Pierre Bouillot1, Olivier Brina2, Rafik Ouared2, Hasan Yilmaz2, Karl-Olof Lovblad2, Mohamed Farhat3, Vitor Mendes Pereira4. 1. Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. 2. Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland. 3. Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. 4. Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
Abstract
BACKGROUND AND PURPOSE: Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities. MATERIAL AND METHODS: The recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density. RESULTS: Velocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD-PIV matching in IA was found for intermediate porosity stents. CONCLUSIONS: CFD reproduced fully PIV measurements in unstented and high porosity stented IAs. With low porosity stents, CFD reproduced velocity reduction and high velocities close to the neck, while a marked mismatch on sluggish flow was found at the dome. CFD was unable to match PIV with intermediate porosity stents for which hemodynamic transition occurred. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
BACKGROUND AND PURPOSE: Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities. MATERIAL AND METHODS: The recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density. RESULTS: Velocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD-PIV matching in IA was found for intermediate porosity stents. CONCLUSIONS:CFD reproduced fully PIV measurements in unstented and high porosity stented IAs. With low porosity stents, CFD reproduced velocity reduction and high velocities close to the neck, while a marked mismatch on sluggish flow was found at the dome. CFD was unable to match PIV with intermediate porosity stents for which hemodynamic transition occurred. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Authors: Ronak J Dholakia; Ari D Kappel; Andrew Pagano; Henry H Woo; Baruch B Lieber; David J Fiorella; Chander Sadasivan Journal: Interv Neuroradiol Date: 2017-12-14 Impact factor: 1.610
Authors: Alifer D Bordones; Matthew Leroux; Vitaly O Kheyfets; Yu-An Wu; Chia-Yuan Chen; Ender A Finol Journal: Ann Biomed Eng Date: 2018-05-21 Impact factor: 3.934