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Wang J, Zhang H, Ji J, Wang L, Lv W, He Y, Li X, Feng G, Chen K. A histological study of atherosclerotic characteristics in age-related macular degeneration. Heliyon 2022; 8:e08973. [PMID: 35252605 PMCID: PMC8891972 DOI: 10.1016/j.heliyon.2022.e08973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/19/2021] [Accepted: 02/11/2022] [Indexed: 01/03/2023] Open
Abstract
This study investigated the pathogenesis of age-related macular degeneration (AMD) using histological methods that are commonly used for atherosclerotic vascular disease (ASVD). 1 normal, 3 early dry AMD, and 1 late dry AMD eyes were obtained from the Lions Eye Bank of Oregon and systematically dissected. They were stained with hematoxylin and eosin, Oil red O, Masson, Elastica van Gieson, Alizarin red, and Prussian blue. Additionally, the normal and late dry AMD eyes were immunostained for a-smooth muscle actin, CD45, and CD68 with Nile red and DAPI. Correlations were found between severity of AMD and lipid accumulation in the deep sclera (+), numbers of drusen between the Bruch's membrane and retinal pigment epithelium (RPE) (+), amount of collagen in the deep sclera (+), and amount of elastin in the deep sclera (-) (P < 0.1). Geographic atrophy, RPE detachment, and abnormal capillary shape and distribution in the choriocapillaris were observed in the fovea of late AMD. There were no stenosis, plaque, hemorrhage, and calcification. Additionally, late AMD tended to have higher smooth muscle thicknesses of the choroidal vascular walls, lower numbers of T lymphocytes in the choroid, and higher numbers of macrophages near the RPE and in the choroid relative to normal (P < 0.1). Macrophages-derived foam cells were detected near the Bruch's membrane in late AMD. Therefore, the present study showed many histological characteristics of ASVD in AMD, which suggests an association between them; however, there were also some histological characteristics of ASVD that were not found in AMD, which indicates that there exist pathogenic differences between them. The results generally support the vascular model of AMD, but some details still need clarification.
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Torii R, Tenekecioglu E, Katagiri Y, Chichareon P, Sotomi Y, Dijkstra J, Asano T, Modolo R, Takahashi K, Jonker H, van Geuns R, Onuma Y, Pekkan K, Bourantas CV, Serruys PW. The impact of plaque type on strut embedment/protrusion and shear stress distribution in bioresorbable scaffold. Eur Heart J Cardiovasc Imaging 2021; 21:454-462. [PMID: 31215995 DOI: 10.1093/ehjci/jez155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/17/2019] [Accepted: 05/22/2019] [Indexed: 11/13/2022] Open
Abstract
AIMS Scaffold design and plaque characteristics influence implantation outcomes and local flow dynamics in treated coronary segments. Our aim is to assess the impact of strut embedment/protrusion of bioresorbable scaffold on local shear stress distribution in different atherosclerotic plaque types. METHODS AND RESULTS Fifteen Absorb everolimus-eluting Bioresorbable Vascular Scaffolds were implanted in human epicardial coronary arteries. Optical coherence tomography (OCT) was performed post-scaffold implantation and strut embedment/protrusion were analysed using a dedicated software. OCT data were fused with angiography to reconstruct 3D coronary anatomy. Blood flow simulation was performed and wall shear stress (WSS) was estimated in each scaffolded surface and the relationship between strut embedment/protrusion and WSS was evaluated. There were 9083 struts analysed. Ninety-seven percent of the struts (n = 8840) were well-apposed and 243 (3%) were malapposed. At cross-section level (n = 1289), strut embedment was significantly increased in fibroatheromatous plaques (76 ± 48 µm) and decreased in fibrocalcific plaques (35 ± 52 µm). Compatible with strut embedment, WSS was significantly higher in lipid-rich fibroatheromatous plaques (1.50 ± 0.81 Pa), whereas significantly decreased in fibrocalcified plaques (1.05 ± 0.91 Pa). After categorization of WSS as low (<1.0 Pa) and normal/high WSS (≥1.0 Pa), the percent of low WSS in the plaque subgroups were 30.1%, 31.1%, 25.4%, and 36.2% for non-diseased vessel wall, fibrous plaque, fibroatheromatous plaque, and fibrocalcific plaque, respectively (P-overall < 0.001). CONCLUSION The composition of the underlying plaque influences strut embedment which seems to have effect on WSS. The struts deeply embedded in lipid-rich fibroatheromas plaques resulted in higher WSS compared with the other plaque types.
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Affiliation(s)
- Ryo Torii
- Department of Mechanical Engineering, University College London, London, UK
| | - Erhan Tenekecioglu
- Department of Interventional Cardiology, Erasmus University Medical Center, Thoraxcenter, Rotterdam, The Netherlands
| | - Yuki Katagiri
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Ply Chichareon
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Yohei Sotomi
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jouke Dijkstra
- LKEB-Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Taku Asano
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Rodrigo Modolo
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Kuniaki Takahashi
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Robert van Geuns
- Department of Interventional Cardiology, Erasmus University Medical Center, Thoraxcenter, Rotterdam, The Netherlands
| | - Yoshinobu Onuma
- Department of Interventional Cardiology, Erasmus University Medical Center, Thoraxcenter, Rotterdam, The Netherlands
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koc University, Istanbul, Turkey
| | - Christos V Bourantas
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiology, Barts Heart Centre, London, UK
| | - Patrick W Serruys
- Department of Interventional Cardiology, Erasmus University Medical Center, Thoraxcenter, Rotterdam, The Netherlands.,Imperial College, London, UK
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O'Reilly BL, Hynes N, Sultan S, McHugh PE, McGarry JP. An experimental and computational investigation of the material behaviour of discrete homogenous iliofemoral and carotid atherosclerotic plaque constituents. J Biomech 2020; 106:109801. [DOI: 10.1016/j.jbiomech.2020.109801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/28/2020] [Accepted: 04/14/2020] [Indexed: 12/23/2022]
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4
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Paritala PK, Yarlagadda PKDV, Kansky R, Wang J, Mendieta JB, Gu Y, McGahan T, Lloyd T, Li Z. Stress-Relaxation and Cyclic Behavior of Human Carotid Plaque Tissue. Front Bioeng Biotechnol 2020; 8:60. [PMID: 32117939 PMCID: PMC7026010 DOI: 10.3389/fbioe.2020.00060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/23/2020] [Indexed: 12/12/2022] Open
Abstract
Atherosclerotic plaque rupture is a catastrophic event that contributes to mortality and long-term disability. A better understanding of the plaque mechanical behavior is essential for the identification of vulnerable plaques pre-rupture. Plaque is subjected to a natural dynamic mechanical environment under hemodynamic loading. Therefore, it is important to understand the mechanical response of plaque tissue under cyclic loading conditions. Moreover, experimental data of such mechanical properties are fundamental for more clinically relevant biomechanical modeling and numerical simulations for risk stratification. This study aims to experimentally and numerically characterize the stress-relaxation and cyclic mechanical behavior of carotid plaque tissue. Instron microtester equipped with a custom-developed setup was used for the experiments. Carotid plaque samples excised at endarterectomy were subjected to uniaxial tensile, stress-relaxation, and cyclic loading protocols. Thirty percent of the underlying load level obtained from the uniaxial tensile test results was used to determine the change in mechanical properties of the tissue over time under a controlled testing environment (Control tests). The stress-relaxation test data was used to calibrate the hyperelastic (neo-Hookean, Ogden, Yeoh) and linear viscoelastic (Prony series) material parameters. The normalized relaxation force increased initially and slowly stabilized toward the end of relaxation phase, highlighting the viscoelastic behavior. During the cyclic tests, there was a decrease in the peak force as a function of the cycle number indicating mechanical distension due to repeated loading that varied with different frequencies. The material also accumulated residual deformation, which increased with the cycle number. This trend showed softening behavior of the samples. The results of this preliminary study provide an enhanced understanding of in vivo stress-relaxation and cyclic behavior of the human atherosclerotic plaque tissue.
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Affiliation(s)
- Phani Kumari Paritala
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Prasad K D V Yarlagadda
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Rhys Kansky
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Jiaqiu Wang
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Jessica Benitez Mendieta
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - YuanTong Gu
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Tim McGahan
- Department of Vascular Surgery, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Thomas Lloyd
- Department of Radiology, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Zhiyong Li
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
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Barrett HE, Van der Heiden K, Farrell E, Gijsen FJH, Akyildiz AC. Calcifications in atherosclerotic plaques and impact on plaque biomechanics. J Biomech 2019; 87:1-12. [PMID: 30904335 DOI: 10.1016/j.jbiomech.2019.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/09/2019] [Indexed: 12/13/2022]
Abstract
The catastrophic mechanical rupture of an atherosclerotic plaque is the underlying cause of the majority of cardiovascular events. The infestation of vascular calcification in the plaques creates a mechanically complex tissue composite. Local stress concentrations and plaque tissue strength properties are the governing parameters required to predict plaque ruptures. Advanced imaging techniques have permitted insight into fundamental mechanisms driving the initiating inflammatory-driven vascular calcification of the diseased intima at the (sub-) micron scale and up to the macroscale. Clinical studies have potentiated the biomechanical relevance of calcification through the derivation of links between local plaque rupture and specific macrocalcification geometrical features. The clinical implications of the data presented in this review indicate that the combination of imaging, experimental testing, and computational modelling efforts are crucial to predict the rupture risk for atherosclerotic plaques. Specialised experimental tests and modelling efforts have further enhanced the knowledge base for calcified plaque tissue mechanical properties. However, capturing the temporal instability and rupture causality in the plaque fibrous caps remains elusive. Is it necessary to move our experimental efforts down in scale towards the fundamental (sub-) micron scales in order to interpret the true mechanical behaviour of calcified plaque tissue interactions that is presented on a macroscale in the clinic and to further optimally assess calcified plaques in the context of biomechanical modelling.
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Affiliation(s)
- Hilary E Barrett
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Kim Van der Heiden
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eric Farrell
- Department of Oral and Maxillofacial Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Frank J H Gijsen
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ali C Akyildiz
- Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
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Zhang ZH, Pan MX, Cai JT, Weiland JD, Chen K. Viscoelastic properties of the posterior eye of normal subjects, patients with age-related macular degeneration, and pigs. J Biomed Mater Res A 2018; 106:2151-2157. [DOI: 10.1002/jbm.a.36417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zhen Huan Zhang
- School of Biological Science and Medical Engineering; Beihang University - Yifu Science Hall, 37 Xueyuan Road; Haidian Beijing 100191 China
- Beijing Advanced Innovation Center for Biomedical Engineering; Beihang University; Beijing 100191 China
| | - Meng Xin Pan
- School of Biological Science and Medical Engineering; Beihang University - Yifu Science Hall, 37 Xueyuan Road; Haidian Beijing 100191 China
- Beijing Advanced Innovation Center for Biomedical Engineering; Beihang University; Beijing 100191 China
| | - Jia Tong Cai
- School of Biological Science and Medical Engineering; Beihang University - Yifu Science Hall, 37 Xueyuan Road; Haidian Beijing 100191 China
- Beijing Advanced Innovation Center for Biomedical Engineering; Beihang University; Beijing 100191 China
| | - James D. Weiland
- Department of Ophthalmology; University of Southern California - 1450 San Pablo Street; Los Angeles California 90033
- Department of Biomedical Engineering; University of Southern California - Denney Research Center, 1042 Downey Way; Los Angeles California 90089
| | - Kinon Chen
- School of Biological Science and Medical Engineering; Beihang University - Yifu Science Hall, 37 Xueyuan Road; Haidian Beijing 100191 China
- Beijing Advanced Innovation Center for Biomedical Engineering; Beihang University; Beijing 100191 China
- Department of Ophthalmology; University of Southern California - 1450 San Pablo Street; Los Angeles California 90033
- Department of Biomedical Engineering; University of Southern California - Denney Research Center, 1042 Downey Way; Los Angeles California 90089
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Towards the development of an in vitro model of atherosclerotic peripheral vessels for evaluating drug-coated endovascular technologies. Drug Discov Today 2016; 21:1512-1520. [PMID: 27297733 DOI: 10.1016/j.drudis.2016.05.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/27/2016] [Accepted: 05/27/2016] [Indexed: 11/20/2022]
Abstract
Here, we review the in vitro models used to evaluate drug-coated endovascular technologies. The models are assessed in the context of representing the drug transport/uptake and mechanical properties of atherosclerotic peripheral vessels. Studies to date have incorporated a vessel-simulating hydrogel compartment to examine drug elution from endovascular devices. However, comparisons between in vitro models and atherosclerotic tissue are difficult because ex vivo data are limited in their applicability to diseased peripheral vessels. Furthermore, appropriate ex vivo mechanical properties are not incorporated into these models. Therefore, there is a need to characterise the drug transport/uptake properties of appropriate atherosclerotic tissue and incorporate existing ex vivo mechanical data into current in vitro models to more accurately represent drug behaviour in atherosclerotic peripheral vessels.
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9
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Razaghi R, Karimi A, Rahmani S, Navidbakhsh M. A computational fluid–structure interaction model of the blood flow in the healthy and varicose saphenous vein. Vascular 2015; 24:254-63. [DOI: 10.1177/1708538115594095] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective Varicose vein has become enlarged and twisted and, consequently, has lost its mechanical strength. As a result of the varicose saphenous vein (SV) mechanical alterations, the hemodynamic parameters of the blood flow, such as blood velocity as well as vein wall stress and strain, would change accordingly. However, little is known about stress and strain and there consequences under experimental conditions on blood flow and velocity within normal and varicose veins. In this study, a three-dimensional (3D) computational fluid–structure interaction (FSI) model of a human healthy and varicose SVs was established to determine the hemodynamic characterization of the blood flow as a function of vein wall mechanical properties, i.e. elastic and hyperelastic. Methods The mechanical properties of the human healthy and varicose SVs were experimentally measured and implemented into the computational model. The fully coupled fluid and structure models were solved using the explicit dynamics finite element code LS-DYNA. Results The results revealed that, regardless of healthy and varicose, the elastic walls reach to the ultimate strength of the vein wall, whereas the hyperelastic wall can tolerate more stress. The highest von Mises stress compared to the healthy ones was seen in the elastic and hyperelastic varicose SVs with 1.412 and 1.535 MPa, respectively. In addition, analysis of the resultant displacement in the vein wall indicated that the varicose SVs experienced a higher displacement compared to the healthy ones irrespective of elastic and hyperelastic material models. The highest blood velocity was also observed for the healthy hyperelastic SV wall. Conclusion The findings of this study may have implications not only for determining the role of the vein wall mechanical properties in the hemodynamic alterations of the blood, but also for employing as a null information in balloon-angioplasty and bypass surgeries.
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Affiliation(s)
- Reza Razaghi
- Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16887, Iran
| | - Alireza Karimi
- Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16887, Iran
| | - Shahrokh Rahmani
- Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16887, Iran
| | - Mahdi Navidbakhsh
- Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16887, Iran
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Karimi A, Razaghi R, Shojaei A, Navidbakhsh M. An experimental-nonlinear finite element study of a balloon expandable stent inside a realistic stenotic human coronary artery to investigate plaque and arterial wall injury. ACTA ACUST UNITED AC 2015; 60:593-602. [PMID: 25870956 DOI: 10.1515/bmt-2014-0144] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/11/2015] [Indexed: 11/15/2022]
Abstract
The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial wall rupture. The distribution and magnitude of the stresses in the plaque-artery-stent structure might be distinctly different for different plaque types. In this study, the mechanical properties of six healthy and atherosclerotic human coronary arteries were determined for application in plaque and arterial vulnerability assessment. A nonlinear finite element simulation based on an Ogden material model was established to investigate the effect of plaque types on the stresses induced in the arterial wall during implantation of a balloon expandable coronary stent. The atherosclerotic artery was assumed to consist of a plaque and normal arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial wall during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was 3.161 MPa, whereas cellular and hypocellular plaques showed relatively less stress on their wall. The highest von Mises stresses within the arterial wall were observed on the hypocellular plaque, whereas the lowest stresses were seen to be located in the calcified and cellular plaques. Although the computed stresses on the arterial wall for the calcified and cellular plaques were not high enough to invoke a rupture, the stress on the hypocellular plaque was relatively higher than that of the strength of the arterial wall. These findings may have implications not only for understanding the stresses induced in plaque and the arterial wall, but also for developing surgeries such as balloon-angioplasty and stenting.
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11
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Modelling of Atherosclerotic Plaque for Use in a Computational Test-Bed for Stent Angioplasty. Ann Biomed Eng 2014; 42:2425-39. [DOI: 10.1007/s10439-014-1107-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
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12
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Karimi A, Navidbakhsh M, Yamada H, Razaghi R. A nonlinear finite element simulation of balloon expandable stent for assessment of plaque vulnerability inside a stenotic artery. Med Biol Eng Comput 2014; 52:589-99. [PMID: 24888756 DOI: 10.1007/s11517-014-1163-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 05/20/2014] [Indexed: 11/25/2022]
Abstract
The stresses induced on plaque wall during stent implantation inside a stenotic artery are associated with plaque rupture. The stresses in the plaque-artery-stent structure appear to be distinctly different for different plaque types in terms of both distribution and magnitude. In this study, a nonlinear finite element simulation was executed to analyze the influence of plaque composition (calcified, cellular, and hypocellular) on plaque, artery layers (intima, media, and adventitia), and stent stresses during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal arterial tissues on its outer side. The results revealed a significant influence of plaque types on the maximum stresses induced within plaque wall and artery layers during stenting, but not when calculating maximum stress on stent. The stress on stiffer calcified plaque wall was in the fracture level (2.21 MPa), whereas cellular and hypocellular plaques play a protective role by displaying less stress on their wall. The highest von Mises stresses were observed on less stiff media layer. The findings of this study suggest a lower risk of arterial vascular injury for calcified plaque, while higher risk of plaque ruptures for cellular and hypocellular plaques.
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Affiliation(s)
- Alireza Karimi
- School of Mechanical Engineering, Iran University of Science and Technology, 16846, Tehran, Iran,
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13
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Akyildiz AC, Speelman L, Gijsen FJ. Mechanical properties of human atherosclerotic intima tissue. J Biomech 2014; 47:773-83. [DOI: 10.1016/j.jbiomech.2014.01.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 12/13/2022]
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14
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Compressive mechanical properties of atherosclerotic plaques—Indentation test to characterise the local anisotropic behaviour. J Biomech 2014; 47:784-92. [DOI: 10.1016/j.jbiomech.2014.01.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 11/20/2022]
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Sadat U, Teng Z, Gillard JH. Biomechanical structural stresses of atherosclerotic plaques. Expert Rev Cardiovasc Ther 2014; 8:1469-81. [DOI: 10.1586/erc.10.130] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Aboodi MS, Milewski K, Tellez A, Cheng Y, Yi GH, Kaluza GL, Granada JF. Long-term impact of balloon postdilatation on neointimal formation: An experimental comparative study between second-generation self-expanding versus balloon-expandable stent technologies. Catheter Cardiovasc Interv 2013; 83:397-404. [DOI: 10.1002/ccd.24452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Michael S. Aboodi
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Krzysztof Milewski
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Armando Tellez
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Yanping Cheng
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Geng-Hua Yi
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Greg L. Kaluza
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
| | - Juan F. Granada
- Skirball Center for Cardiovascular Research; Cardiovascular Research Foundation; Orangeburg New York
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Removing vascular obstructions: a challenge, yet an opportunity for interventional microdevices. Biomed Microdevices 2012; 14:511-32. [PMID: 22331446 DOI: 10.1007/s10544-011-9627-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cardiovascular diseases are the leading cause of death worldwide; they are mainly due to vascular obstructions which, in turn, are mainly caused by thrombi and atherosclerotic plaques. Although a variety of removal strategies has been developed for the considered obstructions, none of them is free from limitations and conclusive. The present paper analyzes the physical mechanisms underlying state-of-art removal strategies and classifies them into chemical, mechanical, laser and hybrid (namely chemo-mechanical and mechano-chemical) approaches, while also reviewing corresponding commercial/research tools/devices and procedures. Furthermore, challenges and opportunities for interventional micro/nanodevices are highlighted. In this spirit, the present review should support engineers, researchers active in the micro/nanotechnology field, as well as medical doctors in the development of innovative biomedical solutions for treating vascular obstructions. Data were collected by using the ISI Web of Knowledge portal, buyer's guides and FDA databases; devices not reported on scientific publications, as well as commercial devices no more for sale were discarded. Nearly 70% of the references were published since 2006, 55% since 2008; these percentages respectively raise to 85% and 65% as regards the section specifically reviewing state-of-art removal tools/devices and procedures.
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3D computational parametric analysis of eccentric atheroma plaque: influence of axial and circumferential residual stresses. Biomech Model Mechanobiol 2012; 11:1001-13. [DOI: 10.1007/s10237-011-0369-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 12/23/2011] [Indexed: 11/27/2022]
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Gu L, Zhao S, Muttyam AK, Hammel JM. The Relation Between the Arterial Stress and Restenosis Rate After Coronary Stenting. J Med Device 2010. [DOI: 10.1115/1.4002238] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Two commercially available stents (the Palmaz–Schatz (PS) and S670 stents) with reported high and low restenosis rates, respectively, have been investigated in this paper. Finite element models simulating the stent, plaque, and artery interactions in 3 mm stenosed right coronary arteries were developed. These models were used to determine the stress field in artery walls after stent implantation. The material properties of porcine arteries were measured and implemented in the numerical models. The stress concentration induced in the artery by the PS stent was found to be more than double that of the S670 stent. It demonstrated a good correlation with the reported restenosis rate. The effects of stent structures, compliance mismatch, plaque geometry, and level of stenosis were studied. Results suggested that stent designs and tissue properties cause alterations in vascular anatomy that adversely affect arterial stress distributions within the wall, which impact vessel responses such as restenosis. Appropriate modeling of stent, plaque, and artery interactions provided insights for evaluating alterations to the arterial mechanical environment, as well as biomechanical factors leading to restenosis.
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Affiliation(s)
- Linxia Gu
- Department of Mechanical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656
| | - Shijia Zhao
- Department of Mechanical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656
| | | | - James M. Hammel
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68114
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Milewski K, Granada JF. Low-pressure self-expandable luminal shield system: mechanical stabilization of high-risk coronary atherosclerotic lesions. Interv Cardiol 2010. [DOI: 10.2217/ica.10.56] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Call for Standards in Technical Documentation of Intracoronary Stents. Herz 2010; 35:27-33. [DOI: 10.1007/s00059-010-3278-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 12/02/2009] [Indexed: 10/18/2022]
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The influence of plaque composition on underlying arterial wall stress during stent expansion: The case for lesion-specific stents. Med Eng Phys 2009; 31:428-33. [DOI: 10.1016/j.medengphy.2008.11.005] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 04/21/2008] [Accepted: 11/12/2008] [Indexed: 11/15/2022]
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Timmins LH, Meyer CA, Moreno MR, Moore JE. Effects of stent design and atherosclerotic plaque composition on arterial wall biomechanics. J Endovasc Ther 2009; 15:643-54. [PMID: 19090628 DOI: 10.1583/08-2443.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To examine the solid mechanical effects of varying stent design and atherosclerotic plaque stiffness on the biomechanical environment induced in a diseased artery wall model. METHODS Computational modeling techniques were employed to investigate the final radius of the lumen and artery wall stresses after stent implantation. Two stent designs were studied (one stiff and one less stiff). The stenotic artery was modeled as an axisymmetrical diseased vessel with a 20% stenosis by diameter. The material properties of the diseased tissue in the artery models varied. Atherosclerotic plaques half as stiff (0.5x), of equal stiffness (1.0x), or twice as stiff (2.0x) as the artery wall were investigated. RESULTS Final lumen radius was dependent on stent design, and the stiffer stent deformed the artery to an approximately 10% greater radius than the more compliant design. Alternatively, circumferential stress levels were dependent on both stent design and plaque material properties. Overall, the stiffer stent subjected the artery wall to much higher stress values than the more compliant design, with differences in peak values of 0.50, 0.31, and 0.09 MPa for the 2.0x, 1.0x, and 0.5x stiff plaques, respectively. CONCLUSION Evidence suggests that a judicious choice of stent design can minimize stress while maintaining a patent lumen in stenotic arteries. If confronted with a rigid, calcified plaque, stent design is more important, as design differences can impose dramatically different stress fields, while still providing arterial patency. Alternatively, stent design is not as much of an issue when treating a soft, lipid-laden plaque, as stress fields do not vary significantly among stent designs.
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Affiliation(s)
- Lucas H Timmins
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 78843-3120, USA
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Schmidt W, Lanzer P, Behrens P, Topoleski L, Schmitz KP. A comparison of the mechanical performance characteristics of seven drug-eluting stent systems. Catheter Cardiovasc Interv 2009; 73:350-60. [DOI: 10.1002/ccd.21832] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Walraevens J, Willaert B, De Win G, Ranftl A, De Schutter J, Sloten JV. Correlation between compression, tensile and tearing tests on healthy and calcified aortic tissues. Med Eng Phys 2008; 30:1098-104. [DOI: 10.1016/j.medengphy.2008.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 09/12/2007] [Accepted: 01/30/2008] [Indexed: 11/27/2022]
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Young PP, Modur V, Teleron AA, Ladenson JH. Enrichment of genes in the aortic intima that are associated with stratified epithelium: implications of underlying biomechanical and barrier properties of the arterial intima. Circulation 2005; 111:2382-90. [PMID: 15867175 DOI: 10.1161/01.cir.0000164235.26339.78] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Arteries and veins are exposed to different pressures and are easily distinguished by morphology. Although several recent studies have focused on differential gene expression between the arterial and venous endothelium, the molecular distinctions that give rise to the dramatic structural distinctions between arteries and veins, such as in the organization of the intima, are not known. METHODS AND RESULTS We used high-density oligonucleotide arrays to analyze the transcriptional profile of the mouse aorta and inferior vena cava (IVC), not restricting our analysis to the endothelium, to identify genes whose expression was enriched in aorta over other tissues and the IVC. By quantitative reverse transcription-polymerase chain reaction analysis, these genes have been shown to be highly expressed in the mouse aorta and were either expressed at low levels or were undetectable in the murine IVC. By immunofluorescence analysis of human tissue, we determined that a subset of these aorta-enriched proteins exhibited a primarily intima-restricted expression. Intimal expression of at least a subset of these genes, plakoglobin, galectin 7, sciellin, and SPRR3, was also detected in other types of arteries but not in veins. Furthermore, SPRR3 expression in the intima was primarily associated with atheromas. The proteins identified are functionally related in that they are known to also be enriched in stratified epithelia, where they play an important role in stress-bearing and barrier properties. CONCLUSIONS Vascular expression of these genes has not been reported previously. Our observations suggest that they may play a significant role in the mechanisms by which large arteries may adapt to biomechanical stress.
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Affiliation(s)
- Pampee P Young
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tenn, USA.
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