1
|
Sauer TJ, Buckler AJ, Abadi E, Daubert M, Douglas PS, Samei E, Segars WP. Development of physiologically-informed computational coronary artery plaques for use in virtual imaging trials. Med Phys 2024; 51:1583-1596. [PMID: 38306457 DOI: 10.1002/mp.16959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/30/2023] [Accepted: 01/16/2024] [Indexed: 02/04/2024] Open
Abstract
BACKGROUND As a leading cause of death, worldwide, cardiovascular disease is of great clinical importance. Among cardiovascular diseases, coronary artery disease (CAD) is a key contributor, and it is the attributed cause of death for 10% of all deaths annually. The prevalence of CAD is commensurate with the rise in new medical imaging technologies intended to aid in its diagnosis and treatment. The necessary clinical trials required to validate and optimize these technologies require a large cohort of carefully controlled patients, considerable time to complete, and can be prohibitively expensive. A safer, faster, less expensive alternative is using virtual imaging trials (VITs), utilizing virtual patients or phantoms combined with accurate computer models of imaging devices. PURPOSE In this work, we develop realistic, physiologically-informed models for coronary plaques for application in cardiac imaging VITs. METHODS Histology images of plaques at micron-level resolution were used to train a deep convolutional generative adversarial network (DC-GAN) to create a library of anatomically variable plaque models with clinical anatomical realism. The stability of each plaque was evaluated by finite element analysis (FEA) in which plaque components and vessels were meshed as volumes, modeled as specialized tissues, and subjected to the range of normal coronary blood pressures. To demonstrate the utility of the plaque models, we combined them with the whole-body XCAT computational phantom to perform initial simulations comparing standard energy-integrating detector (EID) CT with photon-counting detector (PCD) CT. RESULTS Our results show the network is capable of generating realistic, anatomically variable plaques. Our simulation results provide an initial demonstration of the utility of the generated plaque models as targets to compare different imaging devices. CONCLUSIONS Vast, realistic, and variable CAD pathologies can be generated to incorporate into computational phantoms for VITs. There they can serve as a known truth from which to optimize and evaluate cardiac imaging technologies quantitatively.
Collapse
Affiliation(s)
- Thomas J Sauer
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, the Duke University Medical Center, Durham, North Carolina, USA
| | | | - Ehsan Abadi
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, the Duke University Medical Center, Durham, North Carolina, USA
| | - Melissa Daubert
- Duke Department of Medicine, the Duke University Medical Center, Durham, North Carolina, USA
| | - Pamela S Douglas
- Duke Department of Medicine, the Duke University Medical Center, Durham, North Carolina, USA
| | - Ehsan Samei
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, the Duke University Medical Center, Durham, North Carolina, USA
| | - William P Segars
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, the Duke University Medical Center, Durham, North Carolina, USA
| |
Collapse
|
2
|
Conway C, Nezami FR, Rogers C, Groothuis A, Squire JC, Edelman ER. Acute Stent-Induced Endothelial Denudation: Biomechanical Predictors of Vascular Injury. Front Cardiovasc Med 2021; 8:733605. [PMID: 34722666 PMCID: PMC8553954 DOI: 10.3389/fcvm.2021.733605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/15/2021] [Indexed: 01/03/2023] Open
Abstract
Recent concern for local drug delivery and withdrawal of the first Food and Drug Administration-approved bioresorbable scaffold emphasizes the need to optimize the relationships between stent design and drug release with imposed arterial injury and observed pharmacodynamics. In this study, we examine the hypothesis that vascular injury is predictable from stent design and that the expanding force of stent deployment results in increased circumferential stress in the arterial tissue, which may explain acute injury poststent deployment. Using both numerical simulations and ex vivo experiments on three different stent designs (slotted tube, corrugated ring, and delta wing), arterial injury due to device deployment was examined. Furthermore, using numerical simulations, the consequence of changing stent strut radial thickness on arterial wall shear stress and arterial circumferential stress distributions was examined. Regions with predicted arterial circumferential stress exceeding a threshold of 49.5 kPa compared favorably with observed ex vivo endothelial denudation for the three considered stent designs. In addition, increasing strut thickness was predicted to result in more areas of denudation and larger areas exposed to low wall shear stress. We conclude that the acute arterial injury, observed immediately following stent expansion, is caused by high circumferential hoop stresses in the interstrut region, and denuded area profiles are dependent on unit cell geometric features. Such findings when coupled with where drugs move might explain the drug–device interactions.
Collapse
Affiliation(s)
- Claire Conway
- Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States.,Trinity Centre for Biomedical Engineering, Trinity College Dublin and Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Farhad R Nezami
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States.,Thoracic and Cardiac Surgery Division, Department of Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Campbell Rogers
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States.,Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States.,HeartFlow Inc., Redwood City, CA, United States
| | - Adam Groothuis
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States
| | - James C Squire
- Department of Electrical and Computer Engineering, Virginia Military Institute, Lexington City, KY, United States
| | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States.,Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| |
Collapse
|
3
|
Wiesent L, Spear A, Nonn A. Computational analysis of the effects of geometric irregularities on the interaction of an additively manufactured 316L stainless steel stent and a coronary artery. J Mech Behav Biomed Mater 2021; 125:104878. [PMID: 34655944 DOI: 10.1016/j.jmbbm.2021.104878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 09/24/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
Customized additively manufactured (laser powder bed fused (L-PBF)) stents could improve the treatment of complex lesions by enhancing stent-artery conformity. However, geometric irregularities inherent for L-PBF stents are expected to influence not only their mechanical behavior but also their interaction with the artery. In this study, the influence of geometrical irregularities on stent-artery interaction is evaluated within a numerical framework. Thus, computed arterial stresses induced by a reconstructed L-PBF stent model are compared to those induced by the intended stent model (also representing a stent geometry obtained from conventional manufacturing processes) and a modified CAD stent model that accounts for the increased strut thickness inherent for L-PBF stents. It was found that, similar to conventionally manufactured stents, arterial stresses are initially related to the basic stent design/topology, with the highest stresses occurring at the indentations of the stent struts. Compared to the stent CAD model, the L-PBF stent induces distinctly higher and more maximum volume stresses within the plaque and the arterial wall. In return, the modified CAD model overestimates the arterial stresses induced by the L-PBF stent due to its homogeneously increased strut thickness and thus its homogeneously increased geometric stiffness compared with the L-PBF stent. Therefore, the L-PBF-induced geometric irregularities must be explicitly considered when evaluating the L-PBF stent-induced stresses because the intended stent CAD model underestimates the arterial stresses, whereas the modified CAD model overestimates them. The arterial stresses induced by the L-PBF stent were still within the range of values reported for conventional stents in literature, suggesting that the use of L-PBF stents is conceivable in principle. However, because geometric irregularities, such as protruding features from the stent surface, could potentially damage the artery or lead to premature stent failure, further improvement of L-PBF stents is essential.
Collapse
Affiliation(s)
- Lisa Wiesent
- Computational Mechanics and Materials Lab, Department of Mechanical Engineering, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany; Technology Campus Neustadt a. d. Donau, Department of Mechanical Engineering, OTH Regensburg, Regensburg, Germany.
| | - Ashley Spear
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Aida Nonn
- Computational Mechanics and Materials Lab, Department of Mechanical Engineering, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany; Technology Campus Neustadt a. d. Donau, Department of Mechanical Engineering, OTH Regensburg, Regensburg, Germany
| |
Collapse
|
4
|
Helou B, Bel-Brunon A, Dupont C, Ye W, Silvestro C, Rochette M, Lucas A, Kaladji A, Haigron P. Influence of balloon design, plaque material composition, and balloon sizing on acute post angioplasty outcomes: An implicit finite element analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3499. [PMID: 33998779 DOI: 10.1002/cnm.3499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 05/08/2021] [Indexed: 06/12/2023]
Abstract
In this work we propose a generic modeling approach for simulating percutaneous transluminal angioplasty (PTA) endovascular treatment, and evaluating the influence of balloon design, plaque composition, and balloon sizing on acute post-procedural outcomes right after PTA, without stent implantation. Clinically-used PTA balloons were classified into two categories according to their compliance characteristics, and were modeled correspondingly. Self-defined elastoplastic constitutive laws were implemented within the plaque and artery models, after calibration based on experimental and clinical data. Finite element method (FEM) implicit solver was used to simulate balloon inflation and deflation. Besides balloon profile at max inflation, results are mainly assessed in terms of the elastic recoil ratio (ERR) and lumen gain ratio (LGR) obtained immediately after PTA. No variations in ERR nor LGR values were detected when the balloon design changed, despite the differences observed in their profile at max inflation. Moreover, LGR and ERR inversely varied with the augmentation of calcification level within the plaque (-11% vs. +4% respectively, from fully lipidic to fully calcified plaque). Furthermore, results showed a direct correlation between balloon sizing and LGR and ERR, with noticeably higher rates of change for LGR (+18% and +2% for LGR and ERR respectively for a calcified plaque and a balloon pressure increasing from 10 to 14 atm). However a larger LGR comes with a higher risk of arterial rupture. This proposed methodology opens the way for evaluation of angioplasty balloon selections towards clinical procedure optimization.
Collapse
Affiliation(s)
- Bernard Helou
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Aline Bel-Brunon
- Univ Lyon, INSA-Lyon, CNRS UMR5259, LaMCoS, Villeurbanne, France
| | - Claire Dupont
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | | | - Claudio Silvestro
- Medtronic, Aortic Peripheral & Venous (APV) Group, Santa Rosa, California, USA
| | | | - Antoine Lucas
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Adrien Kaladji
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Pascal Haigron
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| |
Collapse
|
5
|
Maes L, Cloet AS, Fourneau I, Famaey N. A homogenized constrained mixture model of restenosis and vascular remodelling after balloon angioplasty. J R Soc Interface 2021; 18:20210068. [PMID: 33947223 DOI: 10.1098/rsif.2021.0068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Restenosis is one of the main adverse effects of the treatment of atherosclerosis through balloon angioplasty or stenting. During the intervention, the arterial wall is overstretched, causing a cascade of cellular events and subsequent neointima formation. This mechanical stimulus and its mechanobiological effects can be reproduced in biomechanical simulations. The aim of these models is to predict the long-term outcome of these procedures, to help increase the understanding of restenosis formation and to allow for in silico optimization of the treatment. We propose a predictive finite-element model of restenosis, using the homogenized constrained mixture modelling framework designed to model growth and remodelling in soft tissues. We compare the results with clinical observations in human coronary arteries and experimental findings in non-human primate models. We also explore the model's clinical relevance by testing its response to different balloon loads and to the use of drug-eluting balloons. The comparison of the results with experimental data shows the relevance of the model. We show its ability to predict both inward and outward remodelling as observed in vivo and we show the importance of an improved understanding of restenosis formation from a biomechanical point of view.
Collapse
Affiliation(s)
- Lauranne Maes
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
| | - An-Sofie Cloet
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
| | - Inge Fourneau
- Department of Vascular Surgery, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Nele Famaey
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
| |
Collapse
|
6
|
Lin S, Dong P, Zhou C, Dallan LAP, Zimin VN, Pereira GTR, Lee J, Gharaibeh Y, Wilson DL, Bezerra HG, Gu L. Degradation modeling of poly-l-lactide acid (PLLA) bioresorbable vascular scaffold within a coronary artery. NANOTECHNOLOGY REVIEWS 2020; 9:1217-1226. [PMID: 34012762 PMCID: PMC8130847 DOI: 10.1515/ntrev-2020-0093] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this work, a strain-based degradation model was implemented and validated to better understand the dynamic interactions between the bioresorbable vascular scaffold (BVS) and the artery during the degradation process. Integrating the strain-modulated degradation equation into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both strut thinning and discontinuity of the stent struts within an artery were captured and visualized. The predicted results in terms of mass loss and fracture locations were validated by the documented experimental observations. In addition, results suggested that the heterogeneous degradation of the stent depends on its strain distribution following deployment. Degradation is faster at the locations with higher strains and resulted in the strut thinning and discontinuity, which contributes to the continuous mass loss, and the reduced contact force between the BVS and artery. A nonlinear relationship between the maximum principal strain of the stent and the fracture time was obtained, which could be transformed to predict the degradation process of the BVS in different mechanical environments. The developed computational model provided more insights into the degradation process, which could complement the discrete experimental data for improving the design and clinical management of the BVS.
Collapse
Affiliation(s)
- Shengmao Lin
- School of Civil Engineering and Architecture, Xiamen University of Technology, Xiamen, Fujian, 361024, China
| | - Pengfei Dong
- Department of Biomedical and Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, United States of America
| | - Changchun Zhou
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China
| | - Luis Augusto P Dallan
- Cardiovascular Imaging Core Laboratory, Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, United States of America
| | - Vladislav N Zimin
- Cardiovascular Imaging Core Laboratory, Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, United States of America
| | - Gabriel T R Pereira
- Cardiovascular Imaging Core Laboratory, Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, United States of America
| | - Juhwan Lee
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States of America
| | - Yazan Gharaibeh
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States of America
| | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States of America
| | - Hiram G Bezerra
- Interventional Cardiology Center, Heart and Vascular Institute, University of South Florida, Tampa, FL 33606, United States of America
| | - Linxia Gu
- Department of Biomedical and Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, United States of America
| |
Collapse
|
7
|
Díaz C, Peña JA, Martínez MA, Peña E. Unraveling the multilayer mechanical response of aorta using layer-specific residual stresses and experimental properties. J Mech Behav Biomed Mater 2020; 113:104070. [PMID: 33007727 DOI: 10.1016/j.jmbbm.2020.104070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/13/2022]
Abstract
To test the capability of the multilayer model, we used previously published layer-specific experimental data relating to the axial pre-stretch, the opening angle, the fiber distribution obtained by polarized light microscopy measurements, and the uniaxial and biaxial response of the porcine descending and abdominal aorta. We fitted the mechanical behavior of each arterial layer using Gasser, Holzapfel and Ogden strain energy function using the dispersion parameter κ as phenomenological parameter obtained during the fitting procedure or computed from the experimental fiber distribution. A multilayer finite element model of the whole aorta with the dimensions of the circumferential and longitudinal strips were then built using layer-specific material parameters previously fitted. This model was used to capture the whole aorta response under uniaxial and biaxial stress states and to reproduce the response of the whole aorta to internal pressure. Our results show that a model based on a multilayer structure without residual stresses is unable to render the uniaxial and biaxial mechanical response of the aorta (R2=0.6954 and R2=0.8582 for descending thoracic aorta (DTA) and infrarenal abdominal aorta (IAA), respectively). Only an appropriate multilayer model that includes layer-specific residual stresses can reproduce the response of the whole aorta (R2=0.9787 and R2=0.9636 for DTA and IAA respectively). In addition, a multilayer model without residual stresses produces the same stress distribution as a monolayer model without residual stresses where the maximal value of circumferential and longitudinal stresses appears at the inner radius of the intima. Finally, if layer-specific residual stresses are not available, there is less error the stress distribution using a monolayer model with residual stresses that a multilayer model without residual stresses.
Collapse
Affiliation(s)
- Clara Díaz
- Department of Mechanical Engineering, University of Zaragoza, Spain
| | - Juan A Peña
- Department of Management and Manufacturing Engineering, Faculty of Engineering and Architecture, University of Zaragoza, Spain; Applied Mechanics and Bioengineering, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain
| | - Miguel A Martínez
- Department of Mechanical Engineering, University of Zaragoza, Spain; Applied Mechanics and Bioengineering, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; CIBER de Bioingeniería, Biomaterials y Nanomedicine (CIBER-BBN), Zaragoza, Spain
| | - Estefanía Peña
- Department of Mechanical Engineering, University of Zaragoza, Spain; Applied Mechanics and Bioengineering, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; CIBER de Bioingeniería, Biomaterials y Nanomedicine (CIBER-BBN), Zaragoza, Spain.
| |
Collapse
|
8
|
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]
|
9
|
Escuer J, Cebollero M, Peña E, McGinty S, Martínez MA. How does stent expansion alter drug transport properties of the arterial wall? J Mech Behav Biomed Mater 2020; 104:103610. [DOI: 10.1016/j.jmbbm.2019.103610] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/23/2019] [Accepted: 12/29/2019] [Indexed: 11/28/2022]
|
10
|
Chen C, Chen J, Wu W, Shi Y, Jin L, Petrini L, Shen L, Yuan G, Ding W, Ge J, Edelman ER, Migliavacca F. In vivo and in vitro evaluation of a biodegradable magnesium vascular stent designed by shape optimization strategy. Biomaterials 2019; 221:119414. [PMID: 31419654 PMCID: PMC6732791 DOI: 10.1016/j.biomaterials.2019.119414] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 07/30/2019] [Accepted: 08/03/2019] [Indexed: 01/25/2023]
Abstract
The performance of biodegradable magnesium alloy stents (BMgS) requires special attention to non-uniform residual stress distribution and stress concentration, which can accelerate localized degradation after implantation. We now report on a novel concept in stent shape optimization using a finite element method (FEM) toolkit. A Mg-Nd-Zn-Zr alloy with uniform degradation behavior served as the basis of our BMgS. Comprehensive in vitro evaluations drove stent optimization, based on observed crimping and balloon inflation performance, measurement of radial strength, and stress condition validation via microarea-XRD. Moreover, a Rapamycin-eluting polymer coating was sprayed on the prototypical BMgS to improve the corrosion resistance and release anti-hyperplasia drugs. In vivo evaluation of the optimized coated BMgS was conducted in the iliac artery of New Zealand white rabbit with quantitative coronary angiography (QCA), optical coherence tomography (OCT) and micro-CT observation at 1, 3, 5-month follow-ups. Neither thrombus or early restenosis was observed, and the coated BMgS supported the vessel effectively prior to degradation and allowed for arterial healing thereafter. The proposed shape optimization framework based on FEM provides an novel concept in stent design and in-depth understanding of how deformation history affects the biomechanical performance of BMgS. Computational analysis tools can indeed promote the development of biodegradable magnesium stents.
Collapse
Affiliation(s)
- Chenxin Chen
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China; Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy
| | - Jiahui Chen
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Wei Wu
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy; Department of Mechanical Engineering, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249-0669, USA
| | - Yongjuan Shi
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Liang Jin
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Lorenza Petrini
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy
| | - Li Shen
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Guangyin Yuan
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Wenjiang Ding
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Junbo Ge
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy.
| |
Collapse
|
11
|
Boland EL, Grogan JA, McHugh PE. Computational modelling of magnesium stent mechanical performance in a remodelling artery: Effects of multiple remodelling stimuli. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3247. [PMID: 31393090 DOI: 10.1002/cnm.3247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 05/01/2019] [Accepted: 08/03/2019] [Indexed: 06/10/2023]
Abstract
Significant research has been conducted in the area of coronary stents/scaffolds made from resorbable metallic and polymeric biomaterials. These next-generation bioabsorbable stents have the potential to completely revolutionise the treatment of coronary artery disease. The primary advantage of resorbable devices over permanent stents is their temporary presence which, from a theoretical point of view, means only a healed coronary artery will be left behind following degradation of the stent potentially eliminating long-term clinical problems associated with permanent stents. The healing of the artery following coronary stent/scaffold implantation is crucial for the long-term safety of these devices. Computational modelling can be used to evaluate the performance of complex stent devices in silico and assist in the design and development and understanding of the next-generation resorbable stents. What is lacking in computational modelling literature is the representation of the active response of the arterial tissue in the weeks and months following stent implantation, ie, neointimal remodelling, in particular for the case of biodegradable stents. In this paper, a computational modelling framework is developed, which accounts for two major physiological stimuli responsible for neointimal remodelling and combined with a magnesium corrosion model that is capable of simulating localised pitting (realistic) stent corrosion. The framework is used to simulate different neointimal growth patterns and to explore the effects the neointimal remodelling has on the mechanical performance (scaffolding support) of the bioabsorbable magnesium stent.
Collapse
Affiliation(s)
- Enda L Boland
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - James A Grogan
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Peter E McHugh
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| |
Collapse
|
12
|
Escuer J, Martínez MA, McGinty S, Peña E. Mathematical modelling of the restenosis process after stent implantation. J R Soc Interface 2019; 16:20190313. [PMID: 31409233 DOI: 10.1098/rsif.2019.0313] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The stenting procedure has evolved to become a highly successful technique for the clinical treatment of advanced atherosclerotic lesions in arteries. However, the development of in-stent restenosis remains a key problem. In this work, a novel two-dimensional continuum mathematical model is proposed to describe the complex restenosis process following the insertion of a stent into a coronary artery. The biological species considered to play a key role in restenosis development are growth factors, matrix metalloproteinases, extracellular matrix, smooth muscle cells and endothelial cells. Diffusion-reaction equations are used for modelling the mass balance between species in the arterial wall. Experimental data from the literature have been used in order to estimate model parameters. Moreover, a sensitivity analysis has been performed to study the impact of varying the parameters of the model on the evolution of the biological species. The results demonstrate that this computational model qualitatively captures the key characteristics of the lesion growth and the healing process within an artery subjected to non-physiological mechanical forces. Our results suggest that the arterial wall response is driven by the damage area, smooth muscle cell proliferation and the collagen turnover among other factors.
Collapse
Affiliation(s)
- Javier Escuer
- Applied Mechanics and Bioengineering Group (AMB), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - Miguel A Martínez
- Applied Mechanics and Bioengineering Group (AMB), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - Sean McGinty
- Division of Biomedical Engineering, University of Glasgow, Glasgow, UK
| | - Estefanía Peña
- Applied Mechanics and Bioengineering Group (AMB), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| |
Collapse
|
13
|
Finite element evaluation of artery damage in deployment of polymeric stent with pre- and post-dilation. Biomech Model Mechanobiol 2019; 19:47-60. [PMID: 31317295 PMCID: PMC7005093 DOI: 10.1007/s10237-019-01194-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 06/21/2019] [Indexed: 12/02/2022]
Abstract
Using finite element method, this paper evaluates damage in an arterial wall and plaque caused by percutaneous coronary intervention. Hyperelastic damage models, calibrated with experimental results, are used to describe stress–stretch responses of arterial layers and plaque; these models are capable to simulate softening behaviour of the tissue due to damage. Abaqus CAE is employed to create the finite element models for the artery wall (with media and adventitia layers), a symmetric uniform plaque, a bioresorbable polymeric stent and a tri-folded expansion balloon. The effect of percutaneous coronary intervention on vessel damage is investigated by simulating the processes of vessel pre-dilation, stent deployment and post-stenting dilation. Energy dissipation density is used to assess the extent of damage in the tissue. Softening of the plaque and the artery, due to the pre-dilation-induced damage, can facilitate the subsequent stent deployment process. The plaque and the artery experienced heterogeneous damage behaviour after the stent deployment, caused by non-uniform deformation. The post-stenting dilation was effective to achieve a full expansion of the stent, but caused additional damage to the artery. The continuous and discontinuous damage models yielded similar results in the percutaneous coronary intervention simulations, while the incorporation of plaque rupture affected the simulated outcomes of stent deployment. The computational evaluation of the artery damage can be potentially used to assess the risk of in-stent restenosis after percutaneous coronary intervention.
Collapse
|
14
|
Maso Talou GD, Blanco PJ, Ares GD, Guedes Bezerra C, Lemos PA, Feijóo RA. Mechanical Characterization of the Vessel Wall by Data Assimilation of Intravascular Ultrasound Studies. Front Physiol 2018; 9:292. [PMID: 29643815 PMCID: PMC5882902 DOI: 10.3389/fphys.2018.00292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/12/2018] [Indexed: 12/24/2022] Open
Abstract
Atherosclerotic plaque rupture and erosion are the most important mechanisms underlying the sudden plaque growth, responsible for acute coronary syndromes and even fatal cardiac events. Advances in the understanding of the culprit plaque structure and composition are already reported in the literature, however, there is still much work to be done toward in-vivo plaque visualization and mechanical characterization to assess plaque stability, patient risk, diagnosis and treatment prognosis. In this work, a methodology for the mechanical characterization of the vessel wall plaque and tissues is proposed based on the combination of intravascular ultrasound (IVUS) imaging processing, data assimilation and continuum mechanics models within a high performance computing (HPC) environment. Initially, the IVUS study is gated to obtain volumes of image sequences corresponding to the vessel of interest at different cardiac phases. These sequences are registered against the sequence of the end-diastolic phase to remove transversal and longitudinal rigid motions prescribed by the moving environment due to the heartbeat. Then, optical flow between the image sequences is computed to obtain the displacement fields of the vessel (each associated to a certain pressure level). The obtained displacement fields are regarded as observations within a data assimilation paradigm, which aims to estimate the material parameters of the tissues within the vessel wall. Specifically, a reduced order unscented Kalman filter is employed, endowed with a forward operator which amounts to address the solution of a hyperelastic solid mechanics model in the finite strain regime taking into account the axially stretched state of the vessel, as well as the effect of internal and external forces acting on the arterial wall. Due to the computational burden, a HPC approach is mandatory. Hence, the data assimilation and computational solid mechanics computations are parallelized at three levels: (i) a Kalman filter level; (ii) a cardiac phase level; and (iii) a mesh partitioning level. To illustrate the capabilities of this novel methodology toward the in-vivo analysis of patient-specific vessel constituents, mechanical material parameters are estimated using in-silico and in-vivo data retrieved from IVUS studies. Limitations and potentials of this approach are exposed and discussed.
Collapse
Affiliation(s)
- Gonzalo D Maso Talou
- National Laboratory for Scientific Computing, Department of Mathematical and Computational Methods, Petrópolis, Brazil.,National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil
| | - Pablo J Blanco
- National Laboratory for Scientific Computing, Department of Mathematical and Computational Methods, Petrópolis, Brazil.,National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil
| | - Gonzalo D Ares
- National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil.,National Scientific and Technical Research Council, Buenos Aires, Argentina.,CAE Group, National University of Mar del Plata, Mar del Plata, Argentina
| | - Cristiano Guedes Bezerra
- National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil.,Department of Interventional Cardiology, Heart Institute (Incor), São Paulo, Brazil
| | - Pedro A Lemos
- National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil.,Department of Interventional Cardiology, Heart Institute (Incor), São Paulo, Brazil
| | - Raúl A Feijóo
- National Laboratory for Scientific Computing, Department of Mathematical and Computational Methods, Petrópolis, Brazil.,National Institute of Science and Technology in Medicine Assisted by Scientific Computing, São Paulo, Brazil
| |
Collapse
|
15
|
Syaifudin A, Takeda R, Sasaki K. Development of asymmetric stent for treatment of eccentric plaque. Biomed Mater Eng 2018; 29:299-317. [PMID: 29578470 DOI: 10.3233/bme-181737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The selection of stent and balloon type is decisive in the stenting process. In the treatment of an eccentric plaque obstruction, a symmetric expansion from stent dilatation generates nonuniform stress distribution, which may aggravate fibrous cap prone to rupture. This paper developed a new stent design to treat eccentric plaque using structural transient dynamic analysis in ANSYS. A non-symmetric structural geometry of stent is generated to obtain reasonable stress distribution safe for the arterial layer surrounding the stent. To derive the novel structural geometry, a Sinusoidal stent type is modified by varying struts length and width, adding bridges, and varying curvature width of struts. An end ring of stent struts was also modified to eliminate dogboning phenomenon and to reduce the Ectropion angle. Two balloon types were used to deploy the stent, an ordinary cylindrical and offset balloon. Positive modification results were used to construct the final non-symmetric stent design, called an Asymmetric stent. Analyses of the deformation characteristics, changes in surface roughness and induced stresses within intact arterial layer were subsequently examined. Interaction between the stent and vessel wall was implemented by means of changes in surface roughness and stress distribution analyses. The Palmaz and the Sinusoidal stent were used for a comparative study. This study indicated that the Asymmetric stent types reduced the central radial recoiling and the dogboning phenomenon. In terms of changes in surface roughness and induced stresses, the Asymmetric stent has a comparable effect with that of the Sinusoidal stent. In addition, it could enhance the distribution of surface roughening as expanded by an offset balloon.
Collapse
Affiliation(s)
- Achmad Syaifudin
- Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - Ryo Takeda
- Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Katsuhiko Sasaki
- Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| |
Collapse
|
16
|
Conway C, McGarry JP, Edelman ER, McHugh PE. Numerical Simulation of Stent Angioplasty with Predilation: An Investigation into Lesion Constitutive Representation and Calcification Influence. Ann Biomed Eng 2017; 45:2244-2252. [PMID: 28488215 DOI: 10.1007/s10439-017-1851-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 05/05/2017] [Indexed: 11/30/2022]
Abstract
It is acceptable clinical practice to predilate a severely occluded vessel to allow better positioning of endovascular stents, and while the impact of this intervention has been examined for aggregate response in animals there has been no means to examine whether there are specific vessels that might benefit. Finite element methods offer the singular ability to explore the mechanical response of arteries with specific pathologic alterations in mechanics to stenting and predilation. We examined varying representations of atherosclerotic tissue including homogeneous and heterogeneous dispersion of calcified particles, and elastic, pseudo-elastic, and elastic-plastic constitutive representations of bulk atherosclerotic tissue. The constitutive representations of the bulk atherosclerotic tissue were derived from experimental test data and highlight the importance of accounting for testing mode of loading. The impact of arterial predilation is presented and, in particular, its effect on intimal predicted damage, atherosclerotic tissue von Mises and maximum principal stresses, and luminal deformation was dependent on the type of constitutive representation of diseased tissue, particularly in the presence of calcifications.
Collapse
Affiliation(s)
- C Conway
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland.
- Institute for Medical Engineering and Science (IMES), Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - J P McGarry
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - E R Edelman
- Institute for Medical Engineering and Science (IMES), Massachusetts Institute of Technology, Cambridge, MA, USA
- Cardiovascular Division, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA
| | - P E McHugh
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| |
Collapse
|
17
|
Boland EL, Grogan JA, McHugh PE. Computational Modeling of the Mechanical Performance of a Magnesium Stent Undergoing Uniform and Pitting Corrosion in a Remodeling Artery. J Med Device 2017. [DOI: 10.1115/1.4035895] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Coronary stents made from degradable biomaterials such as magnesium alloy are an emerging technology in the treatment of coronary artery disease. Biodegradable stents provide mechanical support to the artery during the initial scaffolding period after which the artery will have remodeled. The subsequent resorption of the stent biomaterial by the body has potential to reduce the risk associated with long-term placement of these devices, such as in-stent restenosis, late stent thrombosis, and fatigue fracture. Computational modeling such as finite-element analysis has proven to be an extremely useful tool in the continued design and development of these medical devices. What is lacking in computational modeling literature is the representation of the active response of the arterial tissue in the weeks and months following stent implantation, i.e., neointimal remodeling. The phenomenon of neointimal remodeling is particularly interesting and significant in the case of biodegradable stents, when both stent degradation and neointimal remodeling can occur simultaneously, presenting the possibility of a mechanical interaction and transfer of load between the degrading stent and the remodeling artery. In this paper, a computational modeling framework is developed that combines magnesium alloy degradation and neointimal remodeling, which is capable of simulating both uniform (best case) and localized pitting (realistic) stent corrosion in a remodeling artery. The framework is used to evaluate the effects of the neointima on the mechanics of the stent, when the stent is undergoing uniform or pitting corrosion, and to assess the effects of the neointimal formation rate relative to the overall stent degradation rate (for both uniform and pitting conditions).
Collapse
Affiliation(s)
- Enda L. Boland
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland e-mail:
| | - James A. Grogan
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland
| | - Peter E. McHugh
- Professor Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland e-mail:
| |
Collapse
|
18
|
Deokar RR, Klamecki BE. Computational Modeling and Comparative Tissue Damage Analysis of Angioplasty and Orbital Atherectomy Interventional Procedures. J Med Device 2017. [DOI: 10.1115/1.4036299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This research was directed toward quantitatively characterizing the effects of arterial mechanical treatment procedures on the stress and strain energy states of the artery wall. Finite element simulations of percutaneous transluminal angioplasty (PTA) and orbital atherectomy (OA) were performed on arterial lesion models with various extents and types of plaque. Stress fields in the artery were calculated and strain energy density was used as an explicit description of potential damage to the artery. The research also included numerical simulations of changes in arterial compliance due to orbital atherectomy. The angioplasty simulations show that the damage energy fields in the media and adventitia are predominant in regions of the lesion that are not protected by a layer of calcification. In addition, it was observed that softening the plaque components leads to a lower peak stress and therefore lesser damage energy in the media and adventitia under the action of a semicompliant balloon. Orbital atherectomy simulations revealed that the major portion of strain energy dissipated is concentrated in the plaque components in contact with the spinning tool. The damage and peak stress fields in the media and adventitia components of the vessel were significantly less. This observation suggests less mechanically induced trauma during a localized procedure like orbital atherectomy. Artery compliance was calculated pre- and post-treatment and an increase was observed after the orbital atherectomy procedure. The localized plaque disruption produced in atherectomy suggests that the undesirable stress states in angioplasty can be mitigated by a combination of procedures such as atherectomy followed by angioplasty.
Collapse
Affiliation(s)
- Rohit R. Deokar
- Department of Mechanical Engineering, University of Minnesota—Twin Cities, 111 Church Street SE, Minneapolis, MN 55455 e-mail:
| | - Barney E. Klamecki
- Department of Mechanical Engineering, University of Minnesota—Twin Cities, 111 Church Street SE, Minneapolis, MN 55455 e-mail:
| |
Collapse
|
19
|
Vo T, Lee W, Peddle A, Meere M. Modelling chemistry and biology after implantation of a drug-eluting stent. Part I: Drug transport. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2017; 14:491-509. [PMID: 27879111 DOI: 10.3934/mbe.2017030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Drug-eluting stents have been used widely to prevent restenosis of arteries following percutaneous balloon angioplasty. Mathematical modelling plays an important role in optimising the design of these stents to maximise their efficiency. When designing a drug-eluting stent system, we expect to have a sufficient amount of drug being released into the artery wall for a sufficient period to prevent restenosis. In this paper, a simple model is considered to provide an elementary description of drug release into artery tissue from an implanted stent. From the model, we identified a parameter regime to optimise the system when preparing the polymer coating. The model provides some useful order of magnitude estimates for the key quantities of interest. From the model, we can identify the time scales over which the drug traverses the artery wall and empties from the polymer coating, as well as obtain approximate formulae for the total amount of drug in the artery tissue and the fraction of drug that has released from the polymer. The model was evaluated by comparing to in-vivo experimental data and good agreement was found.
Collapse
Affiliation(s)
- Tuoi Vo
- Mathematics Applications Consortium for Science and Industry, University of Limerick, Castletroy, Co. Limerick, Ireland.
| | | | | | | |
Collapse
|
20
|
Numerical Modeling of Nitinol Stent Oversizing in Arteries with Clinically Relevant Levels of Peripheral Arterial Disease: The Influence of Plaque Type on the Outcomes of Endovascular Therapy. Ann Biomed Eng 2017; 45:1420-1433. [PMID: 28150055 DOI: 10.1007/s10439-017-1803-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 01/27/2017] [Indexed: 10/20/2022]
|
21
|
McGrath D, O’Brien B, Bruzzi M, Kelly N, Clauser J, Steinseifer U, McHugh P. Evaluation of cover effects on bare stent mechanical response. J Mech Behav Biomed Mater 2016; 61:567-580. [DOI: 10.1016/j.jmbbm.2016.04.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/25/2016] [Accepted: 04/15/2016] [Indexed: 11/28/2022]
|
22
|
Experimental and computational study of mechanical and transport properties of a polymer coating for drug-eluting stents. Ther Deliv 2015; 6:1255-68. [DOI: 10.4155/tde.15.74] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Background: Experimental and computational characterizations in the preclinical development of biomedical devices are complementary and can significantly help in a thorough analysis of the performances before clinical evaluation. Methodology: Here mechanical and drug delivery properties of a polymer platform, ad hoc prepared to obtain coatings for drug-eluting stents, is reported; polymer formulation and starting drug loading were varied to study the behavior of the platform; a finite element model was constructed starting from experimental data. Results: Different platform formulations affected mechanical and drug transport properties; these properties can be fine tuned by varying the starting platform formulation. Finite element analysis allowed visualizing drug distribution maps over time in biological tissues for different commercial stents and polymer platform formulations.
Collapse
|
23
|
Structural Mechanics Predictions Relating to Clinical Coronary Stent Fracture in a 5 Year Period in FDA MAUDE Database. Ann Biomed Eng 2015; 44:391-403. [PMID: 26467552 DOI: 10.1007/s10439-015-1476-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 09/25/2015] [Indexed: 10/22/2022]
Abstract
Endovascular stents are the mainstay of interventional cardiovascular medicine. Technological advances have reduced biological and clinical complications but not mechanical failure. Stent strut fracture is increasingly recognized as of paramount clinical importance. Though consensus reigns that fractures can result from material fatigue, how fracture is induced and the mechanisms underlying its clinical sequelae remain ill-defined. In this study, strut fractures were identified in the prospectively maintained Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience Database (MAUDE), covering years 2006-2011, and differentiated based on specific coronary artery implantation site and device configuration. These data, and knowledge of the extent of dynamic arterial deformations obtained from patient CT images and published data, were used to define boundary conditions for 3D finite element models incorporating multimodal, multi-cycle deformation. The structural response for a range of stent designs and configurations was predicted by computational models and included estimation of maximum principal, minimum principal and equivalent plastic strains. Fatigue assessment was performed with Goodman diagrams and safe/unsafe regions defined for different stent designs. Von Mises stress and maximum principal strain increased with multimodal, fully reversed deformation. Spatial maps of unsafe locations corresponded to the identified locations of fracture in different coronary arteries in the clinical database. These findings, for the first time, provide insight into a potential link between patient adverse events and computational modeling of stent deformation. Understanding of the mechanical forces imposed under different implantation conditions may assist in rational design and optimal placement of these devices.
Collapse
|
24
|
McHugh PE, Grogan JA, Conway C, Boland E. Computational Modeling for Analysis and Design of Metallic Biodegradable Stents1. J Med Device 2015. [DOI: 10.1115/1.4030576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Peter E. McHugh
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Galway, Ireland
| | - James A. Grogan
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Galway, Ireland
| | - Claire Conway
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Galway, Ireland
| | - Enda Boland
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Galway, Ireland
| |
Collapse
|
25
|
Gökgöl C, Diehm N, Nezami FR, Büchler P. Nitinol Stent Oversizing in Patients Undergoing Popliteal Artery Revascularization: A Finite Element Study. Ann Biomed Eng 2015; 43:2868-80. [PMID: 26101031 DOI: 10.1007/s10439-015-1358-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/09/2015] [Indexed: 11/26/2022]
Abstract
Nitinol stent oversizing is frequently performed in peripheral arteries to ensure a desirable lumen gain. However, the clinical effect of mis-sizing remains controversial. The goal of this study was to provide a better understanding of the structural and hemodynamic effects of Nitinol stent oversizing. Five patient-specific numerical models of non-calcified popliteal arteries were developed to simulate the deployment of Nitinol stents with oversizing ratios ranging from 1.1 to 1.8. In addition to arterial biomechanics, computational fluid dynamics methods were adopted to simulate the physiological blood flow inside the stented arteries. Results showed that stent oversizing led to a limited increase in the acute lumen gain, albeit at the cost of a significant increase in arterial wall stresses. Furthermore, localized areas affected by low Wall Shear Stress increased with higher oversizing ratios. Stents were also negatively impacted by the procedure as their fatigue safety factors gradually decreased with oversizing. These adverse effects to both the artery walls and stents may create circumstances for restenosis. Although the ideal oversizing ratio is stent-specific, this study showed that Nitinol stent oversizing has a very small impact on the immediate lumen gain, which contradicts the clinical motivations of the procedure.
Collapse
Affiliation(s)
- Can Gökgöl
- Institute for Surgical Technology & Biomechanics, University of Bern, Bern, Switzerland
| | - Nicolas Diehm
- Clinical and Interventional Angiology, Kantonsspital Aarau, Tellstrasse, Aarau, 5001, Switzerland.
- University of Applied Sciences Furtwangen, Villingen-Schwenningen, Germany.
| | - Farhad Rikhtegar Nezami
- Institute for Surgical Technology & Biomechanics, University of Bern, Bern, Switzerland
- Harvard-MIT Biomedical Engineering Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Philippe Büchler
- Institute for Surgical Technology & Biomechanics, University of Bern, Bern, Switzerland
| |
Collapse
|
26
|
Migliavacca F, Chiastra C, Chatzizisis YS, Dubini G. Virtual bench testing to study coronary bifurcation stenting. EUROINTERVENTION 2015; 11 Suppl V:V31-4. [DOI: 10.4244/eijv11sva7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|