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Perinajová R, van Ooij P, Kenjereš S. On the identification of hypoxic regions in subject-specific cerebral vasculature by combined CFD/MRI. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220645. [PMID: 36636311 PMCID: PMC9810418 DOI: 10.1098/rsos.220645] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/30/2022] [Indexed: 05/22/2023]
Abstract
A long-time exposure to lack of oxygen (hypoxia) in some regions of the cerebrovascular system is believed to be one of the causes of cerebral neurological diseases. In the present study, we show how a combination of magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) can provide a non-invasive alternative for studying blood flow and transport of oxygen within the cerebral vasculature. We perform computer simulations of oxygen mass transfer in the subject-specific geometry of the circle of Willis. The computational domain and boundary conditions are based on four-dimensional (4D)-flow MRI measurements. Two different oxygen mass transfer models are considered: passive (where oxygen is treated as a dilute chemical species in plasma) and active (where oxygen is bonded to haemoglobin) models. We show that neglecting haemoglobin transport results in a significant underestimation of the arterial wall mass transfer of oxygen. We identified the hypoxic regions along the arterial walls by introducing the critical thresholds that are obtained by comparison of the estimated range of Damköhler number (Da ⊂ 〈9; 57〉) with the local Sherwood number. Finally, we recommend additional validations of the combined MRI/CFD approach proposed here for larger groups of subject- or patient-specific brain vasculature systems.
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Affiliation(s)
- Romana Perinajová
- Department of Chemical Engineering, Delft University of Technology, Faculty of Applied Sciences, 2628 CD Delft, The Netherlands
- J.M. Burgerscentrum Research School for Fluid Mechanics, 2628 CD Delft, The Netherlands
| | - Pim van Ooij
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Location AMC, 1007 MB Amsterdam, The Netherlands
| | - Saša Kenjereš
- Department of Chemical Engineering, Delft University of Technology, Faculty of Applied Sciences, 2628 CD Delft, The Netherlands
- J.M. Burgerscentrum Research School for Fluid Mechanics, 2628 CD Delft, The Netherlands
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Prashantha B, Anish S. Computational investigations on the hemodynamic performance of a new swirl generator in bifurcated arteries. Comput Methods Biomech Biomed Engin 2019; 22:364-375. [DOI: 10.1080/10255842.2018.1556974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- B. Prashantha
- Department of Mechanical Engineering, M S Ramaiah Institute of Technology, Bengaluru, Karnataka, India
| | - S. Anish
- Advanced Fluid Mechanics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Surathkal, Karnataka, India
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Li Z, Yan F, Yang J, Chen Y, Xu Z, Jiang W, Yuan D. Hemodynamics and Oxygen Transport through Pararenal Aortic Aneurysm Treated with Multilayer Stent: A Numerical Study. Ann Vasc Surg 2018; 54:290-297. [PMID: 30081175 DOI: 10.1016/j.avsg.2018.05.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/14/2018] [Accepted: 05/28/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND As opposed to an endoluminal stent graft, a multilayer stent (MS) consists of a porous mesh, which allows for the possibility of treating pararenal aortic aneurysms (PRAAs) that involve a significant branch vessel. However, the choice of the density of the MS plays a vital role in isolating the aneurysm and allowing unobstructed blood flow in the branch vessel. METHOD In the present study, we examined 3 cases (without a stent and with single-layer and double-layer stents) via numerical simulations to explore the feasibility of the MSs used in the treatment of such aneurysms and estimate whether there is a more appropriate or optimal stent density. RESULTS With stent intervention, the velocity of blood flow in the sac decreased, but the pressure on the surface of the aneurysm did not decrease although it became more uniform. In addition, the "region of double low" (with low wall shear stress and a low Sherwood number) enlarged after stent implantation. Even with the double-layer stent, however, the flux of the branch vessel was still above normal, and we could predict that the optimal stent porosity was approximately 49.9%. CONCLUSIONS Unlike in previous studies, an MS could not be feasibly applied to high-risk PRAAs. However, an MS can induce sac thrombosis in the later stages while maintaining visceral vessel patency, and our results suggest that the optimal stent may be a 4-layer stent.
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Affiliation(s)
- Zhongyou Li
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Fei Yan
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Jingru Yang
- School of Manufacturing Science & Engineering, Sichuan University, Chengdu, China
| | - Yu Chen
- Department of Applied Mechanics, Sichuan University, Chengdu, China.
| | - Zhizhi Xu
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Wentao Jiang
- Department of Applied Mechanics, Sichuan University, Chengdu, China.
| | - Ding Yuan
- Department of Vascular Surgery of West China Hospital, Sichuan University, Chengdu, China
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4
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Chen Y, Deng X, Shan X, Xing Y. Study of helical flow inducers with different thread pitches and diameters in vena cava. PLoS One 2018; 13:e0190609. [PMID: 29298357 PMCID: PMC5752007 DOI: 10.1371/journal.pone.0190609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/18/2017] [Indexed: 11/25/2022] Open
Abstract
Pulmonary embolism is a severe, potentially life-threatening condition. Inferior vena cava filters have been used to prevent recurrent pulmonary embolisms. However, the build-up of thrombosis in vena cava filters after deployment presents a severe problem to patients. Previous studies proposed that filters with helical flow are beneficial and capable of alleviating this problem. In this study, the hemodynamic performances of four typical helical flow inducers in the vena cava are determined using computational fluid dynamics simulations (steady-state and pulsatile flow) and compared. Pilot in vitro experiments were also conducted. The simulation results demonstrate that large-diameter inducers produce helical flow. Among inducers with identical diameter, those with a smaller thread pitch are more likely to induce increased helical flow. We also observed that the small thread pitch inducers can yield higher shear rates. Furthermore, a large diameter, small thread pitch helical flow inducer increases the time-averaged wall shear stress and reduces the oscillating shear index and relative residence time on the vessel wall in the vicinity of the helical flow inducer. In vitro experiments also verify that large diameter inducers generate a helical flow. A notable observation of this study is that the diameter is the key parameter that affects the induction of a helical flow. This study will likely provide important guidance for the design of interventional treatments and the deployment of filters associated with helical flow in the vena cava.
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Affiliation(s)
- Ying Chen
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
- * E-mail:
| | - Xinying Shan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
| | - Yubin Xing
- Department of Infection Management and Disease Control, The General Hospital of People’s Liberation Army, Beijing, China
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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.
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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
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6
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Bioinspired helical graft with taper to enhance helical flow. J Biomech 2016; 49:3643-3650. [DOI: 10.1016/j.jbiomech.2016.09.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 09/09/2016] [Accepted: 09/19/2016] [Indexed: 11/23/2022]
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Hansen KL, Møller-Sørensen H, Kjaergaard J, Jensen MB, Lund JT, Pedersen MM, Lange T, Jensen JA, Nielsen MB. Analysis of Systolic Backflow and Secondary Helical Blood Flow in the Ascending Aorta Using Vector Flow Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:899-908. [PMID: 26774468 DOI: 10.1016/j.ultrasmedbio.2015.11.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/14/2015] [Accepted: 11/24/2015] [Indexed: 06/05/2023]
Abstract
Secondary rotational flow and systolic backflow are seen in the ascending aorta and, in this study, were analyzed with the vector velocity method transverse oscillation. Twenty-five patients were scanned intra-operatively, and the vector velocities were related to estimates of transesophageal echocardiography and pulmonary artery catheter thermodilution, and associated with gender, age, aortic diameter, atherosclerotic plaques, left ventricular ejection fraction and previous myocardial infarctions. Secondary flow was present for all patients. The duration and rotational frequency (p < 0.001) and the duration and flow direction of the secondary flow (p < 0.002) were associated. Systolic backflow was present in 40% of the patients and associated with systolic velocities (p < 0.002) and the presence of atherosclerotic plaques (p < 0.001). No other significant associations were observed. The study indicates that backflow is injurious and that secondary flow is a normal flow phenomenon. The study also shows that transverse oscillation can provide new information on blood flow in the ascending aorta.
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Affiliation(s)
| | - Hasse Møller-Sørensen
- Cardiothoracic Anesthesiology Department, Rigshospitalet, Blegdamsvej, Copenhagen, Denmark
| | - Jesper Kjaergaard
- Cardiology Department, Rigshospitalet, Blegdamsvej, Copenhagen, Denmark
| | - Maiken Brit Jensen
- Cardiothoracic Anesthesiology Department, Rigshospitalet, Blegdamsvej, Copenhagen, Denmark
| | - Jens Teglgaard Lund
- Cardiothoracic Surgery Department, Rigshospitalet, Blegdamsvej, Copenhagen, Denmark
| | | | - Theis Lange
- Biostatistic Department, University of Copenhagen, Øster Farimagsgade, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, DTU Elektro, Technical University of Denmark, Lyngby, Denmark
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Physiological Significance of Helical Flow in the Arterial System and its Potential Clinical Applications. Ann Biomed Eng 2014; 43:3-15. [DOI: 10.1007/s10439-014-1097-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/16/2014] [Indexed: 01/12/2023]
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9
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Lee CH, Liu KS, Jhong GH, Liu SJ, Hsu MY, Wang CJ, Hung KC. Finite element analysis of helical flows in human aortic arch: a novel index. BIOMICROFLUIDICS 2014; 8:024111. [PMID: 24803960 PMCID: PMC4000403 DOI: 10.1063/1.4871037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
This study investigates the helical secondary flows in the aortic arch using finite element analysis. The relationship between helical flow and the configuration of the aorta in patients of whose three-dimensional images constructed from computed tomography scans was examined. A finite element model of the pressurized root, arch, and supra-aortic vessels was developed to simulate the pattern of helical secondary flows. Calculations indicate that most of the helical secondary flow was formed in the ascending aorta. Angle α between the zero reference point and the aortic ostium (correlation coefficient (r) = -0.851, P = 0.001), the dispersion index of the cross section of the ascending (r = 0.683, P = 0.021) and descending aorta (r = 0.732, P = 0.010), all correlated closely with the presence of helical flow (P < 0.05). Stepwise multiple linear regression analysis confirmed angel α to be independently associated with the helical flow pattern in therein (standardized coefficients = -0.721, P = 0.023). The presence of helical fluid motion based on the atherosclerotic risks of patients, including those associated with diabetes, hypertension, hyperlipidemia, or renal insufficiency, was also evaluated. Numerical simulation of the flow patterns in aortas incorporating the atherosclerotic risks may better explain the mechanism of formation of helical flows and provide insight into causative factors that underlie them.
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Affiliation(s)
- Cheng-Hung Lee
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan ; Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan
| | - Kuo-Sheng Liu
- Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan ; Department of Cardiovascular Surgery, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan
| | - Guan-Heng Jhong
- Graduate Institute of Medical Mechatronics, Chang Gung University, Tao-Yuan, Taiwan
| | - Shih-Jung Liu
- Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan
| | - Ming-Yi Hsu
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan
| | - Chao-Jan Wang
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan
| | - Kuo-Chun Hung
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan
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Chiastra C, Morlacchi S, Gallo D, Morbiducci U, Cárdenes R, Larrabide I, Migliavacca F. Computational fluid dynamic simulations of image-based stented coronary bifurcation models. J R Soc Interface 2013; 10:20130193. [PMID: 23676893 DOI: 10.1098/rsif.2013.0193] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
One of the relevant phenomenon associated with in-stent restenosis in coronary arteries is an altered haemodynamics in the stented region. Computational fluid dynamics (CFD) offers the possibility to investigate the haemodynamics at a level of detail not always accessible within experimental techniques. CFD can quantify and correlate the local haemodynamics structures which might lead to in-stent restenosis. The aim of this work is to study the fluid dynamics of realistic stented coronary artery models which replicate the complete clinical procedure of stent implantation. Two cases of pathologic left anterior descending coronary arteries with their bifurcations are reconstructed from computed tomography angiography and conventional coronary angiography images. Results of wall shear stress and relative residence time show that the wall regions more prone to the risk of restenosis are located next to stent struts, to the bifurcations and to the stent overlapping zone for both investigated cases. Considering a bulk flow analysis, helical flow structures are generated by the curvature of the zone upstream from the stent and by the bifurcation regions. Helical recirculating microstructures are also visible downstream from the stent struts. This study demonstrates the feasibility to virtually investigate the haemodynamics of patient-specific coronary bifurcation geometries.
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Affiliation(s)
- Claudio Chiastra
- Chemistry, Materials and Chemical Engineering Department, Politecnico di Milano, Milan, Italy.
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