1
|
Wiśniewski K, Reorowicz P, Tyfa Z, Price B, Jian A, Fahlström A, Obidowski D, Jaskólski DJ, Jóźwik K, Drummond K, Wessels L, Vajkoczy P, Adamides AA. Computational fluid dynamics; a new diagnostic tool in giant intracerebral aneurysm treatment. Comput Biol Med 2024; 181:109053. [PMID: 39217964 DOI: 10.1016/j.compbiomed.2024.109053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 08/05/2024] [Accepted: 08/20/2024] [Indexed: 09/04/2024]
Abstract
Giant intracerebral aneurysms (GIA) comprise up to 5 % of all intracranial aneurysms. The indirect surgical strategy, which leaves the GIA untouched but reverses the blood flow by performing a bypass in combination with proximal parent artery occlusion is a useful method to achieve spontaneous aneurysm occlusion. The goal of this study was to assess the utility of computational fluid dynamics (CFD) in preoperative GIA treatment planning. We hypothesise that CFD simulations will predict treatment results. A fluid-structure interaction (FSI) CFD investigation was performed for the entire arterial brain circulation. The analyses were performed in three patient-specific CT angiogram models. The first served as the reference geometry with a C6 internal carotid artery (ICA) GIA, the second a proximal parent artery occlusion (PAO) and virtual bypass to the frontal M2 branch of the middle cerebral artery (MCA), and the third a proximal PAO in combination with a temporal M2 branch bypass. The volume of "old blood", flow residence time (FRT), dynamic viscosity and haemodynamic changes were also analysed. The "old blood" within the aneurysm in the bypass models reached 41 % after 20 cardiac cycles while in the reference model it was fully washed out. In Bypass 2 "old blood" was also observed in the main trunk of the MCA after 20 cardiac cycles. Extrapolation of the results yielded a duration of 4 years required to replace the "old blood" inside the aneurysm after bypass revascularization. In both bypass models a 7-fold increase in mean blood viscosity in the aneurysm region was noted. Bypass revascularization combined with proximal PAO favours thrombosis. Areas prone to thrombus formation, and subsequently the treatment outcomes, were accurately identified in the preoperative model. Virtual surgical operations can give a remarkable insight into haemodynamics that could support operative decision-making.
Collapse
Affiliation(s)
- Karol Wiśniewski
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia; Department of Neurosurgery and Neurooncology, Medical University of Łódź, Kopcińskiego 22, 90-153, Łódź, Poland; Lodz University of Technology, Institute of Turbomachinery, 219/223 Wolczanska Str., 90-924, Lodz, Poland.
| | - Piotr Reorowicz
- Lodz University of Technology, Institute of Turbomachinery, 219/223 Wolczanska Str., 90-924, Lodz, Poland.
| | - Zbigniew Tyfa
- Lodz University of Technology, Institute of Turbomachinery, 219/223 Wolczanska Str., 90-924, Lodz, Poland.
| | - Benjamin Price
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia.
| | - Anne Jian
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia.
| | - Andreas Fahlström
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia; Department of Medical Sciences, Section of Neurosurgery, Uppsala University, Uppsala, 75185, Sweden.
| | - Damian Obidowski
- Lodz University of Technology, Institute of Turbomachinery, 219/223 Wolczanska Str., 90-924, Lodz, Poland.
| | - Dariusz J Jaskólski
- Department of Neurosurgery and Neurooncology, Medical University of Łódź, Kopcińskiego 22, 90-153, Łódź, Poland.
| | - Krzysztof Jóźwik
- Lodz University of Technology, Institute of Turbomachinery, 219/223 Wolczanska Str., 90-924, Lodz, Poland.
| | - Katharine Drummond
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia; Department of Surgery, University of Melbourne, 300 Grattan St, Parkville, 3050, Australia.
| | - Lars Wessels
- Department of Neurosurgery and Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Peter Vajkoczy
- Department of Neurosurgery and Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Alexios A Adamides
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia; Department of Surgery, University of Melbourne, 300 Grattan St, Parkville, 3050, Australia.
| |
Collapse
|
2
|
Ngwenya T, Grundlingh D, Ngoepe MN. Influence of vortical structures on fibrin clot formation in cerebral aneurysms: A two-dimensional computational study. J Biomech 2024; 165:111994. [PMID: 38394954 DOI: 10.1016/j.jbiomech.2024.111994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
Thrombosis is an important contributor to cerebral aneurysm growth and progression. A number of sophisticated multiscale and multiphase in silico models have been developed with a view towards interventional planning. Many of these models are able to account for clotting outcomes, but do not provide detailed insight into the role of flow during clot development. In this study, we present idealised, two-dimensional in silico cerebral fibrin clot model based on computational fluid dynamics (CFD), biochemical modelling and variable porosity, permeability, and diffusivity. The model captures fibrin clot growth in cerebral aneurysms over a period at least 1000 s in five different geometries. The fibrin clot growth results were compared to an experiment presented in literature. The biochemistry was found to be more sensitive to mesh size compared to the haemodynamics, while larger timesteps overpredicted clot size in pulsatile flow. When variable diffusivity was used, the predicted clot size was 25.4% lesser than that with constant diffusivity. The predicted clot size in pulsatile flow was 14.6% greater than in plug flow. Different vortex modes were observed in plug and pulsatile flow; the latter presented smaller intermediate modes where the main vortex was smaller and less likely to disrupt the growing fibrin clot. Furthermore, smaller vortex modes were seen to support fibrin clot propagation across geometries. The model clearly demonstrates how the growing fibrin clot alters vortical structures within the aneurysm sac and how this changing flow, in turn, shapes the growing fibrin clot.
Collapse
Affiliation(s)
- Tinashe Ngwenya
- Centre for Research in Computational and Applied Mechanics (CERECAM), University of Cape Town, South Africa; Department of Mechanical Engineering, University of Cape Town, South Africa
| | - Divan Grundlingh
- Department of Mechanical Engineering, University of Cape Town, South Africa
| | - Malebogo N Ngoepe
- Centre for Research in Computational and Applied Mechanics (CERECAM), University of Cape Town, South Africa; Department of Mechanical Engineering, University of Cape Town, South Africa.
| |
Collapse
|
3
|
Chen L, Leng X, Zheng C, Shan Y, Wang M, Bao X, Wu J, Zou R, Liu X, Xu S, Xiang J, Wan S. Computational fluid dynamics (CFD) analysis in a ruptured vertebral artery dissecting aneurysm implanted by Pipeline when recurrent after LVIS-assisted coiling treatment: Case report and review of the literatures. Interv Neuroradiol 2023; 29:442-449. [PMID: 35484808 PMCID: PMC10399494 DOI: 10.1177/15910199221097766] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUNDS Hemodynamics plays an important role in the natural history of the process of rupture and recurrence of intracranial aneurysms. This study aimed to investigate the role of hemodynamics for recurrence in a vertebral artery dissecting aneurysm (VADA). METHODS A patient with a ruptured VADA firstly treated by low-profile visualized intraluminal support (LVIS)-assisted coiling, and was implanted with a Pipeline Embolization Device (PED) after aneurysm recurrence. Finite element analysis and computational fluid dynamics simulations were conducted in 6 serial imaging procedures, and the calculated hemodynamics was correlated with aneurysm recurrence. RESULTS Wall shear stress (WSS) was not effectively suppressed, resulting in aneurysm recurrence with initial entry tear to occur above the protuberance after 7 months of LVIS stent-assisted coiling. With the implantation of PED, WSS, inflow stream and velocity at the aneurysm neck significantly decreased. During the 3-month follow-up after PED deployment, there was significant shrinkage of the sac and the blood flow in the sac was reduced considerably. The 27-month follow-up after PED deployment indicated the aneurysm was stable. CONCLUSIONS The present case study suggests that insufficient suppression of high WSS and high inflow velocity at the neck of the parent artery, especially near the posterior inferior cerebellar artery, might be associated with aneurysm recurrence.
Collapse
Affiliation(s)
- Linhui Chen
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | | | - Chaobo Zheng
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yejie Shan
- ArteryFlow Technology Co., Ltd. Hangzhou, China
| | - Ming Wang
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiang Bao
- Department of Neurosurgery, Jinhua Central Hospital, Jinhua, China
| | - Jiong Wu
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Rong Zou
- ArteryFlow Technology Co., Ltd. Hangzhou, China
| | - Xiaobo Liu
- Department of Neurosurgery, Jinhua Central Hospital, Jinhua, China
| | - Shanhu Xu
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | | | - Shu Wan
- Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
4
|
He F, Wang X, Hua L, Guo T. Numerical simulation of hemodynamics in patient-specific pulmonary artery stenosis. Biomed Mater Eng 2023; 34:427-437. [PMID: 37125542 DOI: 10.3233/bme-222523] [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] [Indexed: 05/02/2023]
Abstract
BACKGROUND The incidence rate of pulmonary artery stenosis is increasing year by year and its numerical simulation has become a key project of biomedical engineering. OBJECTIVE The purpose of this work is to study the changes of hemodynamic parameters in patient-specific pulmonary artery stenosis. METHODS A pulmonary artery stenosis model is established based on patient-specific computed tomography (CT) images. According to the actual anatomy of patient-specific pulmonary artery stenosis, the stenosis area is simulated using a porous medium to study its hemodynamic changes. The computational fluid dynamics (CFD) method is used to simulate the hemodynamic changes of pulmonary artery stenosis, and to explore the mechanical characteristics between blood flow and vessel wall. RESULTS The results suggest that the blood pressures of arterial branches increase and the pressure drop at both ends of the stenosis is higher. There is a high flow rate and wall shear stress at the stenosis. CONCLUSION This study shows that the hemodynamic model of pulmonary artery stenosis can be accurately reconstructed by achieving numerical simulation of the local stenosis through CT images, and this work has important implications for improving the confidence of clinical diagnosis and treatment of pulmonary artery diseases.
Collapse
Affiliation(s)
- Fan He
- School of Science, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Xinyu Wang
- School of Science, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Lu Hua
- Thrombosis Center, National Clinical Research Center for Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tingting Guo
- Thrombosis Center, National Clinical Research Center for Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| |
Collapse
|
5
|
Jiang Y, Lu G, Ge L, Zou R, Li G, Wan H, Leng X, Xiang J, Zhang X. Hemodynamic Comparison of Treatment Strategies for Intracranial Vertebral Artery Fusiform Aneurysms. Front Neurol 2022; 13:927135. [PMID: 35873788 PMCID: PMC9296783 DOI: 10.3389/fneur.2022.927135] [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: 04/23/2022] [Accepted: 06/06/2022] [Indexed: 11/23/2022] Open
Abstract
Objective This study comparatively analyzed the hemodynamic changes resulting from various simulated stent-assisted embolization treatments to explore an optimal treatment strategy for intracranial vertebral artery fusiform aneurysms. An actual vertebral fusiform aneurysm case treated by large coil post-stenting (PLCS) was used as a control. Materials and Methods A single case of an intracranial vertebral artery fusiform aneurysm underwent a preoperative and eight postoperative finite element treatment simulations: PLCS [single and dual Low-profile Visualized Intraluminal Support (LVIS)], Jailing technique (single and dual LVIS both simulated twice, Pipeline Embolization Device (PED) with or without large coils (LCs). Qualitative and quantitative assessments were performed to analyze the most common hemodynamic risk factors for recurrence. Results Jailing technique and PED-only had a high residual flow volume (RFV) and wall shear stress (WSS) on the large curvature of the blood flow impingement region. Quantitative analysis determined that PLSC and PED had a lower RFV compared to preoperative than did the jailing technique [PED+LC 2.46% < PLCS 1.2 (dual LVIS) 4.75% < PLCS 1.1 (single LVIS) 6.34% < PED 6.58% < Jailing 2.2 12.45% < Jailing 1.2 12.71% < Jailing 1.1 14.28% < Jailing 2.1 16.44%]. The sac-averaged flow velocity treated by PLCS, PED and PED+LC compared to preoperatively was significantly lower than the jailing technique [PED+LC = PLCS 1.2 (dual LVIS) 17.5% < PLCS 1.1 (single LVIS) = PED 27.5% < Jailing 1.2 = Jailing 2.2 32.5% < Jailing 1.1 37.5% < Jailing 2.1 40%]. The sac-averaged WSS for the PLCS 1.2 (dual LVIS) model was lower than the PED+LC, while the high WSS area of the Jailing 1 model was larger than for Jailing 2 [PLCS 1.2 38.94% (dual LVIS) < PED+LC 41% < PLCS 1.1 43.36% (single LVIS) < PED 45.23% < Jailing 2.1 47.49% < Jailing 2.2 47.79% < Jailing 1.1 48.97% < Jailing 1.2 49.85%]. Conclusions For fusiform aneurysms, post large coil stenting can provide a uniform coil configuration potentially reducing the hemodynamic risk factors of recurrence. Flow diverters also may reduce the recurrence risk, with long-term follow-up required, especially to monitor branch blood flow to prevent postoperative ischemia.
Collapse
Affiliation(s)
- Yeqing Jiang
- Huashan Hospital, Fudan University, Shanghai, China
| | - Gang Lu
- Huashan Hospital, Fudan University, Shanghai, China
| | - Liang Ge
- Huashan Hospital, Fudan University, Shanghai, China
| | - Rong Zou
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | - Hailin Wan
- Huashan Hospital, Fudan University, Shanghai, China
| | | | - Jianping Xiang
- ArteryFlow Technology Co., Ltd, Hangzhou, China
- *Correspondence: Jianping Xiang
| | - Xiaolong Zhang
- Huashan Hospital, Fudan University, Shanghai, China
- Xiaolong Zhang
| |
Collapse
|
6
|
Nabaei M. Cerebral aneurysm evolution modeling from microstructural computational models to machine learning: A review. Comput Biol Chem 2022; 98:107676. [DOI: 10.1016/j.compbiolchem.2022.107676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 02/13/2022] [Accepted: 03/30/2022] [Indexed: 11/03/2022]
|
7
|
Shi Z, Chen GZ, Mao L, Li XL, Zhou CS, Xia S, Zhang YX, Zhang B, Hu B, Lu GM, Zhang LJ. Machine Learning-Based Prediction of Small Intracranial Aneurysm Rupture Status Using CTA-Derived Hemodynamics: A Multicenter Study. AJNR Am J Neuroradiol 2021; 42:648-654. [PMID: 33664115 PMCID: PMC8041003 DOI: 10.3174/ajnr.a7034] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 11/09/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Small intracranial aneurysms are being increasingly detected while the rupture risk is not well-understood. We aimed to develop rupture-risk models of small aneurysms by combining clinical, morphologic, and hemodynamic information based on machine learning techniques and to test the models in external validation datasets. MATERIALS AND METHODS From January 2010 to December 2016, five hundred four consecutive patients with only small aneurysms (<5 mm) detected by CTA and invasive cerebral angiography (or surgery) were retrospectively enrolled and randomly split into training (81%) and internal validation (19%) sets to derive and validate the proposed machine learning models (support vector machine, random forest, logistic regression, and multilayer perceptron). Hemodynamic parameters were obtained using computational fluid dynamics simulation. External validation was performed in other hospitals to test the models. RESULTS The support vector machine performed the best with areas under the curve of 0.88 (95% CI, 0.85-0.92) and 0.91 (95% CI, 0.74-0.98) in the training and internal validation datasets, respectively. Feature ranks suggested hemodynamic parameters, including stable flow pattern, concentrated inflow streams, and a small (<50%) flow-impingement zone, and the oscillatory shear index coefficient of variation, were the best predictors of aneurysm rupture. The support vector machine showed an area under the curve of 0.82 (95% CI, 0.69-0.94) in the external validation dataset, and no significant difference was found for the areas under the curve between internal and external validation datasets (P = .21). CONCLUSIONS This study revealed that machine learning had a good performance in predicting the rupture status of small aneurysms in both internal and external datasets. Aneurysm hemodynamic parameters were regarded as the most important predictors.
Collapse
Affiliation(s)
- Z Shi
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G Z Chen
- Department of Medical Imaging (G.Z.C.), Nanjing First Hospital, Nanjing, Jiangsu, China
| | - L Mao
- Deepwise AI Lab (L.M., X.L.L.), Beijing, China
| | - X L Li
- Deepwise AI Lab (L.M., X.L.L.), Beijing, China
| | - C S Zhou
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - S Xia
- Department of Radiology (S.X.), Tianjin First Central Hospital, Tianjin, China
| | - Y X Zhang
- Laboratory of Image Science and Technology (Y.X.Z.), School of Computer Science and Engineering, Southeast University, Nanjing, China
| | - B Zhang
- Department of Radiology (B.Z.), Taizhou People's Hospital, Taizhou, Jiangsu, China
| | - B Hu
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G M Lu
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - L J Zhang
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| |
Collapse
|
8
|
A review of hemodynamic parameters in cerebral aneurysm. INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT 2020. [DOI: 10.1016/j.inat.2020.100716] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
9
|
Sharma T, Datta KK, Kumar M, Dey G, Khan AA, Mangalaparthi KK, Saharan P, Chinnapparaj S, Aggarwal A, Singla N, Ghosh S, Rawat A, Dhandapani S, Salunke P, Chhabra R, Singh D, Takkar A, Gupta SK, Prasad TSK, Gowda H, Mukherjee KK, Pandey A, Bhagat H. Intracranial Aneurysm Biomarker Candidates Identified by a Proteome-Wide Study. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 24:483-492. [PMID: 32525733 DOI: 10.1089/omi.2020.0057] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The scientific basis of intracranial aneurysm (IA) formation, its rupture and further development of cerebral vasospasm is incompletely understood. Aberrant protein expression may drive structural alterations of vasculature found in IA. Deciphering the molecular mechanisms underlying these events will lead to identification of early detection biomarkers and in turn, improved treatment outcomes. To unravel differential protein expression in three clinical subgroups of IA patients: (1) unruptured aneurysm, (2) ruptured aneurysm without vasospasm, (3) ruptured aneurysm who developed vasospasm, we performed untargeted quantitative proteomic analysis of aneurysm tissue and serum samples from three subgroups of IA patients and control subjects. Candidate molecules were then validated in a larger cohort of patients using enzyme-linked immunosorbent assay. A total of 937 and 294 proteins were identified from aneurysm tissue and serum samples, respectively. Several proteins that are known to maintain structural integrity of vasculature were found to be dysregulated in the context of aneurysm. ORM1, a glycoprotein, was significantly upregulated in both tissue and serum samples of unruptured aneurysm patients. We employed a larger cohort of subjects (n = 26) and validated ORM1 as a potential biomarker for screening of unruptured aneurysms. Samples from ruptured aneurysms with vasospasm showed significant upregulation of MMP9, a protease, compared with ruptured aneurysms without vasospasm. We validated MMP9 as a potential biomarker for vasospasm in a larger cohort (n = 52). This study reports the first global proteomic analysis of the entire clinical spectrum of IA. Furthermore, this study suggests ORM1 and MMP9 as potential biomarkers for unruptured aneurysm and cerebral vasospasm, respectively.
Collapse
Affiliation(s)
- Tanavi Sharma
- Division of Neuroanesthesia, Department of Anesthesia and Intensive Care, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Keshava K Datta
- Institute of Bioinformatics, International Tech Park, Bangalore, India
| | - Munish Kumar
- Division of Neuroanesthesia, Department of Anesthesia and Intensive Care, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Gourav Dey
- Institute of Bioinformatics, International Tech Park, Bangalore, India
| | | | | | - Poonam Saharan
- Division of Neuroanesthesia, Department of Anesthesia and Intensive Care, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Shobia Chinnapparaj
- Division of Neuroanesthesia, Department of Anesthesia and Intensive Care, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ashish Aggarwal
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Navneet Singla
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Sujata Ghosh
- Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Amit Rawat
- Pediatric Allergy and Immunology Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Sivashanmugam Dhandapani
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Pravin Salunke
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Rajesh Chhabra
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Dalbir Singh
- Department of Forensic Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Aastha Takkar
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Sunil K Gupta
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Thottethodi Subrahmanya Keshava Prasad
- Institute of Bioinformatics, International Tech Park, Bangalore, India.,Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Mangalore, India
| | - Harsha Gowda
- Institute of Bioinformatics, International Tech Park, Bangalore, India.,Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Mangalore, India.,Manipal Academy of Higher Education, Manipal, India
| | - Kanchan K Mukherjee
- Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Akhilesh Pandey
- Institute of Bioinformatics, International Tech Park, Bangalore, India.,Manipal Academy of Higher Education, Manipal, India.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Hemant Bhagat
- Division of Neuroanesthesia, Department of Anesthesia and Intensive Care, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
10
|
Saqr KM, Rashad S, Tupin S, Niizuma K, Hassan T, Tominaga T, Ohta M. What does computational fluid dynamics tell us about intracranial aneurysms? A meta-analysis and critical review. J Cereb Blood Flow Metab 2020; 40:1021-1039. [PMID: 31213162 PMCID: PMC7181089 DOI: 10.1177/0271678x19854640] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite the plethora of published studies on intracranial aneurysms (IAs) hemodynamic using computational fluid dynamics (CFD), limited progress has been made towards understanding the complex physics and biology underlying IA pathophysiology. Guided by 1733 published papers, we review and discuss the contemporary IA hemodynamics paradigm established through two decades of IA CFD simulations. We have traced the historical origins of simplified CFD models which impede the progress of comprehending IA pathology. We also delve into the debate concerning the Newtonian fluid assumption used to represent blood flow computationally. We evidently demonstrate that the Newtonian assumption, used in almost 90% of studies, might be insufficient to describe IA hemodynamics. In addition, some fundamental properties of the Navier-Stokes equation are revisited in supplementary material to highlight some widely spread misconceptions regarding wall shear stress (WSS) and its derivatives. Conclusively, our study draws a roadmap for next-generation IA CFD models to help researchers investigate the pathophysiology of IAs.
Collapse
Affiliation(s)
- Khalid M Saqr
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan.,Department of Mechanical Engineering, College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt
| | - Sherif Rashad
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Simon Tupin
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Kuniyasu Niizuma
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgical Engineering and Translational Neuroscience, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Tamer Hassan
- Department of Neurosurgery, Alexandria University School of Medicine, Azarita Medical Campus, Alexandria, Egypt
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| |
Collapse
|
11
|
Li Y, Corriveau M, Aagaard-Kienitz B, Ahmed A, Niemann D. Differences in Pressure Within the Sac of Human Ruptured and Nonruptured Cerebral Aneurysms. Neurosurgery 2019; 84:1261-1268. [PMID: 29741656 DOI: 10.1093/neuros/nyy182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 04/10/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Hemodynamics plays a critical role in the development, growth, and rupture of intracranial aneurysms. This data could be vital in determining individual aneurysm rupture risk and could facilitate our understanding of aneurysms. OBJECTIVE To present the largest prospective cross-sectional cohort study of intrasaccular pressure recordings of ruptured and nonruptured intracranial aneurysms and describe the hemodynamic differences that exist between ruptured and nonruptured aneurysms. METHODS During endovascular treatment, a standard 1.8-Fr 200 m length microcatheter was navigated into the dome of the aneurysm prior to coil embolization. With the microcatheter centralized within the dome of the aneurysm, an arterial pressure transducer was attached to the proximal end of the microcatheter to measure the stump pressure inside the aneurysm dome. RESULTS In 68 aneurysms (28 ruptured, 40 nonruptured), we observed that ruptured cerebral aneurysms had a lower systolic and mean arterial pressure compared to nonruptured cohort (P = .0008). Additionally, the pulse pressures within the dome of ruptured aneurysms were significantly more narrow than that of unruptured aneurysms (P = .0001). These findings suggest that there may be an inherent difference between ruptured and nonruptured aneurysms and such recordings obtained during routine digital subtraction angiography could potentially become a widely applied technique to augment risk stratification of aneurysms. CONCLUSION Our preliminary data present new evidence distinguishing ruptured from unruptured aneurysms that may have a critical role as a predictive parameter to stratify the natural history of nonruptured intracranial aneurysms and as a new avenue for future investigation.
Collapse
Affiliation(s)
- Yiping Li
- Department of Neurological Surgery, Neuro Interventional Radiology, University of Wisconsin Medical School, Madison, Wisconsin
| | - Mark Corriveau
- Department of Neurological Surgery, Neuro Interventional Radiology, University of Wisconsin Medical School, Madison, Wisconsin
| | - Beverly Aagaard-Kienitz
- Department of Neurological Surgery, Neuro Interventional Radiology, University of Wisconsin Medical School, Madison, Wisconsin
| | - Azam Ahmed
- Department of Neurological Surgery, Neuro Interventional Radiology, University of Wisconsin Medical School, Madison, Wisconsin
| | - David Niemann
- Department of Neurological Surgery, Neuro Interventional Radiology, University of Wisconsin Medical School, Madison, Wisconsin
| |
Collapse
|
12
|
Sheng B, Wu D, Yuan J, Xu S, Li Z, Dong J, Lai N, Fang X. Hemodynamic Characteristics Associated With Paraclinoid Aneurysm Recurrence in Patients After Embolization. Front Neurol 2019; 10:429. [PMID: 31105640 PMCID: PMC6494928 DOI: 10.3389/fneur.2019.00429] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/08/2019] [Indexed: 12/18/2022] Open
Abstract
Objective: To investigate the hemodynamic features before and after embolization of paraclinoidal aneurysms using hemodynamic numerical simulation and the influence of embolization on recurrence after embolization. Methods: From January 2016 to December 2017, we enrolled a total of 113 paraclinoidal aneurysms treated with embolization. They were divided into recurrent group and stable group depending on follow-up results. An aneurysm model was generated based on 3D-DSA before and after embolization. The hemodynamic characteristics were analyzed between two groups using Computational fluid dynamic (CFD). Results: In the recurrent group, the peak systolic WSS, OSI and velocity around the aneurysm neck areas prior to embolization were 20.47 ± 3.04 Pa, 0.06 ± 0.02 and 0.07 ± 0.03 m/s, respectively. These values were 23.50 ± 4.11 Pa, 0.06 ± 0.01 and 0.11 ± 0.02 m/s, respectively in the stable group (P > 0.05). The WSS, OSI, velocity around the same areas in the recurrent group after embolization were 35.59 ± 8.75 Pa, 0.07 ± 0.02 and 0.12 ± 0.03 m/s, respectively (P < 0.01). In the stable group, the WSS, OSI and velocity were 13.08 ± 2.89 Pa, 0.04 ± 0.01 and 0.07 ± 0.02 m/s, respectively (P < 0.01). After embolization, the WSS, OSI and velocity around the aneurysm neck areas in the recurrent group were significantly higher than those in the stable group. Conclusions: High peak systolic WSS, OSI and velocity around aneurysm neck areas after embolization of paraclinoidal aneurysms may be important factors leading to recurrence.
Collapse
Affiliation(s)
- Bin Sheng
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Degang Wu
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Jinlong Yuan
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Shanshui Xu
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Zhenbao Li
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Jin Dong
- Department of Nursing, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Niansheng Lai
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Xinggen Fang
- Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| |
Collapse
|
13
|
Abstract
The Abdominal Aortic Aneurysm (AAA) is a local dilation of the abdominal aorta and it is a cause for serious concern because of the high mortality associated with its rupture. Consequently, the understanding of the phenomena related to the creation and the progression of an AAA is of crucial importance. In this work, the complicated interaction between the blood flow and the AAA wall is numerically examined using a fully coupled Fluid-Structure Interaction (FSI) method. The study investigates the possible link between the dynamic behavior of an AAA and the blood viscosity variations attributed to the haematocrit value, while it also incorporates the pulsatile blood flow, the non-Newtonian behavior of blood and the hyperelasticity of the arterial wall. It was found that blood viscosity has no significant effect on von Mises stress magnitude and distribution, whereas there is a close relation between the haematocrit value and the Wall Shear Stress (WSS) magnitude in AAAs. This WSS variation can possibly alter the mechanical properties of the arterial wall and increase its growth rate or even its rupture possibility. The relationship between haematocrit and dynamic behavior of an AAA can be helpful in designing a patient specific treatment.
Collapse
|
14
|
A new hypothesis on the role of vessel topology in cerebral aneurysm initiation. Comput Biol Med 2018; 103:244-251. [PMID: 30391796 DOI: 10.1016/j.compbiomed.2018.10.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/17/2018] [Accepted: 10/16/2018] [Indexed: 01/10/2023]
Abstract
Aneurysm pathogenesis is thought to be strongly linked with hemodynamical effects. According to our current knowledge, the formation process is initiated by locally disturbed flow conditions. The aim of the current work is to provide a numerical investigation on the role of the flow field at the stage of the initiation, before the aneurysm formation. Digitally reconstructed pre-aneurysmal geometries are used to examine correlations of the flow patterns to the location and direction of the aneurysms formed later. We argue that a very specific rotational flow pattern is present in all the investigated cases marking the location of the later aneurysm and that these flow patterns provide the mechanical load on the wall that can lead to a destructive remodelling in the vessel wall. Furthermore, these patterns induce elevated vessel surface related variables (e.g. wall shear stress (WSS), wall shear stress gradient (WSSG) and oscillatory shear index (OSI)), in agreement with the previous findings. We emphasise that the analysis of the flow patterns provides a deeper insight and a more robust numerical methodology compared to the sole examination of the aforementioned surface quantities.
Collapse
|
15
|
Osbotne JM, Bernabeu MO. A Fully Discrete Open Source Framework for the Simulation of Vascular Remodelling. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:4552-4555. [PMID: 30441364 DOI: 10.1109/embc.2018.8513223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this paper we present a novel computational framework for the theoretical study of the interaction between haemodynamics and vessel biology, with particular applications to the study of vascular remodelling. We introduce the mathematical formulation, validate the numerical method against an analytical solution derived for a simplified case, and present a case study of tissue remodelling in response to flow.
Collapse
|
16
|
|
17
|
Qiu Y, Yuan D, Wen J, Fan Y, Zheng T. Numerical identification of the rupture locations in patient-specific abdominal aortic aneurysmsusing hemodynamic parameters. Comput Methods Biomech Biomed Engin 2017; 21:1-12. [PMID: 29251991 DOI: 10.1080/10255842.2017.1410796] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The rupture of an abdominal aortic aneurysm (AAA) is generally an unexpected event. Up to now, there is no agreement on an accurate criteria to predict the rupture risk of AAAs. This paper aims to numerically investigate the hemodynamics of three ruptured and one non-ruptured patient-specific AAA models to correlate local hemodynamic parameters with the rupture sites, and for the first time, this study introduced helicity as a potential index for the rupture potential of AAAs.3D reconstructions from CT scans were done. The simulation revealed that all the rupture sites were in regions of stagnation with near zero wall shear stress (WSS) but large WSS gradient (WSSG), which may explain the observation by the former researchers that the rupture site in the ruptured AAA has the lowest recorded wall thickness compared to other non-ruptured regions. Moreover, all the ruptures occurred at regions of zero helicity which represents a purely axial or circumferential flow. In addition, this study revealed that the double low region for the non-ruptured AAA was present with a thick layer of plaques, it suggests that the AAA rupture and the formation of atherosclerotic plaques may share a lot common physiological features. However, the fact that there are no plaques present in the walls of three RAAAs also indicates that AAA is not always a result of atherosclerosis. The current computational study may complement the maximum diameter, peak wall stress and other clinically relevant factors in AAA ruptures to identify the rupture sites of AAAs.
Collapse
Affiliation(s)
- Yue Qiu
- a Department of Applied Mechanics , Sichuan University , Chengdu , China
| | - Ding Yuan
- b Department Vascular Surgery of West China Hospital , Sichuan University , Chengdu , China
| | - Jun Wen
- c School of Civil Engineering and Architecture , Southwest University of Science and Technology , Mianyang , China
| | - Yubo Fan
- d Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering , Beihang University , Beijing , P.R. China
| | - Tinghui Zheng
- a Department of Applied Mechanics , Sichuan University , Chengdu , China
| |
Collapse
|
18
|
Longo M, Granata F, Racchiusa S, Mormina E, Grasso G, Longo GM, Garufi G, Salpietro FM, Alafaci C. Role of Hemodynamic Forces in Unruptured Intracranial Aneurysms: An Overview of a Complex Scenario. World Neurosurg 2017; 105:632-642. [DOI: 10.1016/j.wneu.2017.06.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/04/2017] [Accepted: 06/05/2017] [Indexed: 12/16/2022]
|
19
|
Botar CC, Tóth ÁÁ, Klisurić OR, Nićiforović DD, Vučaj Ćirilović VA, Till VE. Dynamic simulation and Doppler Ultrasonography validation of blood flow behavior in Abdominal Aortic Aneurysm. Phys Med 2017; 37:1-8. [DOI: 10.1016/j.ejmp.2017.03.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022] Open
|
20
|
Shi Y, Zhu M, Chang Y, Qiao H, Liu Y. The risk of stanford type-A aortic dissection with different tear size and location: a numerical study. Biomed Eng Online 2016; 15:128. [PMID: 28155679 PMCID: PMC5259983 DOI: 10.1186/s12938-016-0258-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background This study is to investigate the influence of hemodynamics on Stanford type-A aortic dissection with different tear size and location, to provide some support for the relationships between the risks (rupture, reverse tearing and further tearing) and tear size and location for clinical treatment. Methods Four numerical models of Stanford type-A aortic dissection were established, with different size and location of the tears. The ratio of the area between the entry and re-entry tears(RA) is various within the model; while, the size and the location of the re-entry in the distal descending aorta are fixed. In model A11 and A21, the entry tears are located near the ascending aorta. The RA in these models are 1 and 2, respectively; In the model B11 and B21, the entry tears are located near the proximal descending aorta and the RA in these models are again assigned to 1 and 2, respectively. Then hemodynamics in these models was solved with numerically and the flow patterns and loading distributions were investigated. Results The flow velocity of the true lumen in model A21, B21 is lower than that in A11, B11, respectively; the time-averaged wall shear stress (TAWSS) of the false lumen in model A21 and B21 is higher, and for ascending aorta false lumen, A11, A21 are higher than B11, B21, respectively. False lumen intimal wall pressure of A11, A21 are always higher than the true lumen ones. Conclusion The variation of the RA can significantly affect the dynamics of blood within the aortic dissection. When the entry tear size is larger than the re-entry tear ones, the false lumen, proximal descending aorta and the wall near re-entry tear are prone to cracking. Entry tear location can significantly alter the hemodynamics of aortic dissection as well. When entry tear location is closer to proximal ascending aorta, false lumen continues to expand and compress the true lumen resulting in the true lumen reduction. For proximal ascending aorta, high pressure in false lumen predicts a higher risk of reverse tear.
Collapse
Affiliation(s)
- Yue Shi
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
| | - Minjia Zhu
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
| | - Yu Chang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
| | - Huanyu Qiao
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, People's Republic of China
| | - Yongmin Liu
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, People's Republic of China.
| |
Collapse
|
21
|
Varble N, Xiang J, Lin N, Levy E, Meng H. Flow Instability Detected by High-Resolution Computational Fluid Dynamics in Fifty-Six Middle Cerebral Artery Aneurysms. J Biomech Eng 2016; 138:061009. [PMID: 27109451 DOI: 10.1115/1.4033477] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Indexed: 11/08/2022]
Abstract
Recent high-resolution computational fluid dynamics (CFD) studies have detected persistent flow instability in intracranial aneurysms (IAs) that was not observed in previous in silico studies. These flow fluctuations have shown incidental association with rupture in a small aneurysm dataset. The aims of this study are to explore the capabilities and limitations of a commercial cfd solver in capturing such velocity fluctuations, whether fluctuation kinetic energy (fKE) as a marker to quantify such instability could be a potential parameter to predict aneurysm rupture, and what geometric parameters might be associated with such fluctuations. First, we confirmed that the second-order discretization schemes and high spatial and temporal resolutions are required to capture these aneurysmal flow fluctuations. Next, we analyzed 56 patient-specific middle cerebral artery (MCA) aneurysms (12 ruptured) by transient, high-resolution CFD simulations with a cycle-averaged, constant inflow boundary condition. Finally, to explore the mechanism by which such flow instabilities might arise, we investigated correlations between fKE and several aneurysm geometrical parameters. Our results show that flow instabilities were present in 8 of 56 MCA aneurysms, all of which were unruptured bifurcation aneurysms. Statistical analysis revealed that fKE could not differentiate ruptured from unruptured aneurysms. Thus, our study does not lend support to these flow instabilities (based on a cycle-averaged constant inflow as opposed to peak velocity) being a marker for rupture. We found a positive correlation between fKE and aneurysm size as well as size ratio. This suggests that the intrinsic flow instability may be associated with the breakdown of an inflow jet penetrating the aneurysm space.
Collapse
|
22
|
Yu X, Lu G, Wang S, Huang L, Ge L, Wan J, Di R, Jiang Y, Zhang X. Computational fluid dynamics analysis on recurrence of simple coiling intracranial aneurysms with remnant neck. Chin Neurosurg J 2016. [DOI: 10.1186/s41016-016-0050-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
23
|
Liu J, Jing L, Zhang Y, Song Y, Wang Y, Li C, Wang Y, Mu S, Paliwal N, Meng H, Linfante I, Yang X. Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis. World Neurosurg 2016; 97:344-350. [PMID: 27742509 DOI: 10.1016/j.wneu.2016.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA. METHODS Between September 2009 and November 2013, all consecutive patients with recurrent VADAs after SACE in our institutions were enrolled. Recurrence was defined as recanalization and/or regrowth. We assessed the hemodynamic alterations in wall shear stress (WSS) and velocity after the initial SACE and subsequently after retreatment of the aneurysms that recurred. RESULTS Five patients were included. After the initial treatment, 3 patients showed recanalization and 2 showed regrowth. In the 2 patients with regrowth, the 2 original aneurysms maintained complete occlusion; however, de novo aneurysm regrowth was confirmed near the previous site. Compared with 3 recanalized aneurysms, the completely occluded aneurysms showed high mean reductions in velocity and WSS after initial treatment (velocity, 77.6% vs. 57.7%; WSS, 74.2% vs. 52.4%); however, WSS remained high at the region near the previous lesion where the new aneurysm originated. After the second retreatment, there was no recurrence in any patient. Compared with the 3 aneurysms that recanalized, the 4 aneurysms that maintained complete occlusion showed higher reductions in velocity (62.9%) and WSS (71.1%). CONCLUSIONS Our series indicated that hemodynamics might have an important role in recurrence of VADAs. After endovascular treatment, sufficient hemodynamic reduction in aneurysm dome, orifice, and parent vessel may be one of the key factors for preventing recurrence in VADAs.
Collapse
Affiliation(s)
- Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Linkai Jing
- Department of Neurosurgery, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, Beijing, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Ying Song
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yang Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Chuanhui Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yanmin Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Shiqing Mu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Nikhil Paliwal
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, and Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Italo Linfante
- Miami Cardiac and Vascular Institute and Baptist Neuroscience Center, Baptist Hospital, Miami, Florida, USA.
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China.
| |
Collapse
|
24
|
Boyd AJ, Kuhn DC, Lozowy RJ, Kulbisky GP. Low wall shear stress predominates at sites of abdominal aortic aneurysm rupture. J Vasc Surg 2016; 63:1613-9. [DOI: 10.1016/j.jvs.2015.01.040] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/28/2015] [Indexed: 10/23/2022]
|
25
|
Abas A, Mokhtar NH, Ishak MHH, Abdullah MZ, Ho Tian A. Lattice Boltzmann Model of 3D Multiphase Flow in Artery Bifurcation Aneurysm Problem. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:6143126. [PMID: 27239221 PMCID: PMC4864205 DOI: 10.1155/2016/6143126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/05/2016] [Accepted: 03/31/2016] [Indexed: 11/17/2022]
Abstract
This paper simulates and predicts the laminar flow inside the 3D aneurysm geometry, since the hemodynamic situation in the blood vessels is difficult to determine and visualize using standard imaging techniques, for example, magnetic resonance imaging (MRI). Three different types of Lattice Boltzmann (LB) models are computed, namely, single relaxation time (SRT), multiple relaxation time (MRT), and regularized BGK models. The results obtained using these different versions of the LB-based code will then be validated with ANSYS FLUENT, a commercially available finite volume- (FV-) based CFD solver. The simulated flow profiles that include velocity, pressure, and wall shear stress (WSS) are then compared between the two solvers. The predicted outcomes show that all the LB models are comparable and in good agreement with the FVM solver for complex blood flow simulation. The findings also show minor differences in their WSS profiles. The performance of the parallel implementation for each solver is also included and discussed in this paper. In terms of parallelization, it was shown that LBM-based code performed better in terms of the computation time required.
Collapse
Affiliation(s)
- Aizat Abas
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
| | - N. Hafizah Mokhtar
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
| | - M. H. H. Ishak
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
| | - M. Z. Abdullah
- School of Aerospace Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
| | - Ang Ho Tian
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
| |
Collapse
|
26
|
Basic Principles of Hemodynamics and Cerebral Aneurysms. World Neurosurg 2016; 88:311-319. [DOI: 10.1016/j.wneu.2016.01.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 01/03/2016] [Accepted: 01/05/2016] [Indexed: 11/18/2022]
|
27
|
Park W, Song Y, Park KJ, Koo HW, Yang K, Suh DC. Hemodynamic Characteristics Regarding Recanalization of Completely Coiled Aneurysms: Computational Fluid Dynamic Analysis Using Virtual Models Comparison. Neurointervention 2016; 11:30-6. [PMID: 26958410 PMCID: PMC4781914 DOI: 10.5469/neuroint.2016.11.1.30] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 11/24/2022] Open
Abstract
Purpose Hemodynamic factors are considered to play an important role in initiation and progression of the recurrence after endosaccular coiling of the intracranial aneurysms. We made paired virtual models of completely coiled aneurysms which were subsequently recanalized and compared to identify hemodynamic characteristics related to the recurred aneurysmal sac. Materials and Methods We created paired virtual models of computational fluid dynamics (CFD) in five aneurysms which were initially regarded as having achieved complete occlusion and then recurred during follow-up. Paired virtual models consisted of the CFD model of 3D rotational angiography obtained in the recurred aneurysm and the control model of the initial, parent artery after artificial removal of the coiled and recanalized aneurysm. Using the CFD analysis of the virtual model, we analyzed the hemodynamic characteristics on the neck of each aneurysm before and after its recurrence. Results High wall shear stress (WSS) was identified at the cross-sectionally identified aneurysm neck at which recurrence developed in all cases. A small vortex formation with relatively low velocity in front of the neck was also identified in four cases. The aneurysm recurrence locations corresponded to the location of high WSS and/or small vortex formation. Conclusion Recanalized aneurysms revealed increased WSS and small vortex formation at the cross-sectional neck of the aneurysm. This observation may partially explain the hemodynamic causes of future recanalization after coil embolization.
Collapse
Affiliation(s)
- Wonhyoung Park
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.; Department of Neurosurgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Yunsun Song
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Kye Jin Park
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Hae-Won Koo
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Kuhyun Yang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Dae Chul Suh
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| |
Collapse
|
28
|
Jin Z, Arimura H, Kakeda S, Yamashita F, Sasaki M, Korogi Y. An ellipsoid convex enhancement filter for detection of asymptomatic intracranial aneurysm candidates in CAD frameworks. Med Phys 2016; 43:951-60. [DOI: 10.1118/1.4940349] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
29
|
Syed H, Unnikrishnan VU, Olcmen S. Characteristics of time-varying intracranial pressure on blood flow through cerebral artery: A fluid–structure interaction approach. Proc Inst Mech Eng H 2015; 230:111-21. [DOI: 10.1177/0954411915619952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/03/2015] [Indexed: 01/12/2023]
Abstract
Elevated intracranial pressure is a major contributor to morbidity and mortality in severe head injuries. Wall shear stresses in the artery can be affected by increased intracranial pressures and may lead to the formation of cerebral aneurysms. Earlier research on cerebral arteries and aneurysms involves using constant mean intracranial pressure values. Recent advancements in intracranial pressure monitoring techniques have led to measurement of the intracranial pressure waveform. By incorporating a time-varying intracranial pressure waveform in place of constant intracranial pressures in the analysis of cerebral arteries helps in understanding their effects on arterial deformation and wall shear stress. To date, such a robust computational study on the effect of increasing intracranial pressures on the cerebral arterial wall has not been attempted to the best of our knowledge. In this work, fully coupled fluid–structure interaction simulations are carried out to investigate the effect of the variation in intracranial pressure waveforms on the cerebral arterial wall. Three different time-varying intracranial pressure waveforms and three constant intracranial pressure profiles acting on the cerebral arterial wall are analyzed and compared with specified inlet velocity and outlet pressure conditions. It has been found that the arterial wall experiences deformation depending on the time-varying intracranial pressure waveforms, while the wall shear stress changes at peak systole for all the intracranial pressure profiles.
Collapse
Affiliation(s)
- Hasson Syed
- Department of Aerospace Engineering and Mechanics, The University of Alabama, Tuscaloosa, AL, USA
| | - Vinu U Unnikrishnan
- Department of Aerospace Engineering and Mechanics, The University of Alabama, Tuscaloosa, AL, USA
| | - Semih Olcmen
- Department of Aerospace Engineering and Mechanics, The University of Alabama, Tuscaloosa, AL, USA
| |
Collapse
|
30
|
Volokh KY, Aboudi J. Aneurysm strength can decrease under calcification. J Mech Behav Biomed Mater 2015; 57:164-74. [PMID: 26717251 DOI: 10.1016/j.jmbbm.2015.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/04/2015] [Accepted: 11/11/2015] [Indexed: 12/18/2022]
Abstract
Aneurysms are abnormal dilatations of vessels in the vascular system that are prone to rupture. Prediction of the aneurysm rupture is a challenging and unsolved problem. Various factors can lead to the aneurysm rupture and, in the present study, we examine the effect of calcification on the aneurysm strength by using micromechanical modeling. The calcified tissue is considered as a composite material in which hard calcium particles are embedded in a hyperelastic soft matrix. Three experimentally calibrated constitutive models incorporating a failure description are used for the matrix representation. Two constitutive models describe the aneurysmal arterial wall and the third one - the intraluminal thrombus. The stiffness and strength of the calcified tissue are simulated in uniaxial tension under the varying amount of calcification, i.e. the relative volume of the hard inclusion within the periodic unit cell. In addition, the triaxiality of the stress state, which can be a trigger for the cavitation instability, is tracked. Results of the micromechanical simulation show an increase of the stiffness and a possible decrease of the strength of the calcified tissue as compared to the non-calcified one. The obtained results suggest that calcification (i.e. the presence of hard particles) can significantly affect the stiffness and strength of soft tissue. The development of refined experimental techniques that will allow for the accurate quantitative assessment of calcification is desirable.
Collapse
Affiliation(s)
| | - Jacob Aboudi
- Faculty of Engineering, Tel Aviv University, Israel.
| |
Collapse
|
31
|
NABAEI MALIKEH, FATOURAEE NASSER. A 3D MODEL FOR MURAL-CELL-MEDIATED DESTRUCTIVE REMODELING DURING EARLY DEVELOPMENT OF A CEREBRAL ANEURYSM. J MECH MED BIOL 2015. [DOI: 10.1142/s0219519415500347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Development of a diagnostic tool for predicting the behavior of cerebral aneurysms was the inspiration of many research groups in recent years. In the present study a fluid–solid-growth (FSG) model for the early development of a cerebral aneurysm was presented in a 3D model of the internal carotid artery (ICA). This model is the result of two parallel mechanisms: first, defining arterial wall as a living tissue with the ability of degradation, growth and remodeling and second, full coupling of the wall and the blood flow. Taking into account the shear dependent nature of elastin degradation and mural-cell-mediated destructive activities, here, the degradation process has been linked to high effective stress of the vascular wall. The evolving properties of the elastinous and collagenous constituents have been predicted during the early development of the aneurysm and the code is applicable to more complicated aneurismal growth models.
Collapse
Affiliation(s)
- MALIKEH NABAEI
- Biological Fluid Mechanics Research Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology, (Tehran Polytechnic), Tehran, P. O. Box 15875-3413, I.R. Iran, Postal Code 15914, Iran
| | - NASSER FATOURAEE
- Biological Fluid Mechanics Research Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology, (Tehran Polytechnic), Tehran, P. O. Box 15875-3413, I.R. Iran, Postal Code 15914, Iran
| |
Collapse
|
32
|
Volokh KY. Cavitation instability as a trigger of aneurysm rupture. Biomech Model Mechanobiol 2015; 14:1071-9. [PMID: 25637515 DOI: 10.1007/s10237-015-0655-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 01/22/2015] [Indexed: 11/26/2022]
Abstract
Aneurysm formation and growth is accompanied by microstructural alterations in the arterial wall. Particularly, the loss of elastin may lead to tissue disintegration and appearance of voids or cavities at the micron scale. Unstable growth and coalescence of voids may be a predecessor and trigger for the onset of macroscopic cracks. In the present work, we analyze the instability of membrane (2D) and bulk (3D) voids under hydrostatic tension by using two experimentally calibrated constitutive models of abdominal aortic aneurysm enhanced with energy limiters. The limiters provide the saturation value for the strain energy, which indicates the maximum energy that can be stored and dissipated by an infinitesimal material volume. We find that the unstable growth of voids can start when the critical stress is considerably less than the aneurysm strength. Moreover, this critical stress may even approach the arterial wall stress in the physiological range. This finding suggests that cavitation instability can be a rational indicator of the aneurysm rupture.
Collapse
Affiliation(s)
- K Y Volokh
- Faculty of Civil and Environmental Engineering, Technion - I.I.T., Haifa, Israel,
| |
Collapse
|
33
|
Simsek FG, Kwon YW. Investigation of material modeling in fluid-structure interaction analysis of an idealized three-layered abdominal aorta: aneurysm initiation and fully developed aneurysms. J Biol Phys 2015; 41:173-201. [PMID: 25624113 DOI: 10.1007/s10867-014-9372-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 11/06/2014] [Indexed: 01/26/2023] Open
Abstract
Different material models for an idealized three-layered abdominal aorta are compared using computational techniques to study aneurysm initiation and fully developed aneurysms. The computational model includes fluid-structure interaction (FSI) between the blood vessel and the blood. In order to model aneurysm initiation, the medial region was degenerated to mimic the medial loss occurring in the inception of an aneurysm. Various cases are considered in order to understand their effects on the initiation of an abdominal aortic aneurysm. The layers of the blood vessel were modeled using either linear elastic materials or Mooney-Rivlin (otherwise known as hyperelastic) type materials. The degenerated medial region was also modeled in either linear elastic or hyperelastic-type materials and assumed to be in the shape of an arc with a thin width or a circular ring with different widths. The blood viscosity effect was also considered in the initiation mechanism. In addition, dynamic analysis of the blood vessel was performed without interaction with the blood flow by applying time-dependent pressure inside the lumen in a three-layered abdominal aorta. The stresses, strains, and displacements were compared for a healthy aorta, an initiated aneurysm and a fully developed aneurysm. The study shows that the material modeling of the vessel has a sizable effect on aneurysm initiation and fully developed aneurysms. Different material modeling of degeneration regions also affects the stress-strain response of aneurysm initiation. Additionally, the structural analysis without considering FSI (called noFSI) overestimates the peak von Mises stress by 52% at the interfaces of the layers.
Collapse
Affiliation(s)
- Fatma Gulden Simsek
- Institute of Biomedical Engineering, Bogazici University, Kandilli Camp, Istanbul, Turkey,
| | | |
Collapse
|
34
|
MRA study on variation of the circle of willis in healthy Chinese male adults. BIOMED RESEARCH INTERNATIONAL 2015; 2015:976340. [PMID: 25629057 PMCID: PMC4299360 DOI: 10.1155/2015/976340] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 11/17/2022]
Abstract
Aim. To investigate the morphology and variation of the circle of Willis (COW) in healthy Chinese male adults. Materials and Methods. We analyzed cerebral magnetic resonance angiography (MRA) images of 2,246 healthy subjects using typical magnetic resonance imaging (MRI) and MRA. 3D-time of flight (TOF) MRA method was applied to all subjects and the classification was therefore achieved according to the integrity level of COW and the developmental situation of vessels. Results. The overall incidence of COW integrity was 12.24%, with 7.57% nonvariation integral COW. The incidences of partial integrity and nonintegrity were 70.17% and 17.59%, respectively. The integrity rate of anterior circulation was 78.58%, with a close correlation with A1 segment of the anterior cerebral artery (ACA-A1) developmental condition. The developmental variation rate of ACA-A1 was 28.23% and the variation of the right side was higher than that of the left side. The nonintegrity rate of posterior circulation was 83.93% as the hypoplasia of P1 segment of the posterior cerebral artery (PCA-P1) with an incidence rate of 15.85% for PCA-P1 variation. Conclusions. The COW variation is a common phenomenon among the healthy subjects. MRA could enable reflecting the physiological morphology of COW in a comprehensive manner.
Collapse
|
35
|
Saaquib B, Valerie T, David N, Chen M. Spontaneous internal carotid artery occlusion and rapid cerebral aneurysm progression: case series and literature review. Neurointervention 2014; 9:78-82. [PMID: 25426302 PMCID: PMC4239412 DOI: 10.5469/neuroint.2014.9.2.78] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 06/30/2014] [Indexed: 11/24/2022] Open
Abstract
PURPOSE An accurate determination of the natural history of a cerebral aneurysm has implications on management. Few risk factors other than female gender and cigarette smoking have been identified to be associated with cerebral aneurysm progression, particularly rapid progression. MATERIALS AND METHODS This case series and literature review serves to illustrate a relationship between spontaneous carotid occlusion and rapid enlargement of cerebral aneurysms. RESULTS In our case series, we demonstrated that increased hemodynamic stress on collateral vessels caused by a spontaneous carotid occlusion may contribute to unusually rapid aneurysm growth and/or rupture. CONCLUSION Spontaneous carotid occlusive disease may be considered a risk factor for rapid cerebral aneurysm progression and/or rupture that may warrant more aggressive management options, including more frequent surveillance imaging in previously treated aneurysms.
Collapse
Affiliation(s)
- Bakhsh Saaquib
- Departments of Neurological Surgery and Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Toll Valerie
- Departments of Neurological Surgery and Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Neimann David
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Michael Chen
- Departments of Neurological Surgery and Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| |
Collapse
|
36
|
Nabaei M, Fatouraee N. Microstructural modelling of cerebral aneurysm evolution through effective stress mediated destructive remodelling. J Theor Biol 2014; 354:60-71. [PMID: 24657628 DOI: 10.1016/j.jtbi.2014.03.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 11/25/2022]
Abstract
Recently, researchers have shown an increased interest in the biomechanical modelling of cerebral aneurysm development. In the present study a fluid-solid-growth model for the formation of a fusiform aneurysm has been presented in an axi-symmetric geometry of the internal carotid artery. This model is the result of two parallel mechanisms: first, defining arterial wall as a living tissue with the ability of degradation, growth and remodelling and second, full coupling of the wall and the blood flow. Here for the first time the degradation of elastin has been defined as a function of vascular wall effective stress to take into account the shear dependent nature of degradation and the mural-cell-mediated destructive activities. The model has been stabilized in size and mechanical properties and is consistent with other computational or clinical studies. Furthermore, the evolving microstructural properties of the wall during the evolution process have been predicted.
Collapse
|
37
|
Etminan N, Dreier R, Buchholz BA, Beseoglu K, Bruckner P, Matzenauer C, Torner JC, Brown RD, Steiger HJ, Hänggi D, Macdonald RL. Age of collagen in intracranial saccular aneurysms. Stroke 2014; 45:1757-63. [PMID: 24781080 DOI: 10.1161/strokeaha.114.005461] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The chronological development and natural history of cerebral aneurysms (CAs) remain incompletely understood. We used (14)C birth dating of a main constituent of CAs, that is, collagen type I, as an indicator for biosynthesis and turnover of collagen in CAs in relation to human cerebral arteries to investigate this further. METHODS Forty-six ruptured and unruptured CA samples from 43 patients and 10 cadaveric human cerebral arteries were obtained. The age of collagen, extracted and purified from excised CAs, was estimated using (14)C birth dating and correlated with CA and patient characteristics, including the history of risk factors associated with atherosclerosis and potentially aneurysm growth and rupture. RESULTS Nearly all CA samples contained collagen type I, which was <5 years old, irrespective of patient age, aneurysm size, morphology, or rupture status. However, CAs from patients with a history of risk factors (smoking or hypertension) contained significantly younger collagen than CAs from patients with no risk factors (mean, 1.6±1.2 versus 3.9±3.3 years, respectively; P=0.012). CAs and cerebral arteries did not share a dominant structural protein, such as collagen type I, which would allow comparison of their collagen turnover. CONCLUSIONS The abundant amount of relatively young collagen type I in CAs suggests that there is an ongoing collagen remodeling in aneurysms, which is significantly more rapid in patients with risk factors. These findings challenge the concept that CAs are present for decades and that they undergo only sporadic episodes of structural change.
Collapse
Affiliation(s)
- Nima Etminan
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.).
| | - Rita Dreier
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Bruce A Buchholz
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Kerim Beseoglu
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Peter Bruckner
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Christian Matzenauer
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - James C Torner
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Robert D Brown
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Hans-Jakob Steiger
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - Daniel Hänggi
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| | - R Loch Macdonald
- From the Department of Neurosurgery (N.E., K.B., H.-J.S., D.H.) and Institute of Forensic Medicine (C.M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R.D., P.B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B.A.B.); Department of Epidemiology, University of Iowa (J.C.T.); Department of Neurology, Mayo Clinic, Rochester, MN (R.D.B.); Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (R.L.M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R.L.M.)
| |
Collapse
|
38
|
Yamada A, Unuma K, Kojima H, Uemura K. Subarachnoid hemorrhage caused by a traffic accident: De novo aneurysm ruptured 30 years after surgical neck clipping. J Forensic Leg Med 2014; 22:90-2. [DOI: 10.1016/j.jflm.2013.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/03/2013] [Accepted: 12/07/2013] [Indexed: 10/25/2022]
|
39
|
Balakhovsky K, Jabareen M, Volokh KY. Modeling rupture of growing aneurysms. J Biomech 2013; 47:653-8. [PMID: 24359675 DOI: 10.1016/j.jbiomech.2013.11.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 11/19/2013] [Accepted: 11/27/2013] [Indexed: 11/27/2022]
Abstract
Growth and rupture of aneurysms are driven by micro-structural alterations of the arterial wall yet precise mechanisms underlying the process remain to be uncovered. In the present work we examine a scenario when the aneurysm evolution is dominated by turnover of collagen fibers. In the latter case it is natural to hypothesize that rupture of individual fibers (or their bonds) causes the overall aneurysm rupture. We examine this hypothesis in computer simulations of growing aneurysms in which constitutive equations describe both collagen evolution and failure. Failure is enforced in constitutive equations by limiting strain energy that can be accumulated in a fiber. Within the proposed theoretical framework we find a range of parameters that lead to the aneurysm rupture. We conclude in a qualitative agreement with clinical observations that some aneurysms will rupture while others will not.
Collapse
Affiliation(s)
- K Balakhovsky
- Faculty of Civil and Environmental Engineering, Technion - I.I.T., Israel
| | - M Jabareen
- Faculty of Civil and Environmental Engineering, Technion - I.I.T., Israel
| | - K Y Volokh
- Faculty of Civil and Environmental Engineering, Technion - I.I.T., Israel; Department of Structural Engineering, Ben-Gurion University of the Negev, Israel.
| |
Collapse
|
40
|
Abstract
Abstract
The authors present 2 patients who underwent neuroendovascular procedures in syngo iFLOW produced that use the dynamic of fluid in several types of intracranial pathologies. As part of a combined CT/angiography suite, iFLOW offered the major advantage of immediate detection or exclusion of intracranial complication without patient transfer. The study of fluid dynamics constitutes a cornerstone for the evaluation of various intracranial vascular pathologies. These applications include the isolation of cerebral aneurysms by embolization and clipping, embolisation of malformations, as well the evaluation of vasooclussive diseases. The emergence of techniques such as syngo iFLOW, which give a comprehensive picture of angiography, constitute a element that can to contribute to the decision of conduct clinics. Siemens has developed a novel based system which is able to reconstruct in achieving angiography techniques colors define intracranial flow characteristics in a single image. With this technique, is possible to obtain a comprehensive picture of cerebral angiography.
Collapse
|
41
|
Etminan N, Buchholz BA, Dreier R, Bruckner P, Torner JC, Steiger HJ, Hänggi D, Macdonald RL. Cerebral aneurysms: formation, progression, and developmental chronology. Transl Stroke Res 2013; 5:167-73. [PMID: 24323717 DOI: 10.1007/s12975-013-0294-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 10/06/2013] [Accepted: 10/08/2013] [Indexed: 02/08/2023]
Abstract
The prevalence of unruptured intracranial aneurysms (UIAs) in the general population is up to 3%. Existing epidemiological data suggests that only a small fraction of UIAs progress towards rupture over the lifetime of an individual, but the surrogates for subsequent rupture and the natural history of UIAs are discussed very controversially at present. In case of rupture of an UIA, the case fatality is up to 50%, which therefore continues to stimulate interest in the pathogenesis of cerebral aneurysm formation and progression. Actual data on the chronological development of cerebral aneurysm has been especially difficult to obtain and, until recently, the existing knowledge in this respect is mainly derived from animal or mathematical models or short-term observational studies. Here, we review the current data on cerebral aneurysm formation and progression as well as a novel approach to investigate the developmental chronology of cerebral aneurysms.
Collapse
Affiliation(s)
- Nima Etminan
- Department of Neurosurgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Dusseldorf, Germany,
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Fluid structural analysis of human cerebral aneurysm using their own wall mechanical properties. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2013; 2013:293128. [PMID: 24151523 PMCID: PMC3789306 DOI: 10.1155/2013/293128] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/31/2013] [Accepted: 08/01/2013] [Indexed: 11/21/2022]
Abstract
Computational Structural Dynamics (CSD) simulations, Computational Fluid Dynamics (CFD) simulation, and Fluid Structure Interaction (FSI) simulations were carried out in an anatomically realistic model of a saccular cerebral aneurysm with the objective of quantifying the effects of type of simulation on principal fluid and solid mechanics results. Eight CSD simulations, one CFD simulation, and four FSI simulations were made. The results allowed the study of the influence of the type of material elements in the solid, the aneurism's wall thickness, and the type of simulation on the modeling of a human cerebral aneurysm. The simulations use their own wall mechanical properties of the aneurysm. The more complex simulation was the FSI simulation completely coupled with hyperelastic Mooney-Rivlin material, normal internal pressure, and normal variable thickness. The FSI simulation coupled in one direction using hyperelastic Mooney-Rivlin material, normal internal pressure, and normal variable thickness is the one that presents the most similar results with respect to the more complex FSI simulation, requiring one-fourth of the calculation time.
Collapse
|
43
|
Irie K, Anzai H, Kojima M, Honjo N, Ohta M, Hirose Y, Negoro M. Computational fluid dynamic analysis following recurrence of cerebral aneurysm after coil embolization. Asian J Neurosurg 2013; 7:109-15. [PMID: 23293665 PMCID: PMC3532756 DOI: 10.4103/1793-5482.103706] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Hemodynamic factors are thought to play important role in the initiation, growth, and rupture of cerebral aneurysms. However, hemodynamic features in the residual neck of incompletely occluded aneurysms and their influences on recanalization are rarely reported. This study characterized the hemodynamics of incompletely occluded aneurysms that had been confirmed to undergo recanalization during long-term follow-up using computational fluid dynamic analysis. A ruptured left basilar-SCA aneurysm was incompletely occluded and showed recanalization during 11 years follow-up period. We retrospectively characterized on three-dimensional MR angiography. After subtotal occlusion, the flow pattern, wall shear stress (WSS), and velocity at the remnant neck changed during long-term follow-up period. Specifically, high WSS region and high blood flow velocity were found near the neck. Interestingly, these area of the remnant neck coincided with the location of aneurysm recanalization. High WSS and blood flow velocity were consistently observed near the remnant neck of incompletely occluded aneurysm, prone to future recanalization. It will suggest that hemodynamic factors may play important roles in aneurismal recurrence after endovascular treatment.
Collapse
Affiliation(s)
- Keiko Irie
- Department of Neurosurgery, Fujita Health University, Toyoake city Aichi 470-1192, Japan
| | | | | | | | | | | | | |
Collapse
|
44
|
Li C, Wang S, Chen J, Yu H, Zhang Y, Jiang F, Mu S, Li H, Yang X. Influence of hemodynamics on recanalization of totally occluded intracranial aneurysms: a patient-specific computational fluid dynamic simulation study. J Neurosurg 2012; 117:276-83. [PMID: 22680247 DOI: 10.3171/2012.5.jns111558] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Some totally occluded intracranial aneurysms may recur. The role of hemodynamic mechanisms in this process remains to be elucidated. The authors used computational fluid dynamic analysis and investigated the local hemodynamic characteristics at the aneurysm neck before and after total embolization, attempting to identify hemodynamic risk factors leading to recurrence of totally embolized aneurysms.
Methods
Between May 2008 and June 2010, the authors recruited 17 consecutive patients with totally occluded intracranial aneurysms (7 recanalized and 10 stable lesions). Using patient-specific 3D digital subtraction angiography data, the hemodynamic features before and after embolization were retrospectively characterized.
Results
The overall preembolization blood flow patterns were nearly the same in the recanalized and stable groups, with no significant difference in either the maximum wall shear stress (WSS) (p = 0.914) or the spatially averaged WSS (p = 0.322) at peak systole at the aneurysm neck. After occlusion, the overall flow pattern changed, and the WSS distribution at the treated aneurysm neck differed in the 2 groups. In all of the 7 recanalized cases, both the maximum WSS and spatially averaged WSS at peak systole at the treated aneurysm neck were higher than those at the aneurysm neck before embolization. In contrast, both parameters were decreased in 70%–80% of the stable cases. After embolization, both the maximum WSS (p = 0.021) and spatially averaged WSS (p = 0.041) at peak systole at the treated aneurysm neck were higher in the recanalized group than in the stable group.
Conclusions
Higher WSS at the treated aneurysm neck after total embolization can be an important hemodynamic factor that contributes to aneurysm recurrence after endovascular treatment.
Collapse
Affiliation(s)
- Chuanhui Li
- 1Beijing Tiantan Hospital, Beijing Neurosurgical Institute, and
| | - Shengzhang Wang
- 3Department of Mechanics and Engineering Science, Fudan University, Shanghai; and
| | - Jialiang Chen
- 3Department of Mechanics and Engineering Science, Fudan University, Shanghai; and
| | - Hongyu Yu
- 2Department of Biomedical Engineering, Capital Medical University, Beijing
| | - Ying Zhang
- 1Beijing Tiantan Hospital, Beijing Neurosurgical Institute, and
| | - Fan Jiang
- 4Key Laboratory of Cardiovascular Remodeling and Function Research, Medical School and Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Shiqing Mu
- 1Beijing Tiantan Hospital, Beijing Neurosurgical Institute, and
| | - Haiyun Li
- 2Department of Biomedical Engineering, Capital Medical University, Beijing
| | - Xinjian Yang
- 1Beijing Tiantan Hospital, Beijing Neurosurgical Institute, and
| |
Collapse
|
45
|
Bottan S, Poulikakos D, Kurtcuoglu V. Phantom Model of Physiologic Intracranial Pressure and Cerebrospinal Fluid Dynamics. IEEE Trans Biomed Eng 2012; 59:1532-8. [DOI: 10.1109/tbme.2012.2187448] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
46
|
VALENCIA ALVARO, ROJO MAXIMILIANO, RIVERA RODRIGO, BRAVO EDUARDO. SENSITIVITY ANALYSIS OF COMPUTATIONAL STRUCTURAL DYNAMICS IN A CEREBRAL ANEURYSM MODEL TO WALL THICKNESS AND MODEL. J MECH MED BIOL 2012. [DOI: 10.1142/s0219519411004630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Intracranial saccular aneurysms tend to be thin walled and stiffer compared with a normal artery. The current work describes computational structural dynamics (CSD) in an anatomically realistic model of a cerebral aneurysm located in the ophthalmic region, using different wall thickness, model data for the artery and aneurysm, and geometry size. The model was obtained from three-dimensional rotational angiography image data. The wall was assumed three-dimensional hyperelastic solid with different thickness in the artery and in the aneurysm regions. The effects of carotid siphon length are reported. The CSD was solved with the finite elements package ADINA. The predictions of stress and strain on the aneurysm wall were compared.
Collapse
Affiliation(s)
- ALVARO VALENCIA
- Department of Mechanical Engineering, Universidad de Chile, Santiago, Chile
| | - MAXIMILIANO ROJO
- Department of Mechanical Engineering, Universidad de Chile, Santiago, Chile
| | - RODRIGO RIVERA
- Neuroradiology Department, Instituto de Neurocirugía Asenjo, Jose Manuel Infante 553, Santiago, Chile
| | - EDUARDO BRAVO
- Neuroradiology Department, Instituto de Neurocirugía Asenjo, Jose Manuel Infante 553, Santiago, Chile
| |
Collapse
|
47
|
Sforza DM, Putman CM, Cebral JR. Computational fluid dynamics in brain aneurysms. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2012; 28:801-808. [PMID: 25364852 PMCID: PMC4221804 DOI: 10.1002/cnm.1481] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 10/04/2011] [Accepted: 10/05/2011] [Indexed: 05/30/2023]
Abstract
Because of its ability to deal with any geometry, image-based computational fluid dynamics (CFD) has been progressively used to investigate the role of hemodynamics in the underlying mechanisms governing the natural history of cerebral aneurysms. Despite great progress in methodological developments and many studies using patient-specific data, there are still significant controversies about the precise governing processes and divergent conclusions from apparently contradictory results. Sorting out these issues requires a global vision of the state of the art and a unified approach to solving this important scientific problem. Towards this end, this paper reviews the contributions made using patient-specific CFD models to further the understanding of these mechanisms, and highlights the great potential of patient-specific computational models for clinical use in the assessment of aneurysm rupture risk and patient management.
Collapse
Affiliation(s)
- Daniel M Sforza
- Center for Computational Fluid Dynamics, School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, MSN 6A2, Fairfax, VA 22030, USA.
| | | | | |
Collapse
|
48
|
Schneiders JJ, Ferns SP, van Ooij P, Siebes M, Nederveen AJ, van den Berg R, van Lieshout J, Jansen G, vanBavel E, Majoie CB. Comparison of phase-contrast MR imaging and endovascular sonography for intracranial blood flow velocity measurements. AJNR Am J Neuroradiol 2012; 33:1786-90. [PMID: 22576898 DOI: 10.3174/ajnr.a3142] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Local hemodynamic information may help to stratify rupture risk of cerebral aneurysms. Patient-specific modeling of cerebral hemodynamics requires accurate data on BFV in perianeurysmal arteries as boundary conditions for CFD. The aim was to compare the BFV measured with PC-MR imaging with that obtained by using intra-arterial Doppler sonography and to determine interpatient variation in intracranial BFV. MATERIALS AND METHODS In 10 patients with unruptured intracranial aneurysms, BFV was measured in the cavernous ICA with PC-MR imaging in conscious patients before treatment, and measured by using an intra-arterial Doppler sonography wire when the patient was anesthetized with either propofol (6 patients) or sevoflurane (4 patients). RESULTS Both techniques identified a pulsatile blood flow pattern in cerebral arteries. PSV differed >50 cm/s between patients. A mean velocity of 41.3 cm/s (95% CI, 39.3-43.3) was measured with PC-MR imaging. With intra-arterial Doppler sonography, a mean velocity of 29.3 cm/s (95% CI, 25.8-32.8) was measured with the patient under propofol-based intravenous anesthesia. In patients under sevoflurane-based inhaled anesthesia, a mean velocity of 44.9 cm/s (95% CI, 40.6-49.3) was measured. CONCLUSIONS We showed large differences in BFV between patients, emphasizing the importance of using patient-specific hemodynamic boundary conditions in CFD. PC-MR imaging measurements of BFV in conscious patients were comparable with those obtained with the intra-arterial Doppler sonography when the patient was anesthetized with a sevoflurane-based inhaled anesthetic.
Collapse
Affiliation(s)
- J J Schneiders
- Department of Radiology, Academic Medical Center, University of Amsterdam, the Netherlands.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
NABAEI MALIKEH, FATOURAEE NASSER. COMPUTATIONAL MODELING OF FORMATION OF A CEREBRAL ANEURYSM UNDER THE INFLUENCE OF SMOOTH MUSCLE CELL RELAXATION. J MECH MED BIOL 2012. [DOI: 10.1142/s0219519411004599] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The mechanics of cerebral aneurysm pathogenesis, evolution and rupture are not yet well understood. This paper presents a numerical analysis of the formation of a saccular cerebral aneurysm in for the first time in a 3D model of the basilar artery bifurcation under normal and hypertensive blood pressure. Due to the excessive endothelium derived nitric oxide produced in high wall shear stress, we assumed that smooth muscle cell relaxation is the origin of the aneurysm formation. Arterial wall remodeling under constant tension was considered to be the other mechanism of disease evolution. The wall was constructed from two elastic and hyperelastic isotropic regions. The flow was considered steady, laminar, Newtonian, and incompressible. The fully coupled fluid and structure models were solved with the finite elements package ADINA 8.5. The wall shear stress, effective stress and deformation distributions under normal and hypertensive blood pressure were compared to a healthy bifurcation. The model shows that although the malfunction of the endothelial cell layer and the corresponding smooth muscle cell-related loss of vascular tone is important to the inception of the disease; A saccular aneurysm may not be formed by this mechanism alone, and also requires the fiber-related arterial wall remodeling for further development.
Collapse
Affiliation(s)
- MALIKEH NABAEI
- Student of Biomedical Engineering-Biomechanics, Amirkabir University of Technology, Biological Fluid Mechanics Research Laboratory, Tehran 15914, Iran
| | - NASSER FATOURAEE
- Faculty of Biomedical, Engineering, Amirkabir University of Technology, Biological Fluid Mechanics Research Laboratory, Tehran 15914, Iran
| |
Collapse
|
50
|
Hemodynamics of cerebral aneurysms: computational analyses of aneurysm progress and treatment. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2012; 2012:782801. [PMID: 22454695 PMCID: PMC3290806 DOI: 10.1155/2012/782801] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 11/10/2011] [Indexed: 12/02/2022]
Abstract
The progression of a cerebral aneurysm involves degenerative arterial wall remodeling. Various hemodynamic parameters are suspected to be major mechanical factors related to the genesis and progression of vascular diseases. Flow alterations caused by the insertion of coils and stents for interventional aneurysm treatment may affect the aneurysm embolization process. Therefore, knowledge of hemodynamic parameters may provide physicians with an advanced understanding of aneurysm progression and rupture, as well as the effectiveness of endovascular treatments. Progress in medical imaging and information technology has enabled the prediction of flow fields in the patient-specific blood vessels using computational analysis. In this paper, recent computational hemodynamic studies on cerebral aneurysm initiation, progress, and rupture are reviewed. State-of-the-art computational aneurysmal flow analyses after coiling and stenting are also summarized. We expect the computational analysis of hemodynamics in cerebral aneurysms to provide valuable information for planning and follow-up decisions for treatment.
Collapse
|