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Awuah WA, Ahluwalia A, Darko K, Sanker V, Tan JK, Tenkorang PO, Ben-Jaafar A, Ranganathan S, Aderinto N, Mehta A, Shah MH, Lee Boon Chun K, Abdul-Rahman T, Atallah O. Bridging Minds and Machines: The Recent Advances of Brain-Computer Interfaces in Neurological and Neurosurgical Applications. World Neurosurg 2024; 189:138-153. [PMID: 38789029 DOI: 10.1016/j.wneu.2024.05.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 05/26/2024]
Abstract
Brain-computer interfaces (BCIs), a remarkable technological advancement in neurology and neurosurgery, mark a significant leap since the inception of electroencephalography in 1924. These interfaces effectively convert central nervous system signals into commands for external devices, offering revolutionary benefits to patients with severe communication and motor impairments due to a myriad of neurological conditions like stroke, spinal cord injuries, and neurodegenerative disorders. BCIs enable these individuals to communicate and interact with their environment, using their brain signals to operate interfaces for communication and environmental control. This technology is especially crucial for those completely locked in, providing a communication lifeline where other methods fall short. The advantages of BCIs are profound, offering autonomy and an improved quality of life for patients with severe disabilities. They allow for direct interaction with various devices and prostheses, bypassing damaged or nonfunctional neural pathways. However, challenges persist, including the complexity of accurately interpreting brain signals, the need for individual calibration, and ensuring reliable, long-term use. Additionally, ethical considerations arise regarding autonomy, consent, and the potential for dependence on technology. Despite these challenges, BCIs represent a transformative development in neurotechnology, promising enhanced patient outcomes and a deeper understanding of brain-machine interfaces.
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Affiliation(s)
| | - Arjun Ahluwalia
- School of Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Kwadwo Darko
- Department of Neurosurgery, Korle Bu Teaching Hospital, Accra, Ghana
| | - Vivek Sanker
- Department of Neurosurgery, Trivandrum Medical College, India
| | - Joecelyn Kirani Tan
- Faculty of Medicine, University of St Andrews, St. Andrews, Scotland, United Kingdom.
| | | | - Adam Ben-Jaafar
- University College Dublin, School of Medicine, Belfield, Dublin, Ireland
| | - Sruthi Ranganathan
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Nicholas Aderinto
- Internal Medicine Department, LAUTECH Teaching Hospital, Ogbomoso, Nigeria
| | - Aashna Mehta
- University of Debrecen-Faculty of Medicine, Debrecen, Hungary
| | | | | | | | - Oday Atallah
- Department of Neurosurgery, Hannover Medical School, Hannover, Germany
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2
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Liu Z, Zhang M, Wang C, Wang Z, Liao X, Ou C, Si W. Flow diverters treatment planning of small- and medium-sized intracranial saccular aneurysms on the internal carotid artery via constraint-based virtual deployment. Int J Comput Assist Radiol Surg 2024; 19:1175-1183. [PMID: 38619792 DOI: 10.1007/s11548-024-03124-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 04/16/2024]
Abstract
PURPOSE The internal carotid artery (ICA) is a region with a high incidence for small- and medium-sized saccular aneurysms. However, the treatment relies heavily on the surgeon's experience to achieve optimal outcome. Although the finite element method (FEM) and computational fluid dynamics can predict the postoperative outcomes, due to the computational complexity of traditional methods, there is an urgent need for investigating the fast but versatile approaches related to numerical simulations of flow diverters (FDs) deployment coupled with the hemodynamic analysis to determine the treatment plan. METHODS We collected the preoperative and postoperative data from 34 patients (29 females, 5 males; mean age 55.74 ± 9.98 years) who were treated with a single flow diverter for small- to medium-sized intracranial saccular aneurysms on the ICA. The constraint-based virtual deployment (CVD) method is proposed to simulate the FDs expanding outward along the vessel centerline while be constrained by the inner wall of the vessel. RESULTS The results indicate that there were no significant differences in the reduction rates of wall shear stress and aneurysms neck velocity between the FEM and methods. However, the solution time of CVD was greatly reduced by 98%. CONCLUSION In the typical location of small- and medium-sized saccular aneurysms, namely the ICA, our virtual FDs deployment simulation effectively balances the computational accuracy and efficiency. Combined with hemodynamics analysis, our method can accurately represent the blood flow changes within the lesion region to assist surgeons in clinical decision-making.
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Affiliation(s)
- Zehua Liu
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Xueyuan street 1068, Shenzhen University Town, Nanshan District, Shenzhen, 518000, China
| | - Meng Zhang
- Department of Neurosurgery, Shenzhen Second People's Hospital, Sungang West Road 3002, Futian District, Guangdong, 510000, China
| | - Chao Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, TiantanXili 6, Dongcheng District, Beijing, 100000, China
| | - Zhongxiao Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, TiantanXili 6, Dongcheng District, Beijing, 100000, China
| | - Xiangyun Liao
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Xueyuan street 1068, Shenzhen University Town, Nanshan District, Shenzhen, 518000, China
| | - Chubin Ou
- Department of Radiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Zhongshan 2nd Road 106, Yuexiu District, Guangdong, 510000, China.
| | - Weixin Si
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Xueyuan street 1068, Shenzhen University Town, Nanshan District, Shenzhen, 518000, China.
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3
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Sándor L, Paál G. Design space exploration of flow diverter hydraulic resistance parameters in sidewall intracranial aneurysms. Comput Methods Biomech Biomed Engin 2024; 27:931-942. [PMID: 37231591 DOI: 10.1080/10255842.2023.2215369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/07/2023] [Indexed: 05/27/2023]
Abstract
Intracranial aneurysms are nowadays treated with endovascular flow diverter devices to avoid sac rupture. This study explores how different linear and quadratic hydrodynamic resistance parameters reduce the flow in the sac for five patient-specific sidewall aneurysms.The 125 performed blood flow simulations included the stents using a Darcy-Forcheimer porous layer approach based on real-life stent characteristics. Time- and space-averaged velocity magnitudes were strongly affected by the linear coefficient with a power-law relationship. Quadratic coefficients alter the flow in a minor way due to the low-velocity levels in the aneurysm sac and neck region.
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Affiliation(s)
- Levente Sándor
- Faculty of Mechanical Engineering, Department of Hydrodynamic Systems, Budapest University of Technology and Economics, Budapest, Hungary
| | - György Paál
- Faculty of Mechanical Engineering, Department of Hydrodynamic Systems, Budapest University of Technology and Economics, Budapest, Hungary
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Sunderland K, Jiang J, Zhao F. Disturbed flow's impact on cellular changes indicative of vascular aneurysm initiation, expansion, and rupture: A pathological and methodological review. J Cell Physiol 2022; 237:278-300. [PMID: 34486114 PMCID: PMC8810685 DOI: 10.1002/jcp.30569] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/06/2021] [Accepted: 08/16/2021] [Indexed: 01/03/2023]
Abstract
Aneurysms are malformations within the arterial vasculature brought on by the structural breakdown of the microarchitecture of the vessel wall, with aneurysms posing serious health risks in the event of their rupture. Blood flow within vessels is generally laminar with high, unidirectional wall shear stressors that modulate vascular endothelial cell functionality and regulate vascular smooth muscle cells. However, altered vascular geometry induced by bifurcations, significant curvature, stenosis, or clinical interventions can alter the flow, generating low stressor disturbed flow patterns. Disturbed flow is associated with altered cellular morphology, upregulated expression of proteins modulating inflammation, decreased regulation of vascular permeability, degraded extracellular matrix, and heightened cellular apoptosis. The understanding of the effects disturbed flow has on the cellular cascades which initiate aneurysms and promote their subsequent growth can further elucidate the nature of this complex pathology. This review summarizes the current knowledge about the disturbed flow and its relation to aneurysm pathology, the methods used to investigate these relations, as well as how such knowledge has impacted clinical treatment methodologies. This information can contribute to the understanding of the development, growth, and rupture of aneurysms and help develop novel research and aneurysmal treatment techniques.
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Affiliation(s)
- Kevin Sunderland
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
| | - Jingfeng Jiang
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931,Corresponding Authors: Feng Zhao, 101 Bizzell Street, College Station, TX 77843-312, Tel : 979-458-1239, , Jingfeng Jiang, 1400 Townsend Dr., Houghton, MI 49931, Tel: 906-487-1943
| | - Feng Zhao
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843,Corresponding Authors: Feng Zhao, 101 Bizzell Street, College Station, TX 77843-312, Tel : 979-458-1239, , Jingfeng Jiang, 1400 Townsend Dr., Houghton, MI 49931, Tel: 906-487-1943
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5
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Cerebral aneurysm flow diverter modeled as a thin inhomogeneous porous medium in hemodynamic simulations. Comput Biol Med 2021; 139:104988. [PMID: 34717230 DOI: 10.1016/j.compbiomed.2021.104988] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/11/2021] [Accepted: 10/24/2021] [Indexed: 11/24/2022]
Abstract
Rapid and accurate simulation of cerebral aneurysm flow modifications by flow diverters (FDs) can help improving patient-specific intervention and predicting treatment outcome. However, when FD devices are explicitly represented in computational fluid dynamics (CFD) simulations, flow around the stent wires must be resolved, leading to high computational cost. Classic porous medium (PM) methods can reduce computational expense but cannot capture the inhomogeneous FD wire distribution once implanted on a cerebral artery and thus cannot accurately model the post-stenting aneurysmal flow. We report a novel approach that models the FD flow modification as a thin inhomogeneous porous medium (iPM). It improves over the classic PM approaches in two ways. First, the FD is more appropriately treated as a thin screen, which is more accurate than the classic 3D-PM-based Darcy-Forchheimer relation. Second, pressure drop is calculated cell-by-cell using the local FD geometric parameters across an inhomogeneous PM. We applied the iPM technique to simulating the post-stenting hemodynamics of three patient-specific aneurysms. To test its accuracy and speed, we compared the results from the iPM technique against CFD simulations with explicit FD devices. The iPM CFD ran 500% faster than the explicit CFD while achieving 94%-99% accuracy; thus, iPM is a promising clinical bedside modeling tool to assist endovascular interventions with FD and stents.
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Djukic T, Saveljic I, Pelosi G, Parodi O, Filipovic N. A study on the accuracy and efficiency of the improved numerical model for stent implantation using clinical data. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 207:106196. [PMID: 34091419 DOI: 10.1016/j.cmpb.2021.106196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/17/2021] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND OBJECTIVES Stent implantation procedure should be carefully planned and adapted to the particular patient in order to minimize possible complications. Numerical simulations can provide useful quantitative data about the state of the artery after the implantation, as well as information about the benefits of the intervention from the hemodynamical point of view. METHODS In this paper, a numerical model for stent implantation is presented. This numerical model simulates the stent expansion, the interaction of the stent with arterial wall and the deformation of the arterial wall under the influence of the stent. FE method was used to perform CFD simulations and the effects of stenting were analyzed by comparing the hemodynamic parameters before and after stent implantation. RESULTS Clinical data for overall 34 patients was used for the simulations, and for 9 of them data from follow up examinations was used to validate the results of simulations of stent implantation. CONCLUSIONS The good agreement of results (less than 4.1% of SD error for all the 9 validation cases) demonstrated the accuracy of the presented numerical model. The developed approach can be a valuable tool for the improvement of pre-operative planning and patient-specific treatment optimization.
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Affiliation(s)
- Tijana Djukic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Institute for Information Technologies, University of Kragujevac, Jovana Cvijica bb, 34000 Kragujevac, Serbia.
| | - Igor Saveljic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Institute for Information Technologies, University of Kragujevac, Jovana Cvijica bb, 34000 Kragujevac, Serbia.
| | - Gualtiero Pelosi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
| | - Oberdan Parodi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
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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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8
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Fast virtual coiling algorithm for intracranial aneurysms using pre-shape path planning. Comput Biol Med 2021; 134:104496. [PMID: 34077817 DOI: 10.1016/j.compbiomed.2021.104496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 09/30/2022]
Abstract
To aid in predicting and improving treatment outcome of endovascular coiling of intracranial aneurysms, simulation of patient-specific coil deployment should be both accurate and fast. We developed a fast virtual coiling algorithm called Pre-shape Path Planning (P3). It captures the mechanical propensity of a released coil to restore its pre-shape for bending energy minimization, producing coils without unrealistic kinks and bends. A coil is discretized into finite-length segments and extruded from the delivery catheter segment-by-segment following a generic coil pre-shape. With the release of each segment, coil-wall and coil-coil collisions are detected and resolved. Modeling of each case took seconds to minutes. To test the algorithm, we evaluated its output against the literature, experiments, and patient angiograms. The periphery-to-core ratio of coils deployed by P3 decreased with increasing coil packing density, consistent with observations in the literature. Coils deployed by P3 compared well with in vitro experiments, free from unphysical kinks and loops that arose from previous virtual coiling algorithms. Simulations of coiling in four patient-specific aneurysms agreed well with the patient angiograms. To test the influence of coil pre-shape on P3, we performed hemodynamic simulations in aneurysms with coils deployed by P3 using the generic pre-shape, P3 using a coil-specific pre-shape, and full finite-element-method simulation. We found that the generic pre-shape was sufficient to produce results comparable to virtual coiling by finite element modeling. Based on these findings, P3 can rapidly simulate coiling in patient-specific aneurysms with good accuracy and is thus a potential candidate for clinical treatment planning.
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Zhang H, Li L, Miao F, Yu J, Zhou B, Pan Y. Computational fluid dynamics analysis of intracranial aneurysms treated with flow diverters: A case report. Neurochirurgie 2021; 68:235-238. [PMID: 33771614 DOI: 10.1016/j.neuchi.2021.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/05/2021] [Accepted: 03/06/2021] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Intracranial aneurysms (IAs) are localized dilatations of intracranial arteries due to weaknesses of the endothelial layer. IAs may be treated by flow diverters (FDs), alternatively to stents and coils combination. FD is a method for the treatment of IAs especially for large, wide-necked or fusiform aneurysms. In this case report, we described a 65-year-old woman with IA who were treated by FD. CASE PRESENTATION A 65-year-old woman was diagnosed with a giant aneurysm at the posterior inferior cerebellar artery segment of the left internal carotid artery. Then based on the computed tomography data of this woman, aneurysm vascular stent model was constructed before and after FD, and internal pressure, velocity, wall shear stress (WSS) of aneurysms were determined by CFD analysis. Standard boundary conditions were applied. It was found that a single FD stent and double FD stents decreased the blood flow and WSS of aneurysm. The effect of single FD stent+30% filling on blood flow was more obvious, but the aneurysm rupture was caused by excessive coil packing. So, a single stent+10% coil packing rate was the best option for treating aneurysms. CONCLUSIONS CFD analysis for flow velocity and WSS have protection on aneurysms.
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Affiliation(s)
- H Zhang
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China
| | - L Li
- School of Clinical Medicine, Gansu University of Chinese Medicine, 730030 Lanzhou, China
| | - F Miao
- Department of Neurosurgery, Zhangye People's Hospital Affiliated to Hexi University, 734000 Zhangye, China
| | - J Yu
- College of Petroleum and Chemical Engineering, Lanzhou University of Technology, 730050 Lanzhou, China
| | - B Zhou
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China
| | - Y Pan
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China.
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Tian Z, Liu J, Kumar J, Li W, Zhang Y, Zhang Y, Wang K, Wang S, Ren Z, Yang X. Significant flow velocity reduction at the intracranial aneurysm neck after endovascular treatment leads to favourable angiographic outcome: a prospective study. Stroke Vasc Neurol 2021; 6:366-375. [PMID: 33526635 PMCID: PMC8485238 DOI: 10.1136/svn-2020-000413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 11/16/2020] [Accepted: 12/01/2020] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND With widely usage of flow diverter in intracranial aneurysm treatment, some previously used predictors may not be effective in evaluating the recurrence risk. We aimed to comprehensively re-evaluate the predictors of intracranial aneurysm outcome with various endovascular treatment methods and devices. METHODS This is a prospective registered study. We analysed 6-month and 18-month follow-up angiographic data from the prospective study. Data on patient demographics, aneurysm morphology and type of treatment were recorded. Patient-specific haemodynamic simulations were performed. An unfavourable angiographic outcome was defined as recurrence of aneurysm in cases with coiling or stent-assisted coiling, patency of aneurysm in cases with flow diverters or retreatment during follow-up. RESULTS In total, 165 patients (177 intracranial aneurysms) with at least one angiographic follow-up data were analysed. For the short-term (6-month) results, after univariate analysis, the demographic, morphological and treatment-related factors did not achieve significantly statistical differences. The reduction ratio (RR) of velocity at aneurysm neck after embolisation was significantly lower in the unfavourable angiographic group than the favourable angiographic outcome group (p=0.002). After the Cox regression analysis, the RR of velocity at aneurysm neck was the only independent factor associated with favourable angiographic outcome (OR 0.028; p=0.001) and had an acceptable area under the curve (0.714) with a clear cut-off value (46.14%). Similarly, for the analysis of midterm (18-month) results, the RR of velocity at the aneurysm neck was the only independent significant factor for the unfavourable angiographic outcome (OR 0.050; p=0.017). The area under the curve was 0.754 and the cut-off value was 48.20%. CONCLUSIONS The haemodynamics showed an independent effect on angiographic follow-up results and may provide helpful suggestions for clinical practice in the future.
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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
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Jay Kumar
- Department of Neurosurgery, University of South Florida, Tampa, Florida, USA
| | - Wenqiang Li
- 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
| | - 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
| | - Shengzhang Wang
- Department of Mechanics and Engineering Science, Fudan University, Shanghai, China
| | - Zeguang Ren
- Department of Neurosurgery, University of South Florida, Tampa, Florida, USA
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
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王 盛, 蔡 云, 孟 庄, 张 晓, 杨 新, 董 智. [Finite element simulation of stent implantation and its applications in the interventional planning for hemorrhagic cardio-cerebrovascular diseases]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2020; 37:974-982. [PMID: 33369336 PMCID: PMC9929980 DOI: 10.7507/1001-5515.202008063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Indexed: 11/03/2022]
Abstract
Numerical simulation of stent deployment is very important to the surgical planning and risk assess of the interventional treatment for the cardio-cerebrovascular diseases. Our group developed a framework to deploy the braided stent and the stent graft virtually by finite element simulation. By using the framework, the whole process of the deployment of the flow diverter to treat a cerebral aneurysm was simulated, and the deformation of the parent artery and the distributions of the stress in the parent artery wall were investigated. The results provided some information to improve the intervention of cerebral aneurysm and optimize the design of the flow diverter. Furthermore, the whole process of the deployment of the stent graft to treat an aortic dissection was simulated, and the distributions of the stress in the aortic wall were investigated when the different oversize ratio of the stent graft was selected. The simulation results proved that the maximum stress located at the position where the bare metal ring touched the artery wall. The results also can be applied to improve the intervention of the aortic dissection and the design of the stent graft.
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Affiliation(s)
- 盛章 王
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
- 复旦大学 工程与应用技术研究院 生物医学工程技术研究所(上海 200433)Institute of Biomedical Engineering Technology, Academy of Engineering and Technology, Fudan University, Shanghai 200433, P.R.China
| | - 云寒 蔡
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
| | - 庄源 孟
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
| | - 晓龙 张
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
| | - 新健 杨
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
| | - 智慧 董
- 复旦大学 航空航天系 生物力学研究所(上海 200433)Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, P.R.China
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Zhang M, Tupin S, Anzai H, Kohata Y, Shojima M, Suzuki K, Okamoto Y, Tanaka K, Yagi T, Fujimura S, Ohta M. Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis. J Neurointerv Surg 2020; 13:164-170. [PMID: 33097626 PMCID: PMC7848055 DOI: 10.1136/neurintsurg-2020-016724] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/11/2020] [Accepted: 09/17/2020] [Indexed: 12/31/2022]
Abstract
Introduction Despite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent. Methods A systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies. Results We found that differences in the aneurysmal inflow rate (SMD −6.05, 95% CI −10.87 to −1.23, p=0.01) and energy loss (SMD −5.28, 95% CI −7.09 to −3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation. Conclusions Inflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.
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Affiliation(s)
- Mingzi Zhang
- Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan
| | - Simon Tupin
- Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan
| | - Hitomi Anzai
- Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan
| | - Yutaro Kohata
- Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan
| | - Masaaki Shojima
- Department of Neurosurgery, Saitama Medical University Saitama Medical Center, Kawagoe, Saitama, Japan
| | - Kosuke Suzuki
- Department of Mechanical and Electrical Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan
| | - Yoshihiro Okamoto
- Division of Medical Devices, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan
| | - Katsuhiro Tanaka
- Department of Neurosurgery, Mie Central Medical Center, Tsu, Mie, Japan
| | - Takanobu Yagi
- Center for Advanced Biomedical Sciences (TWIns), Waseda University, Shinjuku, Tokyo, Japan
| | - Soichiro Fujimura
- Department of Innovation for Medical Information Technology, Jikei University School of Medicine, Minato, Tokyo, Japan.,Graduate School of Mechanical Engineering, Tokyo University of Science, Shinjuku, Tokyo, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan .,ElyTMaX, CNRS - Université de Lyon - Tohoku University, International Joint Unit, Tohoku University, Sendai, Miyagi, Japan
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13
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Závodszky G, Csippa B, Paál G, Szikora I. A novel virtual flow diverter implantation method with realistic deployment mechanics and validated force response. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3340. [PMID: 32279440 PMCID: PMC7317397 DOI: 10.1002/cnm.3340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Virtual flow diverter deployment techniques underwent significant development during the last couple of years. Each existing technique displays advantageous features, as well as significant limitations. One common drawback is the lack of quantitative validation of the mechanics of the device. In the following work, we present a new spring-mass-based method with validated mechanical responses that combines many of the useful capabilities of previous techniques. The structure of the virtual braids naturally incorporates the axial length changes as a function of the local expansion diameter. The force response of the model was calibrated using the measured response of real FDs. The mechanics of the model allows to replicate the expansion process during deployment, including additional effects such as the push-pull technique that is required for the deployment of braided FDs to achieve full opening and proper wall apposition. Furthermore, it is a computationally highly efficient solution that requires little pre-processing and has a run-time of a few seconds on a general laptop and thus allows for exploratory analyses. The model was applied in a patient-specific geometry, where corresponding accurate control measurements in a 3D-printed model were also available. The analysis shows the effects of FD oversizing and push-pull application on the radial expansion, surface density, and on the wall contact pressure.
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Affiliation(s)
- Gábor Závodszky
- Computational Science Lab, Faculty of Science, Institute for InformaticsUniversity of AmsterdamAmsterdamNetherlands
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - Benjámin Csippa
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - György Paál
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - István Szikora
- Department of NeurointerventionsNational Institute of Clinical NeurosciencesBudapestHungary
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14
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Saqr KM, Rashad S, Tupin S, Niizuma K, Hassan T, Tominaga T, Ohta M. What does computational fluid dynamics tell us about intracranial aneurysms? A meta-analysis and critical review. J Cereb Blood Flow Metab 2020; 40:1021-1039. [PMID: 31213162 PMCID: PMC7181089 DOI: 10.1177/0271678x19854640] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite the plethora of published studies on intracranial aneurysms (IAs) hemodynamic using computational fluid dynamics (CFD), limited progress has been made towards understanding the complex physics and biology underlying IA pathophysiology. Guided by 1733 published papers, we review and discuss the contemporary IA hemodynamics paradigm established through two decades of IA CFD simulations. We have traced the historical origins of simplified CFD models which impede the progress of comprehending IA pathology. We also delve into the debate concerning the Newtonian fluid assumption used to represent blood flow computationally. We evidently demonstrate that the Newtonian assumption, used in almost 90% of studies, might be insufficient to describe IA hemodynamics. In addition, some fundamental properties of the Navier-Stokes equation are revisited in supplementary material to highlight some widely spread misconceptions regarding wall shear stress (WSS) and its derivatives. Conclusively, our study draws a roadmap for next-generation IA CFD models to help researchers investigate the pathophysiology of IAs.
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Affiliation(s)
- Khalid M Saqr
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan.,Department of Mechanical Engineering, College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt
| | - Sherif Rashad
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Simon Tupin
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Kuniyasu Niizuma
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgical Engineering and Translational Neuroscience, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Tamer Hassan
- Department of Neurosurgery, Alexandria University School of Medicine, Azarita Medical Campus, Alexandria, Egypt
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
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15
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Rayz VL, Cohen-Gadol AA. Hemodynamics of Cerebral Aneurysms: Connecting Medical Imaging and Biomechanical Analysis. Annu Rev Biomed Eng 2020; 22:231-256. [PMID: 32212833 DOI: 10.1146/annurev-bioeng-092419-061429] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the last two decades, numerous studies have conducted patient-specific computations of blood flow dynamics in cerebral aneurysms and reported correlations between various hemodynamic metrics and aneurysmal disease progression or treatment outcomes. Nevertheless, intra-aneurysmal flow analysis has not been adopted in current clinical practice, and hemodynamic factors usually are not considered in clinical decision making. This review presents the state of the art in cerebral aneurysm imaging and image-based modeling, discussing the advantages and limitations of each approach and focusing on the translational value of hemodynamic analysis. Combining imaging and modeling data obtained from different flow modalities can improve the accuracy and fidelity of resulting velocity fields and flow-derived factors that are thought to affect aneurysmal disease progression. It is expected that predictive models utilizing hemodynamic factors in combination with patient medical history and morphological data will outperform current risk scores and treatment guidelines. Possible future directions include novel approaches enabling data assimilation and multimodality analysis of cerebral aneurysm hemodynamics.
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Affiliation(s)
- Vitaliy L Rayz
- Weldon School of Biomedical Engineering and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Aaron A Cohen-Gadol
- Department of Neurosurgery, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.,Goodman Campbell Brain and Spine, Carmel, Indiana 46032, USA
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16
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Paliwal N, Jaiswal P, Tutino VM, Shallwani H, Davies JM, Siddiqui AH, Rai R, Meng H. Outcome prediction of intracranial aneurysm treatment by flow diverters using machine learning. Neurosurg Focus 2019; 45:E7. [PMID: 30453461 DOI: 10.3171/2018.8.focus18332] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/21/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVEFlow diverters (FDs) are designed to occlude intracranial aneurysms (IAs) while preserving flow to essential arteries. Incomplete occlusion exposes patients to risks of thromboembolic complications and rupture. A priori assessment of FD treatment outcome could enable treatment optimization leading to better outcomes. To that end, the authors applied image-based computational analysis to clinically FD-treated aneurysms to extract information regarding morphology, pre- and post-treatment hemodynamics, and FD-device characteristics and then used these parameters to train machine learning algorithms to predict 6-month clinical outcomes after FD treatment.METHODSData were retrospectively collected for 84 FD-treated sidewall aneurysms in 80 patients. Based on 6-month angiographic outcomes, IAs were classified as occluded (n = 63) or residual (incomplete occlusion, n = 21). For each case, the authors modeled FD deployment using a fast virtual stenting algorithm and hemodynamics using image-based computational fluid dynamics. Sixteen morphological, hemodynamic, and FD-based parameters were calculated for each aneurysm. Aneurysms were randomly assigned to a training or testing cohort in approximately a 3:1 ratio. The Student t-test and Mann-Whitney U-test were performed on data from the training cohort to identify significant parameters distinguishing the occluded from residual groups. Predictive models were trained using 4 types of supervised machine learning algorithms: logistic regression (LR), support vector machine (SVM; linear and Gaussian kernels), K-nearest neighbor, and neural network (NN). In the testing cohort, the authors compared outcome prediction by each model trained using all parameters versus only the significant parameters.RESULTSThe training cohort (n = 64) consisted of 48 occluded and 16 residual aneurysms and the testing cohort (n = 20) consisted of 15 occluded and 5 residual aneurysms. Significance tests yielded 2 morphological (ostium ratio and neck ratio) and 3 hemodynamic (pre-treatment inflow rate, post-treatment inflow rate, and post-treatment aneurysm averaged velocity) discriminants between the occluded (good-outcome) and the residual (bad-outcome) group. In both training and testing, all the models trained using all 16 parameters performed better than all the models trained using only the 5 significant parameters. Among the all-parameter models, NN (AUC = 0.967) performed the best during training, followed by LR and linear SVM (AUC = 0.941 and 0.914, respectively). During testing, NN and Gaussian-SVM models had the highest accuracy (90%) in predicting occlusion outcome.CONCLUSIONSNN and Gaussian-SVM models incorporating all 16 morphological, hemodynamic, and FD-related parameters predicted 6-month occlusion outcome of FD treatment with 90% accuracy. More robust models using the computational workflow and machine learning could be trained on larger patient databases toward clinical use in patient-specific treatment planning and optimization.
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Affiliation(s)
- Nikhil Paliwal
- Departments of1Mechanical & Aerospace Engineering.,2Canon Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, New York
| | | | - Vincent M Tutino
- 2Canon Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, New York.,4Biomedical Engineering, and
| | | | | | - Adnan H Siddiqui
- 2Canon Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, New York.,3Neurosurgery
| | - Rahul Rai
- Departments of1Mechanical & Aerospace Engineering
| | - Hui Meng
- Departments of1Mechanical & Aerospace Engineering.,4Biomedical Engineering, and
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17
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Kellermann R, Serowy S, Beuing O, Skalej M. Deployment of flow diverter devices: prediction of foreshortening and validation of the simulation in 18 clinical cases. Neuroradiology 2019; 61:1319-1326. [PMID: 31473786 DOI: 10.1007/s00234-019-02287-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/26/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE Flow diverter (FD) devices show severe shortening during deployment in dependency of the vessel geometry. Valid information regarding the geometry of the targeted vessel is therefore mandatory for correct device selection, and to avoid complications. But the geometry of diseased tortuous intracranial vessels cannot be measured accurately with standard methods. The goal of this study is to prove the accuracy of a novel virtual stenting method in prediction of the behavior of a FD in an individual vessel geometry. METHODS We applied a virtual stenting method on angiographic 3D imaging data of the specific vasculature of patients, who underwent FD treatment. The planning tool analyzes the local vessel morphology and deploys the FD virtually. We measured in 18 cases the difference between simulated FD length and real FD length after treatment in a landmark-based registration of pre-/post-interventional 3D angiographic datasets. RESULTS The mean value of length deviation of the virtual FD was 2.2 mm (SD ± 1.9 mm) equaling 9.5% (SD ± 8.2%). Underestimated cases present lower deviations compared with overestimated FDs. Flow diverter cases with a nominal device length of 20 mm had the highest prediction accuracy. CONCLUSION The results suggest that the virtual stenting method used in this study is capable of predicting FD length with a clinically sufficient accuracy in advance and could therefore be a helpful tool in intervention planning. Imaging data of high quality are mandatory, while processing and manipulation of the FD during the intervention may impact the accuracy.
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Affiliation(s)
- Robert Kellermann
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
| | - Steffen Serowy
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany.
| | - Oliver Beuing
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
| | - Martin Skalej
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
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Djukic T, Saveljic I, Pelosi G, Parodi O, Filipovic N. Numerical simulation of stent deployment within patient-specific artery and its validation against clinical data. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 175:121-127. [PMID: 31104701 DOI: 10.1016/j.cmpb.2019.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/02/2019] [Accepted: 04/07/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND OBJECTIVE One of the most widely adopted endovascular treatment procedures is the stent implantation. The effectiveness of the treatment depends on the appropriate stent expansion. However, it is difficult to accurately predict the outcome of such an endovascular intervention. Numerical simulations represent a useful tool to study the complex behavior of the stent during deployment. This study presents a numerical model capable of simulating this process. METHODS The numerical model consists of three parts: modeling of stent expansion, modeling the interaction of the stent with the arterial wall and the deformation of the arterial wall. The model is able to predict the shapes of both stent and arterial wall during the entire deployment process. Simulations are performed using patient-specific clinical data that ensures more realistic results. RESULTS The numerical simulations of stent deployment are performed using the extracted geometry of the coronary arteries of two patients. The obtained results are validated against clinical data from the follow up examination and both quantitative and qualitative analysis of the results is presented. The areas of several slices of the arterial wall are calculated for all the three states (before, after and follow up) and the standard error of the area when comparing simulation and follow up examination is 5.27% for patient #1 and 4.5% for patient #2. CONCLUSIONS The final goal of numerical simulations in stent deployment should be to provide a clinical tool that is capable of reliably predicting the treatment outcome. This study showed through the good agreement of results of the numerical simulations and clinical data that the presented numerical model represents a step towards this final goal. These simulations can also provide valuable information about distribution of forces and stress in the arterial wall that can improve pre-operative planning and treatment optimization.
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Affiliation(s)
- Tijana Djukic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia.
| | - Igor Saveljic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Sestre Janjic 6, 34000 Kragujevac, Serbia.
| | - Gualtiero Pelosi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
| | - Oberdan Parodi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
| | - Nenad Filipovic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Sestre Janjic 6, 34000 Kragujevac, Serbia
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Wu X, Tian Z, Liu J, Zhang Y, Li W, Zhang Y, Chen J, Zhou Y, Yang X, Mu S. Patency of Posterior Circulation Branches Covered by Flow Diverter Device: A Hemodynamic Study. Front Neurol 2019; 10:658. [PMID: 31275237 PMCID: PMC6593048 DOI: 10.3389/fneur.2019.00658] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/04/2019] [Indexed: 11/13/2022] Open
Abstract
Objective: Flow diverter devices are increasingly used in the treatment of posterior circulation aneurysms, sometimes necessarily involving ostia of side branches and perforators. The aim of this study was to identify the hemodynamic influence of flow diverters on side branches and perforators of the posterior circulation. Methods: We performed a retrospective study of consecutive patients treated by a flow diverter device for posterior circulation aneurysms with anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA) involvement. Computational fluid dynamics (CFD) were used to discern hemodynamic changes of branches after deployment of the flow diverter. Results: We studied 18 branches from 17 patients (mean age, 50.72 ± 8.17 years). No branches were occluded on immediate angiography and later follow-up. Average flow velocity in aneurysms decreased from 0.077 ± 0.065 m/s to 0.025 ± 0.025 m/s (p < 0.01). Average flow velocity in branch ostia decreased from 0.29 ± 0.14 m/s to 0.27 ± 0.16 m/s (p = 0.189). The difference in flow velocity reduction ratio between aneurysms and branches was statistically significant (68.8 vs. 9.5%; p < 0.001). The mean pressure in branch ostia increased from 10,717.4 ± 489.0 to 10,859.0 ± 643.4 Pa (p < 0.01). Conclusion: While a flow diverter device is capable of slowing down aneurysmal inflow, it is unable to block the flow into branches and perforators when used in the treatment of posterior circulation aneurysms; flow velocity in branches even increased in some cases. With a low branch occlusion ratio, it may be acceptable to cover posterior circulation branches and perforators if unavoidable.
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Affiliation(s)
- Xinzhi Wu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wenqiang Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Junfan Chen
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yangyang Zhou
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shiqing Mu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Li W, Wang Y, Zhang Y, Wang K, Zhang Y, Tian Z, Yang X, Liu J. Efficacy of LVIS vs. Enterprise Stent for Endovascular Treatment of Medium-Sized Intracranial Aneurysms: A Hemodynamic Comparison Study. Front Neurol 2019; 10:522. [PMID: 31191428 PMCID: PMC6546800 DOI: 10.3389/fneur.2019.00522] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/01/2019] [Indexed: 11/23/2022] Open
Abstract
Background: We conducted a computational fluid dynamics (CFD) study and compared the treatment of medium-sized intracranial aneurysms with LVIS and Enterprise stent-assisted coil embolization (SACE) to determine the effects of hemodynamic changes caused by different stent and coil packing densities (PDs) in endovascular treatment. Methods: We enrolled 87 consecutive patients, with 87 medium-sized intracranial aneurysms (≥7, ≤ 12 mm), who underwent LVIS or Enterprise SACE. Aneurysms treated with LVIS SACE were allocated to the LVIS group, and the remainder were allocated to the Enterprise group. CFD were performed to assess hemodynamic alterations between before treatment, after stent deployment, and after SACE. Results: One aneurysm recanalized in the LVIS group (n = 42), and five recanalized in the Enterprise group (n = 45) (recanalization rate: 2.4 vs. 11.1%, respectively; P = 0.108). Higher complete obliteration rate (P = 0.069) was found in the LVIS group. Velocity at the neck plane showed a greater reduction ratio than velocity and WSS of the aneurysm in both groups after stent deployment, while velocity and WSS of the aneurysm showed a greater reduction ratio after coil placement. Further, there was a greater reduction in velocity at the neck plane (59.52 vs. 39.81%), aneurysmal velocity (88.46 vs. 69.45%), and wall shear stress (WSS) (85.45 vs. 69.49%) on the aneurysm in the LVIS group (P < 0.001 for all). Specifically, the reduction ratio of velocity at the neck plane showed significant difference between the groups in the multivariate analysis (P = 0.013). Conclusions : LVIS SACE showed a lower recanalization for endovascular treatment of medium-sized intracranial aneurysms, and the greater hemodynamic alterations might be the key factors.
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Affiliation(s)
- Wenqiang Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang University, Nanchang, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kun Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Chen J, Zhang Y, Tian Z, Li W, Zhang Q, Zhang Y, Liu J, Yang X. Relationship between haemodynamic changes and outcomes of intracranial aneurysms after implantation of the pipeline embolisation device: a single centre study. Interv Neuroradiol 2019; 25:671-680. [PMID: 31088244 DOI: 10.1177/1591019919849673] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Intracranial aneurysms are increasingly being treated by the placement of flow diverters; however, the factors affecting the outcome of aneurysms treated using flow diverters remain unclarified. METHODS The present study investigated 94 aneurysms treated with pipeline embolisation device placement, and used a computational fluid dynamics method to explore the factors influencing the outcome of aneurysms. RESULTS Seventy-six completely occluded aneurysms and 18 incompletely occluded aneurysms were analysed. Before treatment, inflow jets were found in 13 (72.2%) aneurysms in the incompletely occluded group and 34 (44.7%) in the completely occluded group (P = 0.292). After deployment of the pipeline embolisation device, inflow jets remained in nine (50%) aneurysms in the incompletely occluded group and nine (11.8%) in the completely occluded group (P = 0.001). In the incompletely occluded group, regions with inflow jets after treatment corresponded with the patent areas shown on follow-up digital subtraction angiography. The mean reduction ratios of velocity in the whole aneurysm and on the neck plane were lower in the incompletely occluded than in the completely occluded group (P = 0.003; P = 0.017). Multivariate analysis revealed that the only independent risk factors for incomplete aneurysm occlusion were the reduction ratios of velocity (in the whole aneurysm, threshold 0.362, P = 0.005; on the neck plane, threshold 0.273, P = 0.015). CONCLUSIONS After pipeline embolisation device placement, reduction ratios of velocity in the whole aneurysm of less than 0.362 and on the neck plane of less than 0.273 are significantly associated with a greater risk of aneurysm incomplete occlusion. In addition, the persistence of inflow jets in aneurysms is associated with incomplete occlusion in the inflow jet area.
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Affiliation(s)
- Junfan Chen
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Wenqiang Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Qianqian Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing, China
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22
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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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23
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Beydoun HA, Azarbaijani Y, Cheng H, Anderson-Smits C, Marinac-Dabic D. Predicting Successful Treatment of Intracranial Aneurysms with the Pipeline Embolization Device Through Meta-Regression. World Neurosurg 2018; 114:e938-e958. [DOI: 10.1016/j.wneu.2018.03.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/17/2018] [Accepted: 03/17/2018] [Indexed: 10/17/2022]
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24
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Zhang Q, Liu J, Zhang Y, Zhang Y, Tian Z, Li W, Chen J, Mo X, Cai Y, Paliwal N, Meng H, Wang Y, Wang S, Yang X. Efficient simulation of a low-profile visualized intraluminal support device: a novel fast virtual stenting technique. Chin Neurosurg J 2018; 4:6. [PMID: 32922867 PMCID: PMC7398371 DOI: 10.1186/s41016-018-0112-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/28/2018] [Indexed: 11/17/2022] Open
Abstract
Background The low-profile visualized intraluminal support (LVIS) stent has become a promising endovascular option for treating intracranial aneurysms. To achieve better treatment of aneurysms using LVIS, we developed a fast virtual stenting technique for use with LVIS (F-LVIS) to evaluate hemodynamic changes in the aneurysm and validate its reliability. Methods A patient-specific aneurysm was selected for making comparisons between the real LVIS (R-LVIS) and the F-LVIS. To perform R-LVIS stenting, a hollow phantom based on a patient-specific aneurysm was fabricated using a three-dimensional printer. An R-LVIS was released in the phantom according to standard procedure. F-LVIS was then applied successfully in this aneurysm model. The computational fluid dynamics (CFD) values were calculated for both the F-LVIS and R-LVIS models. Qualitative and quantitative comparisons of the two models focused on hemodynamic parameters. Results The hemodynamic characteristics for R-LVIS and F-LVIS were well matched. Representative contours of velocities and wall shear stress (WSS) were consistently similar in both distribution and magnitude. The velocity vectors also showed high similarity, although the R-LVIS model showed faster and more fluid streams entering the aneurysm. Variation tendencies of the velocity in the aneurysm and the WSS on the aneurysm wall were also similar in the two models, with no statistically significant differences in either velocity or WSS. Conclusions The results of the computational hemodynamics indicate that F-LVIS is suitable for evaluating hemodynamic factors. This novel F-LVIS is considered efficient, practical, and effective.
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Affiliation(s)
- Qianqian Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wenqiang Li
- Department of Neurosurgery, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Junfan Chen
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiao Mo
- Capital Medical University School of Biomedical Engineering, Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Beijing, China
| | - Yunhan Cai
- Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York USA.,Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York USA.,Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York USA.,Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York USA
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Shengzhang Wang
- Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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25
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Li W, Liu J, Zhang Y, Wang K, Tian Z, Zhang Q, Jiang C, Yang X, Wang Y. Flow Diversion and Outcomes of Vertebral Fusiform Aneurysms After Stent-Only Treatment: A Hemodynamic Study. World Neurosurg 2017; 107:202-210. [DOI: 10.1016/j.wneu.2017.07.157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
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26
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Petridis AK, Kaschner M, Cornelius JF, Kamp MA, Tortora A, Steiger HJ, Turowski B. A New Imaging Tool for Realtime Measurement of Flow Velocity in Intracranial Aneurysms. Clin Pract 2017; 7:975. [PMID: 28839527 PMCID: PMC5543827 DOI: 10.4081/cp.2017.975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/19/2017] [Indexed: 12/03/2022] Open
Abstract
With modern imaging modalities of the brain a significant number of unruptured aneurysms are detected. However, not every aneurysm is prone to rupture. Because treatment morbidity is about 10% it is crucial to identify unstable aneurysms for which treatment should be discussed. Recently, new imaging tools allow analysis of flow dynamics and wall stability have become available. It seems that they might provide additional data for better risk profiling. In this study we present a new imaging tool for analysis of flow dynamics, which calculates fluid velocity in an aneurysm (Phillips Electronics, N.V.). It may identify regions with high flow and calculate flow reduction after stenting of aneurysms. Contrast is injected with a stable injection speed of 2 mL/sec for 3 sec. Two clinical cases are illustrated. Velocity in aneurysms and areas of instability can be identified and calculated during angiography in real-time. After stenting and flow diverter deployment flow reduction in the internal carotid aneurysm was reduced by 60% and there was a reduction of about 65% in the posterior cerebral artery in the second case we are reporting. The dynamic flow software calculates the flow profile in the aneurysm immediately after contrast injection. It is a real-time, patient specific tool taking into account systole, diastole and flexibility of the vasculature. These factors are an improvement as compared to current models of computational flow dynamics. We think it is a highly efficient, user friendly tool. Further clinical studies are on their way.
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Affiliation(s)
- Athanasios K Petridis
- Department of Neurosurgery Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Marius Kaschner
- Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Jan F Cornelius
- Department of Neurosurgery Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Marcel A Kamp
- Department of Neurosurgery Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Angelo Tortora
- Department of Neurosurgery Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Hans-Jakob Steiger
- Department of Neurosurgery Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
| | - Bernd Turowski
- Institute of Neuroradiology, Heinrich Heine University Duesseldorf, Germany
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27
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Liu J, Zhang Y, Wang A, Zhang Y, Li Y, Yang X. Haemodynamic analysis for recanalisation of intracranial aneurysms after endovascular treatment: an observational registry study in China. BMJ Open 2017; 7:e014261. [PMID: 28501811 PMCID: PMC5777470 DOI: 10.1136/bmjopen-2016-014261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Recanalisation of intracranial aneurysms following endovascular treatment is a major issue. Many factors, including aneurysm morphology, the method of treatment, and haemodynamics, are considered to be associated with recanalisation. However, the underlying haemodynamic mechanisms are not completely understood. METHODS AND ANALYSIS This is a prospective, observational, registry study for patients with intracranial aneurysms who are treated endovascularly. It will enrol 200 eligible patients. Data on morphological, haemodynamic, and treatment factors will be collected prospectively. The advanced virtual stenting technique and porous media method will be used in haemodynamic simulations. The clinical and angiographic outcomes at 6 months will be measured and analysed. This observational study will determine the haemodynamic factors that affect the recanalisation of aneurysms. ETHICS AND DISSEMINATION Both the study protocol and written informed consent were reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital (KY2016-023-01). The results of study will be disseminated in professional printed media. TRIAL REGISTRATION NUMBER NCT02812108; Pre-results.
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Affiliation(s)
- Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Anxin Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yiying Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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28
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Zhang Q, Jing L, Liu J, Wang K, Zhang Y, Paliwal N, Meng H, Wang Y, Wang S, Yang X. Predisposing factors for recanalization of cerebral aneurysms after endovascular embolization: a multivariate study. J Neurointerv Surg 2017; 10:252-257. [PMID: 28377443 DOI: 10.1136/neurintsurg-2017-013041] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 11/04/2022]
Abstract
BACKGROUND The recanalization of cerebral aneurysms after endovascular embolization (coiling or stent-assisted coiling) has been a matter of concern. OBJECTIVE To systematically evaluate the predisposing factors for cerebral aneurysm recanalization using multidimensional analysis in a large patient cohort. METHODS In 238 patients with 283 aneurysms, patient baseline characteristics, aneurysm morphological characteristics, treatment-related factors, and changes in flow hemodynamics after endovascular treatment (coiling or stent-assisted coiling) were compared between the recanalization and non-recanalization groups. Multivariate logistic regression analysis was performed to determine independent risk factors correlated with recanalization. RESULTS 16 aneurysms treated by coiling recanalized, with a recurrence rate of 18.6%, and 24 recanalized in the lesions treated by stent-assisted coiling, with a recanalization rate of 12.2%. Large aneurysms (>10 mm, p=0.002) and a follow-up interval >1 year (p=0.027) were shown to be statistically significant between the recanalization and non-recanalization groups. For flow hemodynamic changes, three parameters (velocity on the neck plane, wall shear stress on the neck wall, and wall shear stress on the whole aneurysm) showed a relatively lower amplitude of decrease after endovascular treatment in the recanalization group. Interestingly, the velocity on the neck plane and wall shear stress on the neck wall may be elevated after treatment. Specifically, the reduction ratio (RR) of velocity on the neck plane showed significant difference between the groups in the multivariate analysis (p=0.013), and was considered an independent risk factor for recanalization. CONCLUSIONS The aneurysm size, follow-up interval, and flow hemodynamic changes, especially the RR of velocity on the neck plane, have important roles in aneurysm recanalization.
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Affiliation(s)
- Qianqian Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Department of Neurosurgery, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kun Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA.,Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA.,Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA.,Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China
| | - Shengzhang Wang
- Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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29
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Paliwal N, Damiano RJ, Davies JM, Siddiqui AH, Meng H. Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2017; 10135. [PMID: 28515570 DOI: 10.1117/12.2254584] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Treatment of intracranial aneurysms (IAs) has been revolutionized by the advent of endovascular Flow Diverters (FDs), which disrupt blood flow within the aneurysm to induce pro-thrombotic conditions, and serves as a scaffold for endothelial ingrowth and arterial remodeling. Despite good clinical success of FDs, complications like incomplete occlusion and post-treatment rupture leading to subarachnoid hemorrhage have been reported. In silico computational fluid dynamic analysis of the pre- and post-treated geometries of IA patients can shed light on the contrasting blood hemodynamics associated with different clinical outcomes. In this study, we analyzed hemodynamic modifications in 15 IA patients treated using a single FD; 10 IAs were completely occluded (successful) and 5 were partially occluded (unsuccessful) at 12-month follow-up. An in-house virtual stenting workflow was used to recapitulate the clinical intervention on these cases, followed by CFD to obtain pre- and post-treatment hemodynamics. Bulk hemodynamic parameters showed comparable reductions in both groups with average inflow rate and aneurysmal velocity reduction of 40.3% and 52.4% in successful cases, and 34.4% and 49.2% in unsuccessful cases. There was a substantial reduction in localized parameter like vortex coreline length and Energy Loss for successful cases, 38.2% and 42.9% compared to 10.1% and 10.5% for unsuccessful cases. This suggest that for successfully treated IAs, the localized complex blood flow is disrupted more prominently by the FD as compared to unsuccessful cases. These localized hemodynamic parameters can be potentially used in prediction of treatment outcome, thus aiding the clinicians in a priori assessment of different treatment strategies.
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Affiliation(s)
- Nikhil Paliwal
- Mechanical and Aerospace Engineering, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Toshiba Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, NY, USA
| | - Robert J Damiano
- Mechanical and Aerospace Engineering, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Toshiba Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, NY, USA
| | - Jason M Davies
- Department of Neurosurgery, University at Buffalo, the State University of New York, Buffalo, NY, USA
| | - Adnan H Siddiqui
- Toshiba Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Department of Neurosurgery, University at Buffalo, the State University of New York, Buffalo, NY, USA
| | - Hui Meng
- Mechanical and Aerospace Engineering, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Toshiba Stroke and Vascular Research Center, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Department of Neurosurgery, University at Buffalo, the State University of New York, Buffalo, NY, USA.,Department of Biomedical Engineering, University at Buffalo, the State University of New York, Buffalo, NY, USA
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30
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Liu J, Jing L, Zhang Y, Song Y, Wang Y, Li C, Wang Y, Mu S, Paliwal N, Meng H, Linfante I, Yang X. Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis. World Neurosurg 2016; 97:344-350. [PMID: 27742509 DOI: 10.1016/j.wneu.2016.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA. METHODS Between September 2009 and November 2013, all consecutive patients with recurrent VADAs after SACE in our institutions were enrolled. Recurrence was defined as recanalization and/or regrowth. We assessed the hemodynamic alterations in wall shear stress (WSS) and velocity after the initial SACE and subsequently after retreatment of the aneurysms that recurred. RESULTS Five patients were included. After the initial treatment, 3 patients showed recanalization and 2 showed regrowth. In the 2 patients with regrowth, the 2 original aneurysms maintained complete occlusion; however, de novo aneurysm regrowth was confirmed near the previous site. Compared with 3 recanalized aneurysms, the completely occluded aneurysms showed high mean reductions in velocity and WSS after initial treatment (velocity, 77.6% vs. 57.7%; WSS, 74.2% vs. 52.4%); however, WSS remained high at the region near the previous lesion where the new aneurysm originated. After the second retreatment, there was no recurrence in any patient. Compared with the 3 aneurysms that recanalized, the 4 aneurysms that maintained complete occlusion showed higher reductions in velocity (62.9%) and WSS (71.1%). CONCLUSIONS Our series indicated that hemodynamics might have an important role in recurrence of VADAs. After endovascular treatment, sufficient hemodynamic reduction in aneurysm dome, orifice, and parent vessel may be one of the key factors for preventing recurrence in VADAs.
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Affiliation(s)
- Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Department of Neurosurgery, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Ying Song
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yang Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Chuanhui Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yanmin Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Shiqing Mu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Italo Linfante
- Miami Cardiac and Vascular Institute and Baptist Neuroscience Center, Baptist Hospital, Miami, Florida, USA.
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China.
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Hemodynamic Effect of Flow Diverter and Coils in Treatment of Large and Giant Intracranial Aneurysms. World Neurosurg 2016; 89:199-207. [DOI: 10.1016/j.wneu.2016.01.079] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/27/2016] [Accepted: 01/27/2016] [Indexed: 11/19/2022]
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32
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Analysis of Multiple Intracranial Aneurysms with Different Outcomes in the Same Patient After Endovascular Treatment. World Neurosurg 2016; 91:399-408. [PMID: 27132177 DOI: 10.1016/j.wneu.2016.04.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 04/20/2016] [Accepted: 04/20/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Aneurysm recanalization after coiling, with or without stent assistance, is a major issue in the endovascular management of intracranial aneurysms. Multiple intracranial aneurysms with different outcomes after endovascular treatment may represent a useful disease model in which patient-specific risk factors can be balanced to investigate possible features linked to aneurysm recanalization. In the present study, we evaluated the impact of aneurysm-specific, treatment-related, and hemodynamics-related factors on multiple aneurysms and to explore the reason why one aneurysm recanalized and the other did not. METHODS Between 2010 and 2015, 763 multiple intracranial aneurysms in 326 patients were diagnosed by digital subtraction angiography. We retrospectively collected and analyzed 13 pairs of multiple aneurysms with different outcomes (recanalized or stable) in the same patient. Patient-specific models were constructed and analyzed by a computational fluid dynamics method. The virtual stent deployment method was used, and the coils were simulated by a porous medium model. Factors were evaluated for significance with respect to recanalization. RESULTS Aneurysm size (P = 0.021), neck width (P = 0.027), ruptured aneurysms (P = 0.002), reduction ratio of averaged velocity (P = 0.008), and wall shear stress (P = 0.024) were significantly associated with aneurysm recanalization. By contrast, the aneurysm location, all of treatment-related factors (packing density, duration of follow-up, stent use, initial angiographic result) and the reduction ratio of averaged pressure were not significantly associated (P > 0.05). CONCLUSIONS Small aneurysm size and neck width, unruptured aneurysm, and perianeurysmal hemodynamics with marked reduction may be important factors associated with the midterm durability of aneurysm embolization.
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Zhao L, Chen D, Chen Z, Wang X, Paliwal N, Xiang J, Meng H, Corso JJ, Xu J. Rapid Virtual Stenting for Intracranial Aneurysms. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 9786:97860V. [PMID: 27346910 PMCID: PMC4917288 DOI: 10.1117/12.2216123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient.
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