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Xiao M, Wu J, Chen D, Wang C, Wu Y, Sun T, Chen J. Ascending Aortic Volume: A Feasible Indicator for Ascending Aortic Aneurysm Elective Surgery? Acta Biomater 2023:S1742-7061(23)00353-7. [PMID: 37356784 DOI: 10.1016/j.actbio.2023.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
Diameter-based criterion have been widely adopted for preventive surgery of ascending thoracic aortic aneurysm (ATAA). However, recent and growing evidence has shown that diameter-based methods may not be sufficient for identifying patients who are at risk of an ATAA. In this study, fluid-structure interaction (FSI) analysis was performed on one-hundred ATAA geometries reconstructed from clinical data to examine the relationship between hemodynamic conditions, ascending aortic volume (AAV), ascending aortic curvature, and aortic ratios measured from the reconstructed 3D models. The simulated hemodynamic and biomechanical parameters were compared among different groups of ATAA geometries classified based on AAV. The ATAAs with enlarged AAV showed significantly compromised hemodynamic conditions and higher mechanical wall stress. The maximum oscillatory shear index (OSI), particle residence time (PRT) and wall stress (WS) were significantly higher in enlarged ATAAs compared with controls (0.498 [0.497, 0.499] vs 0.499 [0.498, 0.499], p = 0.002, 312.847 [207.445, 519.391] vs 996.047 [640.644, 1573.140], p < 0.001, 769.680 [668.745, 879.795] vs 1072.000 [873.060, 1280.000] kPa, p < 0.001, respectively). Values were reported as median with interquartile range (IQR). AAV was also found to be more strongly correlated with these parameters compared to maximum diameter. The correlation coefficient between AAV and average WS was as high as 0.92 (p < 0.004), suggesting that AAV might be a feasible risk identifier for ATAAs. STATEMENT OF SIGNIFICANCE: Ascending thoracic aortic aneurysm is associated with the risk of dissection or rupture, creating life-threatening conditions. Current surgical intervention guidelines are purely diameter based. Recently, many studies proposed to incorporate other morphological parameters into the current clinical guidelines to better prevent severe adverse aortic events like rupture or dissection. The purpose of this study is to gain a better understanding of the relationship between morphological parameters and hemodynamic parameters in ascending aortic aneurysms using fluid-solid-interaction analysis on patient-specific geometries. Our results suggest that ascending aortic volume may be a better indicator for surgical intervention as it shows a stronger association with pathogenic hemodynamic conditions.
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Affiliation(s)
- Meng Xiao
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000.; Department of Electrical and Computer Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, T6G 2R3..
| | - Jinlin Wu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Duanduan Chen
- Department of Biomedical Engineering, Beijing Institute of Technology, No. 5, South Street, Zhongguancun, Beijing, China..
| | - Chenghu Wang
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Yanfen Wu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Tucheng Sun
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Jie Chen
- Department of Electrical and Computer Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, T6G 2R3..
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Peng C, Liu J, He W, Qin W, Yuan T, Kan Y, Wang K, Wang S, Shi Y. Numerical simulation in the abdominal aorta and the visceral arteries with or without stenosis based on 2D PCMRI. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3569. [PMID: 34967124 DOI: 10.1002/cnm.3569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/10/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
It is important to obtain accurate boundary conditions (BCs) in hemodynamic simulations. This article aimed to improve the accuracy of BCs in computational fluid dynamics (CFD) simulation and analyze the differences in hemodynamics between healthy volunteers and patients with visceral arterial stenosis (VAS). The geometric models of seven cases were reconstructed using the magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging data. The physiological flow waveforms obtained from 2D Phase Contrast Magnetic Resonance Imaging (PCMRI) were imposed on the aortic inlet and the visceral arteries' outlets. The individualized RCR values of the three-element Windkessel model were imposed on the aortic outlet. CFD simulations were run in the open-source software: svSolver. Two specific time points were selected to compare the hemodynamics of healthy volunteers and patients with VAS. The results suggested that blood in the stenotic visceral arteries flowed at high speed throughout the cardiac cycle. The low pressure is distributed at stenotic lesions. The wall shear stress (WSS) reached 4 Pa near stenotic locations. The low time average wall shear stress (TAWSS), high oscillatory shear index (OSI), and high relative residence time (RRT) concentrated in the abdominal aorta. Besides, the ratios of the areas with low TAWSS, high OSI, and high RRT to the computational domain were higher in patients with VAS than which in the healthy volunteers. The individualized BCs were used for hemodynamic simulations and results suggest that patients with stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta.
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Affiliation(s)
- Chen Peng
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
| | - Junzhen Liu
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wei He
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wang Qin
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
| | - Tong Yuan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuanqing Kan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Keqiang Wang
- Institute of Panvascular Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shengzhang Wang
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
- Institute of Biomedical Engineering Technology, Academy for Engineering and Technology, Fudan University, Shanghai, China
| | - Yun Shi
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
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Pillalamarri NR, Piskin S, Patnaik SS, Murali S, Finol EA. Patient-Specific Computational Analysis of Hemodynamics in Adult Pulmonary Hypertension. Ann Biomed Eng 2021; 49:3465-3480. [PMID: 34799807 DOI: 10.1007/s10439-021-02884-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/29/2021] [Indexed: 11/25/2022]
Abstract
Pulmonary hypertension (PH) is a progressive disease characterized by elevated pressure and vascular resistance in the pulmonary arteries. Nearly 250,000 hospitalizations occur annually in the US with PH as the primary or secondary condition. A definitive diagnosis of PH requires right heart catheterization (RHC) in addition to a chest computed tomography, a walking test, and others. While RHC is the gold standard for diagnosing PH, it is invasive and posseses inherent risks and contraindications. In this work, we characterized the patient-specific pulmonary hemodynamics in silico for diverse PH WHO groups. We grouped patients on the basis of mean pulmonary arterial pressure (mPAP) into three disease severity groups: at-risk ([Formula: see text], denoted with A), mild ([Formula: see text], denoted with M), and severe ([Formula: see text], denoted with S). The pulsatile flow hemodynamics was simulated by evaluating the three-dimensional Navier-Stokes system of equations using a flow solver developed by customizing OpenFOAM libraries (v5.0, The OpenFOAM Foundation). Quasi patient-specific boundary conditions were implemented using a Womersley inlet velocity profile and transient resistance outflow conditions. Hemodynamic indices such as spatially averaged wall shear stress ([Formula: see text]), wall shear stress gradient ([Formula: see text]), time-averaged wall shear stress ([Formula: see text]), oscillatory shear index ([Formula: see text]), and relative residence time ([Formula: see text]), were evaluated along with the clinical metrics pulmonary vascular resistance ([Formula: see text]), stroke volume ([Formula: see text]) and compliance ([Formula: see text]), to assess possible spatiotemporal correlations. We observed statistically significant decreases in [Formula: see text], [Formula: see text], and [Formula: see text], and increases in [Formula: see text] and [Formula: see text] with disease severity. [Formula: see text] was moderately correlated with [Formula: see text] and [Formula: see text] at the mid-notch stage of the cardiac cycle when these indices were computed using the global pulmonary arterial geometry. These results are promising in the context of a long-term goal of identifying computational biomarkers that can serve as surrogates for invasive diagnostic protocols of PH.
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Affiliation(s)
- Narasimha R Pillalamarri
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Senol Piskin
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
- Department of Mechanical Engineering, Istinye University, Istanbul, Turkey
| | - Sourav S Patnaik
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Srinivas Murali
- Division of Cardiovascular Medicine, Allegheny Health Network, Pittsburgh, PA, USA
| | - Ender A Finol
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
- UTSA/UTHSA Joint Graduate Program in Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.
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Jamaleddin Mousavi S, Jayendiran R, Farzaneh S, Campisi S, Viallon M, Croisille P, Avril S. Coupling hemodynamics with mechanobiology in patient-specific computational models of ascending thoracic aortic aneurysms. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 205:106107. [PMID: 33933713 DOI: 10.1016/j.cmpb.2021.106107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND OBJECTIVE The prevention of ascending thoracic aortic aneurysms (ATAAs), which affect thousands of persons every year worldwide, remains a major issue. ATAAs may be caused by anything that weakens the aortic wall. Altered hemodynamics, which concerns a majority of patients with bicuspid aortic valves, has been shown to be related to such weakening and to contribute to ATAA development and progression. However the underlying mechanisms remain unclear and computational modeling in this field could help significantly to elucidate how hemodynamics and mechanobiology interact in ATAAs. METHODS Accordingly, we propose a numerical framework combining computational fluid dynamics and 4D flow magnetic resonance imaging (MRI) coupled with finite element (FE) analyses to simulate growth and remodeling (G&R) occurring in patient-specific aortas in relation with altered hemodynamics. The geometries and the blood velocities obtained from 4D flow MRI are used as boundary conditions for CFD simulations. CFD simulations provide an estimation of the wall shear stress (WSS) and relative residence time (RRT) distribution across the luminal surface of the wall. An initial insult is then applied to the FE model of the aortic wall, assuming that the magnitude of the insult correlates spatially with the normalized RRT distribution obtained from CFD simulations. G&R simulations are then performed. The material behavior of each Gauss point in these FE models is evolved continuously to compensate for the deviation of the actual wall stress distribution from the homeostatic state after the initial insult. The whole approach is illustrated on two healthy and two diseased subjects. The G&R parameters are calibrated against previously established statistical models of ATAA growth rates. RESULTS Among the variety of results provided by G&R simulations, the analysis focused especially on the evolution of the wall stiffness, which was shown to be a major risk factor for ATAAs. It was shown that the G&R parameters, such as for instance the rate of collagen production or cell mechanosensitivity, play a critical role in ATAA progression and remodeling. CONCLUSIONS These preliminary findings show that patient-specific computational modeling coupling hemodynamics with mechanobiology is a promising approach to explore aneurysm progression.
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Affiliation(s)
- S Jamaleddin Mousavi
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne F - 42023 France
| | - Raja Jayendiran
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne F - 42023 France
| | - Solmaz Farzaneh
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne F - 42023 France
| | - Salvatore Campisi
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne F - 42023 France; University Hospital of Saint-Étienne, Department of Cardiovascular Surgery, Saint-Étienne cedex, France
| | - Magalie Viallon
- Université de Lyon, UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne,F-42023 France; University Hospital of Saint-Étienne, Department of Radiology, Saint-Étienne, France
| | - Pierre Croisille
- Université de Lyon, UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne,F-42023 France; University Hospital of Saint-Étienne, Department of Radiology, Saint-Étienne, France
| | - Stéphane Avril
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne F - 42023 France.
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Bailoor S, Seo JH, Dasi LP, Schena S, Mittal R. A computational study of the hemodynamics of bioprosthetic aortic valves with reduced leaflet motion. J Biomech 2021; 120:110350. [PMID: 33743394 DOI: 10.1016/j.jbiomech.2021.110350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 02/22/2021] [Indexed: 01/25/2023]
Abstract
We employ a reduced degree-of-freedom aortic valve model to investigate the flow physics associated with early-stage reduced leaflet motion in bioprosthetic aortic valves. The model is coupled with a sharp-interface immersed boundary based incompressible flow solver to efficiently simulate the fluid-structure interaction. A total of 19 cases of flow through aortic valves with varying degrees of reduced leaflet motion (RLM) are considered. The characteristics of the aortic jet and the consequent aorta wall loading patterns are analyzed. Our results show that asymmetric RLM tilts the aortic jet and leads to large reverse and recirculating flow regions downstream from leaflets with restricted mobility. The changes in flow patterns increase wall pressure and shear stress fluctuations, and result in asymmetric oscillating shear on the aorta wall. These findings have implications for auscultation based diagnosis of this condition as well as the health of the aorta.
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Gutierrez MA. Computational Analysis of Fluid Dynamics in the Transcatheter Aortic Valve Replacement. Arq Bras Cardiol 2020; 115:688-689. [PMID: 33111870 PMCID: PMC8386972 DOI: 10.36660/abc.20201002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Marco A Gutierrez
- Instituto do Coração (InCor), Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP - Brasil
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7
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Hemodynamics alteration in patient-specific dilated ascending thoracic aortas with tricuspid and bicuspid aortic valves. J Biomech 2020; 110:109954. [DOI: 10.1016/j.jbiomech.2020.109954] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 01/03/2023]
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8
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Jayendiran R, Condemi F, Campisi S, Viallon M, Croisille P, Avril S. Computational prediction of hemodynamical and biomechanical alterations induced by aneurysm dilatation in patient-specific ascending thoracic aortas. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3326. [PMID: 32087044 DOI: 10.1002/cnm.3326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
The aim of the present work is to propose a robust computational framework combining computational fluid dynamics (CFD) and 4D flow MRI to predict the progressive changes in hemodynamics and wall rupture index (RPI) induced by aortic morphological evolutions in patients harboring ascending thoracic aortic aneurysms (ATAAs). An analytical equation has been proposed to predict the aneurysm progression based on age, sex, and body surface area. Parameters such as helicity, wall shear stress (WSS), time-averaged WSS, oscillatory shear index, relative residence time, and viscosity were evaluated for two patients at different stages of aneurysm growth, and compared with age-sex-matched healthy subjects. The study shows that evolution of hemodynamics and RPI, despite being very slow in ATAAs, is strongly affected by morphological alterations and, in turn could impact biomechanical factors and aortic mechanobiology. An aspect of the current work is that the patient-specific 4D MRI data sets were obtained with a follow-up of 1 year and the measured time-averaged velocity maps and flow eccentricity were compared with the CFD simulation for validation. The computational framework presented here is capable of capturing the blood flow patterns and the hemodynamic descriptors during the various stages of aneurysm growth. Further investigations will be conducted in order to verify these results on a larger cohort of patients and with long follow-up times to finally elucidate the link between deranged hemodynamics, AA geometry, and wall mechanical properties in ATAAs.
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Affiliation(s)
- Raja Jayendiran
- Mines Saint-Etienne, Université de Lyon, INSERM, U1059, SAINBIOSE, Saint-Etienne F-42023, France
| | | | - Salvatore Campisi
- Department of Cardiovascular Surgery, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Magalie Viallon
- UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Université de Lyon, Saint-Etienne, France
- Department of Radiology, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Pierre Croisille
- UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Université de Lyon, Saint-Etienne, France
- Department of Radiology, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Stéphane Avril
- Mines Saint-Etienne, Université de Lyon, INSERM, U1059, SAINBIOSE, Saint-Etienne F-42023, France
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LIU MING, SUN ANQIANG, DENG XIAOYAN. HEMODYNAMIC EFFECT OF OBSTRUCTION TO RENAL ARTERIES CAUSED BY STENT GRAFTS IN PATIENTS WITH ABDOMINAL AORTIC ANEURYSMS. J MECH MED BIOL 2018. [DOI: 10.1142/s0219519418400146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To investigate the hemodynamic effects of partial obstruction to the renal orifice caused by inappropriate stent-graft location. Pre-operative and deployment models of a stent graft with various degrees of obstruction to the renal orifice are constructed based on medical images of abdominal aortic aneurysm. Hemodynamics, including flow pattern, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), as well as relative residence time (RRT) are analyzed using numerical simulations. Flow rate distributions are assessed and verified by in vitro experiments. Results show that partial blockage to the renal branch orifice leads to flow recirculation and vortices with low wall shear stress around the renal ostia, whereas OSI and RRT on the renal arteries increase with the degree of obstruction. While the in vitro experiment indicates a decreasing flow rate to the bilateral renal arteries as renal artery ostia are obstructed. In conclusion, obstruction to the renal arteries induced by an inappropriate stent graft location causes stenosis in the renal artery in the long term. This study reveals a possible pathological mechanism of renal complications due to the implantation of a stent graft.
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Affiliation(s)
- MING LIU
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - ANQIANG SUN
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100083, P. R. China
- Beijing Advanced Innovation, Centre for Biomedical Engineering, Beihang University, Beijing 100083, P. R. China
| | - XIAOYAN DENG
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100083, P. R. China
- Beijing Advanced Innovation, Centre for Biomedical Engineering, Beihang University, Beijing 100083, P. R. China
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Numerical simulations of the pulsatile blood flow in the different types of arterial fenestrations: Comparable analysis of multiple vascular geometries. Biocybern Biomed Eng 2018. [DOI: 10.1016/j.bbe.2018.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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11
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Papadopoulos KP, Gerotziafas GT, Gavaises M. Modelling of thrombin generation under flow in realistic left anterior descending geometries. Med Eng Phys 2017; 50:50-58. [PMID: 29050805 DOI: 10.1016/j.medengphy.2017.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 08/11/2017] [Accepted: 10/01/2017] [Indexed: 01/25/2023]
Abstract
Currently there are no available methods for prediction of thrombotic complications in Coronary Artery disease. Additionally, blood coagulation tests are mainly performed in a steady system while coagulation in vivo occurs under flow conditions. In this work, a phenomenological model for coagulation up-to thrombin generation is proposed; the model is mainly based on the results of thrombin generation assays and therefore it can account for the variation of the coagulability that is observed in different individuals. The model is applied on 3 cases of left anterior descending arteries (LAD) with 50% maximum stenosis placed at a different location and have been statistically assessed as of different complication risk. The simulations showed that parameters of thrombin generation assays obtain different values when they refer to thrombin generation under realistic coronary flow conditions. The flow conditions prevailing locally because of the geometric differences among the arterial trees can lead to different initiation times and thrombin production rates and it also alters the spatial distribution of the coagulation products. Similarly, small changes of the coagulation characteristics of blood under identical flow conditions can allow or prevent the initiation of coagulation. The results indicate that combined consideration of geometry and coagulation characteristics of blood can lead to entirely different conclusions compared to independent assessment of each factor.
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Affiliation(s)
| | | | - Manolis Gavaises
- City University London, Northampton Square, Clerkenwell, London EC1V 0HB, UK
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12
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Chen Z, Yu H, Shi Y, Zhu M, Wang Y, Hu X, Zhang Y, Chang Y, Xu M, Gao W. Vascular Remodelling Relates to an Elevated Oscillatory Shear Index and Relative Residence Time in Spontaneously Hypertensive Rats. Sci Rep 2017; 7:2007. [PMID: 28515420 PMCID: PMC5435712 DOI: 10.1038/s41598-017-01906-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 04/03/2017] [Indexed: 01/25/2023] Open
Abstract
Haemodynamic disorders are common clinical findings in hypertension and lead to adverse cardiovascular events. However, the haemodynamic conditions in hypertension models are poorly understood. This study aimed to observe the characteristics of haemodynamics in spontaneously hypertensive rats (SHRs) and antihypertensive-treated SHRs. Twenty-four adult male SHRs and Wistar-Kyoto rats (WKYs) were randomly divided into four groups and treated for 7 days as follows: WKY-CON (WKYs + saline), WKY-NIF (WKYs + nifedipine, 50 mg/kg/day), SHR-CON (SHRs + saline), and SHR-NIF (SHRs + nifedipine). Aortic computational fluid dynamics (CFD) models were simulated to obtain the haemodynamic parameters. We found that in the hypertensive (SHR-CON) and blood pressure-controlled (SHR-NIF) groups, the oscillatory shear index (OSI) and relative residence time (RRT), which are key haemodynamics indices, were markedly elevated. Furthermore, there was a correlation between both the elevated OSI and RRT with the vascular wall thickening in regions near the inner wall of the aortic arch. Our research demonstrates that haemodynamics remains disturbed even if the blood pressure is normalized. In addition, vascular remodelling may play an important role in maintaining elevated OSI and RRT values.
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Affiliation(s)
- Zhiyan Chen
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China
| | - Haiyi Yu
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China
| | - Yue Shi
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Minjia Zhu
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Yueshen Wang
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China
| | - Xi Hu
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China
| | - Youyi Zhang
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China
| | - Yu Chang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China.
| | - Ming Xu
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China.
| | - Wei Gao
- Department of Cardiology, Peking University Third Hospital and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China.
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