Finite-element modeling of the hemodynamics of stented aneurysms.
BACKGROUND
Computational fluid dynamics (CFD) simulations are used to analyze the wall shear stress distribution and flow streamlines near the throat of a stented basilar side-wall aneurysm. Previous studies of stented aneurysm flows used low mesh resolution, did not include mesh convergence analyses, and depended upon conformal meshing techniques that apply only to very artificial stent geometries.


METHODS
We utilize general-purpose computer assisted design and unstructured mesh generation tools that apply in principle to stents and vasculature of arbitrary complexity. A mesh convergence analysis for stented steady flow is performed, varying node spacing near the stent. Physiologically realistic pulsatile simulations are then performed using the converged mesh.


RESULTS
Artifact-free resolution of the wall shear stress field on stent wires requires a node spacing of approximately 1/3 wire radius. Large-scale flow features tied to the velocity field are, however, captured at coarser resolution (nodes spaced by about one wire radius or more).


CONCLUSIONS
Results are consistent with previous work, but our methods yield more detailed insights into the complex flow dynamics. However, routine applications of CFD to anatomically realistic cases still depend upon further development of dedicated algorithms, most crucially to handle geometry definition and mesh generation for complicated stent deployments.
Stuhne
Gordon R
GR
Imaging Research Labs, Robarts Research Institute, 100 Perth Dr, London, Ontario, Canada N6A 5K8.
Steinman
David A
DA
D001783:Blood Flow Velocity; D001794:Blood Pressure; D001807:Blood Vessel Prosthesis; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D020342:Finite Element Analysis; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D008955:Models, Cardiovascular; D015607:Stents