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Bisighini B, Aguirre M, Biancolini ME, Trovalusci F, Perrin D, Avril S, Pierrat B. Machine learning and reduced order modelling for the simulation of braided stent deployment. Front Physiol 2023; 14:1148540. [PMID: 37064913 PMCID: PMC10090671 DOI: 10.3389/fphys.2023.1148540] [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: 01/20/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
Endoluminal reconstruction using flow diverters represents a novel paradigm for the minimally invasive treatment of intracranial aneurysms. The configuration assumed by these very dense braided stents once deployed within the parent vessel is not easily predictable and medical volumetric images alone may be insufficient to plan the treatment satisfactorily. Therefore, here we propose a fast and accurate machine learning and reduced order modelling framework, based on finite element simulations, to assist practitioners in the planning and interventional stages. It consists of a first classification step to determine a priori whether a simulation will be successful (good conformity between stent and vessel) or not from a clinical perspective, followed by a regression step that provides an approximated solution of the deployed stent configuration. The latter is achieved using a non-intrusive reduced order modelling scheme that combines the proper orthogonal decomposition algorithm and Gaussian process regression. The workflow was validated on an idealized intracranial artery with a saccular aneurysm and the effect of six geometrical and surgical parameters on the outcome of stent deployment was studied. We trained six machine learning models on a dataset of varying size and obtained classifiers with up to 95% accuracy in predicting the deployment outcome. The support vector machine model outperformed the others when considering a small dataset of 50 training cases, with an accuracy of 93% and a specificity of 97%. On the other hand, real-time predictions of the stent deployed configuration were achieved with an average validation error between predicted and high-fidelity results never greater than the spatial resolution of 3D rotational angiography, the imaging technique with the best spatial resolution (0.15 mm). Such accurate predictions can be reached even with a small database of 47 simulations: by increasing the training simulations to 147, the average prediction error is reduced to 0.07 mm. These results are promising as they demonstrate the ability of these techniques to achieve simulations within a few milliseconds while retaining the mechanical realism and predictability of the stent deployed configuration.
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Affiliation(s)
- Beatrice Bisighini
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
- Predisurge, Grande Usine Creative 2, Saint-Etienne, France
- Department of Enterprise Engineering, University Tor Vergata, Rome, Italy
| | - Miquel Aguirre
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
- Laboratori de Càlcul Numèric, Universitat Politècnica de Catalunya, Barcelona, Spain
- International Centre for Numerical Methods in Engineering (CIMNE), Gran Capità, Barcelona, Spain
| | | | | | - David Perrin
- Predisurge, Grande Usine Creative 2, Saint-Etienne, France
| | - Stéphane Avril
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
| | - Baptiste Pierrat
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
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2
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Muram S, Corcoran R, Cooke J, Forrester K, Lapins E, Morrish R, Cheema OZA, Goyal M, Eesa M, Fiorella D, Wong JH, Sadasivan C, Mitha AP. Immediate flow-diversion characteristics of a novel primarily bioresorbable flow-diverting stent. J Neurosurg 2022; 137:1794-1800. [PMID: 35364565 DOI: 10.3171/2022.1.jns212975] [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: 12/30/2021] [Accepted: 01/31/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Flow-diverting stents with a resorbable component have significant theoretical benefits over full metal stents, although currently there are none in clinical use. In this study, the authors sought to determine the immediate flow-diversion characteristics of a novel primarily bioresorbable flow-diverting stent. METHODS Bioresorbable stents were deployed into glass tube models to determine porosity and pore density. In vitro flow diversion behavior was evaluated using high frame rate angiography under pulsatile flow conditions in a patient-specific silicone aneurysm model treated with the resorbable stent as well as the Surpass Evolve stent. In vivo flow diversion was characterized by deployment into 20 rabbit saccular aneurysm models, and grading was based on the O'Kelly-Marotta scale and the 4F-flow diversion predictive score. RESULTS Porosities and pore densities of the bioresorbable stent were in the flow-diverting range for all target vessel diameters. Quantified results of immediate angiography after placement of the bioresorbable stent into a silicone aneurysm model demonstrated greater flow diversion compared to the Evolve stent. Bioresorbable stent placement in saccular aneurysm models resulted in an immediate O'Kelly-Marotta grade of A3 or better and a 4F-flow diversion predictive score of 4 or better in all cases. CONCLUSIONS The bioresorbable stent has immediate flow-diversion characteristics that are comparable to commercially available metal stents. Longer-term studies are underway to determine the ability of the resorbable fibers to act as a neointimal scaffold and result in long-term aneurysm occlusion.
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Affiliation(s)
- Sandeep Muram
- 1Department of Clinical Neurosciences, University of Calgary
| | | | | | | | - Elana Lapins
- 1Department of Clinical Neurosciences, University of Calgary
| | - Rosalie Morrish
- 1Department of Clinical Neurosciences, University of Calgary
| | | | - Mayank Goyal
- 1Department of Clinical Neurosciences, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - Muneer Eesa
- 1Department of Clinical Neurosciences, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - David Fiorella
- 6Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York
| | - John H Wong
- 1Department of Clinical Neurosciences, University of Calgary.,4Hotchkiss Brain Institute, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - Chander Sadasivan
- 6Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York
| | - Alim P Mitha
- 1Department of Clinical Neurosciences, University of Calgary.,3Biomedical Engineering Program, University of Calgary.,4Hotchkiss Brain Institute, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
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3
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Hemodynamic Investigation of the Effectiveness of a Two Overlapping Flow Diverter Configuration for Cerebral Aneurysm Treatment. Bioengineering (Basel) 2021; 8:bioengineering8100143. [PMID: 34677216 PMCID: PMC8533189 DOI: 10.3390/bioengineering8100143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022] Open
Abstract
Flow diverters (FDs) are widely employed as endovascular treatment devices for large or wide-neck cerebral aneurysms. Occasionally, overlapped FDs are deployed to enhance the flow diversion effect. In this study, we investigated the hemodynamics of overlapping FDs via computational fluid dynamics (CFD) simulations. We reproduced the arterial geometry of a patient who had experienced the deployment of two overlapping FDs. We utilized two stent patterns, namely the patterns for one FD and two overlapping FDs. We calculated the velocity, mass flow rate, wall shear stress, and pressure loss coefficient as well as their change rates for each pattern relative to the no-FD pattern results. The CFD simulation results indicated that the characteristics of the blood flow inside the aneurysm were minimally affected by the deployment of a single FD; in contrast, the overlapping FD pattern results revealed significant changes in the flow. Further, the velocity at an inspection plane within the aneurysm sac decreased by up to 92.2% and 31.0% in the cases of the overlapping and single FD patterns, respectively, relative to the no-FD pattern. The simulations successfully reproduced the hemodynamics, and the qualitative and quantitative investigations are meaningful with regard to the clinical outcomes of overlapped FD deployment.
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4
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Kim S, Yang H, Hong I, Oh JH, Kim YB. Computational Study of Hemodynamic Changes Induced by Overlapping and Compacting of Stents and Flow Diverter in Cerebral Aneurysms. Front Neurol 2021; 12:705841. [PMID: 34408723 PMCID: PMC8365227 DOI: 10.3389/fneur.2021.705841] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: The flow diversion effect of an intracranial stent is closely related to its metal coverage rate (MCR). In this study, the flow diversion effects of Enterprise and low-profile visualized intraluminal support (LVIS) stents are compared with those of a Pipeline flow diverter, focusing on the MCR change. Moreover, the changes in the flow diversion effect caused by the additional manipulations of overlapping and compaction are verified using computational fluid dynamics (CFD) analysis. Methods: CFD analysis was performed using virtually generated stents mounted in an idealized aneurysm model. First, the flow diversion effects of single Enterprise, LVIS, and Pipeline devices were analyzed. The Enterprise and LVIS were sequentially overlapped and compared with a Pipeline, to evaluate the effect of stent overlapping. The effect of compacting a stent was evaluated by comparing the flow diversion effects of a single and two compacted LVIS with those of two overlapped, uncompacted LVIS and uncompacted and compacted Pipeline. Quantitative analysis was performed to evaluate the hemodynamic parameters of energy loss, average velocity, and inflow rate. Results: Statistically significant correlations were observed between the reduction rates of the hemodynamic parameters and MCR. The single LVIS without compaction induced a reduction in all the hemodynamic parameters comparable to those of the three overlapped Enterprise. Moreover, the two overlapped, uncompacted LVIS showed a flow diversion effect as large as that induced by the single uncompacted Pipeline. Compacted stents induced a better flow diversion effect than uncompacted stents. The single compacted LVIS induced a flow diversion effect similar to that induced by the two uncompacted LVIS or single uncompacted Pipeline. Conclusions: The MCR of a stent correlates with its flow diversion effect. Overlapping and compaction can increase the MCR of an intracranial stent and achieve a flow diversion effect as large as that observed with a flow diverter.
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Affiliation(s)
- Sunghan Kim
- Department of Neurosurgery, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.,Department of Neurosurgery, Severance Stroke Center, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hyeondong Yang
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Ineui Hong
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Je Hoon Oh
- Department of Mechanical Engineering and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Yong Bae Kim
- Department of Neurosurgery, Severance Stroke Center, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
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5
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Lamooki SR, Tutino VM, Paliwal N, Damiano RJ, Waqas M, Nagesh SSV, Rajabzadeh-Oghaz H, Vakharia K, Siddiqui AH, Meng H. Evaluation of Two Fast Virtual Stenting Algorithms for Intracranial Aneurysm Flow Diversion. Curr Neurovasc Res 2021; 17:58-70. [PMID: 31987021 DOI: 10.2174/1567202617666200120141608] [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: 11/07/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Endovascular treatment of intracranial aneurysms (IAs) by flow diverter (FD) stents depends on flow modification. Patient-specific modeling of FD deployment and computational fluid dynamics (CFD) could enable a priori endovascular strategy optimization. We developed a fast, simplistic, expansion-free balls-weeping algorithm to model FDs in patientspecific aneurysm geometry. However, since such strong simplification could result in less accurate simulations, we also developed a fast virtual stenting workflow (VSW) that explicitly models stent expansion using pseudo-physical forces. METHODS To test which of these two fast algorithms more accurately simulates real FDs, we applied them to virtually treat three representative patient-specific IAs. We deployed Pipeline Embolization Device into 3 patient-specific silicone aneurysm phantoms and simulated the treatments using both balls-weeping and VSW algorithms in computational aneurysm models. We then compared the virtually deployed FD stents against experimental results in terms of geometry and post-treatment flow fields. For stent geometry, we evaluated gross configurations and porosity. For post-treatment aneurysmal flow, we compared CFD results against experimental measurements by particle image velocimetry. RESULTS We found that VSW created more realistic FD deployments than balls-weeping in terms of stent geometry, porosity and pore density. In particular, balls-weeping produced unrealistic FD bulging at the aneurysm neck, and this artifact drastically increased with neck size. Both FD deployment methods resulted in similar flow patterns, but the VSW had less error in flow velocity and inflow rate. CONCLUSION In conclusion, modeling stent expansion is critical for preventing unrealistic bulging effects and thus should be considered in virtual FD deployment algorithms. Also endowed with its high computational efficiency and superior accuracy, the VSW algorithm is a better candidate for implementation into a bedside clinical tool for FD deployment simulation.
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Affiliation(s)
- Saeb R Lamooki
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Biomedical Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Nikhil Paliwal
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Robert J Damiano
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Muhammad Waqas
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Setlur S V Nagesh
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Radiology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Hamidreza Rajabzadeh-Oghaz
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Kunal Vakharia
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Adnan H Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Hui Meng
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Biomedical Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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6
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In-silico trial of intracranial flow diverters replicates and expands insights from conventional clinical trials. Nat Commun 2021; 12:3861. [PMID: 34162852 PMCID: PMC8222326 DOI: 10.1038/s41467-021-23998-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 05/25/2021] [Indexed: 01/18/2023] Open
Abstract
The cost of clinical trials is ever-increasing. In-silico trials rely on virtual populations and interventions simulated using patient-specific models and may offer a solution to lower these costs. We present the flow diverter performance assessment (FD-PASS) in-silico trial, which models the treatment of intracranial aneurysms in 164 virtual patients with 82 distinct anatomies with a flow-diverting stent, using computational fluid dynamics to quantify post-treatment flow reduction. The predicted FD-PASS flow-diversion success rates replicate the values previously reported in three clinical trials. The in-silico approach allows broader investigation of factors associated with insufficient flow reduction than feasible in a conventional trial. Our findings demonstrate that in-silico trials of endovascular medical devices can: (i) replicate findings of conventional clinical trials, and (ii) perform virtual experiments and sub-group analyses that are difficult or impossible in conventional trials to discover new insights on treatment failure, e.g. in the presence of side-branches or hypertension. In-silico trials rely on virtual populations and interventions simulated using patient-specific models and may offer a solution to lower costs. Here, the authors present the flow diverter performance assessment in-silico trial, which models the treatment of intracranial aneurysms with a flow-diverting stent.
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7
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Zhang M, Tupin S, Li Y, Ohta M. Association Between Aneurysmal Haemodynamics and Device Microstructural Characteristics After Flow-Diversion Treatments With Dual Stents of Different Sizes: A Numerical Study. Front Physiol 2021; 12:663668. [PMID: 34113263 PMCID: PMC8185279 DOI: 10.3389/fphys.2021.663668] [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: 02/03/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022] Open
Abstract
Objectives Treating intracranial aneurysms with flow-diverting stents sometimes requires deployment of a second device. Herein we quantify the sizing effects of devices in dual-stent treatments upon the final stent microstructure and the post-treatment aneurysmal haemodynamics. Methods Fifteen sidewall ICA aneurysm geometries were included. Using a virtual stenting technique, we implanted either one or two stents for each aneurysm treatment considered, with each stent specified as one of two different sizes, yielding a total of two single-stent and fouir dual-stent treatment scenarios for each aneurysm. Three stent microstructural parameters and nine aneurysmal haemodynamic parameters were quantified and systematically compared across the 90 treatment scenarios. Results Deployment of a second stent further reduced the aneurysmal inflow rate (IR) and energy loss (EL) by, respectively, 14 ± 11% (p = 0.001) and 9 ± 12% (p = 0.056), relative to the untreated condition. Sizing effects of the earlier-deployed stent led to largest differences of 6.9% for the final IR reduction and 11.1% for the EL, whereas sizing effects from the later-deployed stent were minor (≤2.1%). The change in stent pore size was the only microstructural parameter demonstrating a strong correlation with the reduction in the post-treatment aneurysmal haemodynamics, in terms of the IR (r = 0.50, p < 0.001) and pressure drop (r = 0.63, p < 0.001). Conclusion Size of the earlier-deployed stent has substantial effects on the final haemodynamic outcomes after dual-stent treatment. The average pore size of stent wires at the aneurysm orifice shows promise as a potential index for predicting the efficacy of flow-diversion treatments.
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Affiliation(s)
- Mingzi Zhang
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Japan
| | - Simon Tupin
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Japan
| | - Yujie Li
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Japan.,ElyTMaX, CNRS-Université de Lyon-Tohoku University, International Joint Unit, Tohoku University, Sendai, Japan
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8
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Leng X, Wan H, Li G, Jiang Y, Huang L, Siddiqui AH, Zhang X, Xiang J. Hemodynamic effects of intracranial aneurysms from stent-induced straightening of parent vessels by stent-assisted coiling embolization. Interv Neuroradiol 2021; 27:181-190. [PMID: 33641496 DOI: 10.1177/1591019921995334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Straightening of parent vessels happens for stent-assisted coiling embolization (SACE) treatment of intracranial aneurysms. This study aims to investigate aneurysmal hemodynamic modifications caused by stent-induced vessel straightening. METHODS Stent and coil deployments of a SACE-treated distal bifurcation aneurysm by finite element method were performed first with the preoperative (not straightened, NS) and postoperative (straightened, S) vessel models respectively. Computational fluid dynamics were then performed for eight models, including (I) NS only model, (II) NS+stent model, (III) NS+coils model, (IV) NS+stent+coils model, (V) S only model, (VI) S+stent model, (VII) S+coils model, and (VIII) S+stent+coils model. Finally, changes in aneurysmal flow velocity, isovelocity surface and wall shear stress (WSS) were analyzed qualitatively and quantitatively. RESULTS The flow was less in the S models than that in the corresponding NS models. Coils blocked most of the flow into the aneurysm sac in both NS models and S models and vessel straightening had more profound effect on the high aneurysmal flow volume reduction than coiling, while stenting generated adverse effect on flow reduction. Taking the NS only model as baseline (100%), the sac-averaged velocities of models II to VIII were 112%, 36%, 42%, 45%, 39%, 12%, 13%, and high flow volumes were 119%, 21%, 30%, 10%, 8%, 3%, 3%, while the sac-averaged WSSs were 106%, 37%, 44%, 41%, 35%, 17% and 24%, respectively. CONCLUSIONS Stent-induced vessel straightening combined coil embolization has the best performance in hemodynamic modifications and may reduce the recurrence rate, whereas stenting may generate adverse effect on hemodynamic alterations.
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Affiliation(s)
- Xiaochang Leng
- ArteryFlow Technology Co., Ltd., Hangzhou, China.,School of Civil Engineering and Architecture, Nanchang University, Nanchang, China
| | - Hailin Wan
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd., Hangzhou, China
| | - Yeqing Jiang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Lei Huang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Adnan H Siddiqui
- Department of Neurosurgery and Radiology, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Xiaolong Zhang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
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9
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Sunohara T, Imamura H, Goto M, Fukumitsu R, Matsumoto S, Fukui N, Oomura Y, Akiyama T, Fukuda T, Go K, Kajiura S, Shigeyasu M, Asakura K, Horii R, Sakai C, Sakai N. Neck Location on the Outer Convexity is a Predictor of Incomplete Occlusion in Treatment with the Pipeline Embolization Device: Clinical and Angiographic Outcomes. AJNR Am J Neuroradiol 2021; 42:119-125. [PMID: 33184073 DOI: 10.3174/ajnr.a6859] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE With the increasing use of the Pipeline Embolization Device for the treatment of aneurysms, predictors of clinical and angiographic outcomes are needed. This study aimed to identify predictors of incomplete occlusion at last angiographic follow-up. MATERIALS AND METHODS In our retrospective, single-center cohort study, 105 ICA aneurysms in 89 subjects were treated with Pipeline Embolization Devices. Patients were followed per standardized protocol. Clinical and angiographic outcomes were analyzed. We introduced a new morphologic classification based on the included angle of the parent artery against the neck location: outer convexity type (included angle, <160°), inner convexity type (included angle, >200°), and lateral wall type (160° ≤ included angle ≤200°). This classification reflects the metal coverage rate and flow dynamics. RESULTS Imaging data were acquired in 95.3% of aneurysms persistent at 6 months. Complete occlusion was achieved in 70.5%, and incomplete occlusion, in 29.5% at last follow-up. Multivariable regression analysis revealed that 60 years of age or older (OR, 5.70; P = .001), aneurysms with the branching artery from the dome (OR, 10.56; P = .002), fusiform aneurysms (OR, 10.2; P = .009), and outer convexity-type saccular aneurysms (versus inner convexity type: OR, 30.3; P < .001; versus lateral wall type: OR, 9.71; P = .001) were independently associated with a higher rate of incomplete occlusion at the last follow-up. No permanent neurologic deficits or rupture were observed in the follow-up period. CONCLUSIONS The aneurysm neck located on the outer convexity is a new, incomplete occlusion predictor, joining older age, fusiform aneurysms, and aneurysms with the branching artery from the dome. No permanent neurologic deficits or rupture was observed in the follow-up, even with incomplete occlusion.
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Affiliation(s)
- T Sunohara
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan.
| | - H Imamura
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - M Goto
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - R Fukumitsu
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - S Matsumoto
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - N Fukui
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Y Oomura
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - T Akiyama
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - T Fukuda
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - K Go
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - S Kajiura
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - M Shigeyasu
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - K Asakura
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - R Horii
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - C Sakai
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - N Sakai
- From the Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
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10
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Bender MT, Young RW, Zarrin DA, Campos JK, Caplan JM, Huang J, Tamargo RJ, Lin LM, Colby GP, Coon AL. Twisting: Incidence and Risk Factors of an Intraprocedural Challenge Associated With Pipeline Flow Diversion of Cerebral Aneurysms. Neurosurgery 2020; 88:25-35. [PMID: 32658958 DOI: 10.1093/neuros/nyaa309] [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: 07/02/2019] [Accepted: 05/02/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Pipeline Embolization Device (PED; Medtronic) "twisting" manifests with the appearance of a "figure 8" in perpendicular planes on digital subtraction angiography. This phenomenon has received little attention in the literature, requires technical precision to remediate, and has potential to cause ischemic stroke if not properly remediated. OBJECTIVE To report incidence, risk factors, and sequelae of PED twisting and to discuss techniques to remediate a PED twist. METHODS Case images were reviewed for instances of twisting from a prospectively-maintained, Institutional Review Board-approved cohort of patients undergoing flow diversion for cerebral aneurysm. RESULTS From August 2011 to December 2017, 999 PED flow diverting stents were attempted in 782 cases for 653 patients. A total of 25 PED twists were observed while treating 20 patients (2.50%, 25/999). Multivariate analysis revealed predictors of twisting to be: Large and giant aneurysms (odds ratio (OR) = 9.66, P = .005; OR = 27.47, P < .001), increased PED length (OR = 1.14, P < .001), and advanced patient age (OR = 1.07, P = .002). Twisted PEDs were able to be remediated 75% of the time, and procedural success was achieved in 90% of cases. PED twisting was not found to be a significant cause of major or minor complications. However, at long-term follow-up, there was a trend towards poor occlusion outcomes for the cases that encountered twisting. CONCLUSION Twisting is a rare event during PED deployment that was more likely to occur while treating large aneurysms with long devices in older patients. While twisting did not lead to major complications in this study, remediation can be challenging and may be associated with inferior occlusion outcomes.
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Affiliation(s)
- Matthew T Bender
- Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York
| | - Robert W Young
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David A Zarrin
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jessica K Campos
- Department of Neurosurgery, University of California Irvine, Orange, California
| | - Justin M Caplan
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Judy Huang
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rafael J Tamargo
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Li-Mei Lin
- Department of Neurosurgery, University of California Irvine, Orange, California
| | - Geoffrey P Colby
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, California
| | - Alexander L Coon
- Department of Neurosurgery, Carondelet Neurological Institute, Tucson, Arizona
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11
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Tian Z, Zhang M, Li G, Jin R, Leng X, Zhang Y, Wang K, Zhang Y, Yang X, Xiang J, Liu J. Hemodynamic differences by increasing low profile visualized intraluminal support (LVIS) stent local compaction across intracranial aneurysm orifice. Interv Neuroradiol 2020; 26:557-565. [PMID: 32830566 DOI: 10.1177/1591019920952903] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The Low-profile Visualized Intraluminal Support device (LVIS) has been successfully used to treat cerebral aneurysm, and the push-pull technique has been used clinically to compact the stent across aneurysm orifice. Our aim was to exhibit the hemodynamic effect of the compacted LVIS stent. METHODS Two patient-specific aneurysm models were constructed from three-dimensional angiographic images. The uniform LVIS stent, compacted LVIS and Pipeline Embolization Device (PED) with or without coil embolization were virtually deployed into aneurysm models to perform hemodynamic analysis. Intra-aneurysmal flow parameters were calculated to assess hemodynamic differences among different models. RESULTS The compacted LVIS had the highest metal coverage across the aneurysm orifice (case 1, 46.37%; case 2, 67.01%). However, the PED achieved the highest pore density (case 1, 19.56 pores/mm2; case 2, 18.07 pores/mm2). The compacted LVIS produced a much higher intra-aneurysmal flow reduction than the uniform LVIS. The PED showed a higher intra-aneurysmal flow reduction than the compacted LVIS in case 1, but the results were comparable in case 2. After stent placement, the intra-aneurysmal flow was further reduced as subsequent coil embolization. The compacted LVIS stent with coils produced a similar reduction in intra-aneurysmal flow to that of the PED. CONCLUSIONS The combined characteristics of stent metal coverage and pore density should be considered when assessing the flow diversion effects of stents. More intra-aneurysmal flow reductions could be introduced by compacted LVIS stent than the uniform one. Compared with PED, compacted LVIS stent may exhibit a flow-diverting effect comparable to that of the PED.
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Affiliation(s)
- Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Mingqi Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | - Rongbo Jin
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | | | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Kun Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | | | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
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12
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Su T, Reymond P, Brina O, Bouillot P, Machi P, Delattre BMA, Jin L, Lövblad KO, Vargas MI. Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter. AJNR Am J Neuroradiol 2020; 41:488-494. [PMID: 32054620 DOI: 10.3174/ajnr.a6413] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 12/23/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Flow diverter-induced hemodynamic change plays an important role in the mechanism of intracranial aneurysm occlusion. Our aim was to explore the relationship between aneurysm features and flow-diverter treatment of unruptured sidewall intracranial aneurysms. MATERIALS AND METHODS MR imaging, 4D phase-contrast, was prospectively performed before flow diverter implantation in each patient with unruptured intracranial aneurysm. Two postprocedure follow-ups were scheduled at 6 and 12 months. Responses were grouped according to whether the aneurysms were occluded or remnant. Preprocedural aneurysm geometries and ostium hemodynamics in 38 patients were compared between the 2 groups at 6 and 12 months. Receiver operating characteristic curve analyses were performed for significant geometric and hemodynamic continuous parameters. RESULTS After the 6-month assessment, 21 of 41 intracranial aneurysms were occluded, and 9 additional aneurysms were occluded at 12 months. Geometrically, the ostium maximum diameter was significantly larger in the remnant group at 6 and 12 months (both P < .001). Hemodynamically, the proximal inflow zone was more frequently observed in the remnant group at 6 months. Several preprocedural ostium hemodynamic parameters were significantly higher in the remnant group. As a prediction for occlusion, the areas under the curve of the ostium maximum diameter (for 6 and 12 months), systolic inflow rate ratio (for 6 months), and systolic inflow area (for 12 months) reached 0.843, 0.883, 0.855, and 0.860, respectively. CONCLUSIONS Intracranial aneurysms with a large ostium and strong ostium inflow may need a longer time for occlusion. Preprocedural 4D flow MR imaging can well illustrate ostium hemodynamics and characterize aneurysm treatment responses.
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Affiliation(s)
- T Su
- From the Department of Interventional Radiology (T.S., L.J.), Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China
| | - P Reymond
- Division of Neuroradiology and Neuro-Interventional Radiology (P.R., O.B., P.M., K.O.L., M.I.V.)
| | - O Brina
- Division of Neuroradiology and Neuro-Interventional Radiology (P.R., O.B., P.M., K.O.L., M.I.V.)
| | - P Bouillot
- and Division of Radiology (B.M.A.D.), University Hospitals of Geneva, Geneva, Switzerland
| | - P Machi
- Division of Neuroradiology and Neuro-Interventional Radiology (P.R., O.B., P.M., K.O.L., M.I.V.)
| | - B M A Delattre
- Department of Quantum Matter Physics (P.B.), University of Geneva, Geneva, Switzerland
| | - L Jin
- From the Department of Interventional Radiology (T.S., L.J.), Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China
| | - K O Lövblad
- Division of Neuroradiology and Neuro-Interventional Radiology (P.R., O.B., P.M., K.O.L., M.I.V.)
| | - M I Vargas
- Division of Neuroradiology and Neuro-Interventional Radiology (P.R., O.B., P.M., K.O.L., M.I.V.)
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13
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Li Y, Verrelli DI, Yang W, Qian Y, Chong W. A pilot validation of CFD model results against PIV observations of haemodynamics in intracranial aneurysms treated with flow-diverting stents. J Biomech 2020; 100:109590. [DOI: 10.1016/j.jbiomech.2019.109590] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 12/07/2019] [Accepted: 12/18/2019] [Indexed: 11/30/2022]
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14
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Joshi KC, Larrabide I, Saied A, Elsaid N, Fernandez H, Lopes DK. Software-based simulation for preprocedural assessment of braided stent sizing: a validation study. J Neurosurg 2019; 131:1423-1429. [PMID: 30497172 DOI: 10.3171/2018.5.jns18976] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/29/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The authors sought to validate the use of a software-based simulation for preassessment of braided self-expanding stents in the treatment of wide-necked intracranial aneurysms. METHODS This was a retrospective, observational, single-center study of 13 unruptured and ruptured intracranial aneurysms treated with braided self-expanding stents. Pre- and postprocedural angiographic studies were analyzed. ANKYRAS software was used to compare the following 3 variables: the manufacturer-given nominal length (NL), software-calculated simulated length (SL), and the actual measured length (ML) of the stent. Appropriate statistical methods were used to draw correlations among the 3 lengths. RESULTS In this study, data obtained in 13 patients treated with braided self-expanding stents were analyzed. Data for the 3 lengths were collected for all patients. Error discrepancy was calculated by mean squared error (NL to ML -22.2; SL to ML -6.14, p < 0.05), mean absolute error (NL to ML 3.88; SL to ML -1.84, p < 0.05), and mean error (NL to ML -3.81; SL to ML -1.22, p < 0.05). CONCLUSIONS The ML was usually less than the NL given by the manufacturer, indicating significant change in length in most cases. Computational software-based simulation for preassessment of the braided self-expanding stents is a safe and effective way for accurately calculating the change in length to aid in choosing the right-sized stent for optimal placement in complex intracranial vasculature.
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Affiliation(s)
| | | | - Ahmed Saied
- 3Department of Neurology, Mansoura University, Mansoura, Egypt; and
| | - Nada Elsaid
- 1Department of Neurosurgery, Rush Medical Center, Chicago, Illinois
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15
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Computational methods applied to analyze the hemodynamic effects of flow-diverter devices in the treatment of cerebral aneurysms: Current status and future directions. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2019. [DOI: 10.1016/j.medntd.2019.100018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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16
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Kole MJ, Miller TR, Cannarsa G, Wessell A, Jones S, Le E, Jindal G, Aldrich F, Simard JM, Gandhi D. Pipeline embolization device diameter is an important factor determining the efficacy of flow diversion treatment of small intracranial saccular aneurysms. J Neurointerv Surg 2019; 11:1004-1008. [DOI: 10.1136/neurintsurg-2019-014792] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/24/2019] [Accepted: 02/26/2019] [Indexed: 11/04/2022]
Abstract
ObjectiveFlow diversion using the Pipeline embolization device (PED) has become a widely used treatment method for intracranial aneurysms. However, a subset of aneurysms will fail to occlude following treatment and the factors that influence the efficacy of flow diversion remain uncertain. As smaller diameter PEDs inherently have greater metal density than larger devices, we elected to investigate whether PED diameter influences treatment efficacy when using a single device. We also evaluated other factors that may influence treatment outcomes with PED.MethodsWe retrospectively evaluated all patients treated for an intracranial saccular aneurysm at our institution with a single PED at least 12 months prior to the time of data collection. Patients treated with multiple devices, adjunctive coiling, traumatic and fusiform target aneurysms, as well as patients with inadequate imaging follow-up (<12 months) were excluded.Results158 aneurysms in 124 patients (128 treatments) met the inclusion criteria for our study. 123 aneurysms (80%) were occluded over an average follow-up of 26.6 months. Multivariable logistic regression showed that branch vessel incorporation into the target aneurysm sac (p<0.001, OR=0.15) was significantly associated with aneurysm persistence, while smaller PED diameter was significantly associated with aneurysm occlusion (p=0.008; OR=0.30).ConclusionsPED diameter significantly impacts outcomes when using a single device for the treatment of small anterior circulation intracranial saccular aneurysms, most likely due to the inherent greater metal density of smaller devices. This factor should be taken into account when planning endovascular aneurysm treatment with PED.
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17
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Paliwal N, Tutino VM, Shallwani H, Beecher JS, Damiano RJ, Shakir HJ, Atwal GS, Fennell VS, Natarajan SK, Levy EI, Siddiqui AH, Davies JM, Meng H. Ostium Ratio and Neck Ratio Could Predict the Outcome of Sidewall Intracranial Aneurysms Treated with Flow Diverters. AJNR Am J Neuroradiol 2019; 40:288-294. [PMID: 30679216 DOI: 10.3174/ajnr.a5953] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/07/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Incompletely occluded flow diverter treated aneurysms remain at risk of rupture and thromboembolic complications. Our aim was to identify the potential for incomplete occlusion of intracranial aneurysms treated by flow diverters. We investigated whether aneurysm ostium size in relation to parent artery size affects angiographic outcomes of flow diverter-treated sidewall aneurysms. MATERIALS AND METHODS Flow diverter-treated sidewall aneurysms were divided into "occluded" and "residual" (incomplete occlusion) groups based on 6-month angiographic follow-up. We calculated the ostium ratio, a new parameter defined as the aneurysm ostium surface area versus the circumferential surface area of the parent artery. We also calculated the neck ratio, defined as clinical aneurysm neck diameter versus parent artery diameter from pretreatment 2D DSA, as a 2D surrogate. We compared the performance of these ratios with existing aneurysm morphometrics (size, neck diameter, volume, aspect ratio, size ratio, undulation index, nonsphericity index, ellipticity index, bottleneck factor, aneurysm angle, and parent vessel angle) and flow diverter-related parameters (metal coverage rate and pore density). Statistical tests and receiver operating characteristic analyses were performed to identify significantly different parameters between the 2 groups and test their predictive performances. RESULTS We included 63 flow diverter-treated aneurysms, 46 occluded and 17 residual. The ostium ratio and neck ratio were significantly higher in the residual group than in the occluded group (P < .001 and P = .02, respectively), whereas all other parameters showed no statistical difference. As discriminating parameters for occlusion, ostium ratio and neck ratio achieved areas under the curve of 0.912 (95% CI, 0.838-0.985) and 0.707 (95% CI, 0.558-0.856), respectively. CONCLUSIONS High ostium ratios and neck ratios could predict incomplete occlusion of flow diverter-treated sidewall aneurysms. Neck ratio can be easily calculated by interventionists to predict flow-diverter treatment outcomes.
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Affiliation(s)
- N Paliwal
- From the Department of Mechanical and Aerospace Engineering (N.P., R.J.D., H.M.).,Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.)
| | - V M Tutino
- Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.).,Department of Biomedical Engineering (V.M.T., H.M.), University at Buffalo, Buffalo, New York.,Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.)
| | - H Shallwani
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - J S Beecher
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - R J Damiano
- From the Department of Mechanical and Aerospace Engineering (N.P., R.J.D., H.M.).,Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.)
| | - H J Shakir
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - G S Atwal
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - V S Fennell
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - S K Natarajan
- Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York
| | - E I Levy
- Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.).,Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Radiology (E.I.L., A.H.S.)
| | - A H Siddiqui
- Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.).,Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Radiology (E.I.L., A.H.S.).,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York.,Jacobs Institute (A.H.S., J.M.D.), Buffalo, New York
| | - J M Davies
- Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.).,Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.).,Biomedical Informatics (J.M.D.), Jacobs School of Medicine, University at Buffalo, Buffalo, New York.,Department of Neurosurgery (H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., A.H.S., J.M.D.), Gates Vascular Institute at Kaleida Health, Buffalo, New York.,Jacobs Institute (A.H.S., J.M.D.), Buffalo, New York
| | - H Meng
- From the Department of Mechanical and Aerospace Engineering (N.P., R.J.D., H.M.) .,Canon Stroke and Vascular Research Center (N.P., V.M.T., R.J.D., E.I.L., A.H.S., J.M.D., H.M.).,Department of Biomedical Engineering (V.M.T., H.M.), University at Buffalo, Buffalo, New York.,Departments of Neurosurgery (V.M.T., H.S., J.S.B., H.J.S., G.S.A., V.S.F., S.K.N., E.I.L., A.H.S., J.M.D., H.M.)
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18
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Miller TR, Kole MJ, Le EJ, Cannarsa G, Jones S, Wessell AP, Jindal G, Aldrich EF, Simard JM, Gandhi D. Pipeline Diameter Significantly Impacts the Long-Term Fate of Jailed Side Branches during Treatment of Intracranial Aneurysms. AJNR Am J Neuroradiol 2018; 39:2270-2277. [PMID: 30385475 DOI: 10.3174/ajnr.a5863] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/28/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Although covered side branches typically remain patent acutely following Pipeline Embolization Device embolization of intracranial aneurysms, the long-term fate of these vessels remains uncertain. We therefore elected to investigate factors that may influence the long-term patency of these covered side branches. MATERIALS AND METHODS We retrospectively evaluated the long-term patency of side branches covered by the Pipeline Embolization Device at our institution during treatment of intracranial aneurysms with at least 6 months of conventional angiography follow-up. Procedural and anatomic factors that might influence the fate of covered side branches were explored. RESULTS One hundred forty-eight Pipeline Embolization Device treatments in 137 patients met the inclusion criteria. In 217 covered side branches, 29 (13.4%) were occluded on follow-up, and 40 (18.4%) were stenotic. All stenoses and occlusions were asymptomatic. In the entire cohort and in the largest subset of ophthalmic arteries, a smaller Pipeline Embolization Device diameter was associated with branch vessel occlusion (P = .001, P = .013). When we considered stenotic and occluded side branches together, smaller Pipeline Embolization Device size (P = .029) and administration of intraprocedural abciximab (P = .03) predicted side branch stenosis/occlusion, while anterior choroidal branch type (P = .003) was a predictor of gross side branch patency. CONCLUSIONS A smaller Pipeline Embolization Device diameter is associated with delayed side branch stenosis/occlusion following Pipeline Embolization Device treatment, likely due to the higher metal density of smaller caliber devices. Although hemodynamic factors, including the potential for collateral flow, are still paramount in determining the fate of covered side branches, the amount of metal coverage at the side branch orifice also plays an important role.
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Affiliation(s)
- T R Miller
- From the Departments of Diagnostic Radiology (T.R.M., G.J., D.G.)
| | - M J Kole
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - E J Le
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - G Cannarsa
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - S Jones
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - A P Wessell
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - G Jindal
- From the Departments of Diagnostic Radiology (T.R.M., G.J., D.G.).,Neuroradiology (G.J., D.G.).,Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - E F Aldrich
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - J M Simard
- Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
| | - D Gandhi
- From the Departments of Diagnostic Radiology (T.R.M., G.J., D.G.).,Neuroradiology (G.J., D.G.).,Neurosurgery (M.J.K., E.J.L., G.C., S.J., A.P.W., G.J., E.F.A., J.M.S., D.G.), University of Maryland Medical Center, Baltimore, Maryland
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Multiple Aneurysms AnaTomy CHallenge 2018 (MATCH): Phase I: Segmentation. Cardiovasc Eng Technol 2018; 9:565-581. [DOI: 10.1007/s13239-018-00376-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
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20
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Berg P, Saalfeld S, Janiga G, Brina O, Cancelliere NM, Machi P, Pereira VM. Virtual stenting of intracranial aneurysms: A pilot study for the prediction of treatment success based on hemodynamic simulations. Int J Artif Organs 2018; 41:698-705. [PMID: 29783867 DOI: 10.1177/0391398818775521] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endovascular treatment of intracranial aneurysms using flow-diverting devices has revolutionized the treatment of large and complex lesions due to its minimally invasive nature and potential clinical outcomes. However, incomplete or delayed occlusion and persistent intracranial aneurysm growth are still an issue for up to one-third of the patients. We evaluated two patients with intracranial aneurysm located at the internal carotid artery who were treated with flow-diverting devices and had opposite outcomes. Both patients presented with similar aneurysms and were treated with the same device, but after a 1-year follow-up, one case presented with complete occlusion (Case 1) and the other required further treatment (Case 2). To reproduce the interventions, virtual stents were deployed and blood flow simulations were carried out using the respective patient-specific geometries. Afterward, hemodynamic metrics such as aneurysmal inflow reduction, wall shear stresses, oscillatory shear, and inflow concentration indices were quantified. The hemodynamic simulations reveal that for both cases, the neck inflow was clearly reduced due to the therapy (Case 1: 19%, Case 2: 35%). In addition, relevant hemodynamic parameters such as time-averaged wall shear stress (Case 1: 35.6%, Case 2: 57%) and oscillatory shear (Case 1: 33.1%, Case 2: 26.7%) were decreased considerably. However, although stronger relative reductions occurred in the unsuccessful case, the absolute flow values in the successful case were approximately halved. The findings demonstrate that a high relative effect of endovascular devices is not necessarily associated with the desired treatment outcome. Instead, it appears that a successful intracranial aneurysm therapy requires a certain patient-specific inflow threshold.
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Affiliation(s)
- Philipp Berg
- 1 Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany.,2 Forschungscampus STIMULATE, Magdeburg, Germany
| | - Sylvia Saalfeld
- 2 Forschungscampus STIMULATE, Magdeburg, Germany.,3 Department of Simulation and Graphics, University of Magdeburg, Magdeburg, Germany
| | - Gábor Janiga
- 1 Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany.,2 Forschungscampus STIMULATE, Magdeburg, Germany
| | - Olivier Brina
- 4 Interventional Neuroradiology Unit, University Hospital of Geneva, Geneva, Switzerland
| | - Nicole M Cancelliere
- 5 Joint Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Paolo Machi
- 4 Interventional Neuroradiology Unit, University Hospital of Geneva, Geneva, Switzerland
| | - Vitor M Pereira
- 5 Joint Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.,6 Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
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21
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Parthasarathy R, Gupta V, Gupta A. Safety of Prasugrel loading in ruptured blister like aneurysm treated with a Pipeline device. Br J Radiol 2018; 91:20170476. [PMID: 29509490 DOI: 10.1259/bjr.20170476] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Blister like aneurysm (BLA) is extremely challenging to treat; endoluminal reconstruction has emerged as the most promising treatment method. When to treat after the ictus, the timing of administration of antiplatelet and causal relationship between platelet function testing results and thrombo-embolism is unclear. We theorized that Prasugrel with a lower incidence of resistance may be a safe suitable alternative to clopidogrel in patients treated with a flow diverter (FD). METHODS Prospectively collected data from consecutive patients treated for a ruptured blister with an FD was reviewed. Device deployment was timed to be at 2 h following Prasugrel loading. Thrombo-embolic and hemorrhagic complications, and occlusion rates were documented. RESULTS Nine patients were included. Most were females (55%); the median age was 55 (43, 65). The median Fischer grade was 3 (2, 4). A single pipeline device was deployed in all within 24 h of admission; the median time from ictus to device deployment was 4 days (2, 30). There were no thrombo-embolic or hemorrhagic complication. Complete occlusion was noted in 89% (n = 9). CONCLUSION Prasugrel loading timed 2 h prior to stent delivery did not increase thrombo-embolic or hemorrhagic complications. Single stent that is well apposed against the wall appears to be an effective treatment strategy to treat BLA. Advances in knowledge: Treatment of acutely ruptured BLA with a single pipeline device deployed at 2 h after Prasugrel loading appears to be safe.
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Affiliation(s)
- Rajsrinivas Parthasarathy
- 1 Department of Neurointerventional Surgery, Artemis Agrim Institute of Neuroscience , Haryana , India
| | - Vipul Gupta
- 1 Department of Neurointerventional Surgery, Artemis Agrim Institute of Neuroscience , Haryana , India
| | - Aditya Gupta
- 2 Department of Neurosurgery, Artemis Agrim Institute of Neuroscience , Haryana , India
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22
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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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23
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Verrelli DI, Yang W, Chong W, Ohta M. Sensitivity study on modelling a flow-diverting stent as a porous medium using computational fluid dynamics. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:3389-3392. [PMID: 29060624 DOI: 10.1109/embc.2017.8037583] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The flow-diverting (FD) stent has become a commonly used endovascular device to treat cerebral aneurysms. This discourages blood from entering the aneurysm, thereby reducing the likelihood of aneurysm rupture. Using computational fluid dynamics (CFD) to simulate the aneurysmal haemodynamics after FD treatment could help clinicians predict the stent effectiveness prior to the real procedure in the patient. As an alternative to modelling the stent as a fine wire mesh, modelling the FD stent as a porous medium was established to save computational time, and has also been proved capable of predicting the same haemodynamics as obtained using the real FD stent geometry. The flow resistance effect of a porous-medium stent may differ with respect to its morphology or permeability; however, the flow resistance effect after adjusting these parameters had not been clarified. In this study, we analysed the haemodynamic changes caused by alterations of porous-medium thickness and permeability, thereby providing future porous-medium stent simulations with important information on the respective parametric sensitivities. We found significant sensitivity to permeability. Results were insensitive to thickness when permeability was adjusted beforehand to compensate. We also compared our results with observations from an in-vitro model, and found good agreement. This supports adoption of porous-medium models in future work.
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24
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Zhang M, Li Y, Zhao X, Verrelli DI, Chong W, Ohta M, Qian Y. Haemodynamic effects of stent diameter and compaction ratio on flow-diversion treatment of intracranial aneurysms: A numerical study of a successful and an unsuccessful case. J Biomech 2017; 58:179-186. [PMID: 28576622 DOI: 10.1016/j.jbiomech.2017.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 04/02/2017] [Accepted: 05/05/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Compacting a flow-diverting (FD) stent is an emerging technique to create a denser configuration of wires across the aneurysm ostium. However, quantitative analyses of post-stenting haemodynamics affected by the compaction level of different stent sizes remain inconclusive. OBJECTIVE To compare the aneurysmal haemodynamic alterations after virtual FD treatments with different device diameters at different compaction ratios. METHODS We virtually implanted three sizes of FD stent, with each size deployed at four compaction ratios, into two patient aneurysms previously treated with the Silk+FD-one successful case and the other unsuccessful. Wire configurations of the FD in the 24 treatment scenarios were examined, and aneurysmal haemodynamic alterations were resolved by computational fluid dynamics (CFD) simulations. We investigated the aneurysmal flow patterns, aneurysmal average velocity (AAV), mass flowrate (MF), and energy loss (EL) in each scenario. RESULTS Compactions of the stent in the successful case resulted in a greater metal coverage rate than that achieved in the unsuccessful one. A 25% increment in compaction ratio further decreased the AAV (12%), MF (11%), and EL (9%) in both cases (average values). The averaged maximum differences attributable to device size were 10% (AAV), 8% (MF), and 9% (EL). CONCLUSIONS Both stent size and compaction level could markedly affect the FD treatment outcomes. It is therefore important to individualise the treatment plan by selecting the optimal stent size and deployment procedure. CFD simulation can be used to investigate the treatment outcomes, thereby assisting doctors in choosing a favourable treatment plan.
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Affiliation(s)
- Mingzi Zhang
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia; Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Yujie Li
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia; Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Xi Zhao
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - David I Verrelli
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Winston Chong
- Neuroradiology Department, Monash Medical Centre, Melbourne, Victoria, Australia; Department of Surgery, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Makoto Ohta
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Yi Qian
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia.
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25
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Sarrami-Foroushani A, Lassila T, Frangi AF. Virtual endovascular treatment of intracranial aneurysms: models and uncertainty. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28488754 DOI: 10.1002/wsbm.1385] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/09/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023]
Abstract
Virtual endovascular treatment models (VETMs) have been developed with the view to aid interventional neuroradiologists and neurosurgeons to pre-operatively analyze the comparative efficacy and safety of endovascular treatments for intracranial aneurysms. Based on the current state of VETMs in aneurysm rupture risk stratification and in patient-specific prediction of treatment outcomes, we argue there is a need to go beyond personalized biomechanical flow modeling assuming deterministic parameters and error-free measurements. The mechanobiological effects associated with blood clot formation are important factors in therapeutic decision making and models of post-treatment intra-aneurysmal biology and biochemistry should be linked to the purely hemodynamic models to improve the predictive power of current VETMs. The influence of model and parameter uncertainties associated to each component of a VETM is, where feasible, quantified via a random-effects meta-analysis of the literature. This allows estimating the pooled effect size of these uncertainties on aneurysmal wall shear stress. From such meta-analyses, two main sources of uncertainty emerge where research efforts have so far been limited: (1) vascular wall distensibility, and (2) intra/intersubject systemic flow variations. In the future, we suggest that current deterministic computational simulations need to be extended with strategies for uncertainty mitigation, uncertainty exploration, and sensitivity reduction techniques. WIREs Syst Biol Med 2017, 9:e1385. doi: 10.1002/wsbm.1385 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Ali Sarrami-Foroushani
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
| | - Toni Lassila
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
| | - Alejandro F Frangi
- Center for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), The University of Sheffield, Sheffield, UK
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26
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Valle-Giler EP, Atallah E, Tjoumakaris S, Rosenwasser RH, Jabbour P. Transcirculation Pipeline embolization device deployment: a rescue technique. Neurosurg Focus 2017; 42:E13. [DOI: 10.3171/2017.2.focus16485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The Pipeline embolization device (PED) has become a very important tool in the treatment of nonruptured cerebral aneurysms. However, a patient’s difficult anatomy or vascular stenosis may affect the device delivery. The purpose of this article was to describe an alternate technique for PED deployment when ipsilateral anatomy is not amenable for catheter navigation.A 44-year-old woman with a symptomatic 6-mm right superior hypophyseal artery aneurysm and a known history of right internal carotid artery dissection presented for PED treatment of her aneurysm. An angiogram showed persistence of the arterial dissection with luminal stenosis after 6 months of dual antiplatelet treatment. The contralateral internal carotid artery was catheterized and the PED was deployed via a transcirculation approach, using the anterior communicating artery. Transcirculation deployment of a PED is a viable option when ipsilateral anatomy is difficult or contraindicated for this treatment.
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27
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Damiano RJ, Tutino VM, Paliwal N, Ma D, Davies JM, Siddiqui AH, Meng H. Compacting a Single Flow Diverter versus Overlapping Flow Diverters for Intracranial Aneurysms: A Computational Study. AJNR Am J Neuroradiol 2017; 38:603-610. [PMID: 28057633 DOI: 10.3174/ajnr.a5062] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 10/27/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Locally compacting the mesh of a flow diverter by a dynamic push-pull technique can accelerate intracranial aneurysm healing. We asked how this deployment strategy compares with overlapping 2 flow diverters for aneurysmal flow reduction. MATERIALS AND METHODS Using a high-fidelity virtual stent placement method, we simulated 3 flow-diverter strategies (single noncompacted, 2 overlapped, and single compacted) in 3 aneurysms (fusiform, large saccular, and medium saccular). Computational fluid dynamics analysis provided posttreatment hemodynamic parameters, including time-averaged inflow rate, aneurysm-averaged velocity, wall shear stress, total absolute circulation, and turnover time. We examined the relationship between the achieved degree of compaction and aneurysm orifice area. RESULTS Flow-diverter compaction resulted in a compaction coverage of 57%, 47%, and 22% over the orifice of the fusiform, large, and medium saccular aneurysm, respectively. Compaction coverage increased linearly with orifice area. In the fusiform aneurysm, the single compacted flow diverter accomplished more aneurysmal flow reduction than the other 2 strategies, as indicated by all 5 hemodynamic parameters. In the 2 saccular aneurysms, the overlapped flow diverters achieved the most flow reduction, followed by the single compacted and the noncompacted flow diverter. CONCLUSIONS Compacting a single flow diverter can outperform overlapping 2 flow diverters in aneurysmal flow reduction, provided that the compaction produces a mesh denser than 2 overlapped flow diverters and this denser mesh covers a sufficient portion of the aneurysm orifice area, for which we suggest a minimum of 50%. This strategy is most effective for aneurysms with large orifices, especially fusiform aneurysms.
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Affiliation(s)
- R J Damiano
- From the Department of Mechanical and Aerospace Engineering (R.J.D., N.P., D.M., H.M.).,Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.)
| | - V M Tutino
- Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.).,Department of Biomedical Engineering (V.M.T., H.M.)
| | - N Paliwal
- From the Department of Mechanical and Aerospace Engineering (R.J.D., N.P., D.M., H.M.).,Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.)
| | - D Ma
- From the Department of Mechanical and Aerospace Engineering (R.J.D., N.P., D.M., H.M.).,Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.)
| | - J M Davies
- Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.).,Department of Neurosurgery (J.M.D., A.H.S., H.M.), University at Buffalo, State University of New York, Buffalo, New York
| | - A H Siddiqui
- Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.).,Department of Neurosurgery (J.M.D., A.H.S., H.M.), University at Buffalo, State University of New York, Buffalo, New York
| | - H Meng
- From the Department of Mechanical and Aerospace Engineering (R.J.D., N.P., D.M., H.M.) .,Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.).,Department of Biomedical Engineering (V.M.T., H.M.).,Department of Neurosurgery (J.M.D., A.H.S., H.M.), University at Buffalo, State University of New York, Buffalo, New York
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28
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Zhang Q, Meng Z, Zhang Y, Yao K, Liu J, Zhang Y, Jing L, Yang X, Paliwal N, Meng H, Wang S. Phantom-based experimental validation of fast virtual deployment of self-expandable stents for cerebral aneurysms. Biomed Eng Online 2016; 15:125. [PMID: 28155680 PMCID: PMC5260011 DOI: 10.1186/s12938-016-0250-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Endovascular intervention using a stent is a mainstream treatment for cerebral aneurysms. To assess the effect of intervention strategies on aneurysm hemodynamics, we have developed a fast virtual stenting (FVS) technique to simulate stent deployment in patient-specific aneurysms. However, quantitative validation of the FVS against experimental data has not been fully addressed. In this study, we performed in vitro analysis of a patient-specific model to illustrate the realism and usability of this novel FVS technique. METHODS We selected a patient-specific aneurysm and reproduced it in a manufactured realistic aneurismal phantom. Three numerical simulation models of the aneurysm with an Enterprise stent were constructed. Three models were constructed to obtain the stented aneurysms: a physical phantom scanned by micro-CT, fast virtual stenting technique and finite element method. The flow in the three models was simulated using a computational fluid dynamics software package, and the hemodynamics parameters for the three models were calculated and analyzed. RESULTS The computational hemodynamics in the patient-specific aneurysm of the three models resembled the very well. A qualitative comparison revealed high similarity in the wall shear stress, streamline, and velocity plane among the three different methods. Quantitative comparisons revealed that the difference ratios of the hemodynamic parameters were less than 10%, with the difference ratios for area average of wall shear stress in the aneurysm being very low. CONCLUSIONS In conclusion, the results of the computational hemodynamics indicate that FVS is suitable for evaluation of the hemodynamic factors that affect treatment outcomes.
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Affiliation(s)
- Qianqian Zhang
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhuangyuan Meng
- Department of Mechanics and Engineering Science, Fudan University, 220 Handan Rd., Yangpu District, Shanghai, 200433, China
| | - Ying Zhang
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kai Yao
- Department of Mechanics and Engineering Science, Fudan University, 220 Handan Rd., Yangpu District, Shanghai, 200433, China
| | - Jian Liu
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yisen Zhang
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xinjian Yang
- Beijing Neurosurgical Institute, 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, NY, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Shengzhang Wang
- Department of Mechanics and Engineering Science, Fudan University, 220 Handan Rd., Yangpu District, Shanghai, 200433, China.
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29
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Suzuki T, Takao H, Fujimura S, Dahmani C, Ishibashi T, Mamori H, Fukushima N, Yamamoto M, Murayama Y. Selection of helical braided flow diverter stents based on hemodynamic performance and mechanical properties. J Neurointerv Surg 2016; 9:999-1005. [PMID: 27646987 PMCID: PMC5629929 DOI: 10.1136/neurintsurg-2016-012561] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 08/24/2016] [Accepted: 08/29/2016] [Indexed: 11/04/2022]
Abstract
BACKGROUND Although flow diversion is a promising procedure for the treatment of aneurysms, complications have been reported and it remains poorly understood. The occurrence of adverse outcomes is known to depend on both the mechanical properties and flow reduction effects of the flow diverter stent. OBJECTIVE To clarify the possibility of designing a flow diverter stent considering both hemodynamic performance and mechanical properties. MATERIALS AND METHODS Computational fluid dynamics (CFD) simulations were conducted based on an ideal aneurysm model with flow diverters. Structural analyses of two flow diverter models exhibiting similar flow reduction effects were performed, and the radial stiffness and longitudinal flexibility were compared. RESULTS In CFD simulations, two stents-Pore2-d35 (26.77° weave angle when fully expanded, 35 μm wire thickness) and Pore3-d50 (36.65°, 50 μm respectively)-demonstrated similar flow reduction rates (68.5% spatial-averaged velocity reduction rate, 85.0% area-averaged wall shear stress reduction rate for Pore2-d35, and 68.6%, 85.4%, respectively, for Pore3-d50). However, Pore3-d50 exhibited greater radial stiffness than Pore2-d35 (40.0 vs 21.0 mN/m at a 3.5 mm outer diameter) and less longitudinal flexibility (0.903 vs 0.104 N·mm bending moments at 90°). These measurements indicate that changing the wire thickness and weave angle allows adjustment of the mechanical properties while maintaining the same degree of flow reduction effects. CONCLUSIONS The combination of CFD and structural analysis can provide promising solutions for an optimized stent. Stents exhibiting different mechanical properties but the same flow reduction effects could be designed by varying both the weave angle and wire thickness.
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Affiliation(s)
- Takashi Suzuki
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Hiroyuki Takao
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan.,Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan.,Department of Innovation for Medical Information Technology, Jikei University School of Medicine, Tokyo, Japan
| | - Soichiro Fujimura
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Chihebeddine Dahmani
- Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan.,Siemens Healthcare K.K., Tokyo, Japan
| | - Toshihiro Ishibashi
- Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan
| | - Hiroya Mamori
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Naoya Fukushima
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Makoto Yamamoto
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Yuichi Murayama
- Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan
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30
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Natarajan SK, Lin N, Sonig A, Rai AT, Carpenter JS, Levy EI, Siddiqui AH. The safety of Pipeline flow diversion in fusiform vertebrobasilar aneurysms: a consecutive case series with longer-term follow-up from a single US center. J Neurosurg 2016; 125:111-9. [DOI: 10.3171/2015.6.jns1565] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT
Pessimism exists regarding flow diversion for posterior circulation aneurysms because of reports of perforator territory infarcts and delayed ruptures. The authors report the results of patients who underwent Pipeline Embolization Device (PED) flow diversion using novel strategies for treatment of fusiform posterior circulation aneurysms, and compare these results with those from previously reported series.
METHODS
The authors conducted a retrospective review of data from consecutive patients with fusiform vertebrobasilar artery aneurysms treated with the PED.
RESULTS
This review resulted in the identification of 12 such patients (mean [± SD] age 55.1 ± 14.1 years). Eleven patients had symptoms; 1 had a dissecting aneurysm identified on imaging for neck pain. The average aneurysm size was 13.25 ± 4.5 mm. None of the aneurysms were ruptured or previously treated. The average clinical follow-up duration was 22.1 ± 10.7 months and radiological follow-up was 14.5 ± 11.1 months from the index PED treatment. One patient suffered a perforator stroke and had a modified Rankin Scale (mRS) score of 4 at last follow-up. Another patient had a retained stent pusher requiring retrieval via surgical cut-down but recovered to an mRS score of 0 at last follow-up. Eleven (91.7%) of 12 patients recovered to an mRS score of 0 or 1. Two patients had aneurysmal remnants at 7 and 10 months, respectively, after the index PED, which were retreated with PEDs. At last follow-up, all 12 aneurysms were occluded and PEDs were patent. The minimum follow-up duration was 12 months from the index PED treatment; no patient experienced delayed hemorrhage, stroke, or in-stent stenosis.
CONCLUSIONS
Flow diversion with selective adjunctive techniques is evolving to become a safer treatment option for posterior circulation aneurysms. This is the longest clinical follow-up duration reported for a single-center experience of flow-diversion treatment of these aneurysms.
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Affiliation(s)
- Sabareesh K. Natarajan
- 1Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo
- 2Department of Neurosurgery, Gates Vascular Institute/Kaleida Health, Buffalo
| | - Ning Lin
- 1Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo
- 2Department of Neurosurgery, Gates Vascular Institute/Kaleida Health, Buffalo
- 3Department of Neurosurgery, Weill Cornell Medical College, New York City, New York
| | - Ashish Sonig
- 1Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo
- 2Department of Neurosurgery, Gates Vascular Institute/Kaleida Health, Buffalo
| | - Ansaar T. Rai
- 4Department of Radiology, West Virginia University, Morgantown, West Virginia
| | | | - Elad I. Levy
- 1Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo
- 2Department of Neurosurgery, Gates Vascular Institute/Kaleida Health, Buffalo
- 5Department of Radiology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York
- 6Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo; and
| | - Adnan H. Siddiqui
- 1Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo
- 2Department of Neurosurgery, Gates Vascular Institute/Kaleida Health, Buffalo
- 5Department of Radiology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York
- 6Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo; and
- 7Jacobs Institute, Buffalo, New York
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Geometrical deployment for braided stent. Med Image Anal 2016; 30:85-94. [DOI: 10.1016/j.media.2016.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/20/2015] [Accepted: 01/20/2016] [Indexed: 11/21/2022]
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Paliwal N, Yu H, Xu J, Xiang J, Siddiqui A, Yang X, Li H, Meng H. Virtual stenting workflow with vessel-specific initialization and adaptive expansion for neurovascular stents and flow diverters. Comput Methods Biomech Biomed Engin 2016; 19:1423-1431. [PMID: 26899135 DOI: 10.1080/10255842.2016.1149573] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Endovascular intervention using traditional neurovascular stents and densely braided flow diverters (FDs) have become the preferred treatment strategies for traditionally challenging intracranial aneurysms. Modeling stent and FD deployment in patient-specific aneurysms and its flow modification results prior to the actual intervention can potentially predict the patient outcome and treatment optimization. We present a clinically focused, streamlined virtual stenting workflow that efficiently simulates stent and FD treatment in patient-specific aneurysms based on expanding a simplex mesh structure. The simplex mesh is generated using an innovative vessel-specific initialization technique, which uses the patient's parent artery diameter to identify the initial position of the simplex mesh inside the artery. A novel adaptive expansion algorithm enables the acceleration of deployment process by adjusting the expansion forces based on the distance of the simplex mesh from the parent vessel. The virtual stenting workflow was tested by modeling the treatment of two patient-specific aneurysms using the Enterprise stent and the Pipeline Embolization Device (commercial FD). Both devices were deployed in the aneurysm models in a few seconds. Computational fluid dynamics analyses of pre- and post-treatment aneurysmal hemodynamics show flow reduction in the aneurysmal sac in treated aneurysms, with the FD diverting more flow than the Enterprise stent. The test results show that this workflow can rapidly simulate clinical deployment of stents and FDs, hence paving the way for its future clinical implementation.
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Affiliation(s)
- Nikhil Paliwal
- Department of Mechanical & Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY.,Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY
| | - Hongyu Yu
- School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Jinhui Xu
- Department of Computer Science & Engineering, University at Buffalo, State University of New York, Buffalo, NY
| | - Jianping Xiang
- Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY.,Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY
| | - Adnan Siddiqui
- Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY.,Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY
| | - Xinjian Yang
- Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Beijing, China
| | - Haiyun Li
- School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Hui Meng
- Department of Mechanical & Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY.,Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY.,Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY.,Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY
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Jou LD, Chintalapani G, Mawad ME. Metal coverage ratio of pipeline embolization device for treatment of unruptured aneurysms: Reality check. Interv Neuroradiol 2015; 22:42-8. [PMID: 26628457 DOI: 10.1177/1591019915617315] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/01/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND PURPOSE The metal coverage ratio (MCR) of a flow diverter influences the intra-aneurysmal hemodynamics; a high MCR will occlude an aneurysm early, while a low MCR may delay aneurysm occlusion. The true MCR of a pipeline embolization device (PED) could be lower due to oversize, device deformation, or aneurysm location. In this study deviation of the true MCR from the nominal MCR is assessed and whether their difference affects aneurysm occlusion rate is determined. METHODS A total of 40 consecutive patients, each of them treated by one PED for their aneurysms at the internal carotid artery (ICA), were retrospectively analyzed. The DynaCT images of these deployed PEDs were used to determine their true dimensions and estimate three MCRs (local, mean, and nominal). These data were compared in two groups of patients who had different aneurysm outcomes at six months. RESULTS The difference in the local MCR between two groups is small, but statistically significant (24.5% vs 21.6%, p=05). The local MCR is consistently lower than the nominal MCRs (23.2% vs 30.2%, p<0.001); however, the difference between the mean and local MCRs is small (23.9% vs 23.2%). CONCLUSIONS An expectation that a PED can achieve a MCR of 30% may not be reasonable. Device oversize and deformation during deployment lower the local MCR by 5-7%. A lowered MCR affects the aneurysm occlusion rate at six months.
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Affiliation(s)
- Liang-Der Jou
- Department of Radiology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Michel E Mawad
- Department of Radiology, Baylor College of Medicine, Houston, Texas, USA
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Karmonik C, Anderson JR, Beilner J, Ge JJ, Partovi S, Klucznik RP, Diaz O, Zhang YJ, Britz GW, Grossman RG, Lv N, Huang Q. Relationships and redundancies of selected hemodynamic and structural parameters for characterizing virtual treatment of cerebral aneurysms with flow diverter devices. J Biomech 2015; 49:2112-2117. [PMID: 26654675 DOI: 10.1016/j.jbiomech.2015.11.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE To quantify the relationship and to demonstrate redundancies between hemodynamic and structural parameters before and after virtual treatment with a flow diverter device (FDD) in cerebral aneurysms. METHODS Steady computational fluid dynamics (CFD) simulations were performed for 10 cerebral aneurysms where FDD treatment with the SILK device was simulated by virtually reducing the porosity at the aneurysm ostium. Velocity and pressure values proximal and distal to and at the aneurysm ostium as well as inside the aneurysm were quantified. In addition, dome-to-neck ratios and size ratios were determined. Multiple correlation analysis (MCA) and hierarchical cluster analysis (HCA) were conducted to demonstrate dependencies between both structural and hemodynamic parameters. RESULTS Velocities in the aneurysm were reduced by 0.14m/s on average and correlated significantly (p<0.05) with velocity values in the parent artery (average correlation coefficient: 0.70). Pressure changes in the aneurysm correlated significantly with pressure values in the parent artery and aneurysm (average correlation coefficient: 0.87). MCA found statistically significant correlations between velocity values and between pressure values, respectively. HCA sorted velocity parameters, pressure parameters and structural parameters into different hierarchical clusters. HCA of aneurysms based on the parameter values yielded similar results by either including all (n=22) or only non-redundant parameters (n=2, 3 and 4). CONCLUSION Hemodynamic and structural parameters before and after virtual FDD treatment show strong inter-correlations. Redundancy of parameters was demonstrated with hierarchical cluster analysis.
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Affiliation(s)
- C Karmonik
- MRI Core, Houston Methodist Research Institute, Houston, TX, USA; Cerebrovascular Center, Neurosurgery, Houston Methodist, Houston, TX, USA.
| | - J R Anderson
- MRI Core, Houston Methodist Research Institute, Houston, TX, USA
| | | | - J J Ge
- Siemens AX, Shanghai, China
| | - S Partovi
- Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH, USA
| | - R P Klucznik
- Cerebrovascular Center, Radiology, Houston Methodist, Houston, TX, USA
| | - O Diaz
- Cerebrovascular Center, Radiology, Houston Methodist, Houston, TX, USA
| | - Y J Zhang
- Cerebrovascular Center, Neurosurgery, Houston Methodist, Houston, TX, USA
| | - G W Britz
- Cerebrovascular Center, Neurosurgery, Houston Methodist, Houston, TX, USA
| | - R G Grossman
- Cerebrovascular Center, Neurosurgery, Houston Methodist, Houston, TX, USA
| | - N Lv
- Neurosurgery, The Affiliated Changhai Hospital of Second Military Medical University, Shanghai, China
| | - Q Huang
- Neurosurgery, The Affiliated Changhai Hospital of Second Military Medical University, Shanghai, China
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Gentric JC, Salazkin I, Gevry G, Raymond J, Darsaut T. Compaction of flow diverters improves occlusion of experimental wide-necked aneurysms. J Neurointerv Surg 2015; 8:1072-7. [PMID: 26453605 DOI: 10.1136/neurintsurg-2015-012016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/17/2015] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Flow diverters (FDs) are increasingly used in the treatment of wide-necked aneurysms. OBJECTIVE To examine the hypothesis that intentional FD compaction might improve aneurysm occlusion rates. METHODS Bilateral wide-necked carotid aneurysms were created in 12 dogs. Endovascular treatment was performed 1 month later, using Pipeline embolization devices deployed with compaction across the aneurysm neck (n=12). Group 1a consisted of aneurysms treated with a single compacted FD (n=8), while group 1b aneurysms required two compacted FDs (n=4). Control aneurysms were treated with a single non-compacted FD (group 3; n=6), or not treated (group 4; n=4). Angiographic results were compared at 3 months. Pathology specimens were photographed and the neointimal coverage of devices scored using an ordinal grading system. RESULTS Twenty-two of 24 aneurysms were patent at 1 month. Deployment with compaction was successful in eight cases (group 1a aneurysms). The compaction maneuver led to immediate FD prolapse into the aneurysm in four cases, rescued by deploying a second, telescoping FD (forming group 1b aneurysms). One compacted device later migrated distally, leaving the aneurysm untreated. Angiographic results differed significantly between groups (p=0.0002). At 3 months, aneurysms successfully treated with a single compacted FD were more often occluded at 3 months (7/7) than aneurysms flow-diverted without compaction (2/6; p=0.021). All aneurysms treated with two compacted FDs were occluded, while all untreated aneurysms remained patent. There were no parent vessel stenoses. CONCLUSIONS Compaction of FDs can improve angiographic occlusion of experimental wide-necked aneurysms.
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Affiliation(s)
- Jean-Christophe Gentric
- Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Notre-Dame Hospital, Montreal, Quebec, Canada Groupe d'étude de la Thrombose en Bretagne Occidentale (GETBO, EA 3878), Brest, France
| | - Igor Salazkin
- Laboratory of Interventional Neuroradiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Guylaine Gevry
- Laboratory of Interventional Neuroradiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Jean Raymond
- Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Notre-Dame Hospital, Montreal, Quebec, Canada Laboratory of Interventional Neuroradiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Tim Darsaut
- Division of Neurosurgery, Department of Surgery, University of Alberta Hospital, Mackenzie Health Sciences Centre, Edmonton, Alberta, Canada
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Damiano RJ, Ma D, Xiang J, Siddiqui AH, Snyder KV, Meng H. Finite element modeling of endovascular coiling and flow diversion enables hemodynamic prediction of complex treatment strategies for intracranial aneurysm. J Biomech 2015; 48:3332-40. [PMID: 26169778 DOI: 10.1016/j.jbiomech.2015.06.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 04/13/2015] [Accepted: 06/15/2015] [Indexed: 11/29/2022]
Abstract
Endovascular interventions using coil embolization and flow diversion are becoming the mainstream treatment for intracranial aneurysms (IAs). To help assess the effect of intervention strategies on aneurysm hemodynamics and treatment outcome, we have developed a finite-element-method (FEM)-based technique for coil deployment along with our HiFiVS technique for flow diverter (FD) deployment in patient-specific IAs. We tested four clinical intervention strategies: coiling (1-8 coils), single FD, FD with adjunctive coils (1-8 coils), and overlapping FDs. By evaluating post-treatment hemodynamics using computational fluid dynamics (CFD), we compared the flow-modification performance of these strategies. Results show that a single FD provides more reduction in inflow rate than low packing density (PD) coiling, but less reduction in average velocity inside the aneurysm. Adjunctive coils add no additional reduction of inflow rate beyond a single FD until coil PD exceeds 11%. This suggests that the main role of FDs is to divert inflow, while that of coils is to create stasis in the aneurysm. Overlapping FDs decreases inflow rate, average velocity, and average wall shear stress (WSS) in the aneurysm sac, but adding a third FD produces minimal additional reduction. In conclusion, our FEM-based techniques for virtual coiling and flow diversion enable recapitulation of complex endovascular intervention strategies and detailed hemodynamics to identify hemodynamic factors that affect treatment outcome.
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Affiliation(s)
- Robert J Damiano
- Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Ding Ma
- Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Jianping Xiang
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Adnan H Siddiqui
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Radiology, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Kenneth V Snyder
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Radiology, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
| | - Hui Meng
- Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Biomedical Engineering, University at Buffalo,State University of New York, Buffalo, NY 14203, USA.
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AView: An Image-based Clinical Computational Tool for Intracranial Aneurysm Flow Visualization and Clinical Management. Ann Biomed Eng 2015; 44:1085-96. [PMID: 26101034 DOI: 10.1007/s10439-015-1363-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
Intracranial aneurysms (IAs) occur in around 3% of the entire population. IA rupture is responsible for the most devastating type of hemorrhagic strokes, with high fatality and disability rates as well as healthcare costs. With increasing detection of unruptured aneurysms, clinicians are routinely faced with the dilemma whether to treat IA patients and how to best treat them. Hemodynamic and morphological characteristics are increasingly considered in aneurysm rupture risk assessment and treatment planning, but currently no computational tools allow routine integration of flow visualization and quantitation of these parameters in clinical workflow. In this paper, we introduce AView, a prototype of a clinician-oriented, integrated computation tool for aneurysm hemodynamics, morphology, and risk and data management to aid in treatment decisions and treatment planning in or near the procedure room. Specifically, we describe how we have designed the AView structure from the end-user's point of view, performed a pilot study and gathered clinical feedback. The positive results demonstrate AView's potential clinical value on enhancing aneurysm treatment decision and treatment planning.
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38
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Macdonald RL. Flow diverters: one device does not fit all. J Neurosurg 2015; 123:829-30. [PMID: 26090837 DOI: 10.3171/2014.12.jns142537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- R Loch Macdonald
- Division of Neurosurgery, St. Michael's Hospital, Labatt Family Centre of Excellence in Brain Injury and Trauma Research, Keenan Research Centre for Biomedical Science, and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Department of Surgery, University of Toronto, Ontario, Canada
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Xiang J, Damiano RJ, Lin N, Snyder KV, Siddiqui AH, Levy EI, Meng H. High-fidelity virtual stenting: modeling of flow diverter deployment for hemodynamic characterization of complex intracranial aneurysms. J Neurosurg 2015; 123:832-40. [PMID: 26090829 DOI: 10.3171/2014.11.jns14497] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Flow diversion via Pipeline Embolization Device (PED) represents the most recent advancement in endovascular therapy of intracranial aneurysms. This exploratory study aims at a proof of concept for an advanced device-modeling tool in conjunction with computational fluid dynamics (CFD) to evaluate flow modification effects by PED in actual, treated cases. METHODS The authors performed computational modeling of 3 PED-treated complex aneurysm cases. The patient in Case 1 had a fusiform vertebral aneurysm treated with a single PED. In Case 2 the patient had a giant internal carotid artery (ICA) aneurysm treated with 2 PEDs. Case 3 consisted of tandem ICA aneurysms (III-a and III-b) treated by a single PED. The authors' recently developed high-fidelity virtual stenting (HiFiVS) technique was used to recapitulate the clinical deployment process of PEDs in silico for these 3 cases. Pretreatment and posttreatment aneurysmal hemodynamics studies performed using CFD simulation were analyzed. Changes in aneurysmal flow velocity, inflow rate, wall shear stress (WSS), and turnover time were calculated and compared with the clinical outcome. RESULTS In Case 1 (occluded within the first 3 months), the aneurysm had the most drastic flow reduction after PED placement; the aneurysmal average velocity, inflow rate, and average WSS were decreased by 76.3%, 82.5%, and 74.0%, respectively, whereas the turnover time was increased to 572.1% of its pretreatment value. In Case 2 (occluded at 6 months), aneurysmal average velocity, inflow rate, and average WSS were decreased by 39.4%, 38.6%, and 59.1%, respectively, and turnover time increased to 163.0%. In Case 3, Aneurysm III-a (occluded at 6 months) had a decrease by 38.0%, 28.4%, and 50.9% in average velocity, inflow rate, and average WSS, respectively, and turnover time increased to 139.6%, which was quite similar to Aneurysm II. Surprisingly, the adjacent Aneurysm III-b had more substantial flow reduction (a decrease by 77.7%, 53.0%, and 84.4% in average velocity, inflow rate, and average WSS, respectively, and an increase to 213.0% in turnover time) than Aneurysm III-a, which qualitatively agreed with angiographic observation at 3-month follow-up. However, Aneurysm III-b remained patent at both 6 months and 9 months. A closer examination of the vascular anatomy in Case 3 revealed blood draining to the ophthalmic artery off Aneurysm III-b, which may have prevented its complete thrombosis. CONCLUSIONS This proof-of-concept study demonstrates that HiFiVS modeling of flow diverter deployment enables detailed characterization of hemodynamic alteration by PED placement. Posttreatment aneurysmal flow reduction may be correlated with aneurysm occlusion outcome. However, predicting aneurysm treatment outcome by flow diverters also requires consideration of other factors, including vascular anatomy.
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Affiliation(s)
- Jianping Xiang
- Toshiba Stroke and Vascular Research Center.,Department of Neurosurgery.,Department of Mechanical and Aerospace Engineering
| | - Robert J Damiano
- Toshiba Stroke and Vascular Research Center.,Department of Mechanical and Aerospace Engineering
| | - Ning Lin
- Department of Neurosurgery.,Department of Neurosurgery, Weill Cornell Medical Center and NewYork-Presbyterian Hospital, New York, New York
| | - Kenneth V Snyder
- Toshiba Stroke and Vascular Research Center.,Department of Neurosurgery.,Department of Radiology, University at Buffalo, The State University of New York, Buffalo; and
| | - Adnan H Siddiqui
- Toshiba Stroke and Vascular Research Center.,Department of Neurosurgery.,Department of Radiology, University at Buffalo, The State University of New York, Buffalo; and
| | - Elad I Levy
- Toshiba Stroke and Vascular Research Center.,Department of Neurosurgery.,Department of Radiology, University at Buffalo, The State University of New York, Buffalo; and
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center.,Department of Neurosurgery.,Department of Mechanical and Aerospace Engineering.,Department of Biomedical Engineering, and
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Kono K, Shintani A, Terada T. Hemodynamic effects of stent struts versus straightening of vessels in stent-assisted coil embolization for sidewall cerebral aneurysms. PLoS One 2014; 9:e108033. [PMID: 25247794 PMCID: PMC4172595 DOI: 10.1371/journal.pone.0108033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/18/2014] [Indexed: 11/18/2022] Open
Abstract
Background Recent clinical studies have shown that recanalization rates are lower in stent-assisted coil embolization than in coiling alone in the treatment of cerebral aneurysms. Objective This study aimed to assess and compare the hemodynamic effect of stent struts and straightening of vessels by stent placement on reducing flow velocity in sidewall aneurysms, with the goal of reducing recanalization rates. Methods We evaluated 16 sidewall aneurysms treated with Enterprise stents. We performed computational fluid dynamics simulations using patient-specific geometries before and after treatment, with or without stent struts. Results Stent placement straightened vessels by a mean (±standard deviation) of 12.9°±13.1° 6 months after treatment. Placement of stent struts in the initial vessel geometries reduced flow velocity in aneurysms by 23.1%±6.3%. Straightening of vessels without stent struts reduced flow velocity by 9.6%±12.6%. Stent struts had significantly stronger effects on reducing flow velocity than straightening (P = 0.004, Wilcoxon test). Deviation of the effects was larger by straightening than by stent struts (P = 0.01, F-test). The combination of stent struts and straightening reduced flow velocity by 32.6%±12.2%. There was a trend that larger inflow angles produced a larger reduction in flow velocity by straightening of vessels (P = 0.16). Conclusion In sidewall aneurysms, stent struts have stronger effects (approximately 2 times) on reduction in flow velocity than straightening of vessels. Hemodynamic effects by straightening vary in each case and can be predicted by inflow angles of pre-operative vessel geometry. These results may be useful to design a treatment strategy for reducing recanalization rates.
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Affiliation(s)
- Kenichi Kono
- Department of Neurosurgery, Wakayama Rosai Hospital, Wakayama, Japan
- * E-mail:
| | - Aki Shintani
- Department of Neurosurgery, Wakayama Rosai Hospital, Wakayama, Japan
| | - Tomoaki Terada
- Department of Neurosurgery, Wakayama Rosai Hospital, Wakayama, Japan
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