Computational fluid dynamic simulation to assess flow characteristics of an in vitro aneurysm model

Background: Modifications of in vitro aneurysm modeling to study the effects of morphology on flow dynamics are time consuming, costly and analysis tends to be more qualitative than quantitative. This study develops a virtual two-dimensional flow model replicating an in vitro aneurysm model and analyzes how changes in morphology modify flow characteristics. Methods: Using finite volume analysis, a twodimensional saccular aneurysm model was created with a configuration matching a published, experimental, in vitro model. Qualitative comparisons were made determining whether a two-dimensional fluid dynamic model can replicate the results of an in vitro model. Quantitative changes in flow patterns, wall shear stress, dynamic pressure and maximum velocities were assessed by modifying the shape of the neck and proximal dome without modifying the overall size of the aneurysm. Results: A two-dimensional computational fluid dynamic model reproducing the shape of a published aneurysm demonstrated excellent qualitative fidelity to an in vitro flow model. Additional information regarding dynamic pressure, shear stress and velocity along the aneurysm neck and within the aneurysm dome were determined. Although all dimensions were kept constant, slight modifications of the neck and proximal dome resulted in quantitative changes in studied parameters, such as wall shear stress and dynamic pressure. Conclusions: Computer generated aneurysm flow models, when carefully developed, reproduce flow events within in vitro aneurysms providing objective data on biophysical parameters. Effective flow modeling of aneurysms depends on flow input, size of the parent vessel and aneurysm, and other factors. These data suggest that neck and proximal dome configuration, independent of size, are important characteristics of flow.