1
|
Kalogeropoulou M, Kracher A, Fucile P, Mihăilă SM, Moroni L. Blueprints of Architected Materials: A Guide to Metamaterial Design for Tissue Engineering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2408082. [PMID: 39370588 DOI: 10.1002/adma.202408082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 09/09/2024] [Indexed: 10/08/2024]
Abstract
Mechanical metamaterials are rationally designed structures engineered to exhibit extraordinary properties, often surpassing those of their constituent materials. The geometry of metamaterials' building blocks, referred to as unit cells, plays an essential role in determining their macroscopic mechanical behavior. Due to their hierarchical design and remarkable properties, metamaterials hold significant potential for tissue engineering; however their implementation in the field remains limited. The major challenge hindering the broader use of metamaterials lies in the complexity of unit cell design and fabrication. To address this gap, a comprehensive guide is presented detailing the design principles of well-established metamaterials. The essential unit cell geometric parameters and design constraints, as well as their influence on mechanical behavior, are summarized highlighting essential points for effective fabrication. Moreover, the potential integration of artificial intelligence techniques is explored in meta-biomaterial design for patient- and application-specific design. Furthermore, a comprehensive overview of current applications of mechanical metamaterials is provided in tissue engineering, categorized by tissue type, thereby showcasing the versatility of different designs in matching the mechanical properties of the target tissue. This review aims to provide a valuable resource for tissue engineering researchers and aid in the broader use of metamaterials in the field.
Collapse
Affiliation(s)
- Maria Kalogeropoulou
- Complex Tissue Regeneration Department, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Anna Kracher
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, Utrecht, 3584 CG, The Netherlands
| | - Pierpaolo Fucile
- Complex Tissue Regeneration Department, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Silvia M Mihăilă
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, Utrecht, 3584 CG, The Netherlands
| | - Lorenzo Moroni
- Complex Tissue Regeneration Department, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, 6229 ER, The Netherlands
| |
Collapse
|
2
|
Pham J, Kong F, James DL, Feinstein JA, Marsden AL. Deforming Patient-Specific Models of Vascular Anatomies to Represent Stent Implantation via Extended Position Based Dynamics. Cardiovasc Eng Technol 2024:10.1007/s13239-024-00752-z. [PMID: 39354259 DOI: 10.1007/s13239-024-00752-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 09/05/2024] [Indexed: 10/03/2024]
Abstract
PURPOSE Angioplasty with stent placement is a widely used treatment strategy for patients with stenotic blood vessels. However, it is often challenging to predict the outcomes of this procedure for individual patients. Image-based computational fluid dynamics (CFD) is a powerful technique for making these predictions. To perform CFD analysis of a stented vessel, a virtual model of the vessel must first be created. This model is typically made by manipulating two-dimensional contours of the vessel in its pre-stent state to reflect its post-stent shape. However, improper contour-editing can cause invalid geometric artifacts in the resulting mesh that then distort the subsequent CFD predictions. To address this limitation, we have developed a novel shape-editing method that deforms surface meshes of stenosed vessels to create stented models. METHODS Our method uses physics-based simulations via Extended Position Based Dynamics to guide these deformations. We embed an inflating stent inside a vessel and apply collision-generated forces to deform the vessel and expand its cross-section. RESULTS We demonstrate that this technique is feasible and applicable for a wide range of vascular anatomies, while yielding clinically compatible results. We also illustrate the ability to parametrically vary the stented shape and create models allowing CFD analyses. CONCLUSION Our stenting method will help clinicians predict the hemodynamic results of stenting interventions and adapt treatments to achieve target outcomes for patients. It will also enable generation of synthetic data for data-intensive applications, such as machine learning, to support cardiovascular research endeavors.
Collapse
Affiliation(s)
- Jonathan Pham
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Fanwei Kong
- Department of Pediatrics, Stanford University, Stanford, CA, USA
| | - Doug L James
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Jeffrey A Feinstein
- Department of Pediatrics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Alison L Marsden
- Department of Pediatrics, Stanford University, Stanford, CA, USA.
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
| |
Collapse
|
3
|
Psarras S, Skafidas AN, Kostopoulos V. In Silico Investigation of the Interlaminar and Mechanical Fracture of Arteries with Atheromatic Plaque during Angioplasty Treatment. Biomedicines 2024; 12:2105. [PMID: 39335617 PMCID: PMC11429184 DOI: 10.3390/biomedicines12092105] [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: 08/02/2024] [Revised: 09/02/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024] Open
Abstract
The reduction in the inner diameter of the artery due to the creation of atheromatic plaque on the artery lumen, known as artery stenosis, disrupts the blood flow, leading to medical complications, which can be fatal. The angioplasty procedure aims to reopen the artery and uses a stent to keep it open. In this study, an effort is made to determine the point of the stent, the plaque and the artery during the expansion phase of the angioplasty using the in silico Finite Element Analysis method. A literature-based design was chosen for the stent geometry, whereas simplified shapes of the balloon and the two artery layers were used. Additionally, two plaque designs were the benchmark for the eight distinct artery stenosis models within the Abaqus environment. In the context of stent angioplasty simulations, failure patterns were investigated. An inverse relationship was observed between artery stenosis and pressure at the artery failure point, while an increased danger of interlaminar failure was detected in models with larger artery stenosis. This study verifies the necessity for the inclusion of interlaminar failure in future angioplasty research.
Collapse
Affiliation(s)
- Spyridon Psarras
- Department of Mechanical Engineering and Aeronautics, University of Patras, 26504 Patras, Greece
| | | | | |
Collapse
|
4
|
Teong YW, Mustapha KB, Ibitoye MO. Finite element analysis and surrogate-optimized design of a nature-inspired auxetic stent. Comput Methods Biomech Biomed Engin 2024:1-17. [PMID: 39256915 DOI: 10.1080/10255842.2024.2399018] [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: 10/09/2023] [Revised: 02/06/2024] [Accepted: 08/21/2024] [Indexed: 09/12/2024]
Abstract
Prior studies have revealed that the structural design of stents is critical to reducing some of the alarming post-operative complications associated with stent-related intervention. However, the technical search for stents that guarantee robustness against stent-induced post-intervention complications remains an open problem. Along this objective, this study investigates a re-entrant auxetic stent's structural response and performance optimizations. In pursuit of the goal, a nonlinear finite element analysis (FEA) is employed to uncover metrics characterizing the auxetic stent's mechanical behavior. Subsequently, the non-dominated sorting genetic algorithm (NSGA-II) is implemented to simultaneously minimize the stent's von Mises stress and the elastic radial recoil (ERR). Results from the FEA revealed a tight connection between the stent's response and the features of the base auxetic building block (the rib length, strut width, and the re-entrant angle). It is observed that the auxetic stent exhibits a much lower ERR. Besides, larger values of its rib length and re-entrant angle are noticed to favor smaller von Mises stress. The Pareto-optimal front from the NSGA-II-based optimization scheme revealed a sharp trade-off in the simultaneous minimization of the von Mises stress and the ERR. Moreover, an optimal combination of the auxetic unit cell's geometric parameters is found to yield a much lower maximum von Mises stress of ≈ 403 MPa and ERR of ≈ 0.4 % .
Collapse
Affiliation(s)
- Y W Teong
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (Malaysia Campus), Semenyih, Malaysia
| | - K B Mustapha
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (Malaysia Campus), Semenyih, Malaysia
| | | |
Collapse
|
5
|
Liu H, Li X, Bamba AL, Song X, Brott BC, Litovsky SH, Gan Y. Toward reliable calcification detection: calibration of uncertainty in object detection from coronary optical coherence tomography images. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:036008. [PMID: 36992694 PMCID: PMC10042069 DOI: 10.1117/1.jbo.28.3.036008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
SIGNIFICANCE Optical coherence tomography (OCT) has become increasingly essential in assisting the treatment of coronary artery disease (CAD). However, unidentified calcified regions within a narrowed artery could impair the outcome of the treatment. Fast and objective identification is paramount to automatically procuring accurate readings on calcifications within the artery. AIM We aim to rapidly identify calcification in coronary OCT images using a bounding box and reduce the prediction bias in automated prediction models. APPROACH We first adopt a deep learning-based object detection model to rapidly draw the calcified region from coronary OCT images using a bounding box. We measure the uncertainty of predictions based on the expected calibration errors, thus assessing the certainty level of detection results. To calibrate confidence scores of predictions, we implement dependent logistic calibration using each detection result's confidence and center coordinates. RESULTS We implemented an object detection module to draw the boundary of the calcified region at a rate of 140 frames per second. With the calibrated confidence score of each prediction, we lower the uncertainty of predictions in calcification detection and eliminate the estimation bias from various object detection methods. The calibrated confidence of prediction results in a confidence error of ∼ 0.13 , suggesting that the confidence calibration on calcification detection could provide a more trustworthy result. CONCLUSIONS Given the rapid detection and effective calibration of the proposed work, we expect that it can assist in clinical evaluation of treating the CAD during the imaging-guided procedure.
Collapse
Affiliation(s)
- Hongshan Liu
- Stevens Institute of Technology, Biomedical Engineering Department, Hoboken, New Jersey, United States
| | - Xueshen Li
- Stevens Institute of Technology, Biomedical Engineering Department, Hoboken, New Jersey, United States
| | - Abdul Latif Bamba
- Columbia University, Department of Electrical Engineering, New York, United States
| | - Xiaoyu Song
- Icahn School of Medicine at Mount Sinai, New York, United States
| | - Brigitta C. Brott
- University of Alabama at Birmingham, School of Medicine, Birmingham, Alabama, United States
| | - Silvio H. Litovsky
- University of Alabama at Birmingham, School of Medicine, Birmingham, Alabama, United States
| | - Yu Gan
- Stevens Institute of Technology, Biomedical Engineering Department, Hoboken, New Jersey, United States
| |
Collapse
|
6
|
Development of 3D printable bioresorbable drug eluting coronary stents: An experimental and computational investigation. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
7
|
InSilc Computational Tool for In Silico Optimization of Drug-Eluting Bioresorbable Vascular Scaffolds. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:5311208. [PMID: 36105243 PMCID: PMC9467806 DOI: 10.1155/2022/5311208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/12/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022]
Abstract
Stents made by different manufacturers must meet the requirements of standard in vitro mechanical tests performed under different physiological conditions in order to be validated. In addition to in vitro research, there is a need for in silico numerical simulations that can help during the stent prototyping phase. In silico simulations have the ability to give the same stent responses as well as the potential to reduce costs and time needed to carry out experimental tests. The goal of this paper is to show the achievements of the computational platform created as a result of the EU-funded project InSilc, used for numerical testing of most standard tests for validation of preproduction bioresorbable vascular scaffolds (BVSs). Within the platform, an ad hoc simulation protocol has been developed based on the finite element (FE) analysis program PAK and user interface software CAD Field and Solid. Two different designs of two different stents have been numerically simulated using this integrated tool, and the results have been demonstrated. The following standard tests have been performed: longitudinal tensile strength, local compression, kinking, and flex 1-3. Strut thickness and additional pocket holes (slots) in two different scaffolds have been used as representative parameters for comparing the mechanical characteristics of the stents (AB-BVS vs. AB-BVS-thinner and PLLA-prot vs. PLLA-plot-slot). The AB-BVS-thinner prototype shows better overall stress distribution than the AB-BVS, while the PLLA-prot shows better overall stress distribution in comparison to the PLLA-plot-slot. In all cases, the values of the maximum effective stresses are below 220 MPa—the value obtained by in vitro experiment. Despite the presented results, additional considerations should be included before the proposed software can be used as a validation tool for stent prototyping.
Collapse
|
8
|
Alizadeh M, Aghajani Koopaie A, Shakeri Jousheghan S. Investigation of changing geometry parameters of nickel-titanium shape memory alloys wire stent in cardiovascular implants. Comput Methods Biomech Biomed Engin 2022; 26:952-959. [PMID: 35855667 DOI: 10.1080/10255842.2022.2100701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The purpose of this investigation was to assess the effects of changing the Nitinol stent's geometrical characteristics on the superelastic behavior of the stent using the finite element method. Four different geometrical parameters were considered and analyzed in sixteen stents. These geometrical parameters consisted of stent length, number of stent's meanders, inside diameter of the stent and wire diameter. Results showed that decreasing either stent length or the number of stent meanders and increasing either the inside diameter of the stent or wire diameter generally result in more sensible superelastic behavior exposure. The effect of changing stent length is independent of the inside diameter and number of the stent's meanders. Effects of changing inside diameter and number of stent's meanders were exactly dependent together. In addition, increasing wire diameter has a great effect on the maximum force. In conclusion, the results of this study may serve as guidelines for future stent design.
Collapse
Affiliation(s)
- Mansour Alizadeh
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
| | | | | |
Collapse
|
9
|
Pan C, Zeng X, Han Y, Lu J. Investigation of braided stents in curved vessels in terms of "Dogbone" deformation. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:5717-5737. [PMID: 35603375 DOI: 10.3934/mbe.2022267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
"Dogbone" deformation that the diameters of two ends are larger than the middle diameter of the stent under the effect of the balloon expanding, is one of the important standards to evaluate the mechanical properties of vascular stents. It is a huge challenge to simulate and evaluate the "Dogbone" behaviors of braided stents in the curved vessels. In this study, the key work was to investigate the "Dogbone" deformations of braided stents in the curved vessels by designing main parameters including strut diameter, braiding angle, and the circumferential number of unit cell. Based on the "Dogbone" stents in the curved vessels, the impact of "Dogbone" on the fatigue properties of braided stents was analyzed under the pulsatile effect of vessels. The influence of "Dogbone" stents on stress distribution of vascular walls was studied. To evaluate the "Dogbone" behaviors of stents in the curved vessels, the calculation method of "Dogbone" was improved by calculating the centerline and the bus bar of the curved vessels. Braided stents with various parameters (strut diameter t = 100,125 and 152 μm, braiding angle α = 30, 40 and 50°, the circumferential number of unit cell N = 8, 10, and 12) were designed respectively. Numerical simulation method was used to mimic the "Dogbone" deformation after stent expansion. The results showed that strut diameter and braiding angle had more influence on "Dogbone" deformations than the circumferential number of unit cell. "Dogbone" deformation could adversely affect fatigue performance and vascular walls.
Collapse
Affiliation(s)
- Chen Pan
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
| | - Xinyun Zeng
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
| | - Yafeng Han
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jiping Lu
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
| |
Collapse
|
10
|
Hoddy B, Ahmed N, Al-Lamee K, Bullett N, Curzen N, Bressloff NW. Investigating the Equivalent Plastic Strain in a Variable Ring Length and Strut Width Thin-Strut Bioresorbable Scaffold. Cardiovasc Eng Technol 2022; 13:899-914. [PMID: 35819580 PMCID: PMC9750924 DOI: 10.1007/s13239-022-00625-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 04/18/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE The ArterioSorb[Formula: see text] bioresorbable scaffold (BRS) developed by Arterius Ltd is about to enter first in man clinical trials. Previous generations of BRS have been vulnerable to brittle fracture, when expanded via balloon inflation in-vivo, which can be extremely detrimental to patient outcome. Therefore, this study explores the effect of variable ring length and strut width (as facilitated by the ArterioSorb[Formula: see text] design) on fracture resistance via analysis of the distribution of equivalent plastic strain in the scaffold struts post expansion. Scaffold performance is also assessed with respect to side branch access, radial strength, final deployed diameter and percentage recoil. METHODS Finite element analysis was conducted of the crimping, expansion and radial crushing of five scaffold designs comprising different variations in ring length and strut width. The Abaqus/Explicit (DS SIMULIA) solution method was used for all simulations. Direct comparison between in-silico predictions and in-vitro measurements of the performance of the open cell variant of the ArterioSorb[Formula: see text] were made. Paths across the width of the crown apex and around the scaffold rings were defined along which the plastic strain distribution was analysed. RESULTS The in-silico results demonstrated good predictions of final shape for the baseline scaffold design. Percentage recoil and radial strength were predicted to be, respectively, 2.8 and 1.7 times higher than the experimentally measured values, predominantly due to the limitations of the anisotropic elasto-plastic material property model used for the scaffold. Average maximum values of equivalent plastic strain were up to 2.4 times higher in the wide strut designs relative to the narrow strut scaffolds. As well as the concomitant risk of strut fracture, the wide strut designs also exhibited twisting and splaying behaviour at the crowns located on the scaffold end rings. Not only are these phenomena detrimental to the radial strength and risk of strut fracture but they also increase the likelihood of damage to the vessel wall. However, the baseline scaffold design was observed to tolerate significant over expansion without inducing excessive plastic strains, a result which is particularly encouraging, due to post-dilatation being commonplace in clinical practice. CONCLUSION Therefore, the narrow strut designs investigated herein, are likely to offer optimal performance and potentially better patient outcomes. Further work should address the material modelling of next generation polymeric BRS to more accurately capture their mechanical behaviour. Observation of the in-vitro testing indicates that the ArterioSorb[Formula: see text] BRS can tolerate greater levels of over expansion than anticipated.
Collapse
Affiliation(s)
- Ben Hoddy
- grid.5491.90000 0004 1936 9297Computational Engineering and Design Research Group, University of Southampton, Southampton, UK
| | - Naveed Ahmed
- grid.498018.c0000 0004 0581 8370Arterius Ltd, Leeds, UK
| | | | - Nial Bullett
- grid.498018.c0000 0004 0581 8370Arterius Ltd, Leeds, UK
| | - Nick Curzen
- grid.430506.40000 0004 0465 4079Coronary Research Group, Southampton University Hospitals NHS Trust, Southampton, UK ,grid.5491.90000 0004 1936 9297Faculty of Medicine, University of Southampton, Southampton, UK
| | - Neil W. Bressloff
- grid.5491.90000 0004 1936 9297Computational Engineering and Design Research Group, University of Southampton, Southampton, UK
| |
Collapse
|
11
|
Kokkinos C, Drakoulas G, Fotiadis D, Kokkinos S, Loukas K, Moulas AN, Semertzioglou A. FEA of Drug-Eluting Stents and Sensitivity Analysis of a Continuum Damage Model for the Degradation of PLGA Coating. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:4324-4328. [PMID: 34892178 DOI: 10.1109/embc46164.2021.9630612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Drug-Eluting Stents (DES) are commonly used in coronary angioplasty operations as a solution against artery stenosis and restenosis. Computational Bioengineering allows for the in-silico analysis of their performance. The scope of this work is to develop a DES Digital Twin, focusing on the mechanical integrity of its biodegradable coating throughout the operational lifecycle. The implementation leverages the Finite Element Method (FEM) to compute the developed mechanical stress field on the DES during the inflation/deflation stage, followed by the degradation of the polymer-based coating. The simulation of the degradation process is based on a Continuum Damage Mechanics (CDM) model that considers bulk degradation. The CDM algorithm is implemented on the NX Nastran solver through a user-defined material (UMAT) subroutine. For benchmarking purposes and to compare with the baseline design of the BioCoStent project, this conceptual study implements an alternative stent design, to study the effect of the geometry on the developed stresses. Additionally, the effect of the degradation rate on the polymer-based coating's lifecycle is studied via sensitivity analysis.
Collapse
|
12
|
Russ JB, Li RL, Herschman AR, Waisman H, Vedula V, Kysar JW, Kalfa D. Design optimization of a cardiovascular stent with application to a balloon expandable prosthetic heart valve. MATERIALS & DESIGN 2021; 209:109977. [PMID: 34366534 PMCID: PMC8336925 DOI: 10.1016/j.matdes.2021.109977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A cardiovascular stent design optimization method is proposed with application to a pediatric balloon-expandable prosthetic heart valve. The prosthetic valved conduit may be expanded to a larger permanent diameter in vivo via subsequent transcatheter balloon dilation procedures. While multiple expandable prosthetic heart valves are currently at different stages of development, this work is focused on one particular design in which a stent is situated inside of an expandable polymeric valved conduit. Since the valve and conduit must be joined with a robust manufacturing technique, a polymeric glue layer is inserted between the two, which results in radial retraction of the valved region after expansion. Design of an appropriate stent is proposed to counteract this phenomenon and maintain the desired permanent diameter throughout the device after a single non-compliant balloon dilation procedure. The finite element method is used to compute performance metrics related to the permanent expansion diameter and required radial force. Additionally, failure due not only to high cycle fatigue but also due to ductile fracture is incorporated into the design study through the use of an existing ductile fracture criterion for metals. Surrogate models are constructed with the results of the high fidelity simulations and are subsequently used to numerically obtain a set of Pareto-optimal stent designs. Finally, a single design is identified by optimizing a normalized aggregate objective function with equal weighting of all design objectives.
Collapse
Affiliation(s)
- Jonathan B. Russ
- Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, USA
| | - Richard L. Li
- Columbia University, Department of Mechanical Engineering, New York, NY, USA
- Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Medical Center, New York, NY, USA
| | - Abigail R. Herschman
- Columbia University, Department of Mechanical Engineering, New York, NY, USA
- Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Medical Center, New York, NY, USA
| | - Haim Waisman
- Columbia University, Department of Civil Engineering and Engineering Mechanics, New York, NY, USA
| | - Vijay Vedula
- Columbia University, Department of Mechanical Engineering, New York, NY, USA
| | - Jeffrey W. Kysar
- Columbia University, Department of Mechanical Engineering, New York, NY, USA
- Department of Otolaryngology Head and Neck Surgery, Columbia University Medical Center, New York, NY, USA
| | - David Kalfa
- Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Medical Center, New York, NY, USA
| |
Collapse
|
13
|
Milosevic M, Anic M, Nikolic D, Geroski V, Milicevic B, Kojic M, Filipovic N. Application of in silico Platform for the Development and Optimization of Fully Bioresorbable Vascular Scaffold Designs. FRONTIERS IN MEDICAL TECHNOLOGY 2021; 3:724062. [PMID: 35047953 PMCID: PMC8757700 DOI: 10.3389/fmedt.2021.724062] [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: 06/11/2021] [Accepted: 09/08/2021] [Indexed: 11/29/2022] Open
Abstract
Bioresorbable vascular scaffolds (BVS), made either from polymers or from metals, are promising materials for treating coronary artery disease through the processes of percutaneous transluminal coronary angioplasty. Despite the opinion that bioresorbable polymers are more promising for coronary stents, their long-term advantages over metallic alloys have not yet been demonstrated. The development of new polymer-based BVS or optimization of the existing ones requires engineers to perform many very expensive mechanical tests to identify optimal structural geometry and material characteristics. in silico mechanical testing opens the possibility for a fast and low-cost process of analysis of all the mechanical characteristics and also provides the possibility to compare two or more competing designs. In this study, we used a recently introduced material model of poly-l-lactic acid (PLLA) fully bioresorbable vascular scaffold and recently empowered numerical InSilc platform to perform in silico mechanicals tests of two different stent designs with different material and geometrical characteristics. The result of inflation, radial compression, three-point bending, and two-plate crush tests shows that numerical procedures with true experimental constitutive relationships could provide reliable conclusions and a significant contribution to the optimization and design of bioresorbable polymer-based stents.
Collapse
Affiliation(s)
- Miljan Milosevic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Institute for Information Technologies, University of Kragujevac, Kragujevac, Serbia
- Faculty of Information Technologies, Belgrade Metropolitan University, Belgrade, Serbia
| | - Milos Anic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Dalibor Nikolic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Institute for Information Technologies, University of Kragujevac, Kragujevac, Serbia
| | - Vladimir Geroski
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Bogdan Milicevic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Milos Kojic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States
- Serbian Academy of Sciences and Arts, Belgrade, Serbia
| | - Nenad Filipovic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| |
Collapse
|
14
|
Computational Analysis of Mechanical Performance for Composite Polymer Biodegradable Stents. MATERIALS 2021; 14:ma14206016. [PMID: 34683608 PMCID: PMC8539075 DOI: 10.3390/ma14206016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/03/2021] [Accepted: 10/08/2021] [Indexed: 11/20/2022]
Abstract
Bioresorbable stents (BRS) represent the latest generation of vascular scaffolds used for minimally invasive interventions. They aim to overcome the shortcomings of established bare-metal stents (BMS) and drug-eluting stents (DES). Recent advances in the field of bioprinting offer the possibility of combining biodegradable polymers to produce a composite BRS. Evaluation of the mechanical performance of the novel composite BRS is the focus of this study, based on the idea that they are a promising solution to improve the strength and flexibility performance of single material BRS. Finite element analysis of stent crimping and expansion was performed. Polylactic acid (PLA) and polycaprolactone (PCL) formed a composite stent divided into four layers, resulting in sixteen unique combinations. A comparison of the mechanical performance of the different composite configurations was performed. The resulting stresses, strains, elastic recoil, and foreshortening were evaluated and compared to existing experimental results. Similar behaviour was observed for material configurations that included at least one PLA layer. A pure PCL stent showed significant elastic recoil and less shortening compared to PLA and composite structures. The volumetric ratio of the materials was found to have a more significant effect on recoil and foreshortening than the arrangement of the material layers. Composite BRS offer the possibility of customising the mechanical behaviour of scaffolds. They also have the potential to support the fabrication of personalised or plaque-specific stents.
Collapse
|
15
|
Pan C, Han Y, Lu J. Structural Design of Vascular Stents: A Review. MICROMACHINES 2021; 12:mi12070770. [PMID: 34210099 PMCID: PMC8305143 DOI: 10.3390/mi12070770] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 11/18/2022]
Abstract
Percutaneous Coronary Intervention (PCI) is currently the most conventional and effective method for clinically treating cardiovascular diseases such as atherosclerosis. Stent implantation, as one of the ways of PCI in the treatment of coronary artery diseases, has become a hot spot in scientific research with more and more patients suffering from cardiovascular diseases. However, vascular stent implanted into vessels of patients often causes complications such as In-Stent Restenosis (ISR). The vascular stent is one of the sophisticated medical devices, a reasonable structure of stent can effectively reduce the complications. In this paper, we introduce the evolution, performance evaluation standards, delivery and deployment, and manufacturing methods of vascular stents. Based on a large number of literature pieces, this paper focuses on designing structures of vascular stents in terms of “bridge (or link)” type, representative volume unit (RVE)/representative unit cell (RUC), and patient-specific stent. Finally, this paper gives an outlook on the future development of designing vascular stents.
Collapse
Affiliation(s)
- Chen Pan
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
- Institute of Engineering Medicine, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China
| | - Yafeng Han
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
- Correspondence:
| | - Jiping Lu
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
| |
Collapse
|
16
|
Iannaccone M, D'Ascenzo F, Gatti P, Cerrato E, Nuñez-Gil I, Wojakowski W, Capodanno D, Figini F, Wańha W, Chieffo A, De Ferrari GM, Di Mario C. Impact of the metal-to-artery ratio on clinical outcomes in left main and nonleft main bifurcation: insights the RAIN-CARDIOGROUP VII study (veRy thin stents for patients with left mAIn or bifurcatioN in real life). J Cardiovasc Med (Hagerstown) 2021; 21:669-674. [PMID: 32639328 DOI: 10.2459/jcm.0000000000001010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The impact on clinical outcomes of the metal coverage on the coronary surface (namely the metal-to-artery ratio) of currently used drug-eluting stents (DESs) has not been defined. METHODS All patients with a left main or bifurcation stenosis treated with percutaneous coronary intervention (PCI) using ultrathin stents (struts thinner than 81 μm) were enrolled with a prospective multicentre fashion. The rate of device-oriented endpoint [DOE, defined as a composite of target lesion revascularization (TLR) and stent thrombosis] was the primary endpoint, while its single components were the secondary ones, evaluated according to the metal-to-artery ratio. RESULTS After 14 ± 10.4 months 62 (7.5%) of 830 patients undergoing PCI on left main experienced a DOE without differences in the metal-to-artery ratio (14.5 ± 2.1 vs. 14.4 ± 1.9, P = 0.51). Fifty out (2.4%) of 2082 patients treated with PCI on a coronary bifurcation other than left main experienced a DOE, with a higher mean metal-to-artery ratio (15.3 ± 2.1 vs. 14.6 ± 2, P = 0.01). At multivariate analysis, together with hypertension and diabetes, the metal-to-artery ratio was an independent predictor of DOE (hazard ratio 1.7 : 1.02-1.34, P = 0.02) in nonleft main PCI. When analysed for diameter, we found a significant correlation with DOE when the stent diameter was inferior to 3.0 mm (hazard ratio 1.21: 1.06-1.38, P < 0.01, all 95% confidence interval); this result was mainly consistent for patients treated with provisional stenting. The metal-to-artery ratio does not impact on outcomes in left main PCI, both in the provisional or two-stent technique, and generally when a drug-eluting stent more than 3.5 mm in diameter is implanted. Regarding nonleft main PCI, it is independently related to DOE and TLR, especially for DES with a diameter of 3.25 mm or less. CONCLUSION The metal-to-artery ratio does not impact on outcomes in left main PCI, both in the provisional or two-stent technique, and generally when a drug-eluting stent more than 3.5 mm in diameter is implanted. Regarding nonleft main PCI, it is independently related to DOE and TLR, especially for DES with a diameter of 3.25 mm or less.
Collapse
Affiliation(s)
- Mario Iannaccone
- Division of Cardiology, SS. Annunziata Hospital, ASL CN1, Savigliano
| | - Fabrizio D'Ascenzo
- Division of Cardiology, Città Della Salute e della Scienza Hospital, Turin
| | - Paolo Gatti
- Division of Cardiology, Città Della Salute e della Scienza Hospital, Turin
| | - Enrico Cerrato
- Interventional Cardiology, San Luigi Gonzaga University Hospital, Orbassano and Rivoli Infermi Hospital, Rivoli, Turin
| | - Ivan Nuñez-Gil
- Division of Cardiology, Interventional Cardiology, Hospital Clínico San Carlos, Madrid, Spain
| | - Wojciech Wojakowski
- Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Davide Capodanno
- C.A.S.T., P.O. Gaspare Rodolico, Azienda-Ospedaliero Universitaria 'Policlinico-Vittorio Emanuele', Catania, Italy
| | - Filippo Figini
- Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan
| | - Wojciech Wańha
- Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Alaide Chieffo
- Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan
| | | | - Carlo Di Mario
- Structural Interventional Cardiology, Careggi University Hospital, Florence, Italy
| |
Collapse
|
17
|
Computational and experimental mechanical performance of a new everolimus-eluting stent purpose-built for left main interventions. Sci Rep 2021; 11:8728. [PMID: 33888765 PMCID: PMC8062511 DOI: 10.1038/s41598-021-87908-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/06/2021] [Indexed: 12/31/2022] Open
Abstract
Left main (LM) coronary artery bifurcation stenting is a challenging topic due to the distinct anatomy and wall structure of LM. In this work, we investigated computationally and experimentally the mechanical performance of a novel everolimus-eluting stent (SYNERGY MEGATRON) purpose-built for interventions to large proximal coronary segments, including LM. MEGATRON stent has been purposefully designed to sustain its structural integrity at higher expansion diameters and to provide optimal lumen coverage. Four patient-specific LM geometries were 3D reconstructed and stented computationally with finite element analysis in a well-validated computational stent simulation platform under different homogeneous and heterogeneous plaque conditions. Four different everolimus-eluting stent designs (9-peak prototype MEGATRON, 10-peak prototype MEGATRON, 12-peak MEGATRON, and SYNERGY) were deployed computationally in all bifurcation geometries at three different diameters (i.e., 3.5, 4.5, and 5.0 mm). The stent designs were also expanded experimentally from 3.5 to 5.0 mm (blind analysis). Stent morphometric and biomechanical indices were calculated in the computational and experimental studies. In the computational studies the 12-peak MEGATRON exhibited significantly greater expansion, better scaffolding, smaller vessel prolapse, and greater radial strength (expressed as normalized hoop force) than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY (p < 0.05). Larger stent expansion diameters had significantly better radial strength and worse scaffolding than smaller stent diameters (p < 0.001). Computational stenting showed comparable scaffolding and radial strength with experimental stenting. 12-peak MEGATRON exhibited better mechanical performance than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY. Patient-specific computational LM stenting simulations can accurately reproduce experimental stent testing, providing an attractive framework for cost- and time-effective stent research and development.
Collapse
|
18
|
Filipovic N, Nikolic D, Isailovic V, Milosevic M, Geroski V, Karanasiou G, Fawdry M, Flanagan A, Fotiadis D, Kojic M. In vitro and in silico testing of partially and fully bioresorbable vascular scaffold. J Biomech 2020; 115:110158. [PMID: 33360181 DOI: 10.1016/j.jbiomech.2020.110158] [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: 09/11/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 11/28/2022]
Abstract
Coronary artery disease (CAD), one of the leading causes of death globally, occurs due to the growth of atherosclerotic plaques in the coronary arteries, causing lesions which restrict the flow of blood to the myocardium. Percutaneous transluminal coronary angioplasty (PTCA), including balloon angioplasty and coronary stent deployment is a standard clinical invasive treatment for CAD. Coronary stents are delivered using a balloon catheter inserted across the lesion. The balloon is inflated to a nominal pressure, opening the occluded artery, deploying the stent and improving the flow of blood to the myocardium. All stent manufacturers have to perform standard in vitro mechanical testing under different physiological conditions. In this study, partially and fully bioresorbable vascular scaffolds (BVS) from Boston Scientific Limited have been examined in vitro and in silico for three different test methods: inflation, radial compression and crush resistance. We formulated a material model for poly-L-lactic acid (PLLA) and implemented it into our in-house software tool. A comparison of the different experimental results is presented in the form of graphs showing displacement-force curves, diameter - load curves or diameter - pressure curves. There is a strong correlation between simulation and real experiments with a coefficient of determination (R2) > 0.99 and a correlation coefficient (R) > 0.99. This preliminary study has shown that in-silico tests can mimic the applicable ISO standards for mechanical in vitro stent testing, providing the opportunity to use data generated using in-silico testing to partially or fully replacing the mechanical testing required for regulatory submission.
Collapse
Affiliation(s)
- Nenad Filipovic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Serbia.
| | - Dalibor Nikolic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Serbia
| | - Velibor Isailovic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Serbia
| | - Miljan Milosevic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Serbia
| | - Vladimir Geroski
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Serbia
| | | | | | | | | | - Milos Kojic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
| |
Collapse
|
19
|
Kumar A, Bhatnagar N. Finite element simulation and testing of cobalt-chromium stent: a parametric study on radial strength, recoil, foreshortening, and dogboning. Comput Methods Biomech Biomed Engin 2020; 24:245-259. [PMID: 33021106 DOI: 10.1080/10255842.2020.1822823] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The effectiveness of cardiovascular stenting procedure depends on the crimping and expansion characteristics of a stent, influenced by its design parameters. In this study, CoCr stents are fabricated, crimped on a tri-folded balloon, and expanded using manual inflation device. Similarly, in the finite element model, a tri-folded balloon is used to expand the stent. The length and diameter are measured to evaluate the radial strength, recoil, foreshortening, and dogboning. The simulation and experimental results match satisfactorily. The validated FE model can be used with confidence to optimize future stent designs, thus reducing the number of testing and product development time.
Collapse
Affiliation(s)
- Avinash Kumar
- Department of Mechanical Engineering, Indian Institute of Technology-Delhi, New Delhi, India
| | - Naresh Bhatnagar
- Department of Mechanical Engineering, Indian Institute of Technology-Delhi, New Delhi, India
| |
Collapse
|
20
|
Seo J, Schiavazzi DE, Kahn AM, Marsden AL. The effects of clinically-derived parametric data uncertainty in patient-specific coronary simulations with deformable walls. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3351. [PMID: 32419369 PMCID: PMC8211426 DOI: 10.1002/cnm.3351] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 02/20/2020] [Accepted: 05/09/2020] [Indexed: 05/31/2023]
Abstract
Cardiovascular simulations are increasingly used for noninvasive diagnosis of cardiovascular disease, to guide treatment decisions, and in the design of medical devices. Quantitative assessment of the variability of simulation outputs due to input uncertainty is a key step toward further integration of cardiovascular simulations in the clinical workflow. In this study, we present uncertainty quantification in computational models of the coronary circulation to investigate the effect of uncertain parameters, including coronary pressure waveform, intramyocardial pressure, morphometry exponent, and the vascular wall Young's modulus. We employ a left coronary artery model with deformable vessel walls, simulated via an Arbitrary-Lagrangian-Eulerian framework for fluid-structure interaction, with a prescribed inlet pressure and open-loop lumped parameter network outlet boundary conditions. Stochastic modeling of the uncertain inputs is determined from intra-coronary catheterization data or gathered from the literature. Uncertainty propagation is performed using several approaches including Monte Carlo, Quasi Monte Carlo sampling, stochastic collocation, and multi-wavelet stochastic expansion. Variabilities in the quantities of interest, including branch pressure, flow, wall shear stress, and wall deformation are assessed. We find that uncertainty in inlet pressures and intramyocardial pressures significantly affect all resulting QoIs, while uncertainty in elastic modulus only affects the mechanical response of the vascular wall. Variability in the morphometry exponent used to distribute the total downstream vascular resistance to the single outlets, has little effect on coronary hemodynamics or wall mechanics. Finally, we compare convergence behaviors of statistics of QoIs using several uncertainty propagation methods on three model benchmark problems and the left coronary simulations. From the simulation results, we conclude that the multi-wavelet stochastic expansion shows superior accuracy and performance against Quasi Monte Carlo and stochastic collocation methods.
Collapse
Affiliation(s)
- Jongmin Seo
- Department of Pediatrics (Cardiology), Bioengineering and ICME, Stanford University, Stanford, California
| | - Daniele E. Schiavazzi
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Indiana
| | - Andrew M. Kahn
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Alison L. Marsden
- Department of Pediatrics (Cardiology), Bioengineering and ICME, Stanford University, Stanford, California
| |
Collapse
|
21
|
Gagliardi M. Numerical analysis of paclitaxel-eluting coronary stents: Mechanics and drug release properties. Med Eng Phys 2020; 82:78-85. [PMID: 32709268 DOI: 10.1016/j.medengphy.2020.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 04/14/2020] [Accepted: 06/15/2020] [Indexed: 10/23/2022]
Abstract
Since theoretical models provide data that cannot be otherwise gathered, numerical methods applied to medical devices analysis have emerged as fundamental tool in preclinical development. Large efforts were done to study mechanical and drug-eluting properties in stents but often the coating modelling is neglected. This work presents a finite element framework to calculate mechanical loads and drug distribution in three commercial drug-eluting stents (Palmaz-Schatz, Palmaz Genesis and Multi Link Vision), to check coatings strength and drug distribution maps in biological tissues. The promising copolymer poly(methylmethacrylate-co-n-butylmethacrylate), loaded with paclitaxel, is analyzed. Results demonstrated that the coating undergoes localized plastic phenomena, and calculated stresses are lower than the ultimate stress, ensuring coating integrity. Computed drug concentration depends on stent geometry and its values are in all cases lower than the toxicity level for this drug.
Collapse
|
22
|
López-Campos JA, Ferreira JPS, Segade A, Fernández JR, Natal RM. Characterization of hyperelastic and damage behavior of tendons. Comput Methods Biomech Biomed Engin 2020; 23:213-223. [PMID: 31958016 DOI: 10.1080/10255842.2019.1710742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In this paper, we characterized the hyperelastic and damage behavior of the Extensor Digitorum Longus (EDL) human tendon under loading conditions. The study was conducted in both categories of models, phenomenological and physically motivated, to allow the prediction and the macroscopic response of the tendon under specific loading conditions, assuming that its response follows a hyperelastic anisotropic model in conjunction with damage law. We benchmarked multiple hyperelastic and damage models to fit the response of the tendons in uniaxial tensile loading conditions, and by employing a genetic algorithm, we obtained the material parameters for both elastic and damage models. The objective of this study was to explore different mathematical models to determine which would be the best option to predict the behavior of tendons and ligaments in complex biological systems using Finite Elements (FE) models. Therefore, we took into account accuracy as well as computational features. We considered the model proposed by Shearer and coupled it with a sigmoid function, which governs the evolution of damage in tendons, as the most appropriate for the fitting of the experimental data. The achieved solution shows to be of high interest attributable to the simplicity of the damage law function and its low computational cost.
Collapse
Affiliation(s)
- J A López-Campos
- Departamento de Ingeniería Mecánica, Máquinas y Motores Térmicos y Fluídos, Universidade de Vigo, Escola de Enxeñería Industrial, Vigo, Spain
| | - J P S Ferreira
- Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| | - A Segade
- Departamento de Ingeniería Mecánica, Máquinas y Motores Térmicos y Fluídos, Universidade de Vigo, Escola de Enxeñería Industrial, Vigo, Spain
| | - J R Fernández
- Departamento de Matemática Aplicada I, Universidade de Vigo, ETSI Telecomunicación, Vigo, Spain
| | - R M Natal
- Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| |
Collapse
|
23
|
Bukala J, Buszman PP, Małachowski J, Mazurkiewicz L, Sybilski K. Experimental Tests, FEM Constitutive Modeling and Validation of PLGA Bioresorbable Polymer for Stent Applications. MATERIALS 2020; 13:ma13082003. [PMID: 32344744 PMCID: PMC7215386 DOI: 10.3390/ma13082003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 02/04/2023]
Abstract
The use of bioresorbable polymers such as poly(lactic-co-glycolic acid) (PLGA) in coronary stents can hypothetically reduce the risk of complications (e.g., restenosis, thrombosis) after percutaneous coronary intervention. However, there is a need for a constitutive modeling strategy that combines the simplicity of implementation with strain rate dependency. Here, a constitutive modeling methodology for PLGA comprising numerical simulation using a finite element method is presented. First, the methodology and results of PLGA experimental tests are presented, with a focus on tension tests of tubular-type specimens with different strain rates. Subsequently, the constitutive modeling methodology is proposed and described. Material model constants are determined based on the results of the experimental tests. Finally, the developed methodology is validated by experimental and numerical comparisons of stent free compression tests with various compression speeds. The validation results show acceptable correlation in terms of both quality and quantity. The proposed and validated constitutive modeling approach for the bioresorbable polymer provides a useful tool for the design and evaluation of bioresorbable stents.
Collapse
Affiliation(s)
- Jakub Bukala
- Institute of Mechanics and Computational Engineering, Faculty of Mechanical Engineering, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland; (J.B.); (L.M.); (K.S.)
| | - Piotr P. Buszman
- Center for Cardiovascular Research and Development American Heart of Poland, Czajek 41, 40-534 Katowice, Poland;
- Department of Cardiology, Andrzej Frycz-Modrzewski Kraków University, Gustawa Herlinga-Grudzińskiego 1, 30-705 Cracow, Poland
| | - Jerzy Małachowski
- Institute of Mechanics and Computational Engineering, Faculty of Mechanical Engineering, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland; (J.B.); (L.M.); (K.S.)
- Correspondence: ; Tel.: +48-261-839-140
| | - Lukasz Mazurkiewicz
- Institute of Mechanics and Computational Engineering, Faculty of Mechanical Engineering, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland; (J.B.); (L.M.); (K.S.)
| | - Kamil Sybilski
- Institute of Mechanics and Computational Engineering, Faculty of Mechanical Engineering, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland; (J.B.); (L.M.); (K.S.)
| |
Collapse
|
24
|
Song K, Bi Y, Zhao H, Wu T, Xu F, Zhao G. Structural optimization and finite element analysis of poly‐
l
‐lactide acid coronary stent with improved radial strength and acute recoil rate. J Biomed Mater Res B Appl Biomater 2020; 108:2754-2764. [DOI: 10.1002/jbm.b.34605] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/02/2020] [Accepted: 03/01/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Kai Song
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
| | - Yuying Bi
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Haibin Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
- Shenzhen Research Institute of Shandong University, Shenzhen Guangdong China
| | - Tim Wu
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Feng Xu
- Department of Emergency Medicine, Qilu Hospital, Shandong University Jinan China
| | - Guoqun Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
| |
Collapse
|
25
|
Geith MA, Swidergal K, Hochholdinger B, Schratzenstaller TG, Wagner M, Holzapfel GA. On the importance of modeling balloon folding, pleating, and stent crimping: An FE study comparing experimental inflation tests. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3249. [PMID: 31400057 PMCID: PMC9285761 DOI: 10.1002/cnm.3249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/23/2019] [Accepted: 08/03/2019] [Indexed: 06/10/2023]
Abstract
Finite element (FE)-based studies of preoperative processes such as folding, pleating, and stent crimping with a comparison with experimental inflation tests are not yet available. Therefore, a novel workflow is presented in which residual stresses of balloon folding and pleating, as well as stent crimping, and the geometries of all contact partners were ultimately implemented in an FE code to simulate stent expansion by using an implicit solver. The numerical results demonstrate that the incorporation of residual stresses and strains experienced during the production step significantly increased the accuracy of the subsequent simulations, especially of the stent expansion model. During the preoperative processes, stresses inside the membrane and the stent material also reached a rather high level. Hence, there can be no presumption that balloon catheters or stents are undamaged before the actual surgery. The implementation of the realistic geometry, in particular the balloon tapers, and the blades of the process devices improved the simulation of the expansion mechanisms, such as dogboning, concave bending, or overexpansion of stent cells. This study shows that implicit solvers are able to precisely simulate the mentioned preoperative processes and the stent expansion procedure without a preceding manipulation of the simulation time or physical mass.
Collapse
Affiliation(s)
- Markus A. Geith
- Institute of BiomechanicsGraz University of TechnologyGrazAustria
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | - Krzysztof Swidergal
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | | | | | - Marcus Wagner
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | - Gerhard A. Holzapfel
- Institute of BiomechanicsGraz University of TechnologyGrazAustria
- Department of Structural EngineeringNorwegian University of Science and TechnologyTrondheimNorway
| |
Collapse
|
26
|
Wiesent L, Schultheiß U, Schmid C, Schratzenstaller T, Nonn A. Experimentally validated simulation of coronary stents considering different dogboning ratios and asymmetric stent positioning. PLoS One 2019; 14:e0224026. [PMID: 31626662 PMCID: PMC6799901 DOI: 10.1371/journal.pone.0224026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/03/2019] [Indexed: 11/20/2022] Open
Abstract
In-stent restenosis remains a major problem of arteriosclerosis treatment by stenting. Expansion-optimized stents could reduce this problem. With numerical simulations, stent designs/ expansion behaviours can be effectively analyzed. For reasons of efficiency, simplified models of balloon-expandable stents are often used, but their accuracy must be challenged due to insufficient experimental validation. In this work, a realistic stent life-cycle simulation has been performed including balloon folding, stent crimping and free expansion of the balloon-stent-system. The successful simulation and validation of two stent designs with homogenous and heterogeneous stent stiffness and an asymmetrically positioned stent on the balloon catheter confirm the universal applicability of the simulation approach. Dogboning ratio, as well as the final dimensions of the folded balloon, the crimped and expanded stent, correspond well to the experimental dimensions with only slight deviations. In contrast to the detailed stent life-cycle simulation, a displacement-controlled simulation can not predict the transient stent expansion, but is suitable to reproduce the final expanded stent shape and the associated stress states. The detailed stent life-cycle simulation is thus essential for stent expansion analysis/optimization, whereas for reasons of computational efficiency, the displacement-controlled approach can be considered in the context of pure stress analysis.
Collapse
Affiliation(s)
- Lisa Wiesent
- Computational Mechanics and Materials Lab, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany
- Regensburg Center of Biomedical Engineering (RCBE), Regensburg, Germany
- Medical Device Lab, OTH Regensburg, Regensburg, Germany
- * E-mail:
| | - Ulrich Schultheiß
- Material Science and Surface Analytics Lab, OTH Regensburg, Regensburg, Germany
| | - Christof Schmid
- University Hospital Regensburg, Cardiothoracic and Cardiovascular Surgery, Regensburg, Germany
| | - Thomas Schratzenstaller
- Regensburg Center of Biomedical Engineering (RCBE), Regensburg, Germany
- Medical Device Lab, OTH Regensburg, Regensburg, Germany
| | - Aida Nonn
- Computational Mechanics and Materials Lab, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany
| |
Collapse
|
27
|
Blair RW, Dunne NJ, Lennon AB, Menary GH. Multi-objective optimisation of material properties and strut geometry for poly(L-lactic acid) coronary stents using response surface methodology. PLoS One 2019; 14:e0218768. [PMID: 31449528 PMCID: PMC6709949 DOI: 10.1371/journal.pone.0218768] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 08/10/2019] [Indexed: 11/29/2022] Open
Abstract
Coronary stents for treating atherosclerosis are traditionally manufactured from metallic alloys. However, metal stents permanently reside in the body and may trigger undesirable immunological responses. Bioresorbable polymer stents can provide a temporary scaffold that resorbs once the artery heals but are mechanically inferior, requiring thicker struts for equivalent radial support, which may increase thrombosis risk. This study addresses the challenge of designing mechanically effective but sufficiently thin poly(L-lactic acid) stents through a computational approach that optimises material properties and stent geometry. Forty parametric stent designs were generated: cross-sectional area (post-dilation), foreshortening, stent-to-artery ratio and radial collapse pressure were evaluated computationally using finite element analysis. Response surface methodology was used to identify performance trade-offs by formulating relationships between design parameters and response variables. Multi-objective optimisation was used to identify suitable stent designs from approximated Pareto fronts and an optimal design is proposed that offers comparable performance to designs in clinical practice. In summary, a computational framework has been developed that has potential application in the design of high stiffness, thin strut polymeric stents.
Collapse
Affiliation(s)
- Ross W. Blair
- School of Mechanical and Aerospace Engineering, Queen’s University, Belfast, United Kingdom
- * E-mail:
| | - Nicholas J. Dunne
- School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin, Ireland
- Centre for Medical Engineering Research, School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin, Ireland
- School of Pharmacy, Queen’s University, Belfast, United Kingdom
- Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
- Advanced Materials and Bioengineering Research Centre (AMBER), Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland
| | - Alex B. Lennon
- School of Mechanical and Aerospace Engineering, Queen’s University, Belfast, United Kingdom
| | - Gary H. Menary
- School of Mechanical and Aerospace Engineering, Queen’s University, Belfast, United Kingdom
| |
Collapse
|
28
|
Krewcun C, Sarry L, Combaret N, Pery E. Fast simulation of stent deployment with plastic beam elements. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2019:6968-6974. [PMID: 31947442 DOI: 10.1109/embc.2019.8857179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Coronary stent deployment is a reference cardiology intervention, used to treat atherosclerosis and prevent heart attacks. The outcomes of the intervention highly depend on the accuracy of the stent apposition, which could benefit from per-operative prediction tools. In this paper, we propose a fast and mechanically realistic 3D simulation of a coronary stent expansion. Our simulation relies on the finite element method and involves serially linked beam elements to model the slender geometry of a stent. The elements are implemented with a non-linear elasto-plastic behavior, describing realistically the complex deformation of a balloon-expandable stent. As a proof of concept, we simulated the free expansion of a coronary stent. The simulation output was compared with micro-CT data, acquired experimentally during the device expansion. Results show that the plastic beam model is able to reproduce successfully the final geometry of the stent. In addition, the use of 1D elements allows to achieve a significantly lower computational time than for equivalent literature simulations, based on 3D elements. This preliminary work highlights the compatibility of our method with clinical routine in terms of execution time. Further developments include the application of the method to more advanced simulation scenarios, with the addition of a personalized artery model.
Collapse
|
29
|
BOKOV PLAMEN, DANTAN PHILIPPE, FLAUD PATRICE. PALMAZ–SCHATZ STENT-OPENING MECHANICS USING A SIMPLE APPROACH INVOLVING THE BALLOON–STENT AND STENT–ARTERY CONTACT PROBLEM: APPLICATION TO BIOPOLYMER STENTS. J MECH MED BIOL 2019. [DOI: 10.1142/s021951941950009x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We used the finite element method-based toolbox COMSOL Multiphysics to address the important question of biopolymer coronary stent mechanics. We evaluated the diameter of the stent, the immediate elastic recoil, the dogboning and the foreshortening during deployment while using an idealized model that took into account the presence of the balloon and the coronary artery wall (equivalent pressure hypothesis). We validated our model using the well-known mechanics of the Palmaz–Schatz metal stent and acquired new data concerning a poly-L-lactic acid (PLLA) stent and some other biodegradable co-polymer-based stents. The elastic recoil was relatively high (26.1% to 31.1% depending on the biopolymer used) when taking into account the presence of both the balloon and artery. The dogboning varied from 31% to 46% for the polymer stents and was 62% for the metal stent, suggesting that less arterial damage could be expected with biopolymer stents. Various strut thicknesses were tested for the PLLA stent (114, 180 and 250[Formula: see text][Formula: see text]m) and no significant improvement in elastic recoil was observed. We concluded that the stent geometry has a greater impact on the scaffolding role of the structure than the strut thickness, or even the mechanical properties of the stent.
Collapse
Affiliation(s)
- PLAMEN BOKOV
- Laboratoire Matière et Systèmes Complexes, UMR 7057, Université Paris Diderot, Paris, France
| | - PHILIPPE DANTAN
- Laboratoire Matière et Systèmes Complexes, UMR 7057, Université Paris Diderot, Paris, France
| | - PATRICE FLAUD
- Laboratoire Matière et Systèmes Complexes, UMR 7057, Université Paris Diderot, Paris, France
| |
Collapse
|
30
|
Kumar GP, Yuan S, Cui F, Branicio PS, Jafary-Zadeh M. Nanoglass-based balloon expandable stents. J Biomed Mater Res B Appl Biomater 2019; 108:73-79. [PMID: 30895727 DOI: 10.1002/jbm.b.34367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/30/2019] [Accepted: 02/27/2019] [Indexed: 12/17/2022]
Abstract
Here, a prototypical metallic nanoglass is proposed as a new alloy for balloon expandable stents. Traditionally, the stainless steel SS 316L alloy has been used as a preferred material for this application due to its proper combination of mechanical properties, corrosion resistance, and biocompatibility. Recently, metallic glasses (MGs) have been considered as promising materials for biodevice applications. MGs often display outstanding mechanical properties superior to those of conventional metallic alloys and overcome some of the weaknesses of SS 316L, such as radiopacity, stainless steel allergy, and thrombosis-induced restenosis. However, commonly used monolithic MGs, which have an amorphous homogeneous microstructure, suffer from lack of ductility that is necessary for deployment of balloon expandable stents. In contrast, nanoglasses, that is, amorphous alloys with heterogeneous microstructure, exhibit enhanced ductility which makes them promising materials for balloon expandable stents. We evaluate the feasibility of a prototypical Zr64 Cu36 nanoglass with a grain size of 5 nm for balloon expandable stents by performing finite element method modeling of the stent deployment process in a coronary artery. We consider the BX-Velocity stent design and the nanoglass mechanical properties calculated from atomistic simulations. The results suggest that nanoglasses are suitable materials for balloon expandable stent applications. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:73-79, 2020.
Collapse
Affiliation(s)
| | - Suyue Yuan
- Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, California, 90089-0241
| | - Fangsen Cui
- Institute of High Performance Computing, A*STAR, Singapore, 138632
| | - Paulo Sergio Branicio
- Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, California, 90089-0241
| | | |
Collapse
|
31
|
Zhao D, Zhou R, Sun J, Li H, Jin Y. Experimental study of polymeric stent fabrication using homemade 3D printing system. POLYM ENG SCI 2019. [DOI: 10.1002/pen.25091] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Danyang Zhao
- Department of Mechanical EngineeringDalian University of Technology Dalian Liaoning 116023 China
| | - Ruiqi Zhou
- Department of Mechanical EngineeringDalian University of Technology Dalian Liaoning 116023 China
| | - Jianxing Sun
- Department of Mechanical Engineering and Materials ScienceWashington University in Saint Louis St. Louis Missouri 63130
| | - Hongxia Li
- Department of Mechanical EngineeringDalian University of Technology Dalian Liaoning 116023 China
| | - Yifei Jin
- Department of Mechanical and Aerospace EngineeringUniversity of Florida Gainesville Florida 32611
| |
Collapse
|
32
|
Alam ST, Ansari A, Urooj S, Aldobali M. A Review based on Biodegradable and Bioabsorbable Stents for Coronary Artery Disease. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.procs.2019.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
33
|
Ribeiro NS, Folgado J, Rodrigues HC. Surrogate-based visualization and sensitivity analysis of coronary stent performance: A study on the influence of geometric design. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e3125. [PMID: 29956892 DOI: 10.1002/cnm.3125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/21/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
The main goal of this numerical study is to assess the impact of geometric design perturbations on the performance of a representative coronary stent platform. In this context, first, a design parameterization model was defined for the stent under study. After, a set of metrics characterizing stent performance, namely, vessel injury, radial recoil, bending resistance, longitudinal resistance, radial strength, the risk of fracture, prolapse index, and dogboning were evaluated within the context of a finite element analysis. Afterwards, accurate surrogate models were developed, using the efficient global optimization algorithm, as predictive tools in the execution of tasks that normally require a high number of model evaluations, such as global sensitivity analysis and visualization. In the end, the dependence of the output response surfaces on the geometric parameters was mechanically interpreted, which allowed us to understand the complex interplay that exists between the considered design variables and the defined performance metrics.
Collapse
Affiliation(s)
- Nelson S Ribeiro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - João Folgado
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Hélder C Rodrigues
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
34
|
Han Y, Lu W. Optimizing the deformation behavior of stent with nonuniform Poisson's ratio distribution for curved artery. J Mech Behav Biomed Mater 2018; 88:442-452. [PMID: 30218973 DOI: 10.1016/j.jmbbm.2018.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/18/2018] [Accepted: 09/02/2018] [Indexed: 01/29/2023]
Abstract
Stent implantation at a highly curved artery has always been a challenge, considering the relatively high chance of in-stent restenosis (ISR) caused by severe straightening effect and high strain energy over the vessel wall. In this paper, a novel optimization based design method was proposed to manipulate the deformation behavior of the common ring-and-link stent. By changing the location of the connection point between rings and links, traditional ring-and-link structure was modified to achiever tunable Poisson's ratio (PR). With the nonuniform cellular structure design method proposed in a previous study, PR distribution of the stent structure was optimized to achieve the desired curvature. As a result, the obtained stent structure with nonuniform PR could perfectly fit into the curved artery after expansion, without causing any obvious vessel straightening. To validate the proposed method, two different vessel models were introduced. Firstly, a short vessel with a constant curvature was set as the design objective, and both numerical and experimental tests were conducted. Further, a patient-specific vessel was applied. Both test results showed that optimized stents would cause much smaller vessel straightening. Moreover, vessels stented by the optimized structures had much lower stress concentration and strain energy. All those properties will decrease the possibility of ISR significantly.
Collapse
Affiliation(s)
- Yafeng Han
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117975 Singapore, Singapore
| | - Wenfeng Lu
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117975 Singapore, Singapore.
| |
Collapse
|
35
|
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
|
36
|
Strbac V, Pierce DM, Vander Sloten J, Famaey N. GPGPU-based explicit finite element computations for applications in biomechanics: the performance of material models, element technologies, and hardware generations. Comput Methods Biomech Biomed Engin 2018; 20:1643-1657. [PMID: 29199498 DOI: 10.1080/10255842.2017.1404586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Finite element (FE) simulations are increasingly valuable in assessing and improving the performance of biomedical devices and procedures. Due to high computational demands such simulations may become difficult or even infeasible, especially when considering nearly incompressible and anisotropic material models prevalent in analyses of soft tissues. Implementations of GPGPU-based explicit FEs predominantly cover isotropic materials, e.g. the neo-Hookean model. To elucidate the computational expense of anisotropic materials, we implement the Gasser-Ogden-Holzapfel dispersed, fiber-reinforced model and compare solution times against the neo-Hookean model. Implementations of GPGPU-based explicit FEs conventionally rely on single-point (under) integration. To elucidate the expense of full and selective-reduced integration (more reliable) we implement both and compare corresponding solution times against those generated using underintegration. To better understand the advancement of hardware, we compare results generated using representative Nvidia GPGPUs from three recent generations: Fermi (C2075), Kepler (K20c), and Maxwell (GTX980). We explore scaling by solving the same boundary value problem (an extension-inflation test on a segment of human aorta) with progressively larger FE meshes. Our results demonstrate substantial improvements in simulation speeds relative to two benchmark FE codes (up to 300[Formula: see text] while maintaining accuracy), and thus open many avenues to novel applications in biomechanics and medicine.
Collapse
Affiliation(s)
- V Strbac
- a Biomechanics Section, Department of Mechanical Engineering , KULeuven , Heverlee , Belgium
| | - D M Pierce
- b Interdisciplinary Mechanics Laboratory, Departments of Mechanical Engineering/Biomedical Engineering/Mathematics , University of Connecticut , Storrs , CT , USA
| | - J Vander Sloten
- a Biomechanics Section, Department of Mechanical Engineering , KULeuven , Heverlee , Belgium
| | - N Famaey
- a Biomechanics Section, Department of Mechanical Engineering , KULeuven , Heverlee , Belgium
| |
Collapse
|
37
|
Acosta Santamaría VA, Daniel G, Perrin D, Albertini JN, Rosset E, Avril S. Model reduction methodology for computational simulations of endovascular repair. Comput Methods Biomech Biomed Engin 2018; 21:139-148. [DOI: 10.1080/10255842.2018.1427740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- V. A. Acosta Santamaría
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- SaInBioSE, Mines Saint-Etienne, Saint Etienne, France
- SaInBioSE, Université de Lyon, Saint Etienne, France
| | - G. Daniel
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- SaInBioSE, Mines Saint-Etienne, Saint Etienne, France
- SaInBioSE, Université de Lyon, Saint Etienne, France
- Service de Chirurgie Vasculaire, Centre Hospitalier Régional Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - D. Perrin
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- SaInBioSE, Mines Saint-Etienne, Saint Etienne, France
- SaInBioSE, Université de Lyon, Saint Etienne, France
| | - J. N. Albertini
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- SaInBioSE, Université de Lyon, Saint Etienne, France
- Service de Chirurgie Vasculaire, Centre Hospitalier Universitaire de Saint-Etienne, Saint Etienne, France
| | - E. Rosset
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- Service de Chirurgie Vasculaire, Centre Hospitalier Régional Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - S. Avril
- SaInBioSE, INSERM, U1059, Saint Etienne, France
- SaInBioSE, Mines Saint-Etienne, Saint Etienne, France
- SaInBioSE, Université de Lyon, Saint Etienne, France
| |
Collapse
|
38
|
Bobel AC, McHugh PE. Computational Analysis of the Utilisation of the Shape Memory Effect and Balloon Expansion in Fully Polymeric Stent Deployment. Cardiovasc Eng Technol 2017; 9:60-72. [DOI: 10.1007/s13239-017-0333-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 10/23/2017] [Indexed: 11/28/2022]
|
39
|
Bukala J, Kwiatkowski P, Malachowski J. Numerical analysis of crimping and inflation process of balloon-expandable coronary stent using implicit solution. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33. [PMID: 28425201 DOI: 10.1002/cnm.2890] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/01/2017] [Accepted: 04/15/2017] [Indexed: 06/07/2023]
Abstract
The paper presents an applied methodology for numerical finite element analysis of coronary stent crimping and the free inflation process with the use of a folded noncompliant angioplasty balloon. The use of an implicit scheme is considered as the most original part of the work, as an explicit finite element procedure is very often preferred. Hitherto, when the implicit solution was used for the finite element solution, the simulated issue was largely simplified. Therefore, the authors focused on the modelling methodology with minimum possible simplification, ie, a full load path (compression and inflation in single analysis), solid element discretization, and sophisticated contact models (bodies with highly different stiffness). The obtained results are partially compared with experimental data (radial force during the crimping procedure) and present satisfactory compliance. The authors believe that presented methodology allow for significant improvement of the obtained results, as well as potential extension of the research scope, compared to previous efforts performed using the explicit integration scheme. Moreover, the presented methodology is believed to be suitable for sensitivity and optimization studies.
Collapse
Affiliation(s)
- Jakub Bukala
- Department of Mechanics and Applied Computer Science, Military University of Technology, Gen. Sylwestra Kaliskiego 2, Warsaw, 00-908, Poland
| | - Piotr Kwiatkowski
- Clinical Department of Interventional Cardiology, Central Clinical Hospital Ministry of Interior, Woloska 137, Warsaw, 02-507, Poland
| | - Jerzy Malachowski
- Department of Mechanics and Applied Computer Science, Military University of Technology, Gen. Sylwestra Kaliskiego 2, Warsaw, 00-908, Poland
| |
Collapse
|
40
|
Beigzadeh B, Mirmohammadi SA, Ayatollahi MR. A numerical study on the effect of geometrical parameters and loading profile on the expansion of stent. Biomed Mater Eng 2017; 28:463-476. [PMID: 28854490 DOI: 10.3233/bme-171691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Stenting has been proposed as an effective treatment to restore blood flow in obstructed arteries by plaques. Although several modified designs for stents have been suggested, most designs have the risk of disturbing blood flow. OBJECTIVE The main objective is to propose a stent design to attain a uniform lumen section after stent deployment. METHODS Mechanical response of five different designs of J & J Palmaz-Schatz stent with the presence of plaque and artery are investigated; four stents have variable strut thickness of different magnitudes and the rest one is a uniform-strut-thickness stent. Nonlinear finite element is employed to simulate the expansion procedure of the intended designs using ABAQUS explicit. RESULTS The stent design whose first cell thickness linearly increases by 35 percent, exhibits the best performance, that is it has the lowest recoiling and stress induced in the intima for a given lumen gain. It also enjoys the minimal discrepancy between the final at the distal and proximal ends. CONCLUSIONS A uniform widened artery can be achieved by using the stent design with 35 percent increase in its first cell, which provides the possibility to prevent from disturbing blood flow and consequently post-operation complications.
Collapse
Affiliation(s)
- Borhan Beigzadeh
- Biomechatronics and Cognitive Engineering Research Lab, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran. E-mail:
| | - Seyed Alireza Mirmohammadi
- Fatigue and Fracture Research Lab, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran. E-mail:
| | - Majid Reza Ayatollahi
- Fatigue and Fracture Research Lab, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran. E-mail:
| |
Collapse
|
41
|
Puértolas S, Navallas D, Herrera A, López E, Millastre J, Ibarz E, Gabarre S, Puértolas J, Gracia L. A methodology for the customized design of colonic stents based on a parametric model. J Mech Behav Biomed Mater 2017; 71:250-261. [DOI: 10.1016/j.jmbbm.2017.03.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 02/24/2017] [Accepted: 03/25/2017] [Indexed: 12/16/2022]
|
42
|
Khosravi A, Bahreinizad H, Bani MS, Karimi A. A numerical study on the application of the functionally graded materials in the stent design. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 73:182-188. [PMID: 28183596 DOI: 10.1016/j.msec.2016.12.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/08/2016] [Accepted: 12/07/2016] [Indexed: 11/25/2022]
Abstract
Undesirable deformation of the stent can induce a significant amount of injure not only to the blood vessel but also to the plaque. The objective of this study was to reduce/minimize these undesirable deformations by the application of Functionally Graded Materials (FGM). To do this, Finite Element (FE) method was employed to simulate the expansion of a stent and the corresponding displacement of the stenosis plaque. Three hyperelastic plaque types as well as five elastoplastic stents were simulated. Dogboning, foreshortening, maximum stress in the plaque, and the pressure which is needed to fully expand the stent for different stent materials, were acquired. While all FGMs had lower dogboning in comparison to the stents made of the uniform materials, the stent with the lowest heterogeneous index displayed the lowest amount of dogboning. Steel stent showed the lowest foreshortening and fully expansion pressure but the difference was much lower than that the one for dogboning. Therefore, the FGM with the heterogeneous index of 0.5 is expected to exhibit the most suitable results. In addition, the results revealed that the material parameters has crucial effects on the deformation of the stent and, as a result, as a design point of view the FGM parameters can be tailored to achieve the goal of the biomechanical optimization.
Collapse
Affiliation(s)
- Arezoo Khosravi
- Atherosclerosis Research Center, Baqiyatallah University of Medical science, Tehran, Iran
| | - Hossein Bahreinizad
- Mechanical Engineering Department, Sahand University of Technology, Tabriz, Iran
| | - Milad Salimi Bani
- Mechanical Engineering Department, Iran University of Science and Technology, Tehran, Iran.
| | | |
Collapse
|
43
|
Li H, Wang X, Wei Y, Liu T, Gu J, Li Z, Wang M, Zhao D, Qiao A, Liu Y. Multi-Objective Optimizations of Biodegradable Polymer Stent Structure and Stent Microinjection Molding Process. Polymers (Basel) 2017; 9:polym9010020. [PMID: 30970706 PMCID: PMC6432066 DOI: 10.3390/polym9010020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/26/2016] [Accepted: 12/30/2016] [Indexed: 11/16/2022] Open
Abstract
Biodegradable stents made of poly-l-lactic acid (PLLA) have a promising prospect thanks to high biocompatibility and a favorable biodegradation period. However, due to the low stiffness of PLLA, polymeric stents have a lower radial stiffness and larger foreshortening. Furthermore, a stent is a tiny meshed tube, hence, it is difficult to make a polymeric stent. In the present study, a finite element analysis-based optimization method combined with Kriging surrogate modeling is firstly proposed to optimize the stent structure and stent microinjection molding process, so as to improve the stent mechanical properties and microinjection molding quality, respectively. The Kriging surrogate models are constructed to formulate the approximate mathematical relationships between the design variables and design objectives. Expected improvement is employed to balance local and global search to find the global optimal design. As an example, the polymeric ART18Z stent was investigated. The mechanical properties of stent expansion in a stenotic artery and the molding quality were improved after optimization. Numerical results demonstrate the proposed optimization method can be used for the computationally measurable optimality of stent structure design and stent microinjection molding process.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Xinyu Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Yunbo Wei
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Tao Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Junfeng Gu
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116023, China.
| | - Zheng Li
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116023, China.
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Yahua Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| |
Collapse
|
44
|
Li H, Liu T, Wang M, Zhao D, Qiao A, Wang X, Gu J, Li Z, Zhu B. Design optimization of stent and its dilatation balloon using kriging surrogate model. Biomed Eng Online 2017; 16:13. [PMID: 28086895 PMCID: PMC5234108 DOI: 10.1186/s12938-016-0307-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although stents have great success of treating cardiovascular disease, it actually undermined by the in-stent restenosis and their long-term fatigue failure. The geometry of stent affects its service performance and ultimately affects its fatigue life. Besides, improper length of balloon leads to transient mechanical injury to the vessel wall and in-stent restenosis. Conventional optimization method of stent and its dilatation balloon by comparing several designs and choosing the best one as the optimal design cannot find the global optimal design in the design space. In this study, an adaptive optimization method based on Kriging surrogate model was proposed to optimize the structure of stent and the length of stent dilatation balloon so as to prolong stent service life and improve the performance of stent. METHODS A finite element simulation based optimization method combing with Kriging surrogate model is proposed to optimize geometries of stent and length of stent dilatation balloon step by step. Kriging surrogate model coupled with design of experiment method is employed to construct the approximate functional relationship between optimization objectives and design variables. Modified rectangular grid is used to select initial training samples in the design space. Expected improvement function is used to balance the local and global searches to find the global optimal result. Finite element method is adopted to simulate the free expansion of balloon-expandable stent and the expansion of stent in stenotic artery. The well-known Goodman diagram was used for the fatigue life prediction of stent, while dogboning effect was used for stent expansion performance measurement. As the real design cases, diamond-shaped stent and sv-shaped stent were studied to demonstrate how the proposed method can be harnessed to design and refine stent fatigue life and expansion performance computationally. RESULTS The fatigue life and expansion performance of both the diamond-shaped stent and sv-shaped stent are designed and refined, respectively. (a) diamond-shaped stent: The shortest distance from the data points to the failure line in the Goodman diagram was increased by 22.39%, which indicated a safer service performance of the optimal stent. The dogboning effect was almost completely eliminated, which implies more uniform expansion of stent along its length. Simultaneously, radial elastic recoil (RR) at the proximal and distal ends was reduced by 40.98 and 35% respectively and foreshortening (FS) was also decreased by 1.75%. (b) sv-shaped stent: The shortest distance from the data point to the failure line in the Goodman diagram was increased by 15.91%. The dogboning effect was also completely eliminated, RR at the proximal and distal ends was reduced by 82.70 and 97.13%, respectively, and the FS was decreased by 16.81%. Numerical results showed that the fatigue life of both stents was refined and the comprehensive expansion performance of them was improved. CONCLUSIONS This article presents an adaptive optimization method based on the Kriging surrogate model to optimize the structure of stents and the length of their dilatation balloon to prolong stents fatigue life and decreases the dogboning effect of stents during expansion process. Numerical results show that the adaptive optimization method based on Kriging surrogate model can effectively optimize the design of stents and the dilatation balloon. Further investigations containing more design goals and more effective multidisciplinary design optimization method are warranted.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Tao Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Xue Wang
- Mechanical Engineering and Material Science Department, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA
| | - Junfeng Gu
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Zheng Li
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Bao Zhu
- School of Materials Science and Engineering, Dalian University of Technology, No. 2, Linggong Road, Dalian, 116024, Liaoning, China.
| |
Collapse
|
45
|
Wang Q, Fang G, Zhao Y, Wang G, Cai T. Computational and experimental investigation into mechanical performances of Poly-L-Lactide Acid (PLLA) coronary stents. J Mech Behav Biomed Mater 2017; 65:415-427. [DOI: 10.1016/j.jmbbm.2016.08.033] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 11/15/2022]
|
46
|
Wang J, Kaplan JA, Colson YL, Grinstaff MW. Mechanoresponsive materials for drug delivery: Harnessing forces for controlled release. Adv Drug Deliv Rev 2017; 108:68-82. [PMID: 27856307 PMCID: PMC5285479 DOI: 10.1016/j.addr.2016.11.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/01/2016] [Accepted: 11/09/2016] [Indexed: 12/15/2022]
Abstract
Mechanically-activated delivery systems harness existing physiological and/or externally-applied forces to provide spatiotemporal control over the release of active agents. Current strategies to deliver therapeutic proteins and drugs use three types of mechanical stimuli: compression, tension, and shear. Based on the intended application, each stimulus requires specific material selection, in terms of substrate composition and size (e.g., macrostructured materials and nanomaterials), for optimal in vitro and in vivo performance. For example, compressive systems typically utilize hydrogels or elastomeric substrates that respond to and withstand cyclic compressive loading, whereas, tension-responsive systems use composites to compartmentalize payloads. Finally, shear-activated systems are based on nanoassemblies or microaggregates that respond to physiological or externally-applied shear stresses. In order to provide a comprehensive assessment of current research on mechanoresponsive drug delivery, the mechanical stimuli intrinsically present in the human body are first discussed, along with the mechanical forces typically applied during medical device interventions, followed by in-depth descriptions of compression, tension, and shear-mediated drug delivery devices. We conclude by summarizing the progress of current research aimed at integrating mechanoresponsive elements within these devices, identifying additional clinical opportunities for mechanically-activated systems, and discussing future prospects.
Collapse
Affiliation(s)
- Julia Wang
- Department of Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States
| | - Jonah A Kaplan
- Department of Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States
| | - Yolonda L Colson
- Division of Thoracic Surgery, Department of Surgery, Brigham and Women's Hospital, Boston, MA 02115, United States
| | - Mark W Grinstaff
- Department of Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States; Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States; Department of Medicine, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States.
| |
Collapse
|
47
|
Li H, Gu J, Wang M, Zhao D, Li Z, Qiao A, Zhu B. Multi-objective optimization of coronary stent using Kriging surrogate model. Biomed Eng Online 2016; 15:148. [PMID: 28155700 PMCID: PMC5260142 DOI: 10.1186/s12938-016-0268-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background In stent design optimization, the functional relationship between design parameters and design goals is nonlinear, complex, and implicit and the multi-objective design of stents involves a number of potentially conflicting performance criteria. Therefore it is hard and time-consuming to find the optimal design of stent either by experiment or clinic test. Fortunately, computational methods have been developed to the point whereby optimization and simulation tools can be used to systematically design devices in a realistic time-scale. The aim of the present study is to propose an adaptive optimization method of stent design to improve its expansion performance. Methods Multi-objective optimization method based on Kriging surrogate model was proposed to decrease the dogboning effect and the radial elastic recoil of stents to improve stent expansion properties and thus reduce the risk of vascular in-stent restenosis injury. Integrating design of experiment methods and Kriging surrogate model were employed to construct the relationship between measures of stent dilation performance and geometric design parameters. Expected improvement, an infilling sampling criterion, was employed to balance local and global search with the aim of finding the global optimal design. A typical diamond-shaped coronary stent-balloon system was taken as an example to test the effectiveness of the optimization method. Finite element method was used to analyze the stent expansion of each design. Results 27 iterations were needed to obtain the optimal solution. The absolute values of the dogboning ratio at 32 and 42 ms were reduced by 94.21 and 89.43%, respectively. The dogboning effect was almost eliminated after optimization. The average of elastic recoil was reduced by 15.17%. Conclusion This article presents FEM based multi-objective optimization method combining with the Kriging surrogate model to decrease both the dogboning effect and radial elastic recoil of stents. The numerical results prove that the proposed optimization method effectively decreased both the dogboning effect and radial elastic recoil of stent. Further investigations containing more design goals and more effective multidisciplinary design optimization method are warranted.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Junfeng Gu
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Zheng Li
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Bao Zhu
- School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China.
| |
Collapse
|
48
|
Boire TC, Balikov DA, Lee Y, Guth CM, Cheung-Flynn J, Sung HJ. Biomaterial-Based Approaches to Address Vein Graft and Hemodialysis Access Failures. Macromol Rapid Commun 2016; 37:1860-1880. [PMID: 27673474 PMCID: PMC5156561 DOI: 10.1002/marc.201600412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/15/2016] [Indexed: 12/19/2022]
Abstract
Veins used as grafts in heart bypass or as access points in hemodialysis exhibit high failure rates, thereby causing significant morbidity and mortality for patients. Interventional or revisional surgeries required to correct these failures have been met with limited success and exorbitant costs, particularly for the US Centers for Medicare & Medicaid Services. Vein stenosis or occlusion leading to failure is primarily the result of neointimal hyperplasia. Systemic therapies have achieved little long-term success, indicating the need for more localized, sustained, biomaterial-based solutions. Numerous studies have demonstrated the ability of external stents to reduce neointimal hyperplasia. However, successful results from animal models have failed to translate to the clinic thus far, and no external stent is currently approved for use in the US to prevent vein graft or hemodialysis access failures. This review discusses current progress in the field, design considerations, and future perspectives for biomaterial-based external stents. More comparative studies iteratively modulating biomaterial and biomaterial-drug approaches are critical in addressing mechanistic knowledge gaps associated with external stent application to the arteriovenous environment. Addressing these gaps will ultimately lead to more viable solutions that prevent vein graft and hemodialysis access failures.
Collapse
Affiliation(s)
- Timothy C Boire
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Daniel A Balikov
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Yunki Lee
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Christy M Guth
- Division of Vascular Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37235, USA
| | - Joyce Cheung-Flynn
- Division of Vascular Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37235, USA
| | - Hak-Joon Sung
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
- Severance Biomedical Science Institute, College of Medicine, Yonsei University, Seoul, 120-752, Republic of Korea
| |
Collapse
|
49
|
WEI LINGLING, CHEN QIANG, LI ZHIYONG. STUDY ON THE IMPACT OF STRAIGHT STENTS ON ARTERIES WITH DIFFERENT CURVATURES. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Different stent structures lead to different deformations of blood vessels, such as different cross-sectional shapes, which further influence the blood flow patterns. In this paper, six non-commercial stents with different link structures called I-, C-, S-, U-, N- and W-types were considered. Their influences on arteries with five different curvatures (i.e., 0[Formula: see text], 15[Formula: see text], 30[Formula: see text], 45[Formula: see text] and 60[Formula: see text]) were studied using finite element method. Four indices including the maximum plastic strain of stents, the rate of expansion, the maximum von Mises stress and the ellipticity of arteries, were compared for all cases. The results showed that the S-type or U-type stents, with larger plastic strain and lower von Mises stress on the arteries, provided the optimal outcome. As the link structures became complex, the arterial expansion increased monotonically, while the ellipticity of arteries showed a decreasing tendency in the vessel models. The present study could be useful for the commercial design and clinic selection of a stent with different link structures for different curved arteries.
Collapse
Affiliation(s)
- LINGLING WEI
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - QIANG CHEN
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - ZHIYONG LI
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia
| |
Collapse
|
50
|
Galvin E, Cummins C, Yoshihara S, Mac Donald BJ, Lally C. Plastic strains during stent deployment have a critical influence on the rate of corrosion in absorbable magnesium stents. Med Biol Eng Comput 2016; 55:1261-1275. [DOI: 10.1007/s11517-016-1584-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 10/05/2016] [Indexed: 10/20/2022]
|