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Cunnane EM, Weinbaum JS, O'Brien FJ, Vorp DA. Future Perspectives on the Role of Stem Cells and Extracellular Vesicles in Vascular Tissue Regeneration. Front Cardiovasc Med 2018; 5:86. [PMID: 30018970 PMCID: PMC6037696 DOI: 10.3389/fcvm.2018.00086] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/13/2018] [Indexed: 02/06/2023] Open
Abstract
Vascular tissue engineering is an area of regenerative medicine that attempts to create functional replacement tissue for defective segments of the vascular network. One approach to vascular tissue engineering utilizes seeding of biodegradable tubular scaffolds with stem (and/or progenitor) cells wherein the seeded cells initiate scaffold remodeling and prevent thrombosis through paracrine signaling to endogenous cells. Stem cells have received an abundance of attention in recent literature regarding the mechanism of their paracrine therapeutic effect. However, very little of this mechanistic research has been performed under the aegis of vascular tissue engineering. Therefore, the scope of this review includes the current state of TEVGs generated using the incorporation of stem cells in biodegradable scaffolds and potential cell-free directions for TEVGs based on stem cell secreted products. The current generation of stem cell-seeded vascular scaffolds are based on the premise that cells should be obtained from an autologous source. However, the reduced regenerative capacity of stem cells from certain patient groups limits the therapeutic potential of an autologous approach. This limitation prompts the need to investigate allogeneic stem cells or stem cell secreted products as therapeutic bases for TEVGs. The role of stem cell derived products, particularly extracellular vesicles (EVs), in vascular tissue engineering is exciting due to their potential use as a cell-free therapeutic base. EVs offer many benefits as a therapeutic base for functionalizing vascular scaffolds such as cell specific targeting, physiological delivery of cargo to target cells, reduced immunogenicity, and stability under physiological conditions. However, a number of points must be addressed prior to the effective translation of TEVG technologies that incorporate stem cell derived EVs such as standardizing stem cell culture conditions, EV isolation, scaffold functionalization with EVs, and establishing the therapeutic benefit of this combination treatment.
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Affiliation(s)
- Eoghan M Cunnane
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Justin S Weinbaum
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Fergal J O'Brien
- Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland.,Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.,Advanced Materials and Bioengineering Research Centre, Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland
| | - David A Vorp
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, United States
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2
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Li Z, Wang L, Hu X, Zhang P, Chen Y, Liu X, Xu M, Su H, Zhang M. Intravascular ultrasound elastography analysis of the elastic mechanical properties of atherosclerotic plaque. Int J Cardiovasc Imaging 2017; 33:1663-1671. [PMID: 28500378 DOI: 10.1007/s10554-017-1156-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/03/2017] [Indexed: 12/16/2022]
Abstract
To assess the elastic mechanical properties of atherosclerotic plaque with different morphological properties by intravascular ultrasound elastography (IVUSE). 30 purebred New Zealand rabbits were fed a high-cholesterol diet; the abdominal aorta endothelium was balloon-injured after 2 weeks; at week 12, 2 plaques with moderate echo from each rabbit were chosen for in situ imaging, and 2 consecutive frames near the end-diastole images in situ were used to construct an IVUS elastogram. Shear strain (SS) and area strain (AS) were greater for eccentric than centripetal plaque (SS: 2.65(2.45)% vs. 1.79 ± 0.97%, p < 0.05; AS: 4.81(4.99)% vs. 3.23 ± 1.75%, p < 0.05) but were lower with low than high plaque burden (SS: 2.14 ± 0.37% vs. 3.40 ± 0.34%, p < 0.05; AS: 3.88 ± 0.60% vs. 5.81 ± 0.54%, p < 0.05). SS and AS were significantly greater for plaque with negative than no remodeling (SS: 3.98 ± 1.53% vs. 1.82(1.40)%, p < 0.017; AS: 6.94 ± 2.24% vs. 2.59(2.87)%, p < 0.017) and were found correlated with eccentric index and plaque burden (R2 = 0.365 and R2 = 0.359, both p < 0.05). Plaques associated with eccentricity, high plaque burden and negative remodeling showed greater strain than those with centripetalism, low plaque burden and positive remodeling. Eccentric index and plaque burden may be useful to predict the elastic stability of plaque.
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Affiliation(s)
- Zhaohuan Li
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China.,School of Mathematics, Shandong University, Jinan, 250012, Shandong, People's Republic of China
| | - Lin Wang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Xiaobo Hu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Pengfei Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Yifei Chen
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Xinxin Liu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Mingjun Xu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China.,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China
| | - Haijun Su
- School of Mathematics, Shandong University, Jinan, 250012, Shandong, People's Republic of China
| | - Mei Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University, No. 107#, Wenhua West Road, Jinan, 250012, Shandong, People's Republic of China. .,Cardiovascular Ultrasound and Non-invasive Cardiology Department, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, People's Republic of China.
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3
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Mahmood B, Ewertsen C, Carlsen J, Nielsen MB. Ultrasound Vascular Elastography as a Tool for Assessing Atherosclerotic Plaques - A Systematic Literature Review. Ultrasound Int Open 2016; 2:E106-E112. [PMID: 27896334 DOI: 10.1055/s-0042-115564] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/05/2016] [Indexed: 02/02/2023] Open
Abstract
Atherosclerosis is a widespread disease that accounts for nearly 3-quarters of deaths due to cardiovascular disease. Ultrasound elastography might be able to reliably identify characteristics associated with vulnerable plaques. There is a need for the evaluation of elastography and its ability to distinguish between vulnerable and stable plaques. The aim of this paper is to provide an overview of the literature on vascular elastography. A systematic search of the available literature for studies using elastography for assessing atherosclerotic plaques was conducted using the MEDLINE, Embase, Cochrane Library and Web of Science databases. A standardized template was used to extract relevant data following the PRISMA 2009 checklist. 20 articles were included in this paper. The studies were heterogeneous. All studies reported that elastography was a feasible technique and provided additional information compared to B-mode ultrasound alone. Most studies reported higher strain values for vulnerable plaques. Ultrasound elastography has potential as a clinical tool in the assessment of atherosclerotic plaques. Elastography is able to distinguish between different plaque types, but there is considerable methodological variation between studies. There is a need for larger studies in a clinical setting to determine the full potential of elastography.
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Affiliation(s)
- B Mahmood
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - C Ewertsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - J Carlsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - M B Nielsen
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Denmark
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4
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Widman E, Maksuti E, Amador C, Urban MW, Caidahl K, Larsson M. Shear Wave Elastography Quantifies Stiffness in Ex Vivo Porcine Artery with Stiffened Arterial Region. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:2423-2435. [PMID: 27425151 DOI: 10.1016/j.ultrasmedbio.2016.05.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/17/2016] [Accepted: 05/31/2016] [Indexed: 06/06/2023]
Abstract
Five small porcine aortas were used as a human carotid artery model, and their stiffness was estimated using shear wave elastography (SWE) in the arterial wall and a stiffened artery region mimicking a stiff plaque. To optimize the SWE settings, shear wave bandwidth was measured with respect to acoustic radiation force push length and number of compounded angles used for motion detection with plane wave imaging. The mean arterial wall and simulated plaque shear moduli varied from 41 ± 5 to 97 ± 10 kPa and from 86 ± 13 to 174 ± 35 kPa, respectively, over the pressure range 20-120 mmHg. The results revealed that a minimum bandwidth of approximately 1500 Hz is necessary for consistent shear modulus estimates, and a high pulse repetition frequency using no image compounding is more important than a lower pulse repetition frequency with better image quality when estimating arterial wall and plaque stiffness using SWE.
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Affiliation(s)
- Erik Widman
- Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden.
| | - Elira Maksuti
- Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden
| | - Carolina Amador
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Matthew W Urban
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kenneth Caidahl
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden
| | - Matilda Larsson
- Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden
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5
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Effect of rosuvastatin on atherosclerotic plaque stability: An intravascular ultrasound elastography study. Atherosclerosis 2016; 248:27-35. [DOI: 10.1016/j.atherosclerosis.2016.02.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/04/2016] [Accepted: 02/23/2016] [Indexed: 11/21/2022]
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6
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Widman E, Maksuti E, Larsson D, Urban MW, Bjällmark A, Larsson M. Shear wave elastography plaque characterization with mechanical testing validation: a phantom study. Phys Med Biol 2015; 60:3151-74. [PMID: 25803520 DOI: 10.1088/0031-9155/60/8/3151] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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7
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Liu F, Yong Q, Zhang Q, Liu P, Yang Y. Real-time tissue elastography for the detection of vulnerable carotid plaques in patients undergoing endarterectomy: a pilot study. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:705-712. [PMID: 25619789 DOI: 10.1016/j.ultrasmedbio.2014.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 09/19/2014] [Accepted: 10/18/2014] [Indexed: 06/04/2023]
Abstract
We examined the utility of ultrasonic real-time tissue elastography (RTE) and conventional B-mode ultrasound (US) in the detection of vulnerable carotid atherosclerotic plaques. This prospective study comprised 19 patients scheduled for carotid endarterectomy. Results obtained from pre-operative RTE and B-mode US and post-operative pathology were compared. RTE encoded low, average and high deformability as blue, green and red, respectively. Tissue hardness was scored on a 5-point scale, and relative strains were calculated. The relative strain was 1.12 ± 0.14 for fibrous plaques (n = 4), 0.28 ± 0.07 for atherosclerotic plaques (n = 5), 0.47 ± 0.31 for intraplaque hemorrhage/thrombosis (n = 5) and 0.98 ± 1.04 for complex plaques (n = 5). The sensitivity, specificity and accuracy of detection of vulnerable plaques were 25%, 100% and 84.2% for B-mode US, 50%, 100% and 89.4% for RTE and 62.5%, 100% and 94.7% for the combination. Ultrasonic RTE is a potential candidate for a non-invasive and effective approach to identify vulnerable atherosclerotic plaques in the carotid artery.
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Affiliation(s)
- Fengju Liu
- Department of Ultrasound, Capital Medical University Affiliated Beijing Anzhen Hospital, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Qiang Yong
- Department of Ultrasound, Capital Medical University Affiliated Beijing Anzhen Hospital, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China.
| | - Qinyi Zhang
- Stroke Center, Capital Medical University Affiliated Beijing Anzhen Hospital, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Peng Liu
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Yuguang Yang
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
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8
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Holzapfel GA, Mulvihill JJ, Cunnane EM, Walsh MT. Computational approaches for analyzing the mechanics of atherosclerotic plaques: a review. J Biomech 2014; 47:859-69. [PMID: 24491496 DOI: 10.1016/j.jbiomech.2014.01.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 11/18/2022]
Abstract
Vulnerable and stable atherosclerotic plaques are heterogeneous living materials with peculiar mechanical behaviors depending on geometry, composition, loading and boundary conditions. Computational approaches have the potential to characterize the three-dimensional stress/strain distributions in patient-specific diseased arteries of different types and sclerotic morphologies and to estimate the risk of plaque rupture which is the main trigger of acute cardiovascular events. This review article attempts to summarize a few finite element (FE) studies for different vessel types, and how these studies were performed focusing on the used stress measure, inclusion of residual stress, used imaging modality and material model. In addition to histology the most used imaging modalities are described, the most common nonlinear material models and the limited number of models for plaque rupture used for such studies are provided in more detail. A critical discussion on stress measures and threshold stress values for plaque rupture used within the FE studies emphasizes the need to develop a more location and tissue-specific threshold value, and a more appropriate failure criterion. With this addition future FE studies should also consider more advanced strain-energy functions which then fit better to location and tissue-specific experimental data.
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Affiliation(s)
- Gerhard A Holzapfel
- Graz University of Technology, Institute of Biomechanics, Kronesgasse 5-I, 8010 Graz, Austria.
| | - John J Mulvihill
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute, University of Limerick, Ireland
| | - Eoghan M Cunnane
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute, University of Limerick, Ireland
| | - Michael T Walsh
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute, University of Limerick, Ireland
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9
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Walsh MT, Cunnane EM, Mulvihill JJ, Akyildiz AC, Gijsen FJH, Holzapfel GA. Uniaxial tensile testing approaches for characterisation of atherosclerotic plaques. J Biomech 2014; 47:793-804. [PMID: 24508324 DOI: 10.1016/j.jbiomech.2014.01.017] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 01/19/2023]
Abstract
The pathological changes associated with the development of atherosclerotic plaques within arterial vessels result in significant alterations to the mechanical properties of the diseased arterial wall. There are several methods available to characterise the mechanical behaviour of atherosclerotic plaque tissue, and it is the aim of this paper to review the use of uniaxial mechanical testing. In the case of atherosclerotic plaques, there are nine studies that employ uniaxial testing to characterise mechanical behaviour. A primary concern regarding this limited cohort of published studies is the wide range of testing techniques that are employed. These differing techniques have resulted in a large variance in the reported data making comparison of the mechanical behaviour of plaques from different vasculatures, and even the same vasculature, difficult and sometimes impossible. In order to address this issue, this paper proposes a more standardised protocol for uniaxial testing of diseased arterial tissue that allows for better comparisons and firmer conclusions to be drawn between studies. To develop such a protocol, this paper reviews the acquisition and storage of the tissue, the testing approaches, the post-processing techniques and the stress-strain measures employed by each of the nine studies. Future trends are also outlined to establish the role that uniaxial testing can play in the future of arterial plaque mechanical characterisation.
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Affiliation(s)
- M T Walsh
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute University of Limerick, Limerick, Ireland.
| | - E M Cunnane
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute University of Limerick, Limerick, Ireland
| | - J J Mulvihill
- Centre for Applied Biomedical Engineering Research, Department of Mechanical, Aeronautical and Biomedical Engineering and the Materials and Surface Science Institute University of Limerick, Limerick, Ireland
| | - A C Akyildiz
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - F J H Gijsen
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - G A Holzapfel
- Graz University of Technology, Center of Biomedical Engineering Institute of Biomechanics, Kronesgasse 5-I, 8010 Graz, Austria; Royal Institute of Technology (KTH), Department of Solid Mechanics School of Engineering Sciences, Teknikringen 8d, 100 44 Stockholm, Sweden
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10
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Teng Z, Sadat U, Brown AJ, Gillard JH. Plaque hemorrhage in carotid artery disease: pathogenesis, clinical and biomechanical considerations. J Biomech 2014; 47:847-58. [PMID: 24485514 PMCID: PMC3994507 DOI: 10.1016/j.jbiomech.2014.01.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 12/21/2022]
Abstract
Stroke remains the most prevalent disabling illness today, with internal carotid artery luminal stenosis due to atheroma formation responsible for the majority of ischemic cerebrovascular events. Severity of luminal stenosis continues to dictate both patient risk stratification and the likelihood of surgical intervention. But there is growing evidence to suggest that plaque morphology may help improve pre-existing risk stratification criteria. Plaque components such a fibrous tissue, lipid rich necrotic core and calcium have been well investigated but plaque hemorrhage (PH) has been somewhat overlooked. In this review we discuss the pathogenesis of PH, its role in dictating plaque vulnerability, PH imaging techniques, marterial properties of atherosclerotic tissues, in particular, those obtained based on in vivo measurements and effect of PH in modulating local biomechanics.
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Affiliation(s)
- Zhongzhao Teng
- University Department of Radiology, University of Cambridge, UK; Department of Engineering, University of Cambridge, UK.
| | - Umar Sadat
- Department of Surgery, Cambridge University Hospitals NHS Foundation Trust, UK
| | - Adam J Brown
- Department of Cardiovascular Medicine, University of Cambridge, UK
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11
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Teng Z, Sadat U, Wang W, Bahaei NS, Chen S, Young VE, Graves MJ, Gillard JH. Intraplaque stretch in carotid atherosclerotic plaque--an effective biomechanical predictor for subsequent cerebrovascular ischemic events. PLoS One 2013; 8:e61522. [PMID: 23626694 PMCID: PMC3634006 DOI: 10.1371/journal.pone.0061522] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 03/11/2013] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Stretch is a mechanical parameter, which has been proposed previously to affect the biological activities in different tissues. This study explored its utility in determining plaque vulnerability. METHODS One hundred and six patients with mild to moderate carotid stenosis were recruited in this study (53 symptomatic and 53 asymptomatic). High resolution, multi-sequence magnetic resonance (MR) imaging was performed to delineate various plaque components. Finite element method was used to predict high stretch concentration within the plaque. RESULTS During a two-year follow-up, 11 patients in symptomatic group and 3 in asymptomatic group experienced recurrent cerebrovascular events. Plaque stretch at systole and stretch variation during one cardiac cycle was greater in symptomatic group than those in the asymptomatic. Within the symptomatic group, a similar trend was observed in patients with recurrent events compared to those without. CONCLUSION Plaques with high stretch concentration and large stretch variation are associated with increased risk of future cerebrovascular events.
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Affiliation(s)
- Zhongzhao Teng
- University Department of Radiology, University of Cambridge, Cambridge, United Kingdom.
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12
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Soloperto G, Casciaro S. Progress in atherosclerotic plaque imaging. World J Radiol 2012; 4:353-71. [PMID: 22937215 PMCID: PMC3430733 DOI: 10.4329/wjr.v4.i8.353] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/14/2012] [Accepted: 05/21/2012] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular diseases are the primary cause of mortality in the industrialized world, and arterial obstruction, triggered by rupture-prone atherosclerotic plaques, lead to myocardial infarction and cerebral stroke. Vulnerable plaques do not necessarily occur with flow-limiting stenosis, thus conventional luminographic assessment of the pathology fails to identify unstable lesions. In this review we discuss the currently available imaging modalities used to investigate morphological features and biological characteristics of the atherosclerotic plaque. The different imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography, nuclear imaging and their intravascular applications are illustrated, highlighting their specific diagnostic potential. Clinically available and upcoming methodologies are also reviewed along with the related challenges in their clinical translation, concerning the specific invasiveness, accuracy and cost-effectiveness of these methods.
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13
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Graf IM, Kim S, Wang B, Smalling R, Emelianov S. Noninvasive detection of intimal xanthoma using combined ultrasound, strain rate and photoacoustic imaging. ULTRASONICS 2012; 52:435-41. [PMID: 22078093 DOI: 10.1016/j.ultras.2011.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 09/29/2011] [Accepted: 10/10/2011] [Indexed: 05/07/2023]
Abstract
BACKGROUND AND MOTIVATION The structure, composition and mechanics of carotid artery are good indicators of early progressive atherosclerotic lesions. The combination of three imaging modalities (ultrasound, strain rate and photoacoustic imaging) which could provide corroborative information about the named arterial properties could enhance the characterization of intimal xanthoma. METHODS The experiments were performed using a New Zealand white rabbit model of atherosclerosis. The aorta excised from an atherosclerotic rabbit was scanned ex vivo using the three imaging techniques: (1) ultrasound imaging of the longitudinal section: standard ultrasound B-mode (74Hz frame rate); (2) strain rate imaging: the artery was flushed with blood and a 1.5Hz physiologic pulsation was induced, while the ultrasound data were recorded at higher frame rate (296Hz); (3) photoacoustic imaging: the artery was irradiated with nanosecond pulsed laser light of low fluence in the 1210-1230nm wavelength range and the photoacoustic data was recorded at 10Hz frame rate. Post processing algorithms based on cross-correlation and optical absorption variation were implemented to derive strain rate and spectroscopic photoacoustic images, respectively. RESULTS Based on the spatio-temporal variation in displacement of different regions within the arterial wall, strain rate imaging reveals differences in tissue mechanical properties. Additionally, spectroscopic photoacoustic imaging can spatially resolve the optical absorption properties of arterial tissue and identify the location of lipid pools. CONCLUSIONS The study demonstrates that ultrasound, strain rate and photoacoustic imaging can be used to simultaneously evaluate the structure, the mechanics and the composition of atherosclerotic lesions to improve the assessment of plaque vulnerability.
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Affiliation(s)
- Iulia M Graf
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
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14
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Cardiovascular imaging 2011 in the International Journal of Cardiovascular Imaging. Int J Cardiovasc Imaging 2012; 28:439-51. [PMID: 22476909 PMCID: PMC3326368 DOI: 10.1007/s10554-012-0040-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hu XB, Zhang PF, Su HJ, Yi X, Chen L, Rong YY, Zhang K, Li X, Wang L, Sun CL, Cai XJ, Li L, Song JT, Dai XM, Sui XD, Zhang Y, Zhang M. Intravascular ultrasound area strain imaging used to characterize tissue components and assess vulnerability of atherosclerotic plaques in a rabbit model. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:1579-1587. [PMID: 21856069 DOI: 10.1016/j.ultrasmedbio.2011.06.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 06/23/2011] [Accepted: 06/27/2011] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to investigate the association of area strain and tissue components and vulnerability of atherosclerotic plaques in a rabbit model. Forty purebred New Zealand rabbits underwent balloon-induced abdominal aorta endothelium injury, then a high-cholesterol diet for 24 weeks. Intravascular ultrasound (IVUS) images of abdominal aortas were acquired in situ and two consecutive frames near the end-diastole were used to construct an IVUS elastogram. Histologic slices matched with corresponding IVUS images were stained for fatty and collagen components, smooth muscle cells (SMCs) and macrophages. Regions-of-interest (ROIs) in plaques were classified as fibrous, fibro-fatty or fatty according to histologic study. Vulnerability indexes of ROIs were calculated as (fat + macrophage)/(collagen + SMCs). The area strain of these ROIs was calculated by use of an in-house-designed software system with a block-matching-based algorithm. Area strain was significantly higher in fatty ROIs (0.056 ± 0.003) than in fibrous (0.019 ± 0.002, p < 0.001) or fibro-fatty ROIs (0.033 ± 0.003, p < 0.001). The sensitivity and specificity of area strain for fatty ROIs characterization was 75.0% and 80.2% (area under the curve [AUC] 0.858, 95% confidence interval [CI] = 0.800-0.916, p < 0.001) and 75.0% and 75.3% (AUC 0.859, 95% CI = 0.801-0.917, p < 0.001) for fibrous ROIs, as demonstrated by receiver operating characteristic curve analysis. Area strain was positively correlated with vulnerability index (r(2) = 0.495, p < 0.001), fatty components (r(2) = 0.332, p < 0.001) and macrophage infiltration (r(2) = 0.406, p < 0.001); and negatively correlated with collagen and SMC composition (r(2) = 0.115 and r(2) = 0.169, p < 0.001, respectively). Area strain calculation with IVUS elastography based on digital B-mode analysis is feasible and can be useful for tissue characterization and plaque vulnerability assessment.
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Affiliation(s)
- Xiao-Bo Hu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan, China
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