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Vuong TNAM, Bartolf-Kopp M, Andelovic K, Jungst T, Farbehi N, Wise SG, Hayward C, Stevens MC, Rnjak-Kovacina J. Integrating Computational and Biological Hemodynamic Approaches to Improve Modeling of Atherosclerotic Arteries. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2307627. [PMID: 38704690 DOI: 10.1002/advs.202307627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/12/2024] [Indexed: 05/07/2024]
Abstract
Atherosclerosis is the primary cause of cardiovascular disease, resulting in mortality, elevated healthcare costs, diminished productivity, and reduced quality of life for individuals and their communities. This is exacerbated by the limited understanding of its underlying causes and limitations in current therapeutic interventions, highlighting the need for sophisticated models of atherosclerosis. This review critically evaluates the computational and biological models of atherosclerosis, focusing on the study of hemodynamics in atherosclerotic coronary arteries. Computational models account for the geometrical complexities and hemodynamics of the blood vessels and stenoses, but they fail to capture the complex biological processes involved in atherosclerosis. Different in vitro and in vivo biological models can capture aspects of the biological complexity of healthy and stenosed vessels, but rarely mimic the human anatomy and physiological hemodynamics, and require significantly more time, cost, and resources. Therefore, emerging strategies are examined that integrate computational and biological models, and the potential of advances in imaging, biofabrication, and machine learning is explored in developing more effective models of atherosclerosis.
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Affiliation(s)
| | - Michael Bartolf-Kopp
- Department of Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication (IFB), KeyLab Polymers for Medicine of the Bavarian Polymer Institute (BPI), University of Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Kristina Andelovic
- Department of Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication (IFB), KeyLab Polymers for Medicine of the Bavarian Polymer Institute (BPI), University of Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Tomasz Jungst
- Department of Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication (IFB), KeyLab Polymers for Medicine of the Bavarian Polymer Institute (BPI), University of Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
- Department of Orthopedics, Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, 3584, Netherlands
| | - Nona Farbehi
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
- Tyree Institute of Health Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- Garvan Weizmann Center for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Steven G Wise
- School of Medical Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Christopher Hayward
- St Vincent's Hospital, Sydney, Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
| | - Michael Charles Stevens
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
| | - Jelena Rnjak-Kovacina
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, 2052, Australia
- Tyree Institute of Health Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- Australian Centre for NanoMedicine (ACN), University of New South Wales, Sydney, NSW, 2052, Australia
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Cayron AF, Morel S, Allémann E, Bijlenga P, Kwak BR. Imaging of intracranial aneurysms in animals: a systematic review of modalities. Neurosurg Rev 2023; 46:56. [PMID: 36786880 PMCID: PMC9928939 DOI: 10.1007/s10143-023-01953-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/28/2022] [Accepted: 01/23/2023] [Indexed: 02/15/2023]
Abstract
Intracranial aneurysm (IA) animal models are paramount to study IA pathophysiology and to test new endovascular treatments. A number of in vivo imaging modalities are available to characterize IAs at different stages of development in these animal models. This review describes existing in vivo imaging techniques used so far to visualize IAs in animal models. We systematically searched for studies containing in vivo imaging of induced IAs in animal models in PubMed and SPIE Digital library databases between 1 January 1945 and 13 July 2022. A total of 170 studies were retrieved and reviewed in detail, and information on the IA animal model, the objective of the study, and the imaging modality used was collected. A variety of methods to surgically construct or endogenously induce IAs in animals were identified, and 88% of the reviewed studies used surgical methods. The large majority of IA imaging in animals was performed for 4 reasons: basic research for IA models, testing of new IA treatment modalities, research on IA in vivo imaging of IAs, and research on IA pathophysiology. Six different imaging techniques were identified: conventional catheter angiography, computed tomography angiography, magnetic resonance angiography, hemodynamic imaging, optical coherence tomography, and fluorescence imaging. This review presents and discusses the advantages and disadvantages of all in vivo IA imaging techniques used in animal models to help future IA studies finding the most appropriate IA imaging modality and animal model to answer their research question.
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Affiliation(s)
- Anne F Cayron
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, CH-1211, Geneva, Switzerland
- Geneva Center for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Sandrine Morel
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, CH-1211, Geneva, Switzerland
- Geneva Center for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Clinical Neurosciences - Division of Neurosurgery, Geneva University Hospitals and Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Eric Allémann
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Philippe Bijlenga
- Department of Clinical Neurosciences - Division of Neurosurgery, Geneva University Hospitals and Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel-Servet 1, CH-1211, Geneva, Switzerland.
- Geneva Center for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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Xu J, Karmonik C, Yu Y, Lv N, Shi Z, Liu JM, Huang Q. Modeling Flow Diverters using a Porous Medium Approach: A Fast Alternative to Virtual Flow Diverter Deployment. World Neurosurg 2022; 164:e501-e508. [PMID: 35552028 DOI: 10.1016/j.wneu.2022.04.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and eliminating the aneurysm. Numerical simulations based on virtual FD deployment allow the assessment of the complex nature of aneurismal flow changes before the actual intervention but are demanding on computational resources. Here, we evaluate an alternative strategy of modeling FD effects for the Tubridge system using a porous medium. The goal of this study is to reduce demands on time and complexity of the simulation procedure for applications in clinical research. METHODS Ten patient-specific aneurysm models were reconstructed from retrospectively collected diagnostic 3D-DSA images. Virtual FDs were deployed (SolidWorks, Meshmixer) and corresponding porous medium patches were constructed at the ostium with a research CFD prototype (Siemens Healthineers, Forchheim, Germany). Hemodynamic conditions were simulated in two approaches. RESULTS Hemodynamics inside the aneurysm based on these two approaches were compared. Both approaches yielded similar results. Mean wall shear stress (WSS) and mean pressure of the aneurysmal wall correlated significantly (r=0.8, r=1.0, p-value<0.05) as did mean velocity, mean pressure at a region inside the aneurysm, at the ostium and at a cross section containing the main vertex (for velocities r=0.9; for pressures r=1.0, p-value<0.05). The use of porous medium patches reduced the preparation and simulation time together by approximately 50%. CONCLUSION Using a porous medium approach yields comparable mean values for hemodynamic alterations compared to direct virtual FD simulations. Additionally, the porous medium approach greatly reduced the modeling complexity and computation time.
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Affiliation(s)
- Jinyu Xu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Christof Karmonik
- Translational Imaging Center, MRI core, Houston Methodist Research Institute, Houston TX, USA
| | - Ying Yu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Nan Lv
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhaoyue Shi
- Translational Imaging Center, MRI core, Houston Methodist Research Institute, Houston TX, USA
| | - Jian-Min Liu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Qinghai Huang
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
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Mu Z, Liu L, Sun Y, Gao B, Lv H, Zhao P, Liu Y, Wang Z. Multiphysics coupling numerical simulation of flow-diverting stents in the treatment of patients with pulsatile tinnitus. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3526. [PMID: 34463060 DOI: 10.1002/cnm.3526] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Patients with pulsatile tinnitus (PT) have unstable treatment effects after resurfacing surgery. Flow-diverting stents (FDS) are proposed as a potential method for the treatment of PT, but the therapeutic effect is not clear. This study aimed to investigate the efficacy of FDS in the treatment of patients with PT induced by sigmoid sinus diverticulum (SSD) and sigmoid sinus wall dehiscence (SSWD). In addition, we aimed to explore the treatment mechanism of PT. Transient-state multiphysics coupling numerical simulation method based on computed tomography angiography of five patients was used to clarify the biomechanical and acoustic states before and after FDS placement. FDS was placed to prevent the blood flow from impacting the vessel wall in the SSD and SSWD areas. Low blood flow velocity (<0.0391 m/s), high relative residence time (>10 Pa-1 ), and low wall shear stress of SSD might lead to thrombosis after FDS placement. The average pressure on the SSWD area of each patient decreased by 13.77%, 18.82%, 29.23%, 19.03%, and 11.20%. The average displacement of the vessel wall on the SSWD area showed acute pulsation and decreased by 15.29%, 14.64%, 30.22%, 41.03%, and 21.28%. The average sound pressure level at the tympanum decreased by 14.01%, 9.33%, 17.66%, 18.88%, and 25.18%, respectively. In brief, FDS was placed to avoid blood flow impacting vessels and reduce the vibration of vessels in the short term, thereby attenuating the degree of PT. The long-term prognosis was that the SSWD area was blocked after SSD thrombosis. Therefore, FDS might be an effective method for the treatment of PT induced by SSD and SSWD. This study would provide a theoretical basis for the treatment of PT and an exploration of FDS design in the treatment of PT.
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Affiliation(s)
- Zhenxia Mu
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Li Liu
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Yufeng Sun
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Bin Gao
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Han Lv
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Pengfei Zhao
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Youjun Liu
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Zhenchang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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Hadad S, Mut F, Kadirvel R, Ding YH, Kallmes D, Cebral JR. Evaluation of Outcome Prediction of Flow Diversion for Intracranial Aneurysms. AJNR Am J Neuroradiol 2021; 42:1973-1978. [PMID: 34446459 DOI: 10.3174/ajnr.a7263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 06/10/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Identifying and predicting which aneurysms are likely to quickly occlude and which ones are likely to remain open following treatment with flow-diverting devices is important to develop optimal patient management strategies. The purpose of this study was to evaluate predictions based on computational fluid dynamics models using the elastase rabbit aneurysm model. MATERIALS AND METHODS A series of 13 aneurysms created in rabbits were treated with flow diverters, and outcomes were angiographically assessed at 8 weeks' follow-up. Computational fluid dynamics models were constructed from pretreatment 3D rotational angiograms and Doppler ultrasound flow velocity measurements. Postimplantation mean aneurysm inflow rate and flow velocity were used to prospectively predict aneurysm occlusion blinded to the actual outcomes. Specifically, if both variables were below their corresponding thresholds, fast occlusion was predicted, while if one of them was above the threshold, slow or incomplete occlusion was predicted. RESULTS Of the 13 aneurysms included, 8 were incompletely occluded 8 weeks after treatment, and 5 were completely occluded. A total of 10 computational fluid dynamics-based predictions agreed with the angiographic outcome, reaching 77% accuracy, 80% sensitivity, and 75% specificity. Posttreatment mean velocity alone was able to achieve the same predictive power as the combination of inflow rate and velocity. CONCLUSIONS Subject-specific computational fluid dynamics models of the hemodynamic conditions created immediately after implantation of flow-diverting devices in experimental aneurysms created in rabbits are capable of prospectively predicting, with a reasonable accuracy, which aneurysms will completely occlude and which ones will remain incompletely occluded.
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Affiliation(s)
- S Hadad
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
| | - F Mut
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
| | - R Kadirvel
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - Y-H Ding
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - D Kallmes
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - J R Cebral
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
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Kuribara T, Mikami T, Iihoshi S, Hirano T, Sasamori D, Nonaka T, Mikuni N. Virtual test occlusion for assessing ischemic tolerance using computational fluid dynamics. Surg Neurol Int 2021; 12:378. [PMID: 34513145 PMCID: PMC8422534 DOI: 10.25259/sni_439_2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 05/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ischemic tolerance has been evaluated by the balloon test occlusion (BTO) for cerebral aneurysms and tumors that might require parent artery occlusion during surgery. However, because of its invasiveness, a non-invasive evaluation method is needed. In this study, we assessed the possibility of virtual test occlusion using computational fluid dynamics (CFD) as a non-invasive alternative to BTO for evaluating ischemic tolerance. METHODS Twenty-one patients who underwent BTO were included in the study. Virtual test occlusion was performed using CFD analysis, and the flow rate (FR) and wall shear stress (WSS) of the middle cerebral artery on the occlusion side were calculated. The correlations between these parameters and examination data including the parameters of computed tomography perfusion during BTO were assessed and the cutoff value of CFD parameters for detecting the good collateral group was calculated. RESULTS The FR was strongly correlated with mean transit time (MTT) during BTO and moderately correlated with collateral flow grade based on angiographic appearance. The WSS was moderately correlated with collateral flow grade, mean stump pressure (MSP), and MTT. Furthermore, the FR and WSS were strongly correlated with the total FR and the diameters of the inlet vessels. The cutoff value of FR for detecting the good collateral group was 126.2 mL/min, while that of the WSS was 4.54 Pa. CONCLUSION The parameters obtained through CFD analysis were correlated with collateral flow grade and MSP in addition to MTT. CFD analysis may be useful to evaluate ischemic tolerance as a non-invasive alternative to BTO.
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Affiliation(s)
- Tomoyoshi Kuribara
- Department of Neurosurgery, Sapporo Medical University, Sapporo, Hokkaido, Japan
| | - Takeshi Mikami
- Department of Neurosurgery, Sapporo Medical University, Sapporo, Hokkaido, Japan
| | - Satoshi Iihoshi
- Department of Endovascular Neurosurgery, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan
| | - Toru Hirano
- Division of Radiology, Sapporo Medical University Hospital, Sapporo, Hokkaido, Japan
| | - Daisuke Sasamori
- Division of Radiology, Sapporo Shiroishi Memorial Hospital, Sapporo, Hokkaido, Japan
| | - Tadashi Nonaka
- Department of Neurosurgery, Sapporo Shiroishi Memorial Hospital, Sapporo, Hokkaido, Japan
| | - Nobuhiro Mikuni
- Department of Neurosurgery, Sapporo Medical University, Sapporo, Hokkaido, Japan
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Chivukula VK, Marsh L, Chassagne F, Barbour MC, Kelly CM, Levy S, Geindreau C, Roscoat SRD, Kim LJ, Levitt MR, Aliseda A. Lagrangian Trajectory Simulation of Platelets and Synchrotron Microtomography Augment Hemodynamic Analysis of Intracranial Aneurysms Treated With Embolic Coils. J Biomech Eng 2021; 143:1102198. [PMID: 33665669 DOI: 10.1115/1.4050375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Indexed: 11/08/2022]
Abstract
As frequency of endovascular treatments for intracranial aneurysms increases, there is a growing need to understand the mechanisms for coil embolization failure. Computational fluid dynamics (CFD) modeling often simplifies modeling the endovascular coils as a homogeneous porous medium (PM), and focuses on the vascular wall endothelium, not considering the biomechanical environment of platelets. These assumptions limit the accuracy of computations for treatment predictions. We present a rigorous analysis using X-ray microtomographic imaging of the coils and a combination of Lagrangian (platelet) and Eulerian (endothelium) metrics. Four patient-specific, anatomically accurate in vitro flow phantoms of aneurysms are treated with the same patient-specific endovascular coils. Synchrotron tomography scans of the coil mass morphology are obtained. Aneurysmal hemodynamics are computationally simulated before and after coiling, using patient-specific velocity/pressure measurements. For each patient, we analyze the trajectories of thousands of platelets during several cardiac cycles, and calculate residence times (RTs) and shear exposure, relevant to thrombus formation. We quantify the inconsistencies of the PM approach, comparing them with coil-resolved (CR) simulations, showing the under- or overestimation of key hemodynamic metrics used to predict treatment outcomes. We fully characterize aneurysmal hemodynamics with converged statistics of platelet RT and shear stress history (SH), to augment the traditional wall shear stress (WSS) on the vascular endothelium. Incorporating microtomographic scans of coil morphology into hemodynamic analysis of coiled intracranial aneurysms, and augmenting traditional analysis with Lagrangian platelet metrics improves CFD predictions, and raises the potential for understanding and clinical translation of computational hemodynamics for intracranial aneurysm treatment outcomes.
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Affiliation(s)
| | - Laurel Marsh
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195
| | - Fanette Chassagne
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195
| | - Michael C Barbour
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195
| | - Cory M Kelly
- Department of Neurological Surgery, University of Washington, Seattle, WA 98195; Stroke and Applied Neuroscience Center, University of Washington, Seattle, WA 98195
| | - Samuel Levy
- Department of Neurological Surgery, University of Washington, Seattle, WA 98195; Stroke and Applied Neuroscience Center, University of Washington, Seattle, WA 98195
| | - Christian Geindreau
- Laboratoire 3SR, Université Grenoble Alpes, 1270 Rue de la Piscine, Gières 38610, France
| | | | - Louis J Kim
- Department of Neurological Surgery, University of Washington, Seattle, WA 98195; Stroke and Applied Neuroscience Center, University of Washington, Seattle, WA 98195; Department of Radiology, University of Washington, Seattle, WA 98195
| | - Michael R Levitt
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195; Department of Neurological Surgery, University of Washington, Seattle, WA 98195; Stroke and Applied Neuroscience Center, University of Washington, Seattle, WA 98195; Department of Radiology, University of Washington, Seattle, WA 98195
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195; Department of Neurological Surgery, University of Washington, Seattle, WA 98195; Stroke and Applied Neuroscience Center, University of Washington, Seattle, WA 98195
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Preoperatively estimated graft flow rate contributes to the improvement of hemodynamics in revascularization for Moyamoya disease. J Stroke Cerebrovasc Dis 2020; 30:105450. [PMID: 33171424 DOI: 10.1016/j.jstrokecerebrovasdis.2020.105450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/06/2020] [Accepted: 10/31/2020] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass operation is an effective treatment for patients with Moyamoya disease, and the hemodynamic parameters are reported to be improved after operation. However, there is no report concerning hemodynamic changes from the viewpoint of the preoperative anatomical structure of grafts. In this study, we evaluated the correlation between the preoperatively estimated blood flow of the graft obtained through image-based computational fluid dynamics (CFD) analysis and the hemodynamic changes in the acute phase after revascularization. MATERIALS AND METHODS A total of 30 hemispheric sides of 23 patients were examined. The blood flow, that is, flow rate (FR) of the STA branches that were anastomosed to the MCA was evaluated using CFD analysis based on computed tomography (CT) angiography imaging data. The correlations between the FR and the hemodynamic changes in the acute phase after revascularization obtained through CT perfusion were assessed. RESULTS The preoperatively estimated FR of the graft was moderately correlated with the changes in the mean transit time significantly and weakly correlated with those in the cerebral blood flow and cerebral blood volume. In addition, the FR was strongly correlated with age and the diameter of the STA from the origin to the bifurcation. CONCLUSION The preoperatively estimated FR of the graft obtained through image-based CFD analysis contributed to the improvement of the mean transit time after revascularization. Because the FR of the graft was associated with the diameter of the STA, the size of the STA might be an important factor in postoperative hemodynamic changes. This might lead to the risk assessment of acute drastic hemodynamic changes as cerebral hyperperfusion, and consequently, better surgical outcomes might be expected.
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Ding A, Braschkat A, Guber A, Cattaneo G. New Concept of Patient-specific Flow Diversion Treatment of Intracranial Aneurysms : Design Aspects and in vitro Fluid Dynamics. Clin Neuroradiol 2020; 31:671-679. [PMID: 32651611 DOI: 10.1007/s00062-020-00930-1] [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] [Received: 04/17/2020] [Accepted: 06/20/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Current flow diverter (FD) designs limit the possibilities to achieve ideal functional parameters for intra-aneurysmal flow alteration in the implanted state. In this work, we evaluate the technical feasibility of a new patient-specific FD concept and the impact on intra-aneurysmal flow reduction compared to standard FD. METHODS Based on a literature review, we defined functional requirements, followed by the design and manufacturing of two different prototypes, which we implanted in a patient-specific phantom model. Functional porosity distributions and contour parameters were evaluated in the implanted state and compared to standard FD. Subsequently, we carried out a series of particle image velocimetry (PIV) measurements, in order to assess the impact on intra-aneurysmal flow. RESULTS With both patient-specific prototypes, it was possible to achieve stronger intra-aneurysmal flow reductions in terms of maximum and mean velocity and vorticity than a standard FD; however, one design showed a strong sensitivity against malpositioning. Overall, fluid dynamics parameters correlated with geometrical aspects such as the porosity and its grade of homogeneity. Beyond that, we found influences by the FD contour projection within the aneurysm, especially connected to the formation of in-jets. CONCLUSION Our results show that there is a technically feasible concept, which enables a more specific adjustment of functional FD parameters and more effective intra-aneurysmal flow reduction. This could potentially lead to improvements in the efficacy of aneurysm occlusion in cases with challenging fluid dynamics.
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Affiliation(s)
- Andreas Ding
- Acandis GmbH, R&D, Pforzheim, Baden-Württemberg, Germany. .,, Weltzienstr. 24, 76135, Karlsruhe, Germany.
| | | | - Andreas Guber
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Baden-Württemberg, Germany
| | - Giorgio Cattaneo
- Institute of Biomedical Engineering, University of Stuttgart, Stuttgart, Baden-Württemberg, Germany
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10
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Li W, Tian Z, Zhu W, Zhang YS, Wang K, Zhang Y, Wang Y, Yang X, Liu J. Hemodynamic Analysis of Postoperative Rupture of Unruptured Intracranial Aneurysms after Placement of Flow-Diverting Stents: A Matched Case-Control Study. AJNR Am J Neuroradiol 2019; 40:1916-1923. [PMID: 31624118 DOI: 10.3174/ajnr.a6256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/23/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Postoperative rupture of intracranial aneurysm has been reported as a fatal complication after flow-diverter placement. We assessed several hemodynamic variables to explore risk factors in the postoperative rupture process. MATERIALS AND METHODS We enrolled 10 patients with intracranial aneurysms, treated with flow diverters between September 2014 and December 2018, who experienced postoperative aneurysm rupture (postoperative aneurysm rupture group). We matched these subjects 1:2 with 20 patients with postoperative unruptured (postoperative unruptured group) intracranial aneurysms based on clinical and morphologic factors. Using computational fluid dynamics, we assessed hemodynamic changes pre- and posttreatment between the 2 groups on a number of qualitative and quantitative parameters. RESULTS In the postoperative aneurysm rupture group, the proportion of patients with aneurysms with an unstable flow pattern increased to 60.0% after treatment, while the proportion in the postoperative unruptured group decreased to 20.0%, a significant difference between the 2 groups (P = .028). Energy loss in the postoperative unruptured group decreased after treatment but increased in the postoperative aneurysm rupture group. The reduction ratio of energy loss showed a significant difference between the 2 groups (22.73% ± 53.59% for postoperative unruptured versus -158.81% ± 183.95% for postoperative aneurysm rupture, P = .02). Other parameters and changes of pre- and posttreatment hemodynamic parameters showed no significant difference between 2 groups. CONCLUSIONS Compared with pretreatment, unstable flow pattern and higher energy loss after Pipeline Embolization Device placement for intracranial aneurysm may be the important hemodynamic risk factors related to delayed aneurysm rupture.
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Affiliation(s)
- W Li
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Z Tian
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - W Zhu
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Y S Zhang
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - K Wang
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Y Zhang
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Y Wang
- Department of Neurosurgery (Y.W.), The First Affiliated Hospital of Nanchang University, Nanchang University, Nanchang, China
| | - X Yang
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - J Liu
- From the Department of Interventional Neuroradiology (W.L., Z.T., W.Z., Y.S.Z., K.W., Y.Z., X.Y., J.L.), Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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11
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Acuna A, Berman AG, Damen FW, Meyers BA, Adelsperger AR, Bayer KC, Brindise MC, Bungart B, Kiel AM, Morrison RA, Muskat JC, Wasilczuk KM, Wen Y, Zhang J, Zito P, Goergen CJ. Computational Fluid Dynamics of Vascular Disease in Animal Models. J Biomech Eng 2019; 140:2676341. [PMID: 29570754 DOI: 10.1115/1.4039678] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Indexed: 12/19/2022]
Abstract
Recent applications of computational fluid dynamics (CFD) applied to the cardiovascular system have demonstrated its power in investigating the impact of hemodynamics on disease initiation, progression, and treatment outcomes. Flow metrics such as pressure distributions, wall shear stresses (WSS), and blood velocity profiles can be quantified to provide insight into observed pathologies, assist with surgical planning, or even predict disease progression. While numerous studies have performed simulations on clinical human patient data, it often lacks prediagnosis information and can be subject to large intersubject variability, limiting the generalizability of findings. Thus, animal models are often used to identify and manipulate specific factors contributing to vascular disease because they provide a more controlled environment. In this review, we explore the use of CFD in animal models in recent studies to investigate the initiating mechanisms, progression, and intervention effects of various vascular diseases. The first section provides a brief overview of the CFD theory and tools that are commonly used to study blood flow. The following sections are separated by anatomical region, with the abdominal, thoracic, and cerebral areas specifically highlighted. We discuss the associated benefits and obstacles to performing CFD modeling in each location. Finally, we highlight animal CFD studies focusing on common surgical treatments, including arteriovenous fistulas (AVF) and pulmonary artery grafts. The studies included in this review demonstrate the value of combining CFD with animal imaging and should encourage further research to optimize and expand upon these techniques for the study of vascular disease.
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Affiliation(s)
- Andrea Acuna
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Alycia G Berman
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Frederick W Damen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Brett A Meyers
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Amelia R Adelsperger
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Kelsey C Bayer
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Melissa C Brindise
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Brittani Bungart
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Alexander M Kiel
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Rachel A Morrison
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Joseph C Muskat
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Kelsey M Wasilczuk
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Yi Wen
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907 e-mail:
| | - Jiacheng Zhang
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Patrick Zito
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Craig J Goergen
- ASME Membership Bioengineering Division, Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
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12
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Marsh LMM, Barbour MC, Chivukula VK, Chassagne F, Kelly CM, Levy SH, Kim LJ, Levitt MR, Aliseda A. Platelet Dynamics and Hemodynamics of Cerebral Aneurysms Treated with Flow-Diverting Stents. Ann Biomed Eng 2019; 48:490-501. [PMID: 31549329 DOI: 10.1007/s10439-019-02368-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/13/2019] [Indexed: 02/06/2023]
Abstract
Flow-diverting stents (FDS) are used to treat cerebral aneurysms. They promote the formation of a stable thrombus within the aneurysmal sac and, if successful, isolate the aneurysmal dome from mechanical stresses to prevent rupture. Platelet activation, a mechanism necessary for thrombus formation, is known to respond to biomechanical stimuli, particularly to the platelets' residence time and shear stress exposure. Currently, there is no reliable method for predicting FDS treatment outcomes, either a priori or after the procedure. Eulerian computational fluid dynamic (CFD) studies of aneurysmal flow have searched for predictors of endovascular treatment outcome; however, the hemodynamics of thrombus formation cannot be fully understood without considering the platelets' trajectories and their mechanics-triggered activation. Lagrangian analysis of the fluid mechanics in the aneurysmal vasculature provides novel metrics by tracking the platelets' residence time (RT) and shear history (SH). Eulerian and Lagrangian parameters are compared for 19 patient-specific cases, both pre- and post-treatment, to assess the degree of change caused by the FDS and subsequent treatment efficacy.
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Affiliation(s)
- Laurel M M Marsh
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA
| | - Michael C Barbour
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA
| | - Venkat Keshav Chivukula
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA
| | - Fanette Chassagne
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA
| | - Cory M Kelly
- Neurological Surgery, University of Washington, Seattle, WA, USA.,Stroke & Applied NeuroScience Center, University of Washington, Seattle, WA, USA
| | - Samuel H Levy
- Neurological Surgery, University of Washington, Seattle, WA, USA.,Stroke & Applied NeuroScience Center, University of Washington, Seattle, WA, USA
| | - Louis J Kim
- Neurological Surgery, University of Washington, Seattle, WA, USA.,Stroke & Applied NeuroScience Center, University of Washington, Seattle, WA, USA.,Radiology, University of Washington, Seattle, WA, USA
| | - Michael R Levitt
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA.,Neurological Surgery, University of Washington, Seattle, WA, USA.,Stroke & Applied NeuroScience Center, University of Washington, Seattle, WA, USA.,Radiology, University of Washington, Seattle, WA, USA
| | - Alberto Aliseda
- Mechanical Engineering, University of Washington, 4000 15th Ave NE, Box 352600, Seattle, WA, 98195, USA. .,Neurological Surgery, University of Washington, Seattle, WA, USA. .,Stroke & Applied NeuroScience Center, University of Washington, Seattle, WA, USA.
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13
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Mut F, Chung BJ, Chudyk J, Lylyk P, Kadirvel R, Kallmes DF, Cebral JR. Image-based modeling of blood flow in cerebral aneurysms treated with intrasaccular flow diverting devices. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3202. [PMID: 30891958 PMCID: PMC6687514 DOI: 10.1002/cnm.3202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 01/18/2019] [Accepted: 03/17/2019] [Indexed: 05/20/2023]
Abstract
Modeling the flow dynamics in cerebral aneurysms after the implantation of intrasaccular devices is important for understanding the relationship between flow conditions created immediately posttreatment and the subsequent outcomes. This information, ideally available a priori based on computational modeling prior to implantation, is valuable to identify which aneurysms will occlude immediately and which aneurysms will likely remain patent and would benefit from a different procedure or device. In this report, a methodology for modeling the hemodynamics in intracranial aneurysms treated with intrasaccular flow diverting devices is described. This approach combines an image-guided, virtual device deployment within patient-specific vascular models with an immersed boundary method on adaptive unstructured grids. A partial mesh refinement strategy that reduces the number of mesh elements near the aneurysm dome where the flow conditions are largely stagnant was compared with the full refinement strategy that refines the mesh everywhere around the device wires. The results indicate that using the partial mesh refinement approach is adequate for analyzing the posttreatment hemodynamics, at a reduced computational cost. The results obtained on a series of four cerebral aneurysms treated with different intrasaccular devices were in good qualitative agreement with angiographic observations. Promising results were obtained relating posttreatment flow conditions and outcomes of treatments with intrasaccular devices, which need to be confirmed on larger series.
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Affiliation(s)
- Fernando Mut
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, Virginia, USA
| | - Bong Jae Chung
- Department of Mathematical Sciences, Montclair State University, Montclair, New Jersey, USA
| | - Jorge Chudyk
- Interventional Neuroradiology, Clinica ENERI, Buenos Aires, Argentina
| | - Pedro Lylyk
- Interventional Neuroradiology, Clinica ENERI, Buenos Aires, Argentina
| | | | - David F Kallmes
- Interventional Neuroradiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Juan R Cebral
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, Virginia, USA
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14
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Chen J, Zhang Y, Tian Z, Li W, Zhang Q, Zhang Y, Liu J, Yang X. Relationship between haemodynamic changes and outcomes of intracranial aneurysms after implantation of the pipeline embolisation device: a single centre study. Interv Neuroradiol 2019; 25:671-680. [PMID: 31088244 DOI: 10.1177/1591019919849673] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Intracranial aneurysms are increasingly being treated by the placement of flow diverters; however, the factors affecting the outcome of aneurysms treated using flow diverters remain unclarified. METHODS The present study investigated 94 aneurysms treated with pipeline embolisation device placement, and used a computational fluid dynamics method to explore the factors influencing the outcome of aneurysms. RESULTS Seventy-six completely occluded aneurysms and 18 incompletely occluded aneurysms were analysed. Before treatment, inflow jets were found in 13 (72.2%) aneurysms in the incompletely occluded group and 34 (44.7%) in the completely occluded group (P = 0.292). After deployment of the pipeline embolisation device, inflow jets remained in nine (50%) aneurysms in the incompletely occluded group and nine (11.8%) in the completely occluded group (P = 0.001). In the incompletely occluded group, regions with inflow jets after treatment corresponded with the patent areas shown on follow-up digital subtraction angiography. The mean reduction ratios of velocity in the whole aneurysm and on the neck plane were lower in the incompletely occluded than in the completely occluded group (P = 0.003; P = 0.017). Multivariate analysis revealed that the only independent risk factors for incomplete aneurysm occlusion were the reduction ratios of velocity (in the whole aneurysm, threshold 0.362, P = 0.005; on the neck plane, threshold 0.273, P = 0.015). CONCLUSIONS After pipeline embolisation device placement, reduction ratios of velocity in the whole aneurysm of less than 0.362 and on the neck plane of less than 0.273 are significantly associated with a greater risk of aneurysm incomplete occlusion. In addition, the persistence of inflow jets in aneurysms is associated with incomplete occlusion in the inflow jet area.
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Affiliation(s)
- Junfan Chen
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Wenqiang Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Qianqian Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
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15
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Santiago-Dieppa DR, McDonald MA, Brandel MG, Rennert RC, Khalessi AA, Olson SE. Endovascular Flow Diversion for Hemifacial Spasm Induced by a Vertebral Artery Aneurysm: First Experience. Oper Neurosurg (Hagerstown) 2018; 17:E115-E118. [DOI: 10.1093/ons/opy359] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/18/2018] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND AND IMPORTANCE
Flow diversion for the treatment of aneurysm-induced hemifacial spasm (HFS) has not been previously described.
CLINICAL PRESENTATION
The authors present the case of a 60-yr-old woman who presented with 1 yr of progressive left HFS secondary to a vertebral artery aneurysm compressing the root entry zone of cranial nerve VII. The patient's aneurysm was successfully treated with a flow diverting stent.
CONCLUSION
In the immediate postoperative period, the patient had near complete resolution of her HFS symptoms. At her 6-mo follow-up the patient had no angiographic filling of the aneurysm and her HFS symptoms had completely resolved.
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Affiliation(s)
| | - Marin A McDonald
- Department of Radiology, University of California-San Diego, La Jolla, California
| | - Michael G Brandel
- Department of Neurosurgery, University of California-San Diego, La Jolla, California
| | - Robert C Rennert
- Department of Neurosurgery, University of California-San Diego, La Jolla, California
| | - Alexander A Khalessi
- Department of Neurosurgery, University of California-San Diego, La Jolla, California
| | - Scott E Olson
- Department of Neurosurgery, University of California-San Diego, La Jolla, California
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16
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Kelidis P, Konstantinidis E. Pulsatile flow through a constricted tube: effect of stenosis morphology on hemodynamic parameters. Comput Methods Biomech Biomed Engin 2018; 21:479-487. [DOI: 10.1080/10255842.2018.1481505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Panagiotis Kelidis
- Department of Mechanical Engineering, University of Western Macedonia, Kozani, Greece
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17
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Alkhalili K, Hannallah J, Cobb M, Chalouhi N, Philips JL, Echeverria AB, Jabbour P, Babiker MH, Frakes DH, Gonzalez LF. The Effect of Stents in Cerebral Aneurysms: A Review. Asian J Neurosurg 2018; 13:201-211. [PMID: 29682009 PMCID: PMC5898080 DOI: 10.4103/1793-5482.175639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The etiology of up to 95% of cerebral aneurysms may be accounted for by hemodynamically-induced factors that create vascular injury. The purpose of this review is to describe key physical properties that stents have and how they affect cerebral aneurysms. We performed a two-step screening process. First, a structured search was performed using the PubMed database. The following search terms and keywords were used: “Hemodynamics,” “wall shear stress (WSS),” “velocity,” “viscosity,” “cerebral aneurysm,” “intracranial aneurysm,” “stent,” “flow diverter,” “stent porosity,” “stent geometry,” “stent configuration,” and “stent design.” Reports were considered if they included original data, discussed hemodynamic changes after stent-based treatment of cerebral aneurysms, examined the hemodynamic effects of stent deployment, and/or described the geometric characteristics of both stents and the aneurysms they were used to treat. The search strategy yielded a total of 122 articles, 61 were excluded after screening the titles and abstracts. Additional articles were then identified by cross-checking reference lists. The final collection of 97 articles demonstrates that the geometric characteristics and configurations of deployed stents influenced hemodynamic parameters such as aneurysmal WSS, inflow, and pressure. The geometric characteristics of the aneurysm and its position also had significant influences on intra-aneurysmal hemodynamics after treatment. In conclusion, changes in specific aneurysmal hemodynamic parameters that result from stenting relate to a number of factors including the geometric properties and configurations of deployed stents, the geometric properties of the aneurysm, and the pretreatment hemodynamics.
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Affiliation(s)
- Kenan Alkhalili
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Jack Hannallah
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Mary Cobb
- Division of Neurosurgery, Duke University, Durham, NC, USA
| | - Nohra Chalouhi
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jessica L Philips
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Pascal Jabbour
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - David H Frakes
- Division of Neurosurgery, Duke University, Durham, NC, USA
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18
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Awad AW, Moon K, Yoon N, Mazur MD, Kalani MYS, Taussky P, McDougall CG, Albuquerque FC, Park MS. Flow diversion of tandem cerebral aneurysms: a multi-institutional retrospective study. Neurosurg Focus 2018; 42:E10. [PMID: 28565979 DOI: 10.3171/2017.2.focus1731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Flow diversion has proven to be an efficacious means of treating cerebral aneurysms that are refractory to other therapeutic means. Patients with tandem aneurysms treated with flow diversion have been included in larger, previously reported series; however, there are no dedicated reports on using this technique during a single session to treat this unique subset of patients. Therefore, the authors analyzed the outcomes of patients who had undergone single-session flow diversion for the treatment of tandem aneurysms. METHODS The authors conducted a retrospective review of flow diversion with the Pipeline embolization device (PED) for the treatment of tandem aneurysms in a single session at 2 participating medical centers: University of Utah, Salt Lake City, Utah, and Barrow Neurological Institute, Phoenix, Arizona. Patient demographic data, aneurysm characteristics, treatment strategy and results, complications, and follow-up data were collected from the medical record and analyzed. RESULTS Between January 2011 and December 2015, 17 patients (12 female, 5 male) with a total of 38 aneurysms (mean size 4.7 ± 2.7 mm, mean ± SD) were treated. Sixteen patients had aneurysms in the anterior circulation, and 1 patient had tandem aneurysms in the posterior circulation. Twelve patients underwent only placement of a PED, whereas 5 underwent adjunctive coil embolization of at least 1 aneurysm. One PED was used in each of 9 patients, and 2 PEDs were required in each of 8 patients. There were 2 intraprocedural complications; however, in both instances, the patients were asymptomatic at the last follow-up. The follow-up imaging studies were available for 15 patients at a mean of 7 months after treatment (216 days, range 0-540 days). The mean initial Raymond score after treatment was 2.7 ± 0.7, and the mean final score was 1.3 ± 0.7. CONCLUSIONS In this series, the use of flow diversion for the treatment of tandem cerebral aneurysms had an acceptable safety profile, indicating that it should be considered as an effective therapy for this complicated subset of patients. Further prospective studies must be performed before more definitive conclusions can be made.
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Affiliation(s)
- Al-Wala Awad
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
| | - Karam Moon
- Barrow Neurological Institute, Phoenix, Arizona; and
| | - Nam Yoon
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
| | - Marcus D Mazur
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
| | - M Yashar S Kalani
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
| | - Philipp Taussky
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
| | | | | | - Min S Park
- Department of Neurosurgery, University of Utah Health Care, Salt Lake City, Utah
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19
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Bhogal P, AlMatter M, Hellstern V, Ganslandt O, Bäzner H, Henkes H, Aguilar-Pérez M. The Combined Use of Intraluminal and Intrasaccular Flow Diversion for the Treatment of Intracranial Aneurysms: Report of 25 Cases. Neurointervention 2018; 13:20-31. [PMID: 29535895 PMCID: PMC5847887 DOI: 10.5469/neuroint.2018.13.1.20] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The Medina Embolic Device (MED) is a new intrasaccular device with promising early results. Previously we documented our initial experience of this device both alone and in combination with other devices including flow diverter stents (FDS). We sought to determine the effect of the MED + FDS strategy for the treatment of selected aneurysms. MATERIALS AND METHODS We performed a retrospective analysis of prospectively collected data to identify all patients with aneurysms treated using both the MED and intraluminal FDS. We present our technical success rate, early and mid-term angiographic follow-up, and clinical outcome data. RESULTS We identified 25 non-consecutive patients. The treatment was staged in 9 patients and in a single session 16 patients. The average age was 61±12.8 years (range 40-82). The average fundus height was 11±3.6 mm and average fundus width was 10.1±3.4 mm. In the staged cohort (n=9) at delayed angiography (mean 10 mths) 8 aneurysms (89%) showed complete exclusion (mRRC 1) and in one patient there was a parent vessel occlusion. In the simultaneous cohort delayed angiography (n=10, mean 8.1 months) demonstrated complete occlusion (mRRC 1) in 6 aneurysms (60%), 3 neck remnants (mRRC 2) (30%) and 1 patient (10%) showed persistent aneurysmal filling (mRRC 3a). There were 5 complications with permanent morbidity (mRS >2) in two patients. There were no mortalities. CONCLUSION The MED can be successfully used in combination with intraluminal FDS and in selected aneurysms this may represent an alternative to FDS and adjunctive coiling.
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Affiliation(s)
- Pervinder Bhogal
- Neuroradiological Clinic, Neurocenter, Klinikum Stuttgart, Germany
| | | | | | | | - Hansjörg Bäzner
- Neurological Clinic, Neurocenter, Klinikum Stuttgart, Germany
| | - Hans Henkes
- Neuroradiological Clinic, Neurocenter, Klinikum Stuttgart, Germany
- Medical Faculty, University Duisburg-Essen, Germany
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20
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Li W, Liu J, Zhang Y, Wang K, Tian Z, Zhang Q, Jiang C, Yang X, Wang Y. Flow Diversion and Outcomes of Vertebral Fusiform Aneurysms After Stent-Only Treatment: A Hemodynamic Study. World Neurosurg 2017; 107:202-210. [DOI: 10.1016/j.wneu.2017.07.157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
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21
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Suzuki T, Takao H, Fujimura S, Dahmani C, Ishibashi T, Mamori H, Fukushima N, Murayama Y, Yamamoto M. Relationships between geometrical parameters and mechanical properties for a helical braided flow diverter stent. Technol Health Care 2017; 25:611-623. [DOI: 10.3233/thc-160535] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Takashi Suzuki
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Hiroyuki Takao
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Soichiro Fujimura
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Chihebeddine Dahmani
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Toshihiro Ishibashi
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Hiroya Mamori
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Naoya Fukushima
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Yuichi Murayama
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Makoto Yamamoto
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
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22
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Cebral JR, Mut F, Chung BJ, Spelle L, Moret J, van Nijnatten F, Ruijters D. Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics. AJNR Am J Neuroradiol 2017; 38:1180-1186. [PMID: 28385882 DOI: 10.3174/ajnr.a5158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/25/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Hemodynamics is thought to be an important factor for aneurysm progression and rupture. Our aim was to evaluate whether flow fields reconstructed from dynamic angiography data can be used to realistically represent the main flow structures in intracranial aneurysms. MATERIALS AND METHODS DSA-based flow reconstructions, obtained during interventional treatment, were compared qualitatively with flow fields obtained from patient-specific computational fluid dynamics models and quantitatively with projections of the computational fluid dynamics fields (by computing a directional similarity of the vector fields) in 15 cerebral aneurysms. RESULTS The average similarity between the DSA and the projected computational fluid dynamics flow fields was 78% in the parent artery, while it was only 30% in the aneurysm region. Qualitatively, both the DSA and projected computational fluid dynamics flow fields captured the location of the inflow jet, the main vortex structure, the intrasaccular flow split, and the main rotation direction in approximately 60% of the cases. CONCLUSIONS Several factors affect the reconstruction of 2D flow fields from dynamic angiography sequences. The most important factors are the 3-dimensionality of the intrasaccular flow patterns and inflow jets, the alignment of the main vortex structure with the line of sight, the overlapping of surrounding vessels, and possibly frame rate undersampling. Flow visualization with DSA from >1 projection is required for understanding of the 3D intrasaccular flow patterns. Although these DSA-based flow quantification techniques do not capture swirling or secondary flows in the parent artery, they still provide a good representation of the mean axial flow and the corresponding flow rate.
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Affiliation(s)
- J R Cebral
- From the Bioengineering Department (J.R.C., F.M., B.J.C.), Volgenau School of Engineering, George Mason University, Fairfax, Virginia
| | - F Mut
- From the Bioengineering Department (J.R.C., F.M., B.J.C.), Volgenau School of Engineering, George Mason University, Fairfax, Virginia
| | - B J Chung
- From the Bioengineering Department (J.R.C., F.M., B.J.C.), Volgenau School of Engineering, George Mason University, Fairfax, Virginia
| | - L Spelle
- Faculté de Médecine Paris-Sud (L.S.), Le Kremlin-Bicetre, France
| | - J Moret
- Interventional Neuroradiology (J.M.), Beaujon University Hospital, Clichy, France
| | - F van Nijnatten
- Image Guided Therapy Innovation (F.v.N., D.R.), Philips Healthcare, Best, the Netherlands
| | - D Ruijters
- Image Guided Therapy Innovation (F.v.N., D.R.), Philips Healthcare, Best, the Netherlands
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Ambrosi PB, de Vasconcelos CAC, Moret J, Spelle L, Valença MM. Pathogenesis, hemodynamics, and growth of intracranial aneurysms: Future directions. Anat Rec (Hoboken) 2017; 300:1175-1179. [DOI: 10.1002/ar.23530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/29/2016] [Accepted: 08/27/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Patricia Bozzetto Ambrosi
- Interventional Neuroradiology Department; Neuri-Beaujon; Clichy Paris France
- Postgraduate Program in Biological Sciences Federal, University of Pernambuco; Recife Brazil
| | | | - Jacques Moret
- Interventional Neuroradiology Department; Neuri-Beaujon; Clichy Paris France
| | - Laurent Spelle
- Interventional Neuroradiology Department; Neuri-Beaujon; Clichy Paris France
| | - Marcelo Moraes Valença
- Postgraduate Program in Biological Sciences Federal, University of Pernambuco; Recife Brazil
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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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25
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Liu J, Jing L, Zhang Y, Song Y, Wang Y, Li C, Wang Y, Mu S, Paliwal N, Meng H, Linfante I, Yang X. Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis. World Neurosurg 2016; 97:344-350. [PMID: 27742509 DOI: 10.1016/j.wneu.2016.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA. METHODS Between September 2009 and November 2013, all consecutive patients with recurrent VADAs after SACE in our institutions were enrolled. Recurrence was defined as recanalization and/or regrowth. We assessed the hemodynamic alterations in wall shear stress (WSS) and velocity after the initial SACE and subsequently after retreatment of the aneurysms that recurred. RESULTS Five patients were included. After the initial treatment, 3 patients showed recanalization and 2 showed regrowth. In the 2 patients with regrowth, the 2 original aneurysms maintained complete occlusion; however, de novo aneurysm regrowth was confirmed near the previous site. Compared with 3 recanalized aneurysms, the completely occluded aneurysms showed high mean reductions in velocity and WSS after initial treatment (velocity, 77.6% vs. 57.7%; WSS, 74.2% vs. 52.4%); however, WSS remained high at the region near the previous lesion where the new aneurysm originated. After the second retreatment, there was no recurrence in any patient. Compared with the 3 aneurysms that recanalized, the 4 aneurysms that maintained complete occlusion showed higher reductions in velocity (62.9%) and WSS (71.1%). CONCLUSIONS Our series indicated that hemodynamics might have an important role in recurrence of VADAs. After endovascular treatment, sufficient hemodynamic reduction in aneurysm dome, orifice, and parent vessel may be one of the key factors for preventing recurrence in VADAs.
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Affiliation(s)
- Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Department of Neurosurgery, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Ying Song
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yang Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Chuanhui Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yanmin Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Shiqing Mu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Italo Linfante
- Miami Cardiac and Vascular Institute and Baptist Neuroscience Center, Baptist Hospital, Miami, Florida, USA.
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China.
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Zhang X, Lv N, Wang C, Cao W, Liu J, Huang Q. Late recurrence of a completely occluded large intracranial aneurysm treated with a Tubridge flow diverter. J Neurointerv Surg 2016; 9:e6. [PMID: 27342762 DOI: 10.1136/neurintsurg-2016-012268.rep] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2016] [Indexed: 11/04/2022]
Abstract
We report a rare case of recurrence of a large intracavernous aneurysm after angiography proved complete occlusion. The aneurysm was treated by a combination of a Tubridge flow diverter and coils, and balloon angioplasty, after flow diverter devices deployment for parent vessel stenosis. Six month angiographic follow-up demonstrated complete occlusion. Unfortunately, obvious aneurysm recurrence was confirmed on 2 year angiographic follow-up. The probable mechanism of recurrence was analyzed.
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Affiliation(s)
- Xiaoxi Zhang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Nan Lv
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Chi Wang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Wei Cao
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Jianmin Liu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Qinghai Huang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
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27
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Zhang X, Lv N, Wang C, Cao W, Liu J, Huang Q. Late recurrence of a completely occluded large intracranial aneurysm treated with a Tubridge flow diverter. BMJ Case Rep 2016; 2016:bcr-2016-012268. [PMID: 27329093 DOI: 10.1136/bcr-2016-012268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We report a rare case of recurrence of a large intracavernous aneurysm after angiography proved complete occlusion. The aneurysm was treated by a combination of a Tubridge flow diverter and coils, and balloon angioplasty, after flow diverter devices deployment for parent vessel stenosis. Six month angiographic follow-up demonstrated complete occlusion. Unfortunately, obvious aneurysm recurrence was confirmed on 2 year angiographic follow-up. The probable mechanism of recurrence was analyzed.
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Affiliation(s)
- Xiaoxi Zhang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Nan Lv
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Chi Wang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Wei Cao
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Jianmin Liu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Qinghai Huang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
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28
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Hemodynamic Effect of Flow Diverter and Coils in Treatment of Large and Giant Intracranial Aneurysms. World Neurosurg 2016; 89:199-207. [DOI: 10.1016/j.wneu.2016.01.079] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/27/2016] [Accepted: 01/27/2016] [Indexed: 11/19/2022]
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Ou C, Huang W, Yuen MMF. A computational model based on fibrin accumulation for the prediction of stasis thrombosis following flow-diverting treatment in cerebral aneurysms. Med Biol Eng Comput 2016; 55:89-99. [PMID: 27106753 DOI: 10.1007/s11517-016-1501-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/27/2016] [Indexed: 01/09/2023]
Abstract
Flow diverters, the specially designed low porosity stents, have been used to redirect blood flow from entering aneurysm, which induces flow stasis in aneurysm and promote thrombosis for repairing aneurysm. However, it is not clear how thrombus develops following flow-diversion treatment. Our objective was to develop a computation model for the prediction of stasis-induced thrombosis following flow-diversion treatment in cerebral aneurysms. We proposed a hypothesis to initiate coagulation following flow-diversion treatment. An experimental model was used by ligating rat's right common carotid artery (RCCA) to create flow-stasis environment. Thrombus formed in RCCA as a result of flow stasis. The fibrin distributions in different sections along the axial length of RCCA were measured. The fibrin distribution predicted by our computational model displayed a trend of increase from the proximal neck to the distal tip, consistent with the experimental results on rats. The model was applied on a saccular aneurysm treated with flow diverter to investigate thrombus development following flow diversion. Thrombus was predicted to form inside the sac, and the aneurysm was occluded with only a small remnant neck remained. Our model can serve as a tool to evaluate flow-diversion treatment outcome and optimize the design of flow diverters.
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Affiliation(s)
- Chubin Ou
- Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Wei Huang
- Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Matthew Ming-Fai Yuen
- Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
- Division of Biomedical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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31
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Liu J, Jing L, Wang C, Paliwal N, Wang S, Zhang Y, Xiang J, Siddiqui AH, Meng H, Yang X. Effect of hemodynamics on outcome of subtotally occluded paraclinoid aneurysms after stent-assisted coil embolization. J Neurointerv Surg 2015; 8:1140-1147. [PMID: 26610731 DOI: 10.1136/neurintsurg-2015-012050] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/09/2015] [Indexed: 11/03/2022]
Abstract
BACKGROUND Endovascular treatment of paraclinoid aneurysms is preferred in clinical practice. Flow alterations caused by stents and coils may affect treatment outcome. OBJECTIVE To assess hemodynamic changes following stent-assisted coil embolization (SACE) in subtotally embolized paraclinoid aneurysms with residual necks that were predisposed to recanalization. METHODS We studied 27 paraclinoid aneurysms (seven recanalized and 20 stable) treated with coils and Enterprise stents. Computational fluid dynamic simulations were performed on patient-specific aneurysm geometries using virtual stenting and porous media technology. RESULTS After stent placement in 27 cases, aneurysm flow velocity decreased significantly, the reduction gradually increasing from the neck plane (11.9%), to the residual neck (12.3%), to the aneurysm dome (16.3%). Subsequent coil embolization was performed after stent placement and the hemodynamic factors decreased further and significantly at all aneurysm regions except the neck plane. In a comparison of recanalized and stable cases, univariate analysis showed no significant differences in any parameter before treatment. After stent-assisted coiling, only the reduction in area-averaged velocity at the neck plane differed significantly between recanalized (8.1%) and stable cases (20.5%) (p=0.016). CONCLUSIONS Aneurysm flow velocity can be significantly decreased by stent placement and coil embolization. However, hemodynamics at the aneurysm neck plane is less sensitive to coils. Significant reduction in flow velocity at the neck plane may be an important factor in preventing recanalization of paraclinoid aneurysms after subtotal SACE.
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Affiliation(s)
- Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chao Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Shengzhang Wang
- Department of Mechanics and Engineering Science, Fudan University, Shanghai, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jianping Xiang
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Adnan H Siddiqui
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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32
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Xu J, Wu Z, Yu Y, Lv N, Wang S, Karmonik C, Liu JM, Huang Q. Combined Effects of Flow Diverting Strategies and Parent Artery Curvature on Aneurysmal Hemodynamics: A CFD Study. PLoS One 2015; 10:e0138648. [PMID: 26398847 PMCID: PMC4580450 DOI: 10.1371/journal.pone.0138648] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 09/02/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Flow diverters (FD) are increasingly being considered for treating large or giant wide-neck aneurysms. Clinical outcome is highly variable and depends on the type of aneurysm, the flow diverting device and treatment strategies. The objective of this study was to analyze the effect of different flow diverting strategies together with parent artery curvature variations on altering intra-aneurysmal hemodynamics. METHODS Four ideal intracranial aneurysm models with different parent artery curvature were constructed. Computational fluid dynamics (CFD) simulations of the hemodynamics before and after applying five types of flow diverting strategies (single FD, single FD with 5% and 10% packing density of coils, two FDs with 25% and 50% overlapping rate) were performed. Changes in pressure, wall shear stress (WSS), relative residence time (RRT), inflow velocity and inflow volume rate were calculated and compared. RESULTS Each flow diverting strategy resulted in enhancement of RRT and reduction of normalized mean WSS, inflow volume rate and inflow velocity in various levels. Among them, 50% overlapped FD induced most effective hemodynamic changes in RRT and inflow volume rate. The mean pressure only slightly decreased after treatment. Regardless of the kind of implantation of FD, the mean pressure, inflow volume rate and inflow velocity increased and the RRT decreased as the curvature of the parent artery increased. CONCLUSIONS Of all flow diverting strategies, overlapping FDs induced most favorable hemodynamic changes. Hemodynamics alterations post treatment were substantially influenced by parent artery curvature. Our results indicate the need of an individualized flow diverting strategy that is tailored for a specific aneurysm.
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Affiliation(s)
- Jinyu Xu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhichen Wu
- School of International Relations and Public Affairs, Fudan University, Shanghai, China
| | - Ying Yu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Nan Lv
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Shengzhang Wang
- Department of Mechanics and Engineering Science, Fudan University, Shanghai, China
| | - Christof Karmonik
- Cerebrovascular Center, Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, United States of America
| | - Jian-Min Liu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
- * E-mail: (JL); (QH)
| | - Qinghai Huang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
- * E-mail: (JL); (QH)
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Tsang ACO, Lai SSM, Chung WC, Tang AYS, Leung GKK, Poon AKK, Yu ACH, Chow KW. Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models. Ultrasonography 2015; 34:98-108. [PMID: 25754367 PMCID: PMC4372715 DOI: 10.14366/usg.14063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/30/2015] [Accepted: 01/31/2015] [Indexed: 12/19/2022] Open
Abstract
Purpose: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. Methods: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. Results: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. Conclusion: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.
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Affiliation(s)
- Anderson Chun On Tsang
- Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Simon Sui Man Lai
- Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong
| | - Wai Choi Chung
- Departments of Mechanical Engineering, University of Hong Kong, Hong Kong
| | | | - Gilberto Ka Kit Leung
- Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Alexander Kai Kei Poon
- Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong
| | - Alfred Cheuk Hang Yu
- Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong
| | - Kwok Wing Chow
- Departments of Mechanical Engineering, University of Hong Kong, Hong Kong
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Cebral JR, Mut F, Raschi M, Hodis S, Ding YH, Erickson BJ, Kadirvel R, Kallmes DF. Analysis of hemodynamics and aneurysm occlusion after flow-diverting treatment in rabbit models. AJNR Am J Neuroradiol 2014; 35:1567-73. [PMID: 24722302 DOI: 10.3174/ajnr.a3913] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Predicting the outcome of flow diversion treatment of cerebral aneurysms remains challenging. Our aim was to investigate the relationship between hemodynamic conditions created immediately after flow diversion and subsequent occlusion of experimental aneurysms in rabbits. MATERIALS AND METHODS The hemodynamic environment before and after flow-diversion treatment of elastase-induced aneurysms in 20 rabbits was modeled by using image-based computational fluid dynamics. Local aneurysm occlusion was quantified by using a voxelization technique on 3D images acquired 8 weeks after treatment. Global and local voxel-by-voxel hemodynamic variables were used to statistically compare aneurysm regions that later thrombosed to regions that remained patent. RESULTS Six aneurysms remained patent at 8 weeks, while 14 were completely or nearly completely occluded. Patent aneurysms had statistically larger neck sizes (P = .0015) and smaller mean transit times (P = .02). The velocity, vorticity, and shear rate were approximately 2.8 times (P < .0001) larger in patent regions-that is, they had larger "flow activity" than regions that progressed to occlusion. Statistical models based on local hemodynamic variables were capable of predicting local occlusion with good precision (84% accuracy), especially away from the neck (92%-94%). Predictions near the neck were poorer (73% accuracy). CONCLUSIONS These results suggests that the dominant healing mechanism of occlusion within the aneurysm dome is related to slow-flow-induced thrombosis, while near the neck, other processes could be at play simultaneously.
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Affiliation(s)
- J R Cebral
- From the Center for Computational Fluid Dynamics (J.R.C., F.M., M.R.), College of Sciences, George Mason University, Fairfax, Virginia
| | - F Mut
- From the Center for Computational Fluid Dynamics (J.R.C., F.M., M.R.), College of Sciences, George Mason University, Fairfax, Virginia
| | - M Raschi
- From the Center for Computational Fluid Dynamics (J.R.C., F.M., M.R.), College of Sciences, George Mason University, Fairfax, Virginia
| | - S Hodis
- Departments of Radiology (S.H., Y.-H.D., B.J.E., R.K., D.F.K.)
| | - Y-H Ding
- Departments of Radiology (S.H., Y.-H.D., B.J.E., R.K., D.F.K.)
| | - B J Erickson
- Departments of Radiology (S.H., Y.-H.D., B.J.E., R.K., D.F.K.)
| | - R Kadirvel
- Departments of Radiology (S.H., Y.-H.D., B.J.E., R.K., D.F.K.)
| | - D F Kallmes
- Departments of Radiology (S.H., Y.-H.D., B.J.E., R.K., D.F.K.)Neurosurgery (D.F.K.), Mayo Clinic, Rochester, Minnesota
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35
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Farzin B, Brosseau L, Jamali S, Salazkin I, Jack A, Darsaut TE, Raymond J. Flow diverters: inter and intra-rater reliability of porosity and pore density measurements. J Neurointerv Surg 2014; 7:734-9. [DOI: 10.1136/neurintsurg-2014-011240] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 07/11/2014] [Indexed: 11/04/2022]
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