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Gonzalez SM, Iordanou J, Adams W, Tsiang J, Frazzetta J, Kim M, Rezaii E, Pecoraro N, Zsigray B, Simon JE, Zakaria J, Jusue-Torres I, Li D, Heiferman DM, Serrone JC. Effect of Stent Porosity, Platelet Function Test Usage, and Dual Antiplatelet Therapy Duration on Clinical and Radiographic Outcomes After Stenting for Cerebral Aneurysms: A Meta-Analysis. World Neurosurg 2023; 171:159-166.e13. [PMID: 36529432 DOI: 10.1016/j.wneu.2022.12.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND The use of stents with various porosities for treating cerebral aneurysms requires dual antiplatelet therapy (DAPT) without clear guidelines on the utility of platelet function tests (PFTs) and the duration of DAPT. We sought to determine the effects of stent porosity, PFT usage, and DAPT duration on the radiographic and clinical outcomes after stenting of cerebral aneurysms. METHODS PubMed was searched on March 29, 2021 for studies of cerebral aneurysm stenting that had specified the stent type and DAPT duration. A random effects meta-analysis was used to measure the prevalence of nonprocedural thrombotic and hemorrhagic events, clinical outcomes, aneurysm occlusion, and in-stent stenosis stratified by stent porosity, PFT usage, and DAPT duration. RESULTS The review yielded 105 studies (89 retrospective and 16 prospective) with 117 stenting cohorts (50 high porosity, 17 intermediate porosity, and 50 low porosity). In the high-, intermediate-, and low-porosity stenting cohorts, PFT usage was 26.0%, 47.1%, and 62.0% and the mean DAPT duration was 3.51 ± 2.33, 3.97 ± 1.92, and 5.18 ± 2.27 months, respectively. The intermediate-porosity stents showed a reduced incidence of hemorrhagic events (π = 0.32%) compared with low-porosity stents (π = 1.36%; P = 0.01) and improved aneurysm occlusion (π = 6.18%) compared with high-porosity stents (π = 14.42%; P = 0.001) and low-porosity stents (π = 11.71%; P = 0.04). The prevalence of in-stent stenosis was lower for the intermediate-porosity (π = 0.57%) and high-porosity (π = 1.51%) stents than for the low-porosity stents (π = 3.30%; P < 0.05). PFT use had resulted in fewer poor clinical outcomes (π = 3.54%) compared with those without PFT use (π = 5.94%; P = 0.04). The DAPT duration had no effect on the outcomes. CONCLUSIONS In the present meta-analysis, which had selected for studies of cerebral aneurysm stenting that had reported the DAPT duration, intermediate-porosity stents and PFT use had resulted significantly improved outcomes. No effect of DAPT duration could be detected.
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Affiliation(s)
| | - Jordan Iordanou
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - William Adams
- Department of Public Health Sciences, Parkinson School of Health Sciences and Public Health, Loyola University Chicago, Illinois, USA
| | - John Tsiang
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Joseph Frazzetta
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Miri Kim
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Elhaum Rezaii
- Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
| | - Nathan Pecoraro
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Brandon Zsigray
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Joshua E Simon
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Jehad Zakaria
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | | | - Daphne Li
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA
| | - Daniel M Heiferman
- Department of Neurological Surgery, Edward-Elmhurst Health, Naperville, Illinois, USA
| | - Joseph C Serrone
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois, USA; Department of Neurological Surgery, Edward Hines Jr Veterans Affairs Hospital, Hines, Illinois, USA.
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2
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CFD to Quantify Idealized Intra-Aneurysmal Blood Flow in Response to Regular and Flow Diverter Stent Treatment. FLUIDS 2022. [DOI: 10.3390/fluids7080254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cerebral aneurysms are pathological dilatations of the vessels supplying the brain. They carry a certain risk of rupture, which in turn, results in a high risk of mortality and morbidity. Flow diverters (FDs) are high-density meshed stents which are implanted in the vessel segment harboring an intracranial aneurysm to cover the entrance of the aneurysm, thus reducing the blood flow into the aneurysm, promoting thrombosis formation and stable occlusion, which prevents rupture or growth of the aneurysm. In the present study, the blood flow in an idealized aneurysm, treated with an FD stent and a regular stent (RS), were modeled and analyzed considering their design, surface area porosity, and flow reduction to investigate the quantitative and qualitative effect of the stent on intra-aneurysmal hemodynamics. CFD simulations were conducted before and after treatment. Significant reductions were observed for most hemodynamic variables with the use of stents, during both the peak systolic and late diastolic cardiac cycles. FD reduces the intra-aneurysmal wall shear stress (WSS), inflow, and aneurysmal flow velocity, and increases the turnover time when compared to the RS; therefore, the possibility of aneurysm thrombotic occlusion is likely to increase, reducing the risk of rupture in cerebral aneurysms.
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3
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Kim S, Yang H, Hong I, Oh JH, Kim YB. Computational Study of Hemodynamic Changes Induced by Overlapping and Compacting of Stents and Flow Diverter in Cerebral Aneurysms. Front Neurol 2021; 12:705841. [PMID: 34408723 PMCID: PMC8365227 DOI: 10.3389/fneur.2021.705841] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: The flow diversion effect of an intracranial stent is closely related to its metal coverage rate (MCR). In this study, the flow diversion effects of Enterprise and low-profile visualized intraluminal support (LVIS) stents are compared with those of a Pipeline flow diverter, focusing on the MCR change. Moreover, the changes in the flow diversion effect caused by the additional manipulations of overlapping and compaction are verified using computational fluid dynamics (CFD) analysis. Methods: CFD analysis was performed using virtually generated stents mounted in an idealized aneurysm model. First, the flow diversion effects of single Enterprise, LVIS, and Pipeline devices were analyzed. The Enterprise and LVIS were sequentially overlapped and compared with a Pipeline, to evaluate the effect of stent overlapping. The effect of compacting a stent was evaluated by comparing the flow diversion effects of a single and two compacted LVIS with those of two overlapped, uncompacted LVIS and uncompacted and compacted Pipeline. Quantitative analysis was performed to evaluate the hemodynamic parameters of energy loss, average velocity, and inflow rate. Results: Statistically significant correlations were observed between the reduction rates of the hemodynamic parameters and MCR. The single LVIS without compaction induced a reduction in all the hemodynamic parameters comparable to those of the three overlapped Enterprise. Moreover, the two overlapped, uncompacted LVIS showed a flow diversion effect as large as that induced by the single uncompacted Pipeline. Compacted stents induced a better flow diversion effect than uncompacted stents. The single compacted LVIS induced a flow diversion effect similar to that induced by the two uncompacted LVIS or single uncompacted Pipeline. Conclusions: The MCR of a stent correlates with its flow diversion effect. Overlapping and compaction can increase the MCR of an intracranial stent and achieve a flow diversion effect as large as that observed with a flow diverter.
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Affiliation(s)
- Sunghan Kim
- Department of Neurosurgery, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.,Department of Neurosurgery, Severance Stroke Center, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hyeondong Yang
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Ineui Hong
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Je Hoon Oh
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Yong Bae Kim
- Department of Neurosurgery, Severance Stroke Center, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
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4
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Maragkos GA, Dmytriw AA, Salem MM, Tutino VM, Meng H, Cognard C, Machi P, Krings T, Mendes Pereira V. Overview of Different Flow Diverters and Flow Dynamics. Neurosurgery 2020; 86:S21-S34. [PMID: 31838536 DOI: 10.1093/neuros/nyz323] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/30/2019] [Indexed: 12/16/2022] Open
Abstract
Over the past decade, flow diverter technology for endocranial aneurysms has seen rapid evolution, with the development of new devices quickly outpacing the clinical evidence base. However, flow diversion has not yet been directly compared to surgical aneurysm clipping or other endovascular procedures. The oldest and most well-studied device is the Pipeline Embolization Device (PED; Medtronic), recently transitioned to the Pipeline Flex (Medtronic), which still has sparse data regarding outcomes. To date, other flow diverting devices have not been shown to outperform the PED, although information comes primarily from retrospective studies with short follow-up, which are not always comparable. Because of this lack of high-quality outcome data, no reliable recommendations can be made for choosing among flow diversion devices yet. Moreover, the decision to proceed with flow diversion should be individualized to each patient. In this work, we wish to provide a comprehensive overview of the technical specifications of all flow diverter devices currently available, accompanied by a succinct description of the evidence base surrounding each device.
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Affiliation(s)
- Georgios A Maragkos
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Adam A Dmytriw
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.,Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Mohamed M Salem
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Clinical and Translational Research Center, New York
| | - Hui Meng
- Canon Stroke and Vascular Research Center, University at Buffalo, Clinical and Translational Research Center, New York
| | - Christophe Cognard
- Department of Diagnostic and Therapeutic Neuroradiology, Centre Hopitalier de Toulouse, Toulouse, France
| | - Paolo Machi
- Department of Neuroradiology, Montpellier University Hospital, Montpellier, France
| | - Timo Krings
- Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Vitor Mendes Pereira
- Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
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5
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Abali BE, Savaş Ö. Experimental validation of computational fluid dynamics for solving isothermal and incompressible viscous fluid flow. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-03253-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
AbstractIn order to validate a computational method for solving viscous fluid flows, experiments are carried out in an eccentric cylindrical cavity showing various flow formations over a range of Reynolds numbers. Especially, in numerical solution approaches for isothermal and incompressible flows, we search for simple experimental data for evaluating accuracy as well as performance of the computational method. Verification of different computational methods is arduous, and analytic solutions are only obtained for simple geometries like a channel flow. Clearly, a method is expected to predict different flow patterns within a cavity. Thus, we propose a configuration generating different flow formations depending on the Reynolds number and make the experimental results freely available in order to be used as an assessment criterion to demonstrate the reliability of a new computational approach.
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6
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Li Y, Yoneyama Y, Isoda H, Terada M, Kosugi T, Kosugi T, Zhang M, Ohta M. Haemodynamics in a patient-specific intracranial aneurysm according to experimental and numerical approaches: A comparison of PIV, CFD and PC-MRI. Technol Health Care 2020; 29:253-267. [PMID: 32568138 DOI: 10.3233/thc-202252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The haemodynamics determined by different approaches for studying fluid dynamics - i.e. computational fluid dynamics (CFD), particle image velocimetry (PIV), and phase-contrast magnetic resonance imaging (PC-MRI) - have rarely been thoroughly compared; nor have the factors that affect accuracy and precision in each method. As each method has its own advantages and limitations, this knowledge is important for future studies to be able to achieve valid analyses of fluid flows. OBJECTIVE To gauge the capacity of these methods for analysing aneurysmal flows, we compared the haemodynamic behaviours determined by each method within a patient-specific aneurysm model. METHODS An in vitro silicone aneurysm model was fabricated for PIV and PC-MRI, and an in silico aneurysm model with the same geometry was reconstructed for CFD. With the same fluid model prepared numerically and physically, CFD, PIV and PC-MRI were performed to study aneurysmal haemodynamics. RESULTS 2D velocity vectors and magnitudes show good agreement between PIV and CFD, and 3D flow patterns show good similarity between PC-MRI and CFD. CONCLUSIONS These findings give confidence to future haemodynamic studies using CFD technology. For the first time, the morphological inconsistency between the PCMRI model and others is found to affect the measurement of local flow patterns.
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Affiliation(s)
- Yujie Li
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Yuuya Yoneyama
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan.,Department of Radiology, Fujita Health University Hospital, Toyoake, Aichi, Japan
| | - Haruo Isoda
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan.,Brain and Mind Research Center, Nagoya University, Nagoya, Aichi, Japan
| | - Masaki Terada
- Department of Diagnostic Radiological Technology, Iwata City Hospital, Iwata, Shizuoka, Japan
| | - Takafumi Kosugi
- Renaissance of Technology Corporation, Hamamatsu, Shizuoka, Japan
| | - Takashi Kosugi
- Renaissance of Technology Corporation, Hamamatsu, Shizuoka, Japan
| | - Mingzi Zhang
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Makoto Ohta
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
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7
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Li Y, Verrelli DI, Yang W, Qian Y, Chong W. A pilot validation of CFD model results against PIV observations of haemodynamics in intracranial aneurysms treated with flow-diverting stents. J Biomech 2020; 100:109590. [DOI: 10.1016/j.jbiomech.2019.109590] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 12/07/2019] [Accepted: 12/18/2019] [Indexed: 11/30/2022]
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8
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Dmytriw AA, Phan K, Moore JM, Pereira VM, Krings T, Thomas AJ. On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management. AJNR Am J Neuroradiol 2019; 40:591-600. [PMID: 30894358 DOI: 10.3174/ajnr.a6006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/25/2019] [Indexed: 12/15/2022]
Abstract
Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.
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Affiliation(s)
- A A Dmytriw
- From the Department of Medical Imaging (A.A.D., V.M.P., T.K.), Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada .,Neurosurgical Service (A.A.D., K.P., J.M.M., A.J.T.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - K Phan
- Neurosurgical Service (A.A.D., K.P., J.M.M., A.J.T.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.,NeuroSpine Surgery Research Group (K.P.), Prince of Wales Private Hospital, Sydney, Australia
| | - J M Moore
- Neurosurgical Service (A.A.D., K.P., J.M.M., A.J.T.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - V M Pereira
- From the Department of Medical Imaging (A.A.D., V.M.P., T.K.), Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - T Krings
- From the Department of Medical Imaging (A.A.D., V.M.P., T.K.), Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - A J Thomas
- Neurosurgical Service (A.A.D., K.P., J.M.M., A.J.T.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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9
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Mine B, Bonnet T, Vazquez-Suarez JC, Iosif C, Lubicz B. Comparison of stents used for endovascular treatment of intracranial aneurysms. Expert Rev Med Devices 2018; 15:793-805. [DOI: 10.1080/17434440.2018.1538779] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Benjamin Mine
- Department of Interventional Neuroradiology, University Hospital Erasme, Brussels, Belgium
| | - Thomas Bonnet
- Department of Interventional Neuroradiology, University Hospital Erasme, Brussels, Belgium
| | | | - Christina Iosif
- Department of Interventional Neuroradiology, University Hospital Erasme, Brussels, Belgium
| | - Boris Lubicz
- Department of Interventional Neuroradiology, University Hospital Erasme, Brussels, Belgium
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10
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Ha H, Koo HJ, Huh HK, Kim GB, Kweon J, Kim N, Kim YH, Kang JW, Lim TH, Song JK, Lee SJ, Yang DH. Effect of pannus formation on the prosthetic heart valve: In vitro demonstration using particle image velocimetry. PLoS One 2018; 13:e0199792. [PMID: 29953485 PMCID: PMC6023143 DOI: 10.1371/journal.pone.0199792] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 06/13/2018] [Indexed: 02/06/2023] Open
Abstract
Although hemodynamic influence of the subprosthetic tissue, termed as pannus, may contribute to prosthetic aortic valve dysfunction, the relationship between pannus extent and hemodynamics in the prosthetic valve has rarely been reported. We investigated the fluid dynamics of pannus formation using in vitro experiments with particle image velocimetry. Subvalvular pannus formation caused substantial changes in prosthetic valve transvalvular peak velocity, transvalvular pressure gradient (TPG) and opening angle. Maximum flow velocity and corresponding TPG were mostly affected by pannus width. When the pannus width was 25% of the valve diameter, pannus formation elevated TPG to >2.5 times higher than that without pannus formation. Opening dysfunction was observed only for a pannus involvement angle of 360°. Although circumferential pannus with an involvement angle of 360° decreased the opening angle of the valve from approximately 82° to 58°, eccentric pannus with an involvement angle of 180° did not induce valve opening dysfunction. The pannus involvement angle largely influenced the velocity flow field at the aortic sinus and corresponding hemodynamic indices, including wall shear stress, principal shear stress and viscous energy loss distributions. Substantial discrepancy between the velocity-based TPG estimation and direct pressure measurements was observed for prosthetic valve flow with pannus formation.
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Affiliation(s)
- Hojin Ha
- Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon, South Korea
| | - Hyun Jung Koo
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Hyung Kyu Huh
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Guk Bae Kim
- Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jihoon Kweon
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Namkug Kim
- Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Young-Hak Kim
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Joon-Won Kang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Tae-Hwan Lim
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Jae-Kwan Song
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Sang Joon Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Dong Hyun Yang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
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11
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Bouillot P, Brina O, Delattre BMA, Ouared R, Pellaton A, Yilmaz H, Machi P, Lovblad KO, Farhat M, Pereira VM, Vargas MI. Neurovascular stent artifacts in 3D-TOF and 3D-PCMRI: Influence of stent design on flow measurement. Magn Reson Med 2018; 81:560-572. [DOI: 10.1002/mrm.27352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/22/2018] [Accepted: 04/19/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Pierre Bouillot
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
- Laboratory for Hydraulic Machines (LMH); École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - Olivier Brina
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
- Division of Neuroradiology, Department of Medical Imaging; Toronto Western Hospital, University Health Network; Toronto Ontario Canada
| | | | - Rafik Ouared
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Alain Pellaton
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Hasan Yilmaz
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Paolo Machi
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Karl-Olof Lovblad
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Mohamed Farhat
- Laboratory for Hydraulic Machines (LMH); École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - Vitor Mendes Pereira
- Departement of Neuroradiology; Geneva University Hospitals; 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
| | - Maria Isabel Vargas
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
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12
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Computational Fluid Dynamics Modeling of the Human Pulmonary Arteries with Experimental Validation. Ann Biomed Eng 2018; 46:1309-1324. [PMID: 29786774 DOI: 10.1007/s10439-018-2047-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 05/10/2018] [Indexed: 12/22/2022]
Abstract
Pulmonary hypertension (PH) is a chronic progressive disease characterized by elevated pulmonary arterial pressure, caused by an increase in pulmonary arterial impedance. Computational fluid dynamics (CFD) can be used to identify metrics representative of the stage of PH disease. However, experimental validation of CFD models is often not pursued due to the geometric complexity of the model or uncertainties in the reproduction of the required flow conditions. The goal of this work is to validate experimentally a CFD model of a pulmonary artery phantom using a particle image velocimetry (PIV) technique. Rapid prototyping was used for the construction of the patient-specific pulmonary geometry, derived from chest computed tomography angiography images. CFD simulations were performed with the pulmonary model with a Reynolds number matching those of the experiments. Flow rates, the velocity field, and shear stress distributions obtained with the CFD simulations were compared to their counterparts from the PIV flow visualization experiments. Computationally predicted flow rates were within 1% of the experimental measurements for three of the four branches of the CFD model. The mean velocities in four transversal planes of study were within 5.9 to 13.1% of the experimental mean velocities. Shear stresses were qualitatively similar between the two methods with some discrepancies in the regions of high velocity gradients. The fluid flow differences between the CFD model and the PIV phantom are attributed to experimental inaccuracies and the relative compliance of the phantom. This comparative analysis yielded valuable information on the accuracy of CFD predicted hemodynamics in pulmonary circulation models.
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13
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Dholakia RJ, Kappel AD, Pagano A, Woo HH, Lieber BB, Fiorella DJ, Sadasivan C. In vitro angiographic comparison of the flow-diversion performance of five neurovascular stents. Interv Neuroradiol 2017; 24:150-161. [PMID: 29239685 DOI: 10.1177/1591019917748317] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background and purpose Data differentiating flow diversion properties of commercially available low- and high-porosity stents are limited. This in vitro study applies angiographic analysis of intra-aneurysmal flow to compare the flow-diversion performance of five neurovascular devices in idealized sidewall and bifurcation aneurysm models. Methods Five commercial devices (Enterprise, Neuroform, LVIS, FRED, and Pipeline) were implanted in silicone sidewall and bifurcation aneurysm models under physiological average flow of blood analog fluid. High-speed angiographic images were acquired pre- and post-device implantation and contrast concentration-time curves within the aneurysm were recorded. The curves were quantified with five parameters to assess changes in contrast transport, and thus aneurysm hemodynamics, due to each device. Results Inter-device flow-diversion performance was more easily distinguished in the sidewall model than the bifurcation model. There were no obvious overall statistical trends in the bifurcation parameters but the Pipeline performed marginally better than the other devices. In the sidewall geometry, overall evidence suggests that the LVIS performed better than the Neuroform and Enterprise. The Pipeline and FRED devices were statistically superior to the three stents and Pipeline was superior to FRED in all sidewall parameters evaluated. Conclusions Based on this specific set of experiments, lower-porosity flow diverters perform significantly better in reducing intra-aneurysmal flow activity than higher-porosity stents in sidewall-type geometries. The LVIS device is potentially a better flow diverter than the Neuroform and Enterprise devices, while the Pipeline is potentially better than the FRED.
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Affiliation(s)
- Ronak J Dholakia
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Ari D Kappel
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Andrew Pagano
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Henry H Woo
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Baruch B Lieber
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - David J Fiorella
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Chander Sadasivan
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
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Four-Dimensional Phase Contrast Magnetic Resonance Imaging Protocol Optimization Using Patient-Specific 3-Dimensional Printed Replicas for In Vivo Imaging Before and After Flow Diverter Placement. World Neurosurg 2017. [DOI: 10.1016/j.wneu.2017.06.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Sarrami-Foroushani A, Lassila T, Frangi AF. Virtual endovascular treatment of intracranial aneurysms: models and uncertainty. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28488754 DOI: 10.1002/wsbm.1385] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/09/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023]
Abstract
Virtual endovascular treatment models (VETMs) have been developed with the view to aid interventional neuroradiologists and neurosurgeons to pre-operatively analyze the comparative efficacy and safety of endovascular treatments for intracranial aneurysms. Based on the current state of VETMs in aneurysm rupture risk stratification and in patient-specific prediction of treatment outcomes, we argue there is a need to go beyond personalized biomechanical flow modeling assuming deterministic parameters and error-free measurements. The mechanobiological effects associated with blood clot formation are important factors in therapeutic decision making and models of post-treatment intra-aneurysmal biology and biochemistry should be linked to the purely hemodynamic models to improve the predictive power of current VETMs. The influence of model and parameter uncertainties associated to each component of a VETM is, where feasible, quantified via a random-effects meta-analysis of the literature. This allows estimating the pooled effect size of these uncertainties on aneurysmal wall shear stress. From such meta-analyses, two main sources of uncertainty emerge where research efforts have so far been limited: (1) vascular wall distensibility, and (2) intra/intersubject systemic flow variations. In the future, we suggest that current deterministic computational simulations need to be extended with strategies for uncertainty mitigation, uncertainty exploration, and sensitivity reduction techniques. WIREs Syst Biol Med 2017, 9:e1385. doi: 10.1002/wsbm.1385 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Ali Sarrami-Foroushani
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
| | - Toni Lassila
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
| | - Alejandro F Frangi
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
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16
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Bouillot P, Delattre BMA, Brina O, Ouared R, Farhat M, Chnafa C, Steinman DA, Lovblad KO, Pereira VM, Vargas MI. 3D phase contrast MRI: Partial volume correction for robust blood flow quantification in small intracranial vessels. Magn Reson Med 2017; 79:129-140. [PMID: 28244132 DOI: 10.1002/mrm.26637] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE Recent advances in 3D-PCMRI (phase contrast MRI) sequences allow for measuring the complex hemodynamics in cerebral arteries. However, the small size of these vessels vs spatial resolution can lead to non-negligible partial volume artifacts, which must be taken into account when computing blood flow rates. For this purpose, we combined the velocity information provided by 3D-PCMRI with vessel geometry measured with 3DTOF (time of flight MRI) or 3DRA (3D rotational angiography) to correct the partial volume effects in flow rate assessments. METHODS The proposed methodology was first tested in vitro on cylindrical and patient specific vessels subject to fully controlled pulsatile flows. Both 2D- and 3D-PCMRI measurements using various spatial resolutions ranging from 20 to 1.3 voxels per vessel diameter were analyzed and compared with flowmeter baseline. Second, 3DTOF, 2D- and 3D-PCMRI measurements were performed in vivo on 35 patients harboring internal carotid artery (ICA) aneurysms indicated for endovascular treatments requiring 3DRA imaging. RESULTS The in vitro 2D- and 3D-PCMRI mean flow rates assessed with partial volume correction showed very low sensitivity to the acquisition resolution above ≈2 voxels per vessel diameter while uncorrected flow rates deviated critically when decreasing the spatial resolution. 3D-PCMRI flow rates measured in vivo in ICA agreed very well with 2D-PCMRI data and a good flow conservation was observed at the C7 bifurcation. Globally, partial volume correction led to 10-15% lower flow rates than uncorrected values as those reported in most of the published studies on intracranial flows. CONCLUSION Partial volume correction may improve the accuracy of PCMRI flow rate measurements especially in small vessels such as intracranial arteries. Magn Reson Med 79:129-140, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Pierre Bouillot
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bénédicte M A Delattre
- Division of Radiology, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Olivier Brina
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Rafik Ouared
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mohamed Farhat
- Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christophe Chnafa
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - David A Steinman
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - Karl-Olof Lovblad
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Vitor M Pereira
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada.,Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Maria I Vargas
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
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17
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Dholakia R, Sadasivan C, Fiorella DJ, Woo HH, Lieber BB. Hemodynamics of Flow Diverters. J Biomech Eng 2017; 139:2569375. [DOI: 10.1115/1.4034932] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Indexed: 01/17/2023]
Abstract
Cerebral aneurysms are pathological focal evaginations of the arterial wall at and around the junctions of the circle of Willis. Their tenuous walls predispose aneurysms to leak or rupture leading to hemorrhagic strokes with high morbidity and mortality rates. The endovascular treatment of cerebral aneurysms currently includes the implantation of fine-mesh stents, called flow diverters, within the parent artery bearing the aneurysm. By mitigating flow velocities within the aneurysmal sac, the devices preferentially induce thrombus formation in the aneurysm within hours to days. In response to the foreign implant, an endothelialized arterial layer covers the luminal surface of the device over a period of days to months. Organization of the intraneurysmal thrombus leads to resorption and shrinkage of the aneurysm wall and contents, eventually leading to beneficial remodeling of the pathological site to a near-physiological state. The devices' primary function of reducing flow activity within aneurysms is corollary to their mesh structure. Complete specification of the device mesh structure, or alternately device permeability, necessarily involves the quantification of two variables commonly used to characterize porous media—mesh porosity and mesh pore density. We evaluated the flow alteration induced by five commercial neurovascular devices of varying porosity and pore density (stents: Neuroform, Enterprise, and LVIS; flow diverters: Pipeline and FRED) in an idealized sidewall aneurysm model. As can be expected in such a model, all devices substantially reduced intraneurysmal kinetic energy as compared to the nonstented case with the coarse-mesh stents inducing a 65–80% reduction whereas the fine-mesh flow diverters induced a near-complete flow stagnation (∼98% reduction). We also note a trend toward greater device efficacy (lower intraneurysmal flow) with decreasing device porosity and increasing device pore density. Several such flow studies have been and are being conducted in idealized as well as patient-derived geometries with the overarching goals of improving device design, facilitating treatment planning (what is the optimal device for a specific aneurysm), and predicting treatment outcome (will a specific aneurysm treated with a specific device successfully occlude over the long term). While the results are generally encouraging, there is poor standardization of study variables between different research groups, and any consensus will only be reached after standardized studies are conducted on collectively large datasets. Biochemical variables may have to be incorporated into these studies to maximize predictive values.
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Affiliation(s)
- Ronak Dholakia
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Chander Sadasivan
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - David J. Fiorella
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Henry H. Woo
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Baruch B. Lieber
- Professor Department of Neurological Surgery, Stony Brook University Medical Center, HSC T12, Room 080, 100 Nicolls Road, Stony Brook, NY 11794-8122 e-mail:
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18
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Ouared R, Larrabide I, Brina O, Bouillot P, Erceg G, Yilmaz H, Lovblad KO, Mendes Pereira V. Computational fluid dynamics analysis of flow reduction induced by flow-diverting stents in intracranial aneurysms: a patient-unspecific hemodynamics change perspective. J Neurointerv Surg 2016; 8:1288-1293. [DOI: 10.1136/neurintsurg-2015-012154] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/06/2016] [Accepted: 01/11/2016] [Indexed: 11/04/2022]
Abstract
Background and purposeFlow-diverter stents (FDSs) have been used effectively to treat large neck and complex saccular aneurysms on the anterior carotid circulation. Intra-aneurysmal flow reduction induces progressive aneurysm thrombosis in most patients. Understanding the degree of flow modification necessary to induce complete aneurysm occlusion among patients with considerable hemodynamics variability may be important for treatment planning.Materials and methodsPatients with incidental intracranial saccular aneurysms who underwent FDS endovascular procedures were included and studied for a 12 months’ follow-up period. We used computational fluid dynamics on patient-specific geometries from 3D rotational angiography without and with virtual stent placement and thus compared intra-aneurysmal hemodynamic problems. Receiver operating characteristic analysis was used to estimate the stent:no-stent minimum hemodynamic ratio thresholds that significantly (p≤0.05) determined the condition necessary for long-term (12 months) aneurysm occlusion.ResultsWe included 12 consecutive patients with sidewall aneurysms located in the internal carotid or vertebral artery. The measured porosity of the 12 deployed virtual FDSs was 83±3% (mean±SD). Nine aneurysms were occluded during the 12 months’ follow-up, whereas three were not. A significant (p=0.05) area under the curve (AUC) was found for spatiotemporal mean velocity reduction in the aneurysms: AUC=0.889±0.113 (mean±SD) corresponding to a minimum velocity reduction threshold of 0.353 for occlusion to occur. The 95% CI of the AUC was 0.66 to 1.00. The sensitivity and specificity of the method were ∼99% and ∼67%, respectively. For both wall shear stress and pressure reductions in aneurysms no thresholds could be determined: AUC=0.63±0.16 (p=0.518) and 0.67±0.165 (p=0.405), respectively.ConclusionsFor successful FDS treatment the post-stent average velocity in sidewall intracranial aneurysms must be reduced by at least one-third from the initial pre-stent conditions.
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Pérez MA, Henkes H, Bouillot P, Brina O, Slater LA, Pereira VM. Intra-aneurysmal hemodynamics: evaluation of pCONus and pCANvas bifurcation aneurysm devices using DSA optical flow imaging. J Neurointerv Surg 2015; 8:1197-1201. [PMID: 26701125 PMCID: PMC5099319 DOI: 10.1136/neurintsurg-2015-011927] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/02/2015] [Indexed: 11/29/2022]
Abstract
Background Implantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging stents like Solitaire AB, can be used; however, bifurcation devices like pCONus and pCANvas are especially designed for WCT. These devices provide additional support for coil implantation owing to intraluminal nylon fibers (pCONus) or membranes (pCANvas) covering the intracranial aneurysm neck. Objective Assessment of the intra-aneurysmal hemodynamic impact of these three devices: a regular intracranial stent (Solitaire AB) and two bifurcation devices (pCONus and pCANvas). Material and methods An in vitro experiment was set up using a silicone model of a basilar tip aneurysm filled with blood mimicking fluid under a pulsatile circulation. Solitaire AB, pCONus, and pCANvas were successively implanted in the model for hemodynamic evaluation. High frame rate DSA series were acquired under various conditions. Intra-aneurysmal flow changes, including mean aneurysm flow amplitude ratio (R), were subsequently assessed by the optical flow method, measuring the detector velocity field before and after device implantations. Results pCONus and Solitaire minimally reduced the intra-aneurysmal flow (R=0.96, p=0.17 and R=0.91, p=0.01, respectively), whereas pCANvas strongly diminished the intra-aneurysmal flow (R=0.41, p=5×10−12). Conclusions Waffle cone deployment of stents and technique-specific devices had no undesirable effect on the intra-aneurysmal flow. In particular, no increased flow was redirected into the aneurysm sac. The intraluminal membrane of the pCANvas strongly reduced the intra-aneurysmal flow, potentially preventing recanalization problems.
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Affiliation(s)
- Marta Aguilar Pérez
- Klinik für Neuroradiologie, Neurozentrum, Klinikum Stuttgart, Stuttgart, Germany
| | - Hans Henkes
- Klinik für Neuroradiologie, Neurozentrum, Klinikum Stuttgart, Stuttgart, Germany
| | - Pierre Bouillot
- Interventional Neuroradiology Unit, University Hospital of Geneva, Geneva, Switzerland Laboratory for Hydraulic Machines (LMH), Ecole Polytechnique Fédérale de Lausanne (EPFL), Avenue de Cour 33bis, CH-1007 Lausanne, Switzerland
| | - Olivier Brina
- Interventional Neuroradiology Unit, University Hospital of Geneva, Geneva, Switzerland
| | - Lee-Anne Slater
- Joint Division of Medical Imaging, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Vitor Mendes Pereira
- Joint Division of Medical Imaging, 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
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Nam HG, Yoo CM, Baek SM, Kim HK, Shin JH, Hwang MH, Jo GE, Kim KS, Cho JH, Lee SH, Kim HC, Lim CH, Choi H, Sun K. Enhancement of Mechanical Properties and Testing of Nitinol Stents in Cerebral Aneurysm Simulation Models. Artif Organs 2015; 39:E213-26. [DOI: 10.1111/aor.12564] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hyo Geun Nam
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Chang Min Yoo
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Seoung Min Baek
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Han Ki Kim
- Department of Mechanical Engineering; Dankook University; Yongin Korea
| | - Jae Hee Shin
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Min Ho Hwang
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Ga Eun Jo
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Kyong Soo Kim
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Jae Hwa Cho
- College of Medicine; Radiation Applied Life Science; Seoul National University; Seoul Korea
| | - Seung Hoon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery; College of Medicine; Korea University; Seoul Korea
| | - Ho Chul Kim
- Department of Radiological Science; Eulji University; Seongnam Korea
| | - Chun Hak Lim
- Department of Anesthesiology and Pain Medicine; College of Medicine; Korea University; Seoul Korea
| | - Hyuk Choi
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul Korea
| | - Kyung Sun
- Thoracic and Cardiovascular Surgery; College of Medicine; Korea University; Seoul Korea
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Bouillot P, Brina O, Ouared R, Lovblad KO, Farhat M, Mendes Pereira V. Hemodynamic transition driven by stent porosity in sidewall aneurysms. J Biomech 2015; 48:1300-9. [DOI: 10.1016/j.jbiomech.2015.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/04/2015] [Accepted: 02/15/2015] [Indexed: 10/23/2022]
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