O Brina1, P Bouillot2, P Reymond1, A S Luthman1, C Santarosa1, M Fahrat3, K O Lovblad1, P Machi1, B M A Delattre4, V M Pereira1,5,6,7, M I Vargas8. 1. From the Divisions of Neuroradiology (O.B., P.R., A.S.L., C.S., K.O.L., P.M., V.M.P., M.I.V.). 2. Department of Quantum Matter Physics (P.B.), University of Geneva, Geneva, Switzerland. 3. Laboratory for Hydraulic Machines (M.F.), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. 4. Radiology (B.M.A.D.), Geneva University Hospitals, University of Geneva, Geneva, Switzerland. 5. Division of Neuroradiology (V.M.P.). 6. Department of Medical Imaging (V.M.P.). 7. Division of Neurosurgery (V.M.P.), Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada. 8. From the Divisions of Neuroradiology (O.B., P.R., A.S.L., C.S., K.O.L., P.M., V.M.P., M.I.V.) maria.i.vargas@hcuge.ch.
Abstract
BACKGROUND AND PURPOSE: Flow-diverter stents are widely used for the treatment of wide-neck intracranial aneurysms. Various parameters may influence intracranial aneurysm thrombosis, including the flow reduction induced by flow-diverter stent implantation, which is assumed to play a leading role. However, its actual impact remains unclear due to the lack of detailed intra-aneurysmal flow measurements. This study aimed to clarify this relationship by quantitatively measuring the intra-aneurysmal flow using 4D phase-contrast MR imaging. MATERIALS AND METHODS: We acquired prospective pre- and post-stent implantation 4D phase-contrast MR imaging data of a consecutive series of 23 patients treated with flow-diverter stents. Velocity field data were combined with the intraprocedural 3D angiogram vessel geometries for precise intracranial aneurysm extraction and partial volume correction. Intra-aneurysmal hemodynamic modifications were compared with occlusion outcomes at 6 and 12 months. RESULTS: The averaged velocities at systole were lower after flow-diverter stent implantation for all patients and ranged from 21.7 ± 7.1 cm/s before to 7.2 ± 2.9 cm/s after stent placement. The velocity reduction was more important for the group of patients with aneurysm thrombosis at 6 months (68.8%) and decreased gradually from 66.2% to 55% for 12-month thrombosis and no thrombosis, respectively (P = .08). CONCLUSIONS: We propose an innovative approach to measure intracranial flow changes after flow-diverter stent implantation. We identified a trend between flow reduction and thrombosis outcome that brings a new insight into current understanding of the flow-diversion treatment response.
BACKGROUND AND PURPOSE: Flow-diverter stents are widely used for the treatment of wide-neck intracranial aneurysms. Various parameters may influence intracranial aneurysm thrombosis, including the flow reduction induced by flow-diverter stent implantation, which is assumed to play a leading role. However, its actual impact remains unclear due to the lack of detailed intra-aneurysmal flow measurements. This study aimed to clarify this relationship by quantitatively measuring the intra-aneurysmal flow using 4D phase-contrast MR imaging. MATERIALS AND METHODS: We acquired prospective pre- and post-stent implantation 4D phase-contrast MR imaging data of a consecutive series of 23 patients treated with flow-diverter stents. Velocity field data were combined with the intraprocedural 3D angiogram vessel geometries for precise intracranial aneurysm extraction and partial volume correction. Intra-aneurysmal hemodynamic modifications were compared with occlusion outcomes at 6 and 12 months. RESULTS: The averaged velocities at systole were lower after flow-diverter stent implantation for all patients and ranged from 21.7 ± 7.1 cm/s before to 7.2 ± 2.9 cm/s after stent placement. The velocity reduction was more important for the group of patients with aneurysm thrombosis at 6 months (68.8%) and decreased gradually from 66.2% to 55% for 12-month thrombosis and no thrombosis, respectively (P = .08). CONCLUSIONS: We propose an innovative approach to measure intracranial flow changes after flow-diverter stent implantation. We identified a trend between flow reduction and thrombosis outcome that brings a new insight into current understanding of the flow-diversion treatment response.
Authors: Christof Karmonik; Jeff R Anderson; Saba Elias; Richard Klucznik; Orlando Diaz; Yi Jonathan Zhang; Robert G Grossman; Gavin W Britz Journal: World Neurosurg Date: 2017-06-15 Impact factor: 2.104
Authors: Pierre Bouillot; Bénédicte M A Delattre; Olivier Brina; Rafik Ouared; Mohamed Farhat; Christophe Chnafa; David A Steinman; Karl-Olof Lovblad; Vitor M Pereira; Maria I Vargas Journal: Magn Reson Med Date: 2017-02-28 Impact factor: 4.668
Authors: V M Pereira; O Bonnefous; R Ouared; O Brina; J Stawiaski; H Aerts; D Ruijters; A P Narata; P Bijlenga; K Schaller; K-O Lovblad Journal: AJNR Am J Neuroradiol Date: 2012-11-01 Impact factor: 3.825