H G Morales1, O Bonnefous2, A J Geers3,4, O Brina5, V M Pereira6, L Spelle7,8, J Moret7, I Larrabide9. 1. From Medisys-Philips Research (H.G.M., O.Bonnefous), Paris, France hernan.morales@philips.com. 2. From Medisys-Philips Research (H.G.M., O.Bonnefous), Paris, France. 3. Centre for Cardiovascular Science (A.J.G.), University of Edinburgh, Edinburgh, Scotland. 4. Department of Information and Communication Technologies (A.J.G.), Universitat Pompeu Fabra, Barcelona, Spain. 5. Department of Information Neuroradiology (O.Brina), University Hospital of Geneva, Geneva, Switzerland. 6. Department of Medical Imaging and Department of Surgery (V.M.P.), University Health Network, Toronto, Ontario, Canada. 7. Interventional Neuroradiology (L.S., J.M.), Beaujon University Hospital, Clichy, France. 8. Paris Diderot University (L.S.), Paris, France. 9. PLADEMA-CONICET (I.L.), Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.
Abstract
BACKGROUND AND PURPOSE: Our aim was to assess the performance of flow-diverter stents. The pre- and end-of-treatment angiographies are commonly compared. However, the arterial flow rate may change between acquisitions; therefore, a better understanding of its influence on the local intra-aneurysmal hemodynamics before and after flow-diverter stent use is required. MATERIALS AND METHODS: Twenty-five image-based aneurysm models extracted from 3D rotational angiograms were conditioned for computational fluid dynamics simulations. Pulsatile simulations were performed at different arterial flow rates, covering a wide possible range of physiologic flows among 1-5 mL/s. The effect of flow-diverter stents on intra-aneurysmal hemodynamics was numerically simulated with a porous medium model. Spatiotemporal-averaged intra-aneurysmal flow velocity and flow rate were calculated for each case to quantify the hemodynamics after treatment. The short-term flow-diverter stent performance was characterized by the relative velocity reduction inside the aneurysm. RESULTS: Spatiotemporal-averaged intra-aneurysmal flow velocity before and after flow-diverter stent use is linearly proportional to the mean arterial flow rate (minimum R2 > 0.983 of the linear regression models for untreated and stented models). Relative velocity reduction asymptotically decreases with increasing mean arterial flow rate. When the most probable range of arterial flow rate was considered (3-5 mL/s), instead of the wide possible flow range, the mean SD of relative velocity reduction was reduced from 3.6% to 0.48%. CONCLUSIONS: Both intra-aneurysmal aneurysm velocity and flow-diverter stent performance depend on the arterial flow rate. The performance could be considered independent of the arterial flow rates within the most probable range of physiologic flows.
BACKGROUND AND PURPOSE: Our aim was to assess the performance of flow-diverter stents. The pre- and end-of-treatment angiographies are commonly compared. However, the arterial flow rate may change between acquisitions; therefore, a better understanding of its influence on the local intra-aneurysmal hemodynamics before and after flow-diverter stent use is required. MATERIALS AND METHODS: Twenty-five image-based aneurysm models extracted from 3D rotational angiograms were conditioned for computational fluid dynamics simulations. Pulsatile simulations were performed at different arterial flow rates, covering a wide possible range of physiologic flows among 1-5 mL/s. The effect of flow-diverter stents on intra-aneurysmal hemodynamics was numerically simulated with a porous medium model. Spatiotemporal-averaged intra-aneurysmal flow velocity and flow rate were calculated for each case to quantify the hemodynamics after treatment. The short-term flow-diverter stent performance was characterized by the relative velocity reduction inside the aneurysm. RESULTS: Spatiotemporal-averaged intra-aneurysmal flow velocity before and after flow-diverter stent use is linearly proportional to the mean arterial flow rate (minimum R2 > 0.983 of the linear regression models for untreated and stented models). Relative velocity reduction asymptotically decreases with increasing mean arterial flow rate. When the most probable range of arterial flow rate was considered (3-5 mL/s), instead of the wide possible flow range, the mean SD of relative velocity reduction was reduced from 3.6% to 0.48%. CONCLUSIONS: Both intra-aneurysmal aneurysm velocity and flow-diverter stent performance depend on the arterial flow rate. The performance could be considered independent of the arterial flow rates within the most probable range of physiologic flows.
Authors: M Akli Zetchi; Adam A Dmytriw; Albert H Chiu; Brian J Drake; Niki V Alizadeh; Aditya Bharatha; Abhaya V Kulkarni; Thomas R Marotta Journal: Interv Neuroradiol Date: 2018-06-05 Impact factor: 1.610
Authors: Michael C Barbour; Fanette Chassagne; Venkat K Chivukula; Nathanael Machicoane; Louis J Kim; Michael R Levitt; Alberto Aliseda Journal: J Fluid Mech Date: 2021-03-31 Impact factor: 3.627