Entity

Time filter

Source Type

Buenos Aires, Argentina

Mut F.,George Mason University | Ruijters D.,Philips | Babic D.,Philips | Bleise C.,Clinical Institute ENERI | And 2 more authors.
International Journal for Numerical Methods in Biomedical Engineering | Year: 2014

Quantifying the hemodynamic environment within aneurysms and its change after deployment of flow diverting devices is important to assess the device efficacy and understand their long-term effects. The purpose of this study was to estimate deviations in the quantification of the relative change of hemodynamic variables during flow diversion treatment of cerebral aneurysms due to changing physiologic flow conditions. Computational fluid dynamics calculations were carried out on three patient-specific geometries. Three flow diverters were virtually implanted in each geometry and simulations were performed under five pulsatile flow conditions. Hemodynamic variables including aneurysm inflow rate, mean velocity, shear rate, and wall shear stress were quantified before and after stenting. Deviations in the relative change of these variables due to varying flow conditions were calculated. The results indicate that a change in the mean flow of the parent artery of approximately 30-50% can induce large deviations in the relative change of hemodynamic variables in the range of 30-80%. Thus, quantification of hemodynamic changes during flow diversion must be carried out carefully. Variations in the inflow conditions during the procedure may induce large deviations in the quantification of these changes. © 2013 John Wiley & Sons, Ltd.


Mut F.,George Mason University | Scrivano E.,Clinical Institute ENERI | Bleise C.,Clinical Institute ENERI | Lylyk P.,Clinical Institute ENERI | Cebral J.,George Mason University
International Journal for Numerical Methods in Biomedical Engineering | Year: 2014

The purpose of this study was to investigate whether the occlusion time of cerebral aneurysms treated with flow diverters depends on the hemodynamic conditions created immediately after treatment. A case study of a pair of tandem intracranial aneurysms that were treated with flow-diverting devices and occluded at different times was carried out. A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images. Blood flow simulations were carried out under pulsatile physiologic conditions, and hemodynamic variables before and after deployment of the flow-diverting devices were quantified and compared. The flow-diverting devices reduced aneurysm inflow rates, intra-aneurysmal flow velocities, shear rates, and wall shear stresses. The flow patterns after flow modulation by the flow diverters were smoother and with less swirling. The reductions in hemodynamic quantities depended on the aneurysm and parent artery and were larger in the aneurysm that occluded faster. The results of this case study suggest that the larger the reduction in the hemodynamic variables considered, the shorter the time it takes for the aneurysm to thrombose. This result can help us better define the goal of these interventions. © 2013 John Wiley & Sons, Ltd.

Discover hidden collaborations