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Li W, Wang C, Wang Y, Zhao Y, Yang X, Liu X, Liu J. A model with multiple intracranial aneurysms: possible hemodynamic mechanisms of aneurysmal initiation, rupture and recurrence. Chin Neurosurg J 2024; 10:13. [PMID: 38711139 PMCID: PMC11071235 DOI: 10.1186/s41016-024-00364-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/26/2024] [Indexed: 05/08/2024] Open
Abstract
BACKGROUND Hemodynamic factors play an important role in aneurysm initiation, growth, rupture, and recurrence, while the mechanism of the hemodynamic characteristics is still controversial. A unique model of multiple aneurysms (initiation, growth, rupture, and recurrence) is helpful to avoids the confounders and further explore the possible hemodynamic mechanisms of aneurysm in different states. METHODS We present a model with multiple aneurysms, and including the states of initiation, growth, rupture, and recurrence, discuss the proposed mechanisms, and describe computational fluid dynamic model that was used to evaluate the likely hemodynamic effect of different states of the aneurysms. RESULTS The hemodynamic analysis suggests that high flow impingement and high WSS distribution at normal parent artery was found before aneurysmal initiation. The WSS distribution and flow velocity were decreased in the new sac after aneurysmal growth. Low WSS was the risk hemodynamic factor for aneurysmal rupture. High flow concentration region on the neck plane after coil embolization still marked in recanalized aneurysm. CONCLUSIONS Associations have been identified between high flow impingement and aneurysm recanalization, while low WSS is linked to the rupture of aneurysms. High flow concentration and high WSS distribution at normal artery associated with aneurysm initiation and growth, while after growth, the high-risk hemodynamics of aneurysm rupture was occurred, which is low WSS at aneurysm dome.
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Affiliation(s)
- Wenqiang Li
- Department of Interventional Neuroradiology and Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Chao Wang
- Department of Interventional Neuroradiology and Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
| | - Yanmin Wang
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yapeng Zhao
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology and Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
| | - Xianzhi Liu
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
| | - Jian Liu
- Department of Interventional Neuroradiology and Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China.
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Martin T, El Hage G, Chaalala C, Peeters JB, Bojanowski MW. Hemodynamic factors of spontaneous vertebral artery dissecting aneurysms assessed with numerical and deep learning algorithms: Role of blood pressure and asymmetry. Neurochirurgie 2024; 70:101519. [PMID: 38280371 DOI: 10.1016/j.neuchi.2023.101519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 01/29/2024]
Abstract
BACKGROUND AND OBJECTIVES The pathophysiology of spontaneous vertebral artery dissecting aneurysms (SVADA) is poorly understood. Our goal is to investigate the hemodynamic factors contributing to their formation using computational fluid dynamics (CFD) and deep learning algorithms. METHODS We have developed software that can use patient imagery as input to recreate the vertebrobasilar arterial system, both with and without SVADA, which we used in a series of three patients. To obtain the kinematic blood flow data before and after the aneurysm forms, we utilized numerical methods to solve the complex Navier-Stokes partial differential equations. This was accomplished through the application of a finite volume solver (OpenFoam/Helyx OS). Additionally, we trained a neural ordinary differential equation (NODE) to learn and replicate the dynamical streamlines obtained from the computational fluid dynamics (CFD) simulations. RESULTS In all three cases, we observed that the equilibrium of blood pressure distributions across the VAs, at a specific vertical level, accurately predicted the future SVADA location. In the two cases where there was a dominant VA, the dissection occurred on the dominant artery where blood pressure was lower compared to the contralateral side. The SVADA sac was characterized by reduced wall shear stress (WSS) and decreased velocity magnitude related to increased turbulence. The presence of a high WSS gradient at the boundary of the SVADA may explain its extension. Streamlines generated by CFD were learned with a neural ordinary differential equation (NODE) capable of capturing the system's dynamics to output meaningful predictions of the flow vector field upon aneurysm formation. CONCLUSION In our series, asymmetry in the vertebrobasilar blood pressure distributions at and proximal to the site of the future SVADA accurately predicted its location in all patients. Deep learning algorithms can be trained to model blood flow patterns within biological systems, offering an alternative to the computationally intensive CFD. This technology has the potential to find practical applications in clinical settings.
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Affiliation(s)
- Tristan Martin
- Division of Neurosurgery, Department of Surgery, University of Montreal Hospital Center 1000, rue St-Denis Montréal, QC H2X 0C, Canada
| | - Gilles El Hage
- Division of Neurosurgery, Department of Surgery, University of Montreal Hospital Center 1000, rue St-Denis Montréal, QC H2X 0C, Canada
| | - Chiraz Chaalala
- Division of Neurosurgery, Department of Surgery, University of Montreal Hospital Center 1000, rue St-Denis Montréal, QC H2X 0C, Canada
| | - Jean-Baptiste Peeters
- Division of Neurosurgery, Department of Surgery, University of Montreal Hospital Center 1000, rue St-Denis Montréal, QC H2X 0C, Canada
| | - Michel W Bojanowski
- Division of Neurosurgery, Department of Surgery, University of Montreal Hospital Center 1000, rue St-Denis Montréal, QC H2X 0C, Canada.
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Park DC, Park DW. Measurement of Wall Shear Rate Across the Entire Vascular Wall Using Ultrasound Speckle Decorrelation. ULTRASOUND IN MEDICINE & BIOLOGY 2024:S0301-5629(24)00178-9. [PMID: 38688782 DOI: 10.1016/j.ultrasmedbio.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/28/2024] [Accepted: 04/14/2024] [Indexed: 05/02/2024]
Abstract
OBJECTIVE The accurate measurement of the wall shear rate (WSR) plays a crucial role in the early diagnosis of cardiovascular disease progression and acute events such as aneurysms and atherosclerotic plaque ruptures. To address this need, the speckle decorrelation (SDC) technique has been used to measure WSR based on the 2-D out-of-plane blood flow speed. This technique is particularly advantageous because it enables the use of a 1-D array transducer to measure WSR over the entire luminal area. This study aims to develop a region-based singular value decomposition (SVD) filtering technique that selectively suppresses clutter noise in the vascular region to measure WSR using SDC. METHOD Ultrasound simulations, in-vitro flow experiments, and an in-vivo human study were conducted to evaluate the feasibility of this method's clinical application. RESULTS The results demonstrated that WSR can be effectively measured across entire vascular walls using a conventional 1-D array transducer along with the proposed methodology. CONCLUSION This study successfully demonstrates a noninvasive and accurate SDC-based method for measuring vital vascular WSR. This approach holds significant promise for assessing vascular WSR in both healthy individuals and high-risk cardiovascular disease patients.
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Affiliation(s)
- Dong Chan Park
- Division of Convergence Technology, Research Institute and Hospital, National Cancer Center, Goyang 10408, South Korea
| | - Dae Woo Park
- Division of Convergence Technology, Research Institute and Hospital, National Cancer Center, Goyang 10408, South Korea.
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S SN, Bhattacharjee A, Saha S. CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach. Comput Methods Biomech Biomed Engin 2024; 27:570-586. [PMID: 37021363 DOI: 10.1080/10255842.2023.2194474] [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: 10/28/2022] [Accepted: 03/19/2023] [Indexed: 04/07/2023]
Abstract
Recent research has shown that individuals suffering from COVID-19 are accommodating an elevated level of blood viscosity due to the morphological changes in blood cells. As viscosity is a major flow parameter influencing the flow across a stenosis or an aneurysm, the examination of the significance of hyperviscosity in COVID patients is imperative in arterial pathologies. In this research, we have considered a patient-specific case in which the aneurysm is located along the abdominal aortal walls. Recent research on the side effects of COVID-19 voiced out the various effects on the circulatory system of humans. Also, as abdominal aneurysms exist very often among individuals, causing the death of 150-200 million every year, the hyper-viscous effects of blood on the flow across the diseased aorta are explored by considering the elevated viscosity levels. In vitro explorations contribute considerably to the clinical methods and treatments to be regarded. The objective of the present inquest is to research the flow field in aneurysmatic-COVID-affected patients considering the elastic nature of vessel walls, using the arbitrary Lagrangian-Eulerian approach. The study supports the various clinical findings that voiced the detrimental effects associated with blood hyperviscosity. The simulation results obtained, by solving the fluid mechanics' equations coupled with the solid mechanics' equations, employing a FEM solver suggest that the elevated stress imparted by the hyper-viscous flows on the walls of the aneurysmal aorta can trigger the fastening of the aneurysmal sac enlargement or rupture.
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Affiliation(s)
- Shankar Narayan S
- Department of Mathematics and Statistics, Ramaiah University of Applied Sciences, Bengaluru, India
- Department of Mathematics, Dayananda Sagar University, Bengaluru, India
| | | | - Sunanda Saha
- Department of Mathematics, Vellore Institute of Technology, Vellore, India
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Hadad S, Mut F, Slawski M, Robertson AM, Cebral JR. Evaluation of predictive models of aneurysm focal growth and bleb development using machine learning techniques. J Neurointerv Surg 2024; 16:392-397. [PMID: 37230750 PMCID: PMC10674044 DOI: 10.1136/jnis-2023-020241] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/15/2023] [Indexed: 05/27/2023]
Abstract
BACKGROUND The presence of blebs increases the rupture risk of intracranial aneurysms (IAs). OBJECTIVE To evaluate whether cross-sectional bleb formation models can identify aneurysms with focalized enlargement in longitudinal series. METHODS Hemodynamic, geometric, and anatomical variables derived from computational fluid dynamics models of 2265 IAs from a cross-sectional dataset were used to train machine learning (ML) models for bleb development. ML algorithms, including logistic regression, random forest, bagging method, support vector machine, and K-nearest neighbors, were validated using an independent cross-sectional dataset of 266 IAs. The models' ability to identify aneurysms with focalized enlargement was evaluated using a separate longitudinal dataset of 174 IAs. Model performance was quantified by the area under the receiving operating characteristic curve (AUC), the sensitivity and specificity, positive predictive value, negative predictive value, F1 score, balanced accuracy, and misclassification error. RESULTS The final model, with three hemodynamic and four geometrical variables, along with aneurysm location and morphology, identified strong inflow jets, non-uniform wall shear stress with high peaks, larger sizes, and elongated shapes as indicators of a higher risk of focal growth over time. The logistic regression model demonstrated the best performance on the longitudinal series, achieving an AUC of 0.9, sensitivity of 85%, specificity of 75%, balanced accuracy of 80%, and a misclassification error of 21%. CONCLUSIONS Models trained with cross-sectional data can identify aneurysms prone to future focalized growth with good accuracy. These models could potentially be used as early indicators of future risk in clinical practice.
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Affiliation(s)
- Sara Hadad
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
| | - Fernando Mut
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
| | - Martin Slawski
- Statistics Department, George Mason University, Fairfax, Virginia, USA
| | - Anne M Robertson
- Departmnet of Mechanical enginering and Material Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Juan R Cebral
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
- Department of Mechanical Engineering, George Mason University, Fairfax, Virginia, USA
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Richter K, Probst T, Hundertmark A, Eulzer P, Lawonn K. Longitudinal wall shear stress evaluation using centerline projection approach in the numerical simulations of the patient-based carotid artery. Comput Methods Biomech Biomed Engin 2024; 27:347-364. [PMID: 36880851 DOI: 10.1080/10255842.2023.2185478] [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: 10/07/2022] [Revised: 02/07/2023] [Accepted: 02/17/2023] [Indexed: 03/08/2023]
Abstract
In this numerical study, areas of the carotid bifurcation and of a distal stenosis in the internal carotid artery are closely observed to evaluate the patient's current risks of ischemic stroke. An indicator for the vessel wall defects is the stress exerted by blood on the vessel tissue, typically expressed by the amplitude of the wall shear stress vector (WSS) and its oscillatory shear index. To detect negative shear stresses corresponding with reversal flow, we perform orientation-based shear evaluation. We investigate the longitudinal component of the wall shear vector, where tangential vectors aligned longitudinally with the vessel are necessary. However, resulting from imaging segmentation resolution of patients' computed tomography angiography scans and stenotic regions, the geometry model's mesh is non-smooth on its surface areas and the automatically generated tangential vector field is discontinuous and multi-directional, making an interpretation of our orientation-based risk indicators unreliable. We improve the evaluation of longitudinal shear stress by applying the projection of the vessel's centerline to the surface to construct smooth tangential field aligned longitudinally with the vessel. We validate our approach for the longitudinal WSS component and the corresponding oscillatory index by comparing them to results obtained using automatically generated tangents in both rigid and elastic vessel modeling and to amplitude-based indicators. We present the major benefit of our longitudinal WSS evaluation based on its directionality for the cardiovascular risk assessment, which is the detection of negative WSS indicating persistent reversal or transverse flow. This is impossible in the case of the amplitude-based WSS.
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Affiliation(s)
- Kevin Richter
- Institute of Mathematics, Faculty of Natural and Environmental Sciences, University of Kaiserslautern-Landau, Germany
| | - Tristan Probst
- Institute of Mathematics, Faculty of Natural and Environmental Sciences, University of Kaiserslautern-Landau, Germany
| | - Anna Hundertmark
- Institute of Mathematics, Faculty of Natural and Environmental Sciences, University of Kaiserslautern-Landau, Germany
| | - Pepe Eulzer
- Faculty of Mathematics and Computer Science, University of Jena, Germany
| | - Kai Lawonn
- Faculty of Mathematics and Computer Science, University of Jena, Germany
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Korte J, Marsh LMM, Saalfeld S, Behme D, Aliseda A, Berg P. Fusiform versus Saccular Intracranial Aneurysms-Hemodynamic Evaluation of the Pre-Aneurysmal, Pathological, and Post-Interventional State. J Clin Med 2024; 13:551. [PMID: 38256685 PMCID: PMC11154261 DOI: 10.3390/jcm13020551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Minimally-invasive therapies are well-established treatment methods for saccular intracranial aneurysms (SIAs). Knowledge concerning fusiform IAs (FIAs) is low, due to their wide and alternating lumen and their infrequent occurrence. However, FIAs carry risks like ischemia and thus require further in-depth investigation. Six patient-specific IAs, comprising three position-identical FIAs and SIAs, with the FIAs showing a non-typical FIA shape, were compared, respectively. For each model, a healthy counterpart and a treated version with a flow diverting stent were created. Eighteen time-dependent simulations were performed to analyze morphological and hemodynamic parameters focusing on the treatment effect (TE). The stent expansion is higher for FIAs than SIAs. For FIAs, the reduction in vorticity is higher (Δ35-75% case 2/3) and the reduction in the oscillatory velocity index is lower (Δ15-68% case 2/3). Velocity is reduced equally for FIAs and SIAs with a TE of 37-60% in FIAs and of 41-72% in SIAs. Time-averaged wall shear stress (TAWSS) is less reduced within FIAs than SIAs (Δ30-105%). Within this study, the positive TE of FDS deployed in FIAs is shown and a similarity in parameters found due to the non-typical FIA shape. Despite the higher stent expansion, velocity and vorticity are equally reduced compared to identically located SIAs.
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Affiliation(s)
- Jana Korte
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, 39106 Magdeburg, Germany
- Research Campus STIMULATE, University of Magdeburg, 39106 Magdeburg, Germany; (L.M.M.M.); (S.S.); (D.B.); (P.B.)
| | - Laurel M. M. Marsh
- Research Campus STIMULATE, University of Magdeburg, 39106 Magdeburg, Germany; (L.M.M.M.); (S.S.); (D.B.); (P.B.)
- Department of Mechanical Engineering, George Mason University, Fairfax, VA 22030, USA
| | - Sylvia Saalfeld
- Research Campus STIMULATE, University of Magdeburg, 39106 Magdeburg, Germany; (L.M.M.M.); (S.S.); (D.B.); (P.B.)
- Department of Computer Science and Automation, Ilmenau University of Technology, 98693 Ilmenau, Germany
| | - Daniel Behme
- Research Campus STIMULATE, University of Magdeburg, 39106 Magdeburg, Germany; (L.M.M.M.); (S.S.); (D.B.); (P.B.)
- University Hospital Magdeburg, University of Magdeburg, 39106 Magdeburg, Germany
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195, USA;
| | - Philipp Berg
- Research Campus STIMULATE, University of Magdeburg, 39106 Magdeburg, Germany; (L.M.M.M.); (S.S.); (D.B.); (P.B.)
- Department of Medical Engineering, University of Magdeburg, 39106 Magdeburg, Germany
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Zhu Y, Zou R, Sun X, Lei X, Xiang J, Guo Z, Su H. Assessing the risk of intracranial aneurysm rupture using computational fluid dynamics: a pilot study. Front Neurol 2023; 14:1277278. [PMID: 38187159 PMCID: PMC10771834 DOI: 10.3389/fneur.2023.1277278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 12/07/2023] [Indexed: 01/09/2024] Open
Abstract
Objective This study compared 2 representative cases with ruptured aneurysms to explore the role of hemodynamic and morphological parameters in evaluating the rupture risk of intracranial aneurysms (IAs). Methods CTA and 3-dimensional rotational angiography (3DRA) of 3 IAs in 2 patients were retrospectively analyzed in this study. Hemodynamics and morphological parameters were compared between a ruptured IA and an unruptured IA in case1, and between before and after aneurysm rupture in case 2. Results In case 1, the ruptured aneurysm had larger morphological parameters including size ratio (SR), aspect ratio (AR), aneurysm vessel angle (θF), Aneurysm inclination angle (θA), Undulation index (UI), Ellipticity index (EI), and Non-sphericity Index (NSI) than the unruptured aneurysm. And oscillatory shear index (OSI) is also larger. Higher rupture resemblance score (RRS) was shown in the ruptured aneurysm. In case 2, the aneurysm had one daughter sac after 2 years. Partial morphological and hemodynamic parameters including SR, AR, θF, θA, UI, EI, NSI, OSI, and relative residence time (RRT) increased, and normalized wall shear stress (NWSS) was significantly reduced. RRS increased during this period. Conclusion SR and OSI may have predictive values for the risk of intracranial aneurysm rupture. It is possible that WSS Changes before and after IA rupture, yet the influence of high or low WSS on growth and rupture of IA remains unclear. RRS is promising to be used in the clinical assessment of the rupture risk of IAs and to guide the formulation of treatment plans.
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Affiliation(s)
- Yajun Zhu
- Department of Neurosurgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Rong Zou
- ArteryFlow Technology Co., Ltd., Hangzhou, China
| | - Xiaochuan Sun
- Department of Neurosurgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xingwei Lei
- Department of Neurosurgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | | | - Zongduo Guo
- Department of Neurosurgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hai Su
- Yongchuan Hospital of Chongqing Medical University, Chongqing, China
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Weiss AJ, Panduro AO, Schwarz EL, Sexton ZA, Lan IS, Geisbush TR, Marsden AL, Telischak NA. A matched-pair case control study identifying hemodynamic predictors of cerebral aneurysm growth using computational fluid dynamics. Front Physiol 2023; 14:1300754. [PMID: 38162830 PMCID: PMC10757566 DOI: 10.3389/fphys.2023.1300754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction: Initiation and progression of cerebral aneurysms is known to be driven by complex interactions between biological and hemodynamic factors, but the hemodynamic mechanism which drives aneurysm growth is unclear. We employed robust modeling and computational methods, including temporal and spatial convergence studies, to study hemodynamic characteristics of cerebral aneurysms and identify differences in these characteristics between growing and stable aneurysms. Methods: Eleven pairs of growing and non-growing cerebral aneurysms, matched in both size and location, were modeled from MRA and CTA images, then simulated using computational fluid dynamics (CFD). Key hemodynamic characteristics, including wall shear stress (WSS), oscillatory shear index (OSI), and portion of the aneurysm under low shear, were evaluated. Statistical analysis was then performed using paired Wilcoxon rank sum tests. Results: The portion of the aneurysm dome under 70% of the parent artery mean wall shear stress was higher in growing aneurysms than in stable aneurysms and had the highest significance among the tested metrics (p = 0.08). Other metrics of area under low shear had similar levels of significance. Discussion: These results align with previously observed hemodynamic trends in cerebral aneurysms, indicating a promising direction for future study of low shear area and aneurysm growth. We also found that mesh resolution significantly affected simulated WSS in cerebral aneurysms. This establishes that robust computational modeling methods are necessary for high fidelity results. Together, this work demonstrates that complex hemodynamics are at play within cerebral aneurysms, and robust modeling and simulation methods are needed to further study this topic.
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Affiliation(s)
- Allyson J. Weiss
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Aaron O. Panduro
- Department of Biochemistry, California State University, Fresno, CA, United States
| | - Erica L. Schwarz
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Zachary A. Sexton
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Ingrid S. Lan
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Thomas. R. Geisbush
- Department of Radiology, School of Medicine, Stanford University, Stanford, CA, United States
| | - Alison L. Marsden
- Department of Bioengineering, Stanford University, Stanford, CA, United States
- Department of Pediatrics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Nicholas A. Telischak
- Department of Radiology, School of Medicine, Stanford University, Stanford, CA, United States
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Hachem E, Meliga P, Goetz A, Rico PJ, Viquerat J, Larcher A, Valette R, Sanches AF, Lannelongue V, Ghraieb H, Nemer R, Ozpeynirci Y, Liebig T. Reinforcement learning for patient-specific optimal stenting of intracranial aneurysms. Sci Rep 2023; 13:7147. [PMID: 37130900 PMCID: PMC10154322 DOI: 10.1038/s41598-023-34007-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 04/22/2023] [Indexed: 05/04/2023] Open
Abstract
Developing new capabilities to predict the risk of intracranial aneurysm rupture and to improve treatment outcomes in the follow-up of endovascular repair is of tremendous medical and societal interest, both to support decision-making and assessment of treatment options by medical doctors, and to improve the life quality and expectancy of patients. This study aims at identifying and characterizing novel flow-deviator stent devices through a high-fidelity computational framework that combines state-of-the-art numerical methods to accurately describe the mechanical exchanges between the blood flow, the aneurysm, and the flow-deviator and deep reinforcement learning algorithms to identify a new stent concepts enabling patient-specific treatment via accurate adjustment of the functional parameters in the implanted state.
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Affiliation(s)
- E Hachem
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France.
| | - P Meliga
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - A Goetz
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - P Jeken Rico
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - J Viquerat
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - A Larcher
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - R Valette
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - A F Sanches
- Department of Neuroradiology, University Hospital Munich (LMU), Munich, Germany
| | - V Lannelongue
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - H Ghraieb
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - R Nemer
- MINES Paris, PSL Research University, Centre de mise en forme des matériaux (CEMEF), CNRS UMR 7635, 06904, Sophia Antipolis Cedex, France
| | - Y Ozpeynirci
- Department of Neuroradiology, University Hospital Munich (LMU), Munich, Germany
| | - T Liebig
- Department of Neuroradiology, University Hospital Munich (LMU), Munich, Germany
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11
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Sache A, Reymond P, Brina O, Jung B, Farhat M, Vargas MI. Near-wall hemodynamic parameters quantification in in vitro intracranial aneurysms with 7 T PC-MRI. MAGMA (NEW YORK, N.Y.) 2023; 36:295-308. [PMID: 37072539 PMCID: PMC10140017 DOI: 10.1007/s10334-023-01082-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 04/20/2023]
Abstract
OBJECTIVE Wall shear stress (WSS) and its derived spatiotemporal parameters have proven to play a major role on intracranial aneurysms (IAs) growth and rupture. This study aims to demonstrate how ultra-high field (UHF) 7 T phase contrast magnetic resonance imaging (PC-MRI) coupled with advanced image acceleration techniques allows a highly resolved visualization of near-wall hemodynamic parameters patterns in in vitro IAs, paving the way for more robust risk assessment of their growth and rupture. MATERIALS AND METHODS We performed pulsatile flow measurements inside three in vitro models of patient-specific IAs using 7 T PC-MRI. To this end, we built an MRI-compatible test bench, which faithfully reproduced a typical physiological intracranial flow rate in the models. RESULTS The ultra-high field 7 T images revealed WSS patterns with high spatiotemporal resolution. Interestingly, the high oscillatory shear index values were found in the core of low WSS vortical structures and in flow stream intersecting regions. In contrast, maxima of WSS occurred around the impinging jet sites. CONCLUSIONS We showed that the elevated signal-to-noise ratio arising from 7 T PC-MRI enabled to resolve high and low WSS patterns with a high degree of detail.
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Affiliation(s)
- Antoine Sache
- Department of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Philippe Reymond
- Division of Neuroradiology, Geneva University Hospital, University of Geneva, Geneva, Switzerland
| | - Olivier Brina
- Division of Neuroradiology, Geneva University Hospital, University of Geneva, Geneva, Switzerland
| | - Bernd Jung
- Department of Diagnostic, Interventional and Paediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Mohamed Farhat
- Department of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Maria Isabel Vargas
- Division of Neuroradiology, Geneva University Hospital, University of Geneva, Geneva, Switzerland
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Liang X, Peng F, Yao Y, Yang Y, Liu A, Chen D. Aneurysm wall enhancement, hemodynamics, and morphology of intracranial fusiform aneurysms. Front Aging Neurosci 2023; 15:1145542. [PMID: 36993906 PMCID: PMC10040612 DOI: 10.3389/fnagi.2023.1145542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/20/2023] [Indexed: 03/14/2023] Open
Abstract
Background and objectiveIntracranial fusiform aneurysms (IFAs) are considered to have a complex pathophysiology process and poor natural history. The purpose of this study was to investigate the pathophysiological mechanisms of IFAs based on the characteristics of aneurysm wall enhancement (AWE), hemodynamics, and morphology.MethodsA total of 21 patients with 21 IFAs (seven fusiform types, seven dolichoectatic types, and seven transitional types) were included in this study. Morphological parameters of IFAs were measured from the vascular model, including the maximum diameter (Dmax), maximum length (Lmax), and centerline curvature and torsion of fusiform aneurysms. The three-dimensional (3D) distribution of AWE in IFAs was obtained based on high-resolution magnetic resonance imaging (HR-MRI). Hemodynamic parameters including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), gradient oscillatory number (GON), and relative residence time (RRT) were extracted by computational fluid dynamics (CFD) analysis of the vascular model, and the relationship between these parameters and AWE was investigated.ResultsThe results showed that Dmax (p = 0.007), Lmax (p = 0.022), enhancement area (p = 0.002), and proportion of enhancement area (p = 0.006) were significantly different among three IFA types, and the transitional type had the largest Dmax, Lmax, and enhancement area. Compared with the non-enhanced regions of IFAs, the enhanced regions had lower TAWSS but higher OSI, GON, and RRT (p < 0.001). Furthermore, Spearman’s correlation analysis showed that AWE was negatively correlated with TAWSS, but positively correlated with OSI, GON, and RRT.ConclusionThere were significant differences in AWE distributions and morphological features among the three IFA types. Additionally, AWE was positively associated with the aneurysm size, OSI, GON, and RRT, while negatively correlated with TAWSS. However, the underlying pathological mechanism of the three fusiform aneurysm types needs to be further studied.
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Affiliation(s)
- Xinyu Liang
- School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Fei Peng
- Neurointerventional Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yunchu Yao
- School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Yuting Yang
- School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Aihua Liu
- Neurointerventional Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- *Correspondence: Aihua Liu,
| | - Duanduan Chen
- School of Life Sciences, Beijing Institute of Technology, Beijing, China
- School of Medical Technology, Beijing Institute of Technology, Beijing, China
- Duanduan Chen,
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Hanigk M, Burgstaller E, Latus H, Shehu N, Zimmermann J, Martinoff S, Hennemuth A, Ewert P, Stern H, Meierhofer C. Aortic wall shear stress in bicuspid aortic valve disease-10-year follow-up. Cardiovasc Diagn Ther 2023; 13:38-50. [PMID: 36864959 PMCID: PMC9971286 DOI: 10.21037/cdt-22-477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/19/2022] [Indexed: 02/21/2023]
Abstract
Background Bicuspid aortic valve (BAV) disease leads to deviant helical flow patterns especially in the mid-ascending aorta (AAo), potentially causing wall alterations such as aortic dilation and dissection. Among others, wall shear stress (WSS) could contribute to the prediction of long-term outcome of patients with BAV. 4D flow in cardiovascular magnetic resonance (CMR) has been established as a valid method for flow visualization and WSS estimation. The aim of this study is to reevaluate flow patterns and WSS in patients with BAV 10 years after the initial evaluation. Methods Fifteen patients (median age 34.0 years) with BAV were re-evaluated 10 years after the initial study from 2008/2009 using 4D flow by CMR. Our particular patient cohort met the same inclusion criteria as in 2008/2009, all without enlargement of the aorta or valvular impairment at that time. Flow patterns, aortic diameters, WSS and distensibility were calculated in different aortic regions of interest (ROI) with dedicated software tools. Results Indexed aortic diameters in the descending aorta (DAo), but especially in the AAo did not change in the 10-year period. Median difference 0.05 cm/m2 (95% CI: 0.01 to 0.22; P=0.06) for AAo and median difference -0.08 cm/m2 (95% CI: -0.12 to 0.01; P=0.07) for DAo. WSS values were lower in 2018/2019 at all measured levels. Aortic distensibility decreased by median 25.6% in the AAo, while stiffness increased concordantly (median +23.6%). Conclusions After a ten years' follow-up of patients with isolated BAV disease, indexed aortic diameters did not change in this patient cohort. WSS was lower compared to values generated 10 years earlier. Possibly a drop of WSS in BAV could serve as a marker for a benign long-term course and implementation of more conservative treatment strategies.
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Affiliation(s)
- Michael Hanigk
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Elisabeth Burgstaller
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Heiner Latus
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Nerejda Shehu
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Judith Zimmermann
- Department of Computer Science, Technical University of Munich, Munich, Germany
| | - Stefan Martinoff
- Radiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Anja Hennemuth
- Institute for Computational and Imaging Science in Cardiovascular Medicine, Charité Universitätsmedizin, Berlin, Germany;,Fraunhofer MEVIS Institute for Digital Medicine, Bremen, Germany
| | - Peter Ewert
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Heiko Stern
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | - Christian Meierhofer
- Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
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14
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Collins JD. Editorial for "Inflow Angle Impacts Morphology, Hemodynamics, and Inflammation of Side-Wall Intracranial Aneurysms". J Magn Reson Imaging 2023; 57:124-125. [PMID: 35708122 DOI: 10.1002/jmri.28297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/02/2022] [Indexed: 02/03/2023] Open
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15
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Murakami M, Jiang F, Kageyama N, Chen X. Computational Fluid Dynamics Analysis of Blood Flow Changes during the Growth of Saccular Abdominal Aortic Aneurysm. Ann Vasc Dis 2022; 15:260-267. [PMID: 36644268 PMCID: PMC9816029 DOI: 10.3400/avd.oa.22-00098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/24/2022] [Indexed: 11/06/2022] Open
Abstract
Computational fluid dynamics analysis of the growth process of saccular abdominal aortic aneurysm was performed. A 3D model of aortic aneurysm was created based on CT images. Properties in terms of wall shear stress, mean flow velocity, mean pressure, energy loss, and pressure loss coefficient were calculated using thermal fluid analysis software "ANSYS CFX." As the aneurysm expanded, the mean flow velocity decreased and the wall shear stress, mean pressure, energy loss, and pressure loss coefficient increased. Wall shear stress increased when the aneurysm was small, suggesting that is related to the development and growth of the aneurysm. (This is secondary publication from J Jpn Coll Angiol 2021; 61: 3-10.).
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Affiliation(s)
- Masanori Murakami
- Department of Cardiovascular Surgery, National Hospital Organization, Kanmon Medical Center, Shimonoseki, Yamaguchi, Japan,Corresponding author: Masanori Murakami, MD, PhD. Department of Cardiovascular Surgery, National Hospital Organization, Kanmon Medical Center, 1-1 Choufusotoura-chou, Shimonoseki, Yamaguchi 752-8510, Japan Tel: +81-83-241-1199, Fax: +81-83-241-1301, E-mail:
| | - Fei Jiang
- Department of Mechanical Engineering, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
| | - Nobuyasu Kageyama
- Department of Mechanical Engineering, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
| | - Xian Chen
- Department of Mechanical Engineering, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
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16
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Zhang J, Rothenberger SM, Brindise MC, Markl M, Rayz VL, Vlachos PP. Wall Shear Stress Estimation for 4D Flow MRI Using Navier-Stokes Equation Correction. Ann Biomed Eng 2022; 50:1810-1825. [PMID: 35943617 PMCID: PMC10263099 DOI: 10.1007/s10439-022-02993-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/09/2022] [Indexed: 12/30/2022]
Abstract
This study introduces a novel wall shear stress (WSS) estimation method for 4D flow MRI. The method improves the WSS accuracy by using the reconstructed pressure gradient and the flow-physics constraints to correct velocity gradient estimation. The method was tested on synthetic 4D flow data of analytical Womersley flow and flow in cerebral aneurysms and applied to in vivo 4D flow data acquired in cerebral aneurysms and aortas. The proposed method's performance was compared to the state-of-the-art method based on smooth-spline fitting of velocity profile and the WSS calculated from uncorrected velocity gradient. The proposed method improved the WSS accuracy by as much as 100% for the Womersley flow and reduced the underestimation of mean WSS by 39 to 50% for the synthetic aneurysmal flow. The predicted mean WSS from the in vivo aneurysmal data using the proposed method was 31 to 50% higher than the other methods. The predicted aortic WSS using the proposed method was 3 to 6 times higher than the other methods and was consistent with previous CFD studies and the results from recently developed methods that take into account the limited spatial resolution of 4D flow MRI. The proposed method improves the accuracy of WSS estimation from 4D flow MRI, which can help predict blood vessel remodeling and progression of cardiovascular diseases.
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Affiliation(s)
- Jiacheng Zhang
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sean M Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Melissa C Brindise
- Department of Mechanical Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Michael Markl
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
- McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Vitaliy L Rayz
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Pavlos P Vlachos
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
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17
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Krzyżewski RM, Kliś KM, Kwinta BM, Łasocha B, Brzegowy P, Popiela TJ, Gąsowski J. Subarachnoid Hemorrhage from Ruptured Internal Carotid Artery Aneurysm: Association with Arterial Tortuosity. World Neurosurg 2022; 166:e84-e92. [PMID: 35811029 DOI: 10.1016/j.wneu.2022.06.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/18/2022] [Accepted: 06/20/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Many researchers have found a correlation between tortuous arteries and development of aneurysms in cerebral arteries. We decided to determine whether tortuosity of the internal carotid artery can be related to its aneurysm rupture. METHODS We retrospectively analyzed the internal carotid artery anatomy of 149 patients with internal carotid artery aneurysms. For each patient, we calculated relative length (RL), sum of angle metrics (SOAM), triangular index (TI), product of angle distance (PAD), and inflection count metrics (ICM). RESULTS A total of 33 patients (22.15%) had subarachnoid hemorrhage. These patients had significantly lower SOAM (0.31 ± 0.17 vs. 0.42 ± 0.21; P < 0.01), TI (0.27 ± 0.09 vs. 0.31 ± 0.11; P = 0.03) and ICM (0.25 ± 0.11 vs. 0.31 ± 0.17; P = 0.04). In multivariate logistic regression analysis, higher SOAM (odds ratio, 0.780; 95% confidence interval, 0.619-0.961; P = 0.025) remained independently associated with lower risk of internal carotid artery aneurysm rupture. In addition, we found significant positive correlation of aneurysm dome size with SOAM (R = 0.224; P = 0.013) and PAD (0.269; P < 0.01). Our study also showed that age (R = 0.252; P = 0.036), Glasgow Coma Scale score (R = -0.706; P < 0.01), and TI (R = -0.249; P = 0.042) were independently correlated with modified Rankin Scale score on discharge. CONCLUSIONS Lower tortuosity might be a protective factor against internal carotid artery aneurysm rupture and poor outcome after subarachnoid hemorrhage. Higher tortuosity is correlated with internal carotid artery aneurysm growth.
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Affiliation(s)
- Roger M Krzyżewski
- Departments of Neurosurgery and Neurotraumatology, Jagiellonian University Medical College, Kraków, Poland.
| | - Kornelia M Kliś
- Departments of Neurosurgery and Neurotraumatology, Jagiellonian University Medical College, Kraków, Poland
| | - Borys M Kwinta
- Departments of Neurosurgery and Neurotraumatology, Jagiellonian University Medical College, Kraków, Poland
| | - Bartłomiej Łasocha
- Department of Radiology, Jagiellonian University Medical College, Kraków, Poland
| | - Paweł Brzegowy
- Department of Radiology, Jagiellonian University Medical College, Kraków, Poland
| | - Tadeusz J Popiela
- Department of Radiology, Jagiellonian University Medical College, Kraków, Poland
| | - Jerzy Gąsowski
- Departments of Internal Medicine and Gerontology, Jagiellonian University Medical College, Kraków, Poland
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Challenges in Modeling Hemodynamics in Cerebral Aneurysms Related to Arteriovenous Malformations. Cardiovasc Eng Technol 2022; 13:673-684. [PMID: 35106721 DOI: 10.1007/s13239-022-00609-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/07/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE The significantly higher incidence of aneurysms in patients with arteriovenous malformations (AVMs) suggests a strong hemodynamic relationship between these lesions. The presence of an AVM alters hemodynamics in proximal vessels by drastically changing the distal resistance, thus affecting intra-aneurysmal flow. This study discusses the challenges associated with patient-specific modeling of aneurysms in the presence of AVMs. METHODS We explore how the presence of a generic distal AVM affects upstream aneurysms by examining the relationship between distal resistance and aneurysmal wall shear stress using physiologically realistic estimates for the influence of the AVM on hemodynamics. Using image-based computational models of aneurysms and surrounding vasculature, aneurysmal wall-shear stress is calculated for a range of distal resistances corresponding to the presence of AVMs of various sizes and compared with a control case representing the absence of an AVM. RESULTS In the patient cases considered, the alteration in aneurysmal wall shear stress due to the presence of an AVM is considerable, as much as 19 times the base case wall shear stress. Furthermore, the relationship between aneurysmal wall shear stress and distal resistance is shown to be highly geometry-dependent and nonlinear. In most cases, the range of physiologically realistic possibilities for AVM-related distal resistance are so large that patient-specific flow measurements are necessary for meaningful predictions of wall shear stress. CONCLUSIONS The presented work offers insight on the impact of distal AVMs on aneurysmal wall shear stress using physiologically realistic computational models. Patient-specific modeling of hemodynamics in aneurysms and associated AVMs has great potential for understanding lesion pathogenesis, surgical planning, and assessing the effect of treatment of one lesion relative to another. However, we show that modeling approaches cannot usually meaningfully quantify the impact of AVMs if based solely on imaging data from CT and X-ray angiography, currently used in clinical practice. Based on recent studies, it appears that 4D flow MRI is one promising approach to obtaining meaningful patient-specific flow boundary conditions that improve modeling fidelity.
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Hyodo R, Takehara Y, Naganawa S. 4D Flow MRI in the portal venous system: imaging and analysis methods, and clinical applications. Radiol Med 2022; 127:1181-1198. [PMID: 36123520 PMCID: PMC9587937 DOI: 10.1007/s11547-022-01553-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 08/29/2022] [Indexed: 02/07/2023]
Abstract
Thus far, ultrasound, CT, and 2D cine phase-contrast MRI has been adopted to evaluate blood flow and vascular morphology in the portal venous system; however, all these techniques have some shortcomings, such as limited field of view and difficulty in accurately evaluating blood flow. A new imaging technique, namely 3D cine phase-contrast (4D Flow) MRI, can acquire blood flow data of the entire abdomen at once and in a time-resolved manner, allowing visual, quantitative, and comprehensive assessment of blood flow in the portal venous system. In addition, a retrospective blood flow analysis, i.e., "retrospective flowmetry," is possible. Although the development of 4D Flow MRI for the portal system has been delayed compared to that for the arterial system owing to the lower flow velocity of the portal venous system and the presence of respiratory artifacts, several useful reports have recently been published as the technology has advanced. In the first part of this narrative review article, technical considerations of image acquisition and analysis methods of 4D Flow MRI for the portal venous system and the validations of their results are described. In the second part, the current clinical application of 4D Flow MRI for the portal venous system is reviewed.
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Affiliation(s)
- Ryota Hyodo
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
| | - Yasuo Takehara
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
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20
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Futami K, Misaki K, Uno T, Nambu I, Tsutsui T, Kamide T, Nakada M. Minimum wall shear stress points and their underlying intra-aneurysmal flow structures of unruptured cerebral aneurysms on 4D flow MRI. J Neuroradiol 2022; 50:302-308. [PMID: 36084742 DOI: 10.1016/j.neurad.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Minimum wall shear stress (Min-WSS) points may be associated with wall instability of unruptured cerebral aneurysms. We aimed to investigate the relationship between the locations of Min-WSS points and their underlying intra-aneurysmal flow structure patterns in unruptured cerebral aneurysms using four-dimensional (4D) flow magnetic resonance imaging (MRI). MATERIALS AND METHODS Min-WSS points and the intra-aneurysmal flow structure patterns were identified in 50 unruptured aneurysms by 4D flow MRI. RESULTS The Min-WSS points were located around a vortex core tip in 31 (62.0%) aneurysms and on an intra-bleb vortex center in 7 (14.0%). Sixteen (32.0%) aneurysms had the Min-WSS points on the aneurysmal apex, and in 24 (48.0%) were on the neck. The Min-WSS values of aneurysms with the Min-WSS points on an intra-bleb flow were significantly lower than those of the other groups (P = 0.030). Aneurysms with the Min-WSS points on the neck had significantly higher Min-WSS values than the other aneurysms (P = 0.008). CONCLUSIONS The location of the Min-WSS point was corresponding to the vortex core or center in 76% of all aneurysms. The underlying intra-aneurysmal flow structure and location of the Min-WSS point affect the Min-WSS value. Further studies are needed to characterize Min-WSS points to identify aneurysms with a higher risk of wall instability.
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Affiliation(s)
- Kazuya Futami
- Department of Neurosurgery, Hokuriku Central Hospital, 123 Nodera, Oyabe, 932-8503 Toyama, Japan.
| | - Kouichi Misaki
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
| | - Takehiro Uno
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
| | - Iku Nambu
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
| | - Taishi Tsutsui
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
| | - Tomoya Kamide
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
| | - Mitsutoshi Nakada
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
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CFD to Quantify Idealized Intra-Aneurysmal Blood Flow in Response to Regular and Flow Diverter Stent Treatment. FLUIDS 2022. [DOI: 10.3390/fluids7080254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cerebral aneurysms are pathological dilatations of the vessels supplying the brain. They carry a certain risk of rupture, which in turn, results in a high risk of mortality and morbidity. Flow diverters (FDs) are high-density meshed stents which are implanted in the vessel segment harboring an intracranial aneurysm to cover the entrance of the aneurysm, thus reducing the blood flow into the aneurysm, promoting thrombosis formation and stable occlusion, which prevents rupture or growth of the aneurysm. In the present study, the blood flow in an idealized aneurysm, treated with an FD stent and a regular stent (RS), were modeled and analyzed considering their design, surface area porosity, and flow reduction to investigate the quantitative and qualitative effect of the stent on intra-aneurysmal hemodynamics. CFD simulations were conducted before and after treatment. Significant reductions were observed for most hemodynamic variables with the use of stents, during both the peak systolic and late diastolic cardiac cycles. FD reduces the intra-aneurysmal wall shear stress (WSS), inflow, and aneurysmal flow velocity, and increases the turnover time when compared to the RS; therefore, the possibility of aneurysm thrombotic occlusion is likely to increase, reducing the risk of rupture in cerebral aneurysms.
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22
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The Cerebral Arterial Wall in the Development and Growth of Intracranial Aneurysms. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12125964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A considerable number of people harbor intracranial aneurysms (IA), which is a focal or segmental disease of the arterial wall. The pathophysiologic mechanisms of IAs formation, growth, and rupture are complex. The mechanism also differs with respect to the type of aneurysm. In broad aspects, aneurysms may be considered a disease of the vessel wall. In addition to the classic risk factors and the genetic/environmental conditions, altered structural and pathologic events along with the interaction of the surrounding environment and luminal flow dynamics contribute to the aneurysm’s development and growth. In this review, we have tried to simplify the complex interaction of a multitude of events in relation to vessel wall in the formation and growth of IAs.
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Gao F, Chen B, Zhou T, Luo H. Research on the effect of visceral artery Aneurysm's cardiac morphological variation on hemodynamic situation based on time-resolved CT-scan and computational fluid dynamics. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 221:106928. [PMID: 35701249 DOI: 10.1016/j.cmpb.2022.106928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVE Muscular arteries and related aneurysms keep deforming during the cardiac cycle. However, current patient-specific computational fluid dynamics (CFD) analyses of aneurysms are usually based on individual cardiac phase images. The cardiac deformation and displacement characteristics of muscle arteries and aneurysms, as well as their impact on CFD results, have not been adequately explored. The present study tried to illustrate the cardiac morphological variation of visceral muscular arteries (VMAs) & aneurysms (VAAs) and evaluate its influence on the hemodynamic situation at lesion locations. METHODS Four-dimensional computed tomography angiogram (4D-CTA) images of six patients with VAAs were acquired. Medical image registration is used to capture cardiac variations of VMAs. The steady-state CFD simulation is performed on twelve different time-phase geometries. Deformation, displacement, wall shear stress (WSS), velocity, and pressure values at pathological locations are compared to illustrate the deforming characteristics of VAAs and their influence on CFD simulation results. RESULTS The deformation and displacement characteristics of lesion locations for six specific patients show a pulsatile pattern. Maximum displacements are always less than 4 mm. The ratio fluctuations of endovascular cavity volume and vascular inner wall surface area, which were employed to depict cardiac deformation, are always less than 20%. According to CFD simulations based on deformed VMAs, WSS has a larger coefficient of variation (COV) than velocity and pressure. Except for one patient's WSS, the COVs of different hemodynamic parameters obtained from simulation results are always less than 10%. CONCLUSIONS Based on 4D-CTA images, we confirmed that cardiovascular circulation has a periodic impact on the morphologic characteristics of VMAs. A wave that has extended throughout the studied region is observed. It has a dominant influence on the displacement of VMAs. According to CFD results, the influence of the VMAs' deformation and displacement on different hemodynamic parameters is distinct. The variance in WSS is more prominent compared to pressure and velocity. On most occasions, the influence of the VMAs' periodic deformation and displacement on simulation results is insignificant. However, the variant simulation results induced by deforming VMAs cannot be simply ignored.
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Affiliation(s)
- Fan Gao
- Department of Simulation Science and Technology, Boea Wisdom (Hangzhou) Network Technology Co., Ltd, Hangzhou 310000, China.
| | - Bing Chen
- Division of Vascular Surgery, Department of Surgery, Second Affiliated Hospital of Medical College, Zhejiang University, Hangzhou 310052, China.
| | - Tao Zhou
- Department of Simulation Science and Technology, Boea Wisdom (Hangzhou) Network Technology Co., Ltd, Hangzhou 310000, China.
| | - Huan Luo
- Department of Simulation Science and Technology, Boea Wisdom (Hangzhou) Network Technology Co., Ltd, Hangzhou 310000, China.
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Zhong W, Du Y, Kuang H, Liu M, Xue F, Bai X, Wang D, Su W, Wang Y. Hemodynamic Characteristic Analysis of Aneurysm Wall Enhancement in Unruptured Middle Cerebral Artery Aneurysm. Front Neurol 2022; 13:781240. [PMID: 35614912 PMCID: PMC9126028 DOI: 10.3389/fneur.2022.781240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
Background and Purpose Aneurysm wall enhancement (AWE) on vessel wall magnetic resonance imaging has been suggested as a marker of the unstable status of intracranial aneurysm (IA) and may predict IA rupture risk. However, the role of abnormal hemodynamics in unruptured IAs with AWE remains poorly understood. This study aimed to determine the association between abnormal hemodynamics and AWE in unruptured middle cerebral artery (MCA) aneurysms. Methods A total of 28 patients with 32 bifurcation aneurysms of the middle cerebral artery>3mm in size were retrospectively selected for this study. Vessel wall magnetic resonance images were reviewed, and the AWE pattern of each aneurysm was classified as no AWE, partial AWE, and circumferential AWE. Computational fluid dynamics were used to calculate the hemodynamic variables of each aneurysm. Univariate and multivariate analyses investigated the association between AWE and hemodynamic variables. Results AWE was present in 13 aneurysms (40.6%), with 7 (21.9%) showing partial AWE and 6 (18.7%) showing circumferential AWE. Kruskal-Wallis H analysis revealed that hemodynamic variables including wall shear stress (WSS), oscillatory shear index, aneurysm pressure (AP), relative residence time, and low shear area (LSA) were significantly associated with AWE (p < 0.05). Further ordinal logistic regression analysis found that WSS was the only factor with a significant association with AWE (p = 0.048); similar trends were identified for LSA (p = 0.055) and AP (p = 0.058). Spearman's correlation analysis showed that AWE was negatively correlated with WSS (rs = -0.622, p < 0.001) and AP (rs = -0.535, p = 0.002) but positively correlated with LSA (rs = 0.774, p < 0.001). Conclusion Low wall shear stress, low aneurysm pressure, and increased low shear area were associated with aneurysm wall enhancement on vessel wall magnetic resonance imaging in unruptured cerebral aneurysms. These abnormal hemodynamic parameters may induce inflammation and cause aneurysm wall enhancement. However, the association between these parameters and their underlying pathological mechanisms requires further investigation.
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Affiliation(s)
- Weiying Zhong
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, Qilu Hospital of Shandong University, Jinan, China.,State Key Laboratory of Generic Manufacture Technology of Traditional Chinese Medicine, Lunan Pharmaceutical Group Co. Ltd., Linyi, China
| | - Yiming Du
- Department of Pharmacy, Yinan County People's Hospital, Linyi, China
| | - Hong Kuang
- Department of Neurosurgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ming Liu
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
| | - Feng Xue
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Xue Bai
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Donghai Wang
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
| | - Wandong Su
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
| | - Yunyan Wang
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
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Vivas A, Mikhal J, Ong GM, Eigenbrodt A, van der Meer AD, Aquarius R, Geurts BJ, Boogaarts HD. Aneurysm-on-a-Chip: Setting Flow Parameters for Microfluidic Endothelial Cultures Based on Computational Fluid Dynamics Modeling of Intracranial Aneurysms. Brain Sci 2022; 12:603. [PMID: 35624990 PMCID: PMC9139202 DOI: 10.3390/brainsci12050603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/20/2022] [Accepted: 04/27/2022] [Indexed: 11/30/2022] Open
Abstract
Intracranial aneurysms are pouch-like extrusions from the vessels at the base of the brain which can rupture and cause a subarachnoid hemorrhage. The pathophysiological mechanism of aneurysm formation is thought to be a consequence of blood flow (hemodynamic) induced changes on the endothelium. In this study, the results of a personalized aneurysm-on-a-chip model using patient-specific flow parameters and patient-specific cells are presented. CT imaging was used to calculate CFD parameters using an immersed boundary method. A microfluidic device either cultured with human umbilical vein endothelial cells (HUVECs) or human induced pluripotent stem cell-derived endothelial cells (hiPSC-EC) was used. Both types of endothelial cells were exposed for 24 h to either 0.03 Pa or 1.5 Pa shear stress, corresponding to regions of low shear and high shear in the computational aneurysm model, respectively. As a control, both cell types were also cultured under static conditions for 24 h as a control. Both HUVEC and hiPSC-EC cultures presented as confluent monolayers with no particular cell alignment in static or low shear conditions. Under high shear conditions HUVEC elongated and aligned in the direction of the flow. HiPSC-EC exhibited reduced cell numbers, monolayer gap formation and cells with aberrant, spread-out morphology. Future research should focus on hiPSC-EC stabilization to allow personalized intracranial aneurysm models.
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Affiliation(s)
- Aisen Vivas
- Applied Stem Cell Technologies, University of Twente, 7522 NB Enschede, The Netherlands; (A.V.); (A.E.); (A.D.v.d.M.)
| | - Julia Mikhal
- Multiscale Modeling and Simulation Group, Department of Applied Mathematics, University of Twente, 7522 NB Enschede, The Netherlands; (J.M.); (G.M.O.); (B.J.G.)
| | - Gabriela M. Ong
- Multiscale Modeling and Simulation Group, Department of Applied Mathematics, University of Twente, 7522 NB Enschede, The Netherlands; (J.M.); (G.M.O.); (B.J.G.)
| | - Anna Eigenbrodt
- Applied Stem Cell Technologies, University of Twente, 7522 NB Enschede, The Netherlands; (A.V.); (A.E.); (A.D.v.d.M.)
| | - Andries D. van der Meer
- Applied Stem Cell Technologies, University of Twente, 7522 NB Enschede, The Netherlands; (A.V.); (A.E.); (A.D.v.d.M.)
| | - Rene Aquarius
- Department of Neurosurgery, Radboud University Medical Center, 6525 XZ Nijmegen, The Netherlands;
| | - Bernard J. Geurts
- Multiscale Modeling and Simulation Group, Department of Applied Mathematics, University of Twente, 7522 NB Enschede, The Netherlands; (J.M.); (G.M.O.); (B.J.G.)
| | - Hieronymus D. Boogaarts
- Department of Neurosurgery, Radboud University Medical Center, 6525 XZ Nijmegen, The Netherlands;
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Effect of proximal parent artery stenosis on the outcomes of posterior communicating artery aneurysms: A preliminary study based on case-specific hemodynamic analysis. World Neurosurg 2022; 164:e349-e357. [DOI: 10.1016/j.wneu.2022.04.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/23/2022] [Accepted: 04/25/2022] [Indexed: 11/18/2022]
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27
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Tikhvinskii D, Kuianova J, Kislitsin D, Orlov K, Gorbatykh A, Parshin D. Numerical Assessment of the Risk of Abnormal Endothelialization for Diverter Devices: Clinical Data Driven Numerical Study. J Pers Med 2022; 12:jpm12040652. [PMID: 35455768 PMCID: PMC9025183 DOI: 10.3390/jpm12040652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/07/2022] Open
Abstract
Numerical modeling is an effective tool for preoperative planning. The present work is devoted to a retrospective analysis of neurosurgical treatments for the occlusion of cerebral aneurysms using flow-diverters and hemodynamic factors affecting stent endothelization. Several different geometric approaches have been considered for virtual flow-diverters deployment. A comparative analysis of hemodynamic parameters as a result of computational modeling has been carried out basing on the four clinical cases: one successful treatment, one with no occlusion and two with in stent stenosis. For the first time, a quantitative assessment of both: the limiting magnitude of shear stresses that are necessary for the occurrence of in stent stenosis (MaxWSS > 1.23) and for conditions in which endothelialization is insufficiently active and occlusion of the cervical part of the aneurysm does not occur (MaxWSS < 1.68)—has been statistacally proven (p < 0.01).
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Affiliation(s)
- Denis Tikhvinskii
- Lavrentyev Institute of Hydrodynamics SB RAS, Lavrentiev Avenue 15, 630090 Novosibirsk, Russia; (D.T.); (J.K.)
| | - Julia Kuianova
- Lavrentyev Institute of Hydrodynamics SB RAS, Lavrentiev Avenue 15, 630090 Novosibirsk, Russia; (D.T.); (J.K.)
| | - Dmitrii Kislitsin
- Neurosurgery Department, Meshalkin National Medical Research Center, 630055 Novosibirsk, Russia; (D.K.); (K.O.); (A.G.)
| | - Kirill Orlov
- Neurosurgery Department, Meshalkin National Medical Research Center, 630055 Novosibirsk, Russia; (D.K.); (K.O.); (A.G.)
| | - Anton Gorbatykh
- Neurosurgery Department, Meshalkin National Medical Research Center, 630055 Novosibirsk, Russia; (D.K.); (K.O.); (A.G.)
| | - Daniil Parshin
- Lavrentyev Institute of Hydrodynamics SB RAS, Lavrentiev Avenue 15, 630090 Novosibirsk, Russia; (D.T.); (J.K.)
- Correspondence: ; Tel.: +7-383-333-16-12
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EFFECTS OF THE ANEURYSM TREATMENT METHOD ON COIL PACKING DENSITY AND ITS RELATIONSHIP WITH THE OSTIUM AREA. J Vasc Interv Radiol 2022; 33:631-638. [PMID: 35283278 DOI: 10.1016/j.jvir.2021.12.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/01/2021] [Accepted: 12/07/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To test the following hypotheses: (1) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms and (2) CPD is related to the ostium area and volume of the aneurysm. MATERIALS AND METHODS This retrospective study included 60 ruptured and unruptured (54 and 6, respectively) aneurysms treated between August 2017 and December 2019 in the authors' institution with simple coiling (n=18), balloon-assisted coiling (n=7), or stent-assisted coiling (n=35). Aneurysm volume and ostium area measurements were obtained using commercial software from three-dimensional digital subtraction angiography images. Coil sizes were retrieved from patient files, and coil volume measurements were obtained using https://www.angiocalc.com/. Analysis of covariance, multivariable covariance analysis, and Pearson's correlation analyses were performed. RESULTS The median values for the aneurysm volume, coil volume, CPD, and ostium area were 63.4 (range 5.5-1771.4) mm3, 23.13 (2.03-296.95) mm3, 33.29% (13.41%-81.02%), and 10.7 (2.7-49.9) mm2, respectively. Multivariate analysis showed that the CPD values were not significantly different among the treatment groups, although the ostium area differed significantly between the simple and stent-assisted coiling groups (P<.05). Pearson's correlations showed that similar to aneurysm volume, the ostium area was negatively correlated with CPD (r=-0.321, P<.05). CONCLUSION In cerebral aneurysms treated with balloon- or stent-assisted coiling, the CPD value does not differ from that in aneurysms treated with simple coiling.
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29
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Alwalid O, Long X, Xie M, Han P. Artificial Intelligence Applications in Intracranial Aneurysm: Achievements, Challenges and Opportunities. Acad Radiol 2022; 29 Suppl 3:S201-S214. [PMID: 34376335 DOI: 10.1016/j.acra.2021.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 01/10/2023]
Abstract
Intracranial aneurysms present in about 3% of the general population and the number of detected aneurysms is continuously rising with the advances in imaging techniques. Intracranial aneurysm rupture carries a high risk of death or permanent disabilities; therefore assessment of the intracranial aneurysm along the entire course is of great clinical importance. Given the outstanding performance of artificial intelligence (AI) in image-based tasks, many AI-based applications have emerged in recent years for the assessment of intracranial aneurysms. In this review we will summarize the state-of-the-art of AI applications in intracranial aneurysms, emphasizing the achievements, and exploring the challenges. We will also discuss the future prospects and potential opportunities. This article provides an updated view of the AI applications in intracranial aneurysms and may act as a basis for guiding the related future works.
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Affiliation(s)
- Osamah Alwalid
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Xi Long
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Mingfei Xie
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Ping Han
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China.
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30
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Abstract
Alterations in cerebral blood flow are common in several neurological diseases among the elderly including stroke, cerebral small vessel disease, vascular dementia, and Alzheimer's disease. 4D flow magnetic resonance imaging (MRI) is a relatively new technique to investigate cerebrovascular disease, and makes it possible to obtain time-resolved blood flow measurements of the entire cerebral arterial venous vasculature and can be used to derive a repertoire of hemodynamic biomarkers indicative of cerebrovascular health. The information that can be obtained from one single 4D flow MRI scan allows both the investigation of aberrant flow patterns at a focal location in the vasculature as well as estimations of brain-wide disturbances in blood flow. Such focal and global hemodynamic biomarkers show the potential of being sensitive to impending cerebrovascular disease and disease progression and can also become useful during planning and follow-up of interventions aiming to restore a normal cerebral circulation. Here, we describe 4D flow MRI approaches for analyzing the cerebral vasculature. We then survey key hemodynamic biomarkers that can be reliably assessed using the technique. Finally, we highlight cerebrovascular diseases where one or multiple hemodynamic biomarkers are of central interest.
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Affiliation(s)
- Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Clinical Science and Neurosciences, Umeå University, Umeå, Sweden
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31
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Saalfeld S, Stahl J, Korte J, Miller Marsh LM, Preim B, Beuing O, Cherednychenko Y, Behme D, Berg P. Can Endovascular Treatment of Fusiform Intracranial Aneurysms Restore the Healthy Hemodynamic Environment?–A Virtual Pilot Study. Front Neurol 2022; 12:771694. [PMID: 35140672 PMCID: PMC8818669 DOI: 10.3389/fneur.2021.771694] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Abstract
Numerous studies assess intracranial aneurysm rupture risk based on morphological and hemodynamic parameter analysis in addition to clinical information such as aneurysm localization, age, and sex. However, intracranial aneurysms mostly occur with a saccular shape located either lateral to the parent artery or at a bifurcation. In contrast, fusiform intracranial aneurysms (FIAs), i.e., aneurysms with a non-saccular, dilated form, occur in approximately 3–13% of all cases and therefore have not yet been as thoroughly studied. To improve the understanding of FIA hemodynamics, this pilot study contains morphological analyses and image-based blood flow simulations in three patient-specific cases. For a precise and realistic comparison to the pre-pathological state, each dilation was manually removed and the time-dependent blood flow simulations were repeated. Additionally, a validated fast virtual stenting approach was applied to evaluate the effect of virtual endovascular flow-diverter deployment focusing on relevant hemodynamic quantities. For two of the three patients, post-interventional information was available and included in the analysis. The results of this numerical pilot study indicate that complex flow structures, i.e., helical flow phenomena and the presence of high oscillating flow features, predominantly occur in FIAs with morphologically differing appearances. Due to the investigation of the individual healthy states, the original flow environment could be restored which serves as a reference for the virtual treatment target. It was shown that the realistic deployment led to a considerable stabilization of the individual hemodynamics in all cases. Furthermore, a quantification of the stent-induced therapy effect became feasible for the treating physician. The results of the morphological and hemodynamic analyses in this pilot study show that virtual stenting can be used in FIAs to quantify the effect of the planned endovascular treatment.
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Affiliation(s)
- Sylvia Saalfeld
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Simulation and Graphics, University of Magdeburg, Magdeburg, Germany
- *Correspondence: Sylvia Saalfeld
| | - Janneck Stahl
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany
| | - Jana Korte
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Simulation and Graphics, University of Magdeburg, Magdeburg, Germany
| | - Laurel Morgan Miller Marsh
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany
- Department of Mechanical Engineering, University of Washington, Seattle, WA, United States
| | - Bernhard Preim
- Department of Simulation and Graphics, University of Magdeburg, Magdeburg, Germany
| | - Oliver Beuing
- Department of Radiology, AMEOS Hospital Bernburg, Bernburg, Germany
| | - Yurii Cherednychenko
- Endovascular Centre, Dnipropetrovsk Regional Clinical Hospital named after I.I. Mechnikov, Dnipro, Ukraine
| | - Daniel Behme
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Neuroradiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Philipp Berg
- Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany
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32
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Zhai X, Wang Y, Fang G, Hu P, Zhang H, Zhu C. Case Report: Dynamic Changes in Hemodynamics During the Formation and Progression of Intracranial Aneurysms. Front Cardiovasc Med 2022; 8:775536. [PMID: 35127854 PMCID: PMC8814101 DOI: 10.3389/fcvm.2021.775536] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/28/2021] [Indexed: 11/29/2022] Open
Abstract
Despite the devastating consequences of aneurysmal subarachnoid hemorrhage (SAH), the mechanisms underlying the formation, progression, and rupture of intracranial aneurysms (IAs) are complex and not yet fully clear. In a real-world situation, continuously observing the process of aneurysm development in humans appears unrealistic, which also present challenges for the understanding of the underlying mechanism. We reported the relatively complete course of IA development in two real patients. On this basis, computational fluid dynamics simulation (CFD) was performed to evaluate the changes in hemodynamics and analyze the mechanism underlying the formation, progression, and rupture of IAs. Our results suggested that the formation and progression of IAs can be a dynamic process, with constantly changing hemodynamic characteristics. CFD analysis based on medical imaging provides the opportunity to study the hemodynamic conditions over time. From these two rare cases, we found that concentrated high-velocity inflow jets, flows with vortex structures, extremely high WSS, and a very steep WSSG were correlated with the formation of IAs. Complex multi-vortex flows are possibly related to IAs prior to growth, and the rupture of IAs is possibly related to low WSS, extreme instability and complexity of flow patterns. Our findings provide unique insight into the theoretical hemodynamic mechanism underlying the formation and progression of IAs. Given the small sample size the findings of this study have to be considered preliminary and exploratory.
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Wang H, Uhlmann K, Vedula V, Balzani D, Varnik F. Fluid-structure interaction simulation of tissue degradation and its effects on intra-aneurysm hemodynamics. Biomech Model Mechanobiol 2022; 21:671-683. [PMID: 35025011 PMCID: PMC8940862 DOI: 10.1007/s10237-022-01556-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 01/04/2022] [Indexed: 12/03/2022]
Abstract
Tissue degradation plays a crucial role in vascular diseases such as atherosclerosis and aneurysms. Computational modeling of vascular hemodynamics incorporating both arterial wall mechanics and tissue degradation has been a challenging task. In this study, we propose a novel finite element method-based approach to model the microscopic degradation of arterial walls and its interaction with blood flow. The model is applied to study the combined effects of pulsatile flow and tissue degradation on the deformation and intra-aneurysm hemodynamics. Our computational analysis reveals that tissue degradation leads to a weakening of the aneurysmal wall, which manifests itself in a larger deformation and a smaller von Mises stress. Moreover, simulation results for different heart rates, blood pressures and aneurysm geometries indicate consistently that, upon tissue degradation, wall shear stress increases near the flow-impingement region and decreases away from it. These findings are discussed in the context of recent reports regarding the role of both high and low wall shear stress for the progression and rupture of aneurysms.
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34
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Bershad EM, Suarez JI. Aneurysmal Subarachnoid Hemorrhage. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00029-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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35
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Zhang J, Brindise MC, Rothenberger SM, Markl M, Rayz VL, Vlachos PP. A multi-modality approach for enhancing 4D flow magnetic resonance imaging via sparse representation. J R Soc Interface 2022; 19:20210751. [PMID: 35042385 PMCID: PMC8767185 DOI: 10.1098/rsif.2021.0751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
This work evaluates and applies a multi-modality approach to enhance blood flow measurements and haemodynamic analysis with phase-contrast magnetic resonance imaging (4D flow MRI) in cerebral aneurysms (CAs). Using a library of high-resolution velocity fields from patient-specific computational fluid dynamic simulations and in vitro particle tracking velocimetry measurements, the flow field of 4D flow MRI data is reconstructed as the sparse representation of the library. The method was evaluated with synthetic 4D flow MRI data in two CAs. The reconstruction enhanced the spatial resolution and velocity accuracy of the synthetic MRI data, leading to reliable pressure and wall shear stress (WSS) evaluation. The method was applied on in vivo 4D flow MRI data acquired in the same CAs. The reconstruction increased the velocity and WSS by 6-13% and 39-61%, respectively, suggesting that the accuracy of these quantities was improved since the raw MRI data underestimated the velocity and WSS by 10-20% and 40-50%, respectively. The computed pressure fields from the reconstructed data were consistent with the observed flow structures. The results suggest that using the sparse representation flow reconstruction with in vivo 4D flow MRI enhances blood flow measurement and haemodynamic analysis.
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Affiliation(s)
- Jiacheng Zhang
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 USA
| | - Melissa C. Brindise
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 USA
| | - Sean M. Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 USA
| | - Michael Markl
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA,McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Vitaliy L. Rayz
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 USA,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 USA
| | - Pavlos P. Vlachos
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 USA,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 USA
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36
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Hu B, Zhang G. A commentary on "The prognostic effects of hemodynamic parameters on rupture of intracranial aneurysm: A systematic review and meta-analysis" (Int J Surg. 2021; 86:15-23). Int J Surg 2022; 97:106195. [PMID: 34906735 DOI: 10.1016/j.ijsu.2021.106195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 10/19/2022]
Affiliation(s)
- Bimei Hu
- Department of Medical Nursing, Lianyungang TCM Higher Vocational and Technical School, Lianyungang TCM Branch of Jiangsu Union Technical Institute, Jiangsu, 222000, China Department of Neurology, Lianyungang Hospital Affiliated to Xuzhou Medical College, Jiangsu, 222002, China
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37
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Park SH, Kim K. Microplastics induced developmental toxicity with microcirculation dysfunction in zebrafish embryos. CHEMOSPHERE 2022; 286:131868. [PMID: 34399253 DOI: 10.1016/j.chemosphere.2021.131868] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/08/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Microplastics (MPs) and nanoplastics (NPs) have attracted worldwide attention as potential environmental pollutants. However, toxic effects of exposure to MPs and NPs on organisms at developmental stages have not been elucidated yet. In this study, zebrafish embryos at early stage were used to evaluate potential toxic effects of exposure to MPs with diameter of 1 μm and NPs with diameter of 0.4 μm. Solution containing NPs was optically more transparent than solution containing MPs at the same mass concentration. However, exposure to NPs induced significantly higher mortality rate of zebrafish embryos than exposure to MPs. Exposure to MPs or NPs caused pathological changes of caudal vein plexus. In addition, caudal tissues were impaired with inhibition of intact growth of zebrafish embryos. Peripheral microcirculation at caudal region was significantly deteriorated by exposure to MPs or NPs. However, systematic perfusion was still maintained with preservation of RBC velocity profiles regardless of exposure to MPs or NPs. This study provides a new insight to the use of plastics, demonstrating that exposure to MPs or NPs can lead to developmental disorder with significant impairment of growth and peripheral microcirculation dysfunction.
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Affiliation(s)
- Sung Ho Park
- Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Kiwoong Kim
- Mechanical Engineering, Hannam University, Daejeon, 34430, South Korea.
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Pathogenic Factors and Prognosis of De Novo Aneurysms vAfter Aneurysm Clipping. J Craniofac Surg 2021; 33:1800-1805. [PMID: 34974461 DOI: 10.1097/scs.0000000000008451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 11/30/2021] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To confirm this hypothesis, this study aimed to explore the pathogenic factors, prognosis, and their relationship in de novo aneurysms and to reach a consensus on their management. METHODS First, the clinical data of 5 patients with de novo aneurysms from April 1998 to October 2021 were analyzed retrospectively. Then, the English literature on de novo aneurysms reported in Pubmed from 1985 to 2021 was systematically reviewed, and 18 case reports from 17 articles and 16 case series were identified. Univariate and multivariate analyses and modified Fisher test were used to analyze the relationship between pathogenic factors and prognosis. RESULTS Hypertension was noted in 60% of our clinical cases, 50% of the case series identified in the literature review, and 66.7% of the case reports in the literature review. In the case reports identified from our literature review, the proportion of original aneurysms in the anterior circulation was 96.3%. Moreover, in our 5 cases, all original aneurysms occurred in the anterior circulation. The rupture rate of original aneurysms in our 5 cases was 100%, and that of the cases reported in the literature review was 88.9%. Univariate logistic analysis showed that the time interval was related to the prognosis of de novo aneurysms with a P value of 0.048 and an odds ratio of 0.968 (95% confidence interval 0.938-1.000). Modified Fisher exact tests showed that patient age at the occurrence of de novo aneurysm P = 0.029) was related to the prognosis of de novo aneurysms. CONCLUSIONS Hypertension, an original aneurysms located in the anterior circulation and rupture represent the pathogenic factors associated with de novo aneurysms. The time interval to de novo aneurysm and patient age at the occurrence of de novo aneurysm are predictive of prognosis. Based on the above information, we can prevent and improve the prognosis of de novo aneurysms.
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Bappoo N, Syed MBJ, Khinsoe G, Kelsey LJ, Forsythe RO, Powell JT, Hoskins PR, McBride OMB, Norman PE, Jansen S, Newby DE, Doyle BJ. Low Shear Stress at Baseline Predicts Expansion and Aneurysm-Related Events in Patients With Abdominal Aortic Aneurysm. Circ Cardiovasc Imaging 2021; 14:1112-1121. [PMID: 34875845 DOI: 10.1161/circimaging.121.013160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Low shear stress has been implicated in abdominal aortic aneurysm (AAA) expansion and clinical events. We tested the hypothesis that low shear stress in AAA at baseline is a marker of expansion rate and future aneurysm-related events. METHODS Patients were imaged with computed tomography angiography at baseline and followed up every 6 months >24 months with ultrasound measurements of maximum diameter. From baseline computed tomography angiography, we reconstructed 3-dimensional models for automated computational fluid dynamics simulations and computed luminal shear stress. The primary composite end point was aneurysm repair and/or rupture, and the secondary end point was aneurysm expansion rate. RESULTS We included 295 patients with median AAA diameter of 49 mm (interquartile range, 43-54 mm) and median follow-up of 914 (interquartile range, 670-1112) days. There were 114 (39%) aneurysm-related events, with 13 AAA ruptures and 98 repairs (one rupture was repaired). Patients with low shear stress (<0.4 Pa) experienced a higher number of aneurysm-related events (44%) compared with medium (0.4-0.6 Pa; 27%) and high (>0.6 Pa; 29%) shear stress groups (P=0.010). This association was independent of known risk factors (adjusted hazard ratio, 1.72 [95% CI, 1.08-2.73]; P=0.023). Low shear stress was also independently associated with AAA expansion rate (β=+0.28 mm/y [95% CI, 0.02-0.53]; P=0.037). CONCLUSIONS We show for the first time that low shear stress (<0.4 Pa) at baseline is associated with both AAA expansion and future aneurysm-related events. Aneurysms within the lowest tertile of shear stress, versus those with higher shear stress, were more likely to rupture or reach thresholds for elective repair. Larger prospective validation trials are needed to confirm these findings and translate them into clinical management.
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Affiliation(s)
- Nikhilesh Bappoo
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Maaz B J Syed
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Georgia Khinsoe
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Lachlan J Kelsey
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Rachael O Forsythe
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Janet T Powell
- Vascular Surgery Research Group, Imperial College London, London, United Kingdom (J.T.P.)
| | - Peter R Hoskins
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.).,Biomedical Engineering, Dundee University, United Kingdom (P.R.H.)
| | - Olivia M B McBride
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Paul E Norman
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,Medical School (P.E.N., S.J.), The University of Western Australia, Perth
| | - Shirley Jansen
- Medical School (P.E.N., S.J.), The University of Western Australia, Perth.,Heart and Vascular Research Institute, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Perth, Australia (S.J.).,Department of Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Australia (S.J.).,Curtin Medical School, Curtin University, Perth, Australia (S.J.)
| | - David E Newby
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Barry J Doyle
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth.,Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.).,Australian Research Council Centre for Personalised Therapeutics Technologies (B.J.D.)
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Yong KW, Janmaleki M, Pachenari M, Mitha AP, Sanati-Nezhad A, Sen A. Engineering a 3D human intracranial aneurysm model using liquid-assisted injection molding and tuned hydrogels. Acta Biomater 2021; 136:266-278. [PMID: 34547516 DOI: 10.1016/j.actbio.2021.09.022] [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: 05/05/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 12/30/2022]
Abstract
Physiologically relevant intracranial aneurysm (IA) models are crucially required to facilitate testing treatment options for IA. Herein, we report the development of a new in vitro tissue-engineered platform, which recapitulates the microenvironment, structure, and cellular complexity of native human IA. A new modified liquid-assisted injection molding technique was developed to fabricate a three-dimensional hollow IA model with clinically relevant IA dimensions within a mechanically tuned Gelatin Methacryloyl (GelMA) hydrogel. An endothelium lining was created inside the IA model by culturing human umbilical vein endothelial cells over pre-cultured human brain vascular smooth muscle cells. These cellularized IA models were subjected to medium perfusion at flow rates between 6.3 and 15.75 mL/min for inducing biomimetic vessel wall shear stress (10-25 dyn/cm2) to the cells for ten days. Both cell types maintained their secretome profiles and showed more than 96% viability, demonstrating the biocompatibility of the hydrogel during perfusion cell culture at such flow rates. Based on the characterized viscoelastic properties of the GelMA hydrogel and with the aid of a fluid-structure interaction model, the capability of the IA model in predicting the response of the IA to different fluid flow profiles was mathematically shown. With physiologically relevant behavior, our developed in vitro human IA model could allow researchers to better understand the pathophysiology and treatment of IA. STATEMENT OF SIGNIFICANCE: A three-dimensional intracranial aneurysm (IA) tissue model recapitulating the microenvironment, structure, and cellular complexity of native human IA was developed. • An endothelium lining was created inside the IA model over pre-cultured human brain vascular smooth muscle cells over at least 10-day successful culture. • The cells maintained their secretome profiles, demonstrating the biocompatibility of hydrogel during a long-term perfusion cell culture. • The IA model showed its capability in predicting the response of IA to different fluid flow profiles. • The cells in the vessel region behaved differently from cells in the aneurysm region due to alteration in hemodynamic shear stress. • The IA model could allow researchers to better understand the pathophysiology and treatment options of IA.
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Cornelissen BMW, Leemans EL, Slump CH, van den Berg R, Marquering HA, Majoie CBLM. Hemodynamic changes after intracranial aneurysm growth. J Neurosurg 2021:1-7. [PMID: 34715660 DOI: 10.3171/2021.6.jns204155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 06/07/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE For accurate risk assessment of unruptured intracranial aneurysms, it is important to understand the underlying mechanisms that lead to rupture. It is known that hemodynamic anomalies contribute to aneurysm growth and rupture, and that growing aneurysms carry higher rupture risks. However, it is unknown how growth affects hemodynamic characteristics. In this study, the authors assessed how hemodynamic characteristics change over the course of aneurysm growth. METHODS The authors included patients with observed aneurysm growth on longitudinal MRA in the period between 2012 and 2016. Patient-specific vascular models were created from baseline and follow-up images. Subsequently, intraaneurysmal hemodynamic characteristics were computed using computational fluid dynamics. The authors computed the normalized wall shear stress, oscillatory shear index, and low shear area to quantify hemodynamic characteristics. Differences between baseline and follow-up measurements were analyzed using paired t-tests. RESULTS Twenty-five patients with a total of 31 aneurysms were included. The aneurysm volume increased by a median (IQR) of 26 (9-39) mm3 after a mean follow-up period of 4 (range 0.4-10.9) years. The median wall shear stress decreased significantly after growth. Other hemodynamic parameters did not change significantly, although large individual changes with large variability were observed. CONCLUSIONS Hemodynamic characteristics change considerably after aneurysm growth. On average, wall shear stress values decrease after growth, but there is a large variability in hemodynamic changes between aneurysms.
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Affiliation(s)
- Bart M W Cornelissen
- 1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam.,2Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam; and.,3Technical Medical Center, University of Twente, Enschede, The Netherlands
| | - Eva L Leemans
- 1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam.,2Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam; and
| | - Cornelis H Slump
- 3Technical Medical Center, University of Twente, Enschede, The Netherlands
| | - René van den Berg
- 1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam
| | - Henk A Marquering
- 1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam.,2Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam; and
| | - Charles B L M Majoie
- 1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam
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Yevtushenko P, Goubergrits L, Gundelwein L, Setio A, Ramm H, Lamecker H, Heimann T, Meyer A, Kuehne T, Schafstedde M. Deep Learning Based Centerline-Aggregated Aortic Hemodynamics: An Efficient Alternative to Numerical Modelling of Hemodynamics. IEEE J Biomed Health Inform 2021; 26:1815-1825. [PMID: 34591773 DOI: 10.1109/jbhi.2021.3116764] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Image-based patient-specific modelling of hemodynamics are gaining increased popularity as a diagnosis and outcome prediction solution for a variety of cardiovascular diseases. While their potential to improve diagnostic capabilities and thereby clinical outcome is widely recognized, these methods require considerable computational resources since they are mostly based on conventional numerical methods such as computational fluid dynamics (CFD). As an alternative to the numerical methods, we propose a machine learning (ML) based approach to calculate patient-specific hemodynamic parameters. Compared to CFD based methods, our approach holds the benefit of being able to calculate a patient-specific hemodynamic outcome instantly with little need for computational power. In this proof-of-concept study, we present a deep artificial neural network (ANN) capable of computing hemodynamics for patients with aortic coarctation in a centerline aggregated (i.e. locally averaged) form. Considering the complex relation between vessels shape and hemodynamics on the one hand and the limited availability of suitable clinical data on the other, a sufficient accuracy of the ANN may however not be achieved with available data only. Another key aspect of this study is therefore the successful augmentation of available clinical data. Using a statistical shape model, additional training data was generated which substantially increased the ANNs accuracy, showcasing the ability of ML based methods to perform in-silico modelling tasks previously requiring resource intensive CFD simulations.
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Pandey PK, Das MK. Effect of foam insertion in aneurysm sac on flow structures in parent lumen: relating vortex structures with disturbed shear. Phys Eng Sci Med 2021; 44:1231-1248. [PMID: 34581959 DOI: 10.1007/s13246-021-01058-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 09/05/2021] [Indexed: 11/26/2022]
Abstract
Numerous studies suggest that disturbed shear, causing endothelium dysfunction, can be related to neighboring vortex structures. With this motivation, this study presents a methodology to characterize the vortex structures. Precisely, we use mapping and characterization of vortex structures' changes to relate it with the hemodynamic indicators of disturbed shear. Topological features of vortex core lines (VCLs) are used to quantify the changes in vortex structures. We use the Sujudi-Haimes algorithm to extract the VCLs from the flow simulation results. The idea of relating vortex structures with disturbed shear is demonstrated for cerebral arteries with aneurysms virtually treated by inserting foam in the sac. To get physiologically realistic flow fields, we simulate blood flow in two patient-specific geometries before and after foam insertion, with realistic velocity waveform imposed at the inlet, using the Carreau-Yasuda model to mimic the shear-thinning behavior. With homogenous porous medium assumption, flow through the foam is modeled using the Forchheimer-Brinkman extended Darcy model. Results show that foam insertion increases the number of VCLs in the parent lumen. The average length of VCL increases by 168.9% and 55.6% in both geometries. For both geometries under consideration, results demonstrate that the region with increased disturbed shear lies in the same arterial segment exhibiting an increase in the number of oblique VCLs. Based on the findings, we conjecture that an increase in oblique VCLs is related to increased disturbed shear at the neighboring portion of the arterial wall.
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Affiliation(s)
- Pawan Kumar Pandey
- Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, Uttar Pradesh, India
| | - Malay Kumar Das
- Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, Uttar Pradesh, India.
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Swiatek VM, Neyazi B, Roa JA, Zanaty M, Samaniego EA, Ishii D, Lu Y, Sandalcioglu IE, Saalfeld S, Berg P, Hasan DM. Aneurysm Wall Enhancement Is Associated With Decreased Intrasaccular IL-10 and Morphological Features of Instability. Neurosurgery 2021; 89:664-671. [PMID: 34245147 PMCID: PMC8578742 DOI: 10.1093/neuros/nyab249] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 05/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND High-resolution vessel wall imaging plays an increasingly important role in assessing the risk of aneurysm rupture. OBJECTIVE To introduce an approach toward the validation of the wall enhancement as a direct surrogate parameter for aneurysm stability. METHODS A total of 19 patients harboring 22 incidental intracranial aneurysms were enrolled in this study. The aneurysms were dichotomized according to their aneurysm-to-pituitary stalk contrast ratio using a cutoff value of 0.5 (nonenhancing < 0.5; enhancing ≥ 0.5). We evaluated the association of aneurysm wall enhancement with morphological characteristics, hemodynamic features, and inflammatory chemokines directly measured inside the aneurysm. RESULTS Differences in plasma concentration of chemokines and inflammatory molecules, morphological, and hemodynamic parameters were analyzed using the Welch test or Mann-Whitney U test. The concentration ΔIL-10 in the lumen of intracranial aneurysms with low wall enhancement was significantly increased compared to aneurysms with strong aneurysm wall enhancement (P = .014). The analysis of morphological and hemodynamic parameters showed significantly increased values for aneurysm volume (P = .03), aneurysm area (P = .044), maximal diameter (P = .049), and nonsphericity index (P = .021) for intracranial aneurysms with strong aneurysm wall enhancement. None of the hemodynamic parameters reached statistical significance; however, the total viscous shear force computed over the region of low wall shear stress showed a strong tendency toward significance (P = .053). CONCLUSION Aneurysmal wall enhancement shows strong associations with decreased intrasaccular IL-10 and established morphological indicators of aneurysm instability.
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Affiliation(s)
- Vanessa M Swiatek
- Deparment of Neurosurgery, Otto-von-Guericke University, Magdeburg, Saxony Anhalt, Germany
| | - Belal Neyazi
- Deparment of Neurosurgery, Otto-von-Guericke University, Magdeburg, Saxony Anhalt, Germany
| | - Jorge A Roa
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Deparment of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Mario Zanaty
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Edgar A Samaniego
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Deparment of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Daizo Ishii
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Yongjun Lu
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - I Erol Sandalcioglu
- Deparment of Neurosurgery, Otto-von-Guericke University, Magdeburg, Saxony Anhalt, Germany
| | - Sylvia Saalfeld
- Deparment of Simulation and Graphics, University of Magdeburg, Magdeburg, Saxony Anhalt, Germany
- Research Campus STIMULATE, Magdeburg, Saxony Anhalt, Germany
| | - Philipp Berg
- Research Campus STIMULATE, Magdeburg, Saxony Anhalt, Germany
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Saxony Anhalt, Germany
| | - David M Hasan
- Deparment of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
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Bao Q, Meng X, Hu M, Xing J, Jin D, Liu H, Jiang J, Yin Y. Simulation analysis of aneurysm embolization surgery: Hemorheology of aneurysms with different embolization rates (CTA). Biomed Mater Eng 2021; 32:295-308. [PMID: 33998529 DOI: 10.3233/bme-211225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Embolization degree acts as an important factor affecting recurrence of aneurysm. OBJECTIVE To analyze the role of hemodynamics parameters of different degrees of embolization in the occurrence, development and post-treatment of aneurysms, and to determine the specific factors causing the occurrence and recurrence of aneurysms after hemodynamics treatment. Our study provides a theoretical basis for the prevention and treatment of aneurysms. METHODS Computed tomography angiography data of a patient with cerebral aneurysm was used to model 0%, 24%, 52%, 84% and 100% of endovascular embolization, respectively. The time average wall shear stress, time average wall shear stress, oscillatory shear index, hemodynamics formation index and relative retentive time were used to analyze the changes of hemodynamics indexes in different embolic models. RESULTS With the increase of embolic rate, the values of time average wall shear stress, time average wall shear stress grade and aneurysm index formation gradually increased, and the values of relative retention time gradually decreased. Oscillatory shear index was higher in patients with incomplete embolization and decreased in patients with complete embolization. CONCLUSIONS As the degree of embolization increased, the blood flow tended to stabilize, reducing the risk of cerebral aneurysm rupture, and finding that the wall of the vessel junction was susceptible to injury.
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Affiliation(s)
- Quan Bao
- Department of Image, Hongqi Hospital Affiliated with Mudanjiang Medical University, Mudanjiang, China
| | - Xin Meng
- Department of Image, No. 3 Hospital Affiliated with Qiqihaer Medical University, Qiqihaer, China
| | - Mingcheng Hu
- Department of Image, Hongqi Hospital Affiliated with Mudanjiang Medical University, Mudanjiang, China
| | - Jian Xing
- Department of Image, Hongqi Hospital Affiliated with Mudanjiang Medical University, Mudanjiang, China
| | - Dan Jin
- Department of Image, No. 2 Hospital of Mudanjiang, Mudanjiang, China
| | - He Liu
- Department of Image, Hongqi Hospital Affiliated with Mudanjiang Medical University, Mudanjiang, China
| | - Jie Jiang
- Department of Infectious Disease, Mudanjiang Forestry Center Hospital, Mudanjiang, China
| | - Yanwei Yin
- Department of Image, Hongqi Hospital Affiliated with Mudanjiang Medical University, Mudanjiang, China
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Molenberg R, Aalbers MW, Appelman APA, Uyttenboogaart M, van Dijk JMC. Intracranial aneurysm wall enhancement as an indicator of instability: a systematic review and meta-analysis. Eur J Neurol 2021; 28:3837-3848. [PMID: 34424585 PMCID: PMC9292155 DOI: 10.1111/ene.15046] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND PURPOSE Aneurysm wall enhancement (AWE) of intracranial aneurysms on magnetic resonance imaging has been described in previous studies as a surrogate marker of instability. With this study, an updated literature overview and summary risk estimates of the association between AWE and different specific outcomes (i.e., rupture, growth or symptomatic presentation) for both cross-sectional and longitudinal studies are provided. METHODS The PRISMA guideline was followed and a search was performed of PubMed and Embase to 1 January 2021 for studies that reported on AWE and aneurysm instability. In cross-sectional studies, AWE was compared between patients with stable and unstable aneurysms. In longitudinal studies, AWE of stable aneurysms was assessed at baseline after which patients were followed longitudinally. Risk ratios were calculated for longitudinal studies, prevalence ratios for cross-sectional studies and then the ratios were pooled in a random-effects meta-analysis. Also, the performance of AWE to differentiate between stable and unstable aneurysms was evaluated. RESULTS Twelve studies were included with a total of 1761 aneurysms. In cross-sectional studies, AWE was positively associated with rupture (prevalence ratio 11.47, 95% confidence interval [CI] 4.05-32.46) and growth or symptomatic presentation (prevalence ratio 4.62, 95% CI 2.85-7.49). Longitudinal studies demonstrated a positive association between AWE and growth or rupture (risk ratio 8.00, 95% CI 2.14-29.88). Assessment of the performance of AWE showed high sensitivities, mixed specificities, low positive predictive values and high negative predictive values. CONCLUSIONS Although AWE is positively associated with aneurysm instability, current evidence mostly supports the use of its absence as a surrogate marker of aneurysm stability.
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Affiliation(s)
- Rob Molenberg
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marlien W Aalbers
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Auke P A Appelman
- Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Maarten Uyttenboogaart
- Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - J Marc C van Dijk
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Definition and extraction of 2D shape indices of intracranial aneurysm necks for rupture risk assessment. Int J Comput Assist Radiol Surg 2021; 16:1977-1984. [PMID: 34406578 PMCID: PMC8589826 DOI: 10.1007/s11548-021-02469-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 07/27/2021] [Indexed: 11/23/2022]
Abstract
Purpose Intracranial aneurysms are local dilations of brain vessels. Their rupture, as well as their treatment, is associated with high risk of morbidity and mortality. In this work, we propose shape indices for aneurysm ostia for the rupture risk assessment of intracranial aneurysms. Methods We analyzed 84 middle cerebral artery bifurcation aneurysms (27 ruptured and 57 unruptured) and their ostia, with respect to their size and shape. We extracted 3D models of the aneurysms and vascular trees. A semi-automatic approach was used to separate the aneurysm from its parent vessel and to reconstruct the ostium. We used known indices to quantitatively describe the aneurysms. For the ostium, we present new shape indices: the 2D Undulation Index (UI\documentclass[12pt]{minimal}
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\begin{document}$$_\mathrm{2D}$$\end{document}2D), the 2D Ellipticity Index (EI\documentclass[12pt]{minimal}
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\begin{document}$$_\mathrm{2D}$$\end{document}2D) and the 2D Noncircularity Index (NCI\documentclass[12pt]{minimal}
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\begin{document}$$_\mathrm{2D}$$\end{document}2D). Results were analyzed using the Student t test, the Mann–Whitney U test and a correlation analysis between indices of the aneurysms and their ostia. Results Of the indices, none was significantly associated with rupture status. Most aneurysms have an NCI\documentclass[12pt]{minimal}
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\begin{document}$$_\mathrm{2D}$$\end{document}2D below 0.2. Of the aneurysms that have an NCI\documentclass[12pt]{minimal}
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\begin{document}$$_\mathrm{2D}$$\end{document}2D above 0.5, only one is ruptured, which indicates that ruptured aneurysms often have a circular-shaped ostium. Furthermore, the ostia of ruptured aneurysms tend to have a smaller area, which is also correlated with the aneurysm’s size. While also other variables were significantly correlated, strong linear correlations can only be seen between the area of the ostium with the aneurysm’s volume and surface. Conclusion The proposed shape indices open up new possibilities to quantitatively describe and compare ostia, which can be beneficial for rupture risk assessment and subsequent treatment decision. Additionally, this work shows that the ostium area and the size of the aneurysm are correlated. Further longitudinal studies are necessary to analyze whether stable and unstable aneurysms can be distinguished by their ostia.
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Kim T, Oh CW, Bang JS, Ban SP, Lee SU, Kim YD, Kwon OK. Higher oscillatory shear index is related to aneurysm recanalization after coil embolization in posterior communicating artery aneurysms. Acta Neurochir (Wien) 2021; 163:2327-2337. [PMID: 33037924 DOI: 10.1007/s00701-020-04607-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/02/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND The recurrence rate of posterior communicating artery (Pcom) aneurysms after endovascular treatment (EVT) is higher than that for aneurysms located in other sites. However, it is still unclear what mechanisms are responsible for the recanalization of cerebral aneurysms. In this investigation, we compared hemodynamic factors related with recanalization of Pcom aneurysms treated by endoluminal coiling using computational fluid dynamics (CFD) with high-resolution three-dimensional digital subtraction angiography images. METHODS Twenty patients were enrolled. A double-sinogram acquisition was performed with and without contrast injection after coil embolization to get true blood vessel lumen by relatively complementing the first sinogram with the second. Adaptive Cartesian meshing was performed to produce vascular wall objects for CFD simulation. The boundary condition for inlet (ICA) was set for dynamic velocity according to the cardiac cycle (0.8 s). Hemodynamic parameters were recorded at two specific points (branching point of Pcom and residual sac). The peak pressure, peak WSS, and oscillatory shear index (OSI) were recorded and analyzed. RESULTS The median age was 61.0 years, and 18 patients (90%) were female. During a median follow-up of 12 months, seven (35%) treated aneurysms showed recanalization. The median aneurysm volume was significantly higher, and aneurysm height and neck sizes were significantly longer in the recanalization group than those in the stable group. At the branching point of the Pcom, the peak pressure, peak WSS, or OSI did not significantly differ between the two groups. The only statistically significant hemodynamic parameter related with recanalization was the OSI at the aneurysm point. Multivariate logistic regression showed that with an increase of 0.01 OSI at the aneurysm point, the odds ratio for the aneurysm recanalization was 1.19. CONCLUSIONS A higher OSI is related with recanalization after coil embolization for a Pcom aneurysm.
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Affiliation(s)
- Tackeun Kim
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Chang Wan Oh
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae Seung Bang
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seung Pil Ban
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Si Un Lee
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Deok Kim
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - O-Ki Kwon
- Department of Neurosurgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea.
- Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea.
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Schmidt S, Bruschewski M, Flassbeck S, John K, Grundmann S, Ladd ME, Schmitter S. Phase-contrast acceleration mapping with synchronized encoding. Magn Reson Med 2021; 86:3201-3210. [PMID: 34313340 DOI: 10.1002/mrm.28948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/14/2021] [Accepted: 07/15/2021] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop a phase-contrast (PC) -based method for direct and unbiased quantification of the acceleration vector field by synchronization of the spatial and acceleration encoding time points. The proposed method explicitly aims at in-vitro applications, requiring high measurement accuracy, as well as the validation of clinically relevant acceleration-encoded sequences. METHODS A velocity-encoded sequence with synchronized encoding (SYNC SPI) was modified to allow direct acceleration mapping by replacing the bipolar encoding gradients with tripolar gradient waveforms. The proposed method was validated in two in-vitro flow cases: a rotation and a stenosis phantom. The thereby obtained velocity and acceleration vector fields were quantitatively compared to those acquired with conventional PC methods, as well as to theoretical data. RESULTS The rotation phantom study revealed a systematic bias of the conventional PC acceleration mapping method that resulted in an average pixel-wise relative angle between the measured and theoretical vector field of (7.8 ± 3.2)°, which was reduced to (-0.4 ± 2.7)° for the proposed SYNC SPI method. Furthermore, flow features in the stenosis phantom were displaced by up to 10 mm in the conventional PC data compared with the acceleration-encoded SYNC SPI data. CONCLUSIONS This work successfully demonstrates a highly accurate method for direct acceleration mapping. It thus complements the existing velocity-encoded SYNC SPI method to enable the direct and unbiased quantification of both the velocity and acceleration vector field for in vitro studies. Hence, this method can be used for the validation of conventional acceleration-encoded PC methods applicable in-vivo.
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Affiliation(s)
- Simon Schmidt
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Sebastian Flassbeck
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA.,Center for Advanced Imaging Innovation and Research, New York University School of Medicine, New York, New York, USA
| | - Kristine John
- Institute of Fluid Mechanics, University of Rostock, Rostock, Germany
| | - Sven Grundmann
- Institute of Fluid Mechanics, University of Rostock, Rostock, Germany
| | - Mark E Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Sebastian Schmitter
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
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Giotta Lucifero A, Baldoncini M, Bruno N, Galzio R, Hernesniemi J, Luzzi S. Shedding the Light on the Natural History of Intracranial Aneurysms: An Updated Overview. ACTA ACUST UNITED AC 2021; 57:medicina57080742. [PMID: 34440948 PMCID: PMC8400479 DOI: 10.3390/medicina57080742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
The exact molecular pathways underlying the multifactorial natural history of intracranial aneurysms (IAs) are still largely unknown, to the point that their understanding represents an imperative challenge in neurovascular research. Wall shear stress (WSS) promotes the genesis of IAs through an endothelial dysfunction causing an inflammatory cascade, vessel remodeling, phenotypic switching of the smooth muscle cells, and myointimal hyperplasia. Aneurysm growth is supported by endothelial oxidative stress and inflammatory mediators, whereas low and high WSS determine the rupture in sidewall and endwall IAs, respectively. Angioarchitecture, age older than 60 years, female gender, hypertension, cigarette smoking, alcohol abuse, and hypercholesterolemia also contribute to growth and rupture. The improvements of aneurysm wall imaging techniques and the implementation of target therapies targeted against inflammatory cascade may contribute to significantly modify the natural history of IAs. This narrative review strives to summarize the recent advances in the comprehension of the mechanisms underlying the genesis, growth, and rupture of IAs.
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Affiliation(s)
- Alice Giotta Lucifero
- Neurosurgery Unit, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Matías Baldoncini
- Department of Neurological Surgery, Hospital San Fernando, Buenos Aires 1646, Argentina;
| | - Nunzio Bruno
- Division of Neurosurgery, Azienda Ospedaliero Universitaria Consorziale Policlinico di Bari, 70124 Bari, Italy;
| | - Renato Galzio
- Neurosurgery Unit, Maria Cecilia Hospital, 48032 Cotignola, Italy;
| | - Juha Hernesniemi
- Juha Hernesniemi International Center for Neurosurgery, Henan Provincial People’s Hospital, Zhengzhou 450000, China;
| | - Sabino Luzzi
- Neurosurgery Unit, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy;
- Neurosurgery Unit, Department of Surgical Sciences, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
- Correspondence:
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