This is only observed when placing the stent in the appropriate position, showing that virtual stenting might be employed for operation support.