Brian Thomas Jankowitz1, Bradley A Gross2, Santhosh Seshadhri3, Gaurav Girdhar3, Ashutosh Jadhav4, Tudor G Jovin4, John Michael Wainwright3.
Abstract
INTRODUCTION: Modern coil-adjunctive intracranial stent designs have increased metal surface coverage to construct putative 'flow diverter lights.' This is rooted in the assumption that flow diversion is linearly correlated with metal surface coverage rather than being a threshold to be reached by device porosity and design.
OBJECTIVE: To evaluate this assumption, by performing computational flow analysis on three aneurysm models treated with low metal surface coverage stents (ATLAS and Enterprise), a Pipeline flow diverter, and the LVIS Blue stent.
METHODS: Computational flow analysis was performed on virtual deployment models entailing deployment of an ATLAS, Enterprise, LVIS Blue, or Pipeline. The impact of device deployment on velocity vectors at the neck, maximum wall shear stress, inflow rate into the aneurysm, and turnover time was determined.
RESULTS: Velocity vector plots demonstrated low magnitude, localized inflow jets for Pipeline only; asymmetric, selectively high inflow jets were seen for LVIS Blue, and broader velocity vector clusters were seen for Atlas and Enterprise. Reduction in wall shear stress as compared with baseline was significant for all devices and greatest for the Pipeline. Mean peak wall shear stress was significantly lower for LVIS Blue in comparison with ATLAS or Enterprise but significantly lower for Pipeline than for LVIS Blue. Reduction of inflow rate into the aneurysm was significant for LVIS Blue and Pipeline but significantly lower for Pipeline than for LVIS Blue. Turnover time was statistically similar for ATLAS, Enterprise, and LVIS Blue, but significantly increased for Pipeline.
CONCLUSION: Considerable differences in peak wall shear stress, inflow rates, and turnover time between flow diverters, moderate- and low-porosity stents reinforce the assumption that effective flow diversion represents a threshold in device design, encompassing metal surface coverage only in part. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
INTRODUCTION: Modern coil-adjunctive intracranial stent designs have increased metal surface coverage to construct putative 'flow diverter lights.' This is rooted in the assumption that flow diversion is linearly correlated with metal surface coverage rather than being a threshold to be reached by device porosity and design.
OBJECTIVE: To evaluate this assumption, by performing computational flow analysis on three aneurysm models treated with low metal surface coverage stents (ATLAS and Enterprise), a Pipeline flow diverter, and the LVIS Blue stent.
METHODS: Computational flow analysis was performed on virtual deployment models entailing deployment of an ATLAS, Enterprise, LVIS Blue, or Pipeline. The impact of device deployment on velocity vectors at the neck, maximum wall shear stress, inflow rate into the aneurysm, and turnover time was determined.
RESULTS: Velocity vector plots demonstrated low magnitude, localized inflow jets for Pipeline only; asymmetric, selectively high inflow jets were seen for LVIS Blue, and broader velocity vector clusters were seen for Atlas and Enterprise. Reduction in wall shear stress as compared with baseline was significant for all devices and greatest for the Pipeline. Mean peak wall shear stress was significantly lower for LVIS Blue in comparison with ATLAS or Enterprise but significantly lower for Pipeline than for LVIS Blue. Reduction of inflow rate into the aneurysm was significant for LVIS Blue and Pipeline but significantly lower for Pipeline than for LVIS Blue. Turnover time was statistically similar for ATLAS, Enterprise, and LVIS Blue, but significantly increased for Pipeline.
CONCLUSION: Considerable differences in peak wall shear stress, inflow rates, and turnover time between flow diverters, moderate- and low-porosity stents reinforce the assumption that effective flow diversion represents a threshold in device design, encompassing metal surface coverage only in part. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
Entities:
Keywords:
aneurysm; flow diverter; stent
Mesh：
Year: 2019
PMID： 30814328 DOI： 10.1136/neurintsurg-2018-014439
Source DB: PubMed Journal: J Neurointerv Surg ISSN： 1759-8478 Impact factor: 5.836