Virtual stenting of intracranial aneurysms: application of hemodynamic modification analysis

Background: Practical application of hemodynamic modification analysis based on computational fluid dynamics (CFD) in intracranial aneurysms is still under study.

Purpose: To determine the clinical applicability of virtual stenting of aneurysms by comparing the simulated results with clinical outcome of real stenting.

Material and methods: Three-dimensional (3D) digital subtraction angiography (DSA) images were imported to a dedicated integrated prototypic CFD platform (Siemens Healthcare GmbH) which allows all necessary steps of 3D models for CFD analysis. The results of CFD simulation with virtual implantation of a stent can be visualized in the same platform for qualitative comparisons on a color-coded volume visualization window. Five small intracranial aneurysms with and without virtual stenting were analyzed and assessed on a qualitative level. Expert rating were performed for evaluating the simulated results, and comparing those to the long-term follow-up outcomes of real stenting.

Results: CFD simulation after virtual stenting was feasible in five differently located aneurysms and corresponded to the long-term changes of stented aneurysms by showing alteration in flow pattern. There was no significant difference (P = 0.5) between the simulated hemodynamic changes after virtual stenting and the angiographic changes after stenting in four aneurysms except one. There was good agreement regarding the assessment of the changes by two raters (kappa = 0.657).

Conclusion: CFD analysis using patient-specific virtual stenting of the CFD platform may be used as a simple and less time-consuming test tool predicting the involution of aneurysms after stent placement by analyzing the vector visualization of the flow changes.