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Kreinin Y, Epshtein M, Bolotin G, Korin N. Taking inspiration from birds to improve flow in prosthetic heart valves: an European Research Council granted project. Eur Heart J 2024:ehae330. [PMID: 38984412 DOI: 10.1093/eurheartj/ehae330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/11/2024] Open
Affiliation(s)
- Yevgeniy Kreinin
- Department of Biomedical Engineering, Technion Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Mark Epshtein
- Department of Biomedical Engineering, Technion Israel Institute of Technology, Technion City, Haifa 3200003, Israel
- Department of Radiology, New England Center for Stroke Research, University of Massachusetts Medical School, Worcester, MA, USA
| | - Gil Bolotin
- Department of Cardiac Surgery, Rambam Health Care Campus, Haifa 3109601, Israel
- Technion-IIT, The Ruth Bruce Rappaport Faculty of Medicine, Haifa 3525433, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion Israel Institute of Technology, Technion City, Haifa 3200003, Israel
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2
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Ucak K, Karatas F, Pekkan K. Effect of impeller rotational phase on the FDA blood pump velocity fields. Artif Organs 2024. [PMID: 38957988 DOI: 10.1111/aor.14811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 05/10/2024] [Accepted: 06/11/2024] [Indexed: 07/04/2024]
Abstract
BACKGROUND The Food and Drug Administration (FDA) blood pump is an open-source benchmark cardiovascular device introduced for validating computational and experimental performance analysis tools. The time-resolved velocity field for the whole impeller has not been established, as is undertaken in this particle image velocimetry (PIV) study. The level of instantaneous velocity fluctuations is important, to assess the flow-induced rotor vibrations which may contribute to the total blood damage. METHODS To document these factors, time-resolved two-dimensional PIV experiments were performed that were precisely phase-locked with the impeller rotation angle. The velocity fields in the impeller and in the volute conformed with the previous single blade passage experiments of literature. RESULTS Depending on the impeller orientation, present experiments showed that volute outlet nozzle flow can fluctuate up to 34% during impeller rotation, with a maximum standard experimental uncertainty of 2.2%. Likewise, the flow fields in each impeller passage also altered in average 33.5%. Considerably different vortex patterns were observed for different blade passages, with the largest vortical structures reaching an average core radii of 7 mm. The constant volute area employed in the FDA pump design contributes to the observed velocity imbalance, as illustrated in our velocity measurements. CONCLUSIONS By introducing the impeller orientation parameter for the nozzle flow, this study considers the possible uncertainties influencing pump flow. Expanding the available literature data, analysis of inter-blade relative velocity fields is provided here for the first-time to the best of our knowledge. Consequently, our research fills a critical knowledge gap in the understanding of the flow dynamics of an important benchmark cardiovascular device. This study prompts the need for improved hydrodynamic designs and optimized devices to be used as benchmark test devices, to build more confidence and safety in future ventricular assist device performance assessment studies.
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Affiliation(s)
- Kagan Ucak
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
| | - Faruk Karatas
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
| | - Kerem Pekkan
- Mechanical Engineering Department, Koc University, Istanbul, Turkey
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3
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Bornoff J, Gill HS, Najar A, Perkins IL, Cookson AN, Fraser KH. Overset meshing in combination with novel blended weak-strong fluid-structure interactions for simulations of a translating valve in series with a second valve. Comput Methods Biomech Biomed Engin 2024; 27:736-750. [PMID: 37071538 DOI: 10.1080/10255842.2023.2199903] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
Mechanical circulatory support (MCS) devices can bridge the gap to transplant whilst awaiting a viable donor heart. The Realheart Total Artificial Heart is a novel positive-displacement MCS that generates pulsatile flow via bileaflet mechanical valves. This study developed a combined computational fluid dynamics and fluid-structure interaction (FSI) methodology for simulating positive displacement bileaflet valves. Overset meshing discretised the fluid domain, and a blended weak-strong coupling FSI algorithm was combined with variable time-stepping. Four operating conditions of relevant stroke lengths and rates were assessed. The results demonstrated this modelling strategy is stable and efficient for modelling positive-displacement artificial hearts.
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Affiliation(s)
- J Bornoff
- Department of Mechanical Engineering, University of Bath, Bath, UK
| | - H S Gill
- Department of Mechanical Engineering, University of Bath, Bath, UK
- Centre for Therapeutic Innovation, University of Bath, Bath, UK
| | - A Najar
- Scandinavian Real Heart AB, Västerås, Västmanland, Sweden
| | - I L Perkins
- Scandinavian Real Heart AB, Västerås, Västmanland, Sweden
| | - A N Cookson
- Department of Mechanical Engineering, University of Bath, Bath, UK
- Centre for Therapeutic Innovation, University of Bath, Bath, UK
| | - K H Fraser
- Department of Mechanical Engineering, University of Bath, Bath, UK
- Centre for Therapeutic Innovation, University of Bath, Bath, UK
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4
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Agrafiotis E, Zimpfer D, Mächler H, Holzapfel GA. Review of Systemic Mock Circulation Loops for Evaluation of Implantable Cardiovascular Devices and Biological Tissues. J Endovasc Ther 2024:15266028241235876. [PMID: 38528650 DOI: 10.1177/15266028241235876] [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: 03/27/2024]
Abstract
CLINICAL IMPACT On needs-based ex vivo monitoring of implantable devices or tissues/organs in cardiovascular simulators provides new insights and paves new paths for device prototypes. The insights gained could not only support the needs of patients, but also inform engineers, scientists and clinicians about undiscovered aspects of diseases (during routine monitoring). We analyze seminal and current work and highlight a variety of opportunities for developing preclinical tools that would improve strategies for future implantable devices. Holistically, mock circulation loop studies can bridge the gap between in vivo and in vitro approaches, as well as clinical and laboratory settings, in a mutually beneficial manner.
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Affiliation(s)
| | - Daniel Zimpfer
- Division of Cardiac Surgery, Medical University of Graz, Graz, Austria
| | - Heinrich Mächler
- Division of Cardiac Surgery, Medical University of Graz, Graz, Austria
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, Graz, Austria
- Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway
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5
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Laha S, Fourtakas G, Das PK, Keshmiri A. Smoothed particle hydrodynamics based FSI simulation of the native and mechanical heart valves in a patient-specific aortic model. Sci Rep 2024; 14:6762. [PMID: 38514703 PMCID: PMC10957961 DOI: 10.1038/s41598-024-57177-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/14/2024] [Indexed: 03/23/2024] Open
Abstract
The failure of the aortic heart valve is common, resulting in deterioration of the pumping function of the heart. For the end stage valve failure, bi-leaflet mechanical valve (most popular artificial valve) is implanted. However, due to its non-physiological behaviour, a significant alteration is observed in the normal haemodynamics of the aorta. While in-vivo experimentation of a human heart valve (native and artificial) is a formidable task, in-silico study using computational fluid dynamics (CFD) with fluid structure interaction (FSI) is an effective and economic tool for investigating the haemodynamics of natural and artificial heart valves. In the present work, a haemodynamic model of a natural and mechanical heart valve has been developed using meshless particle-based smoothed particle hydrodynamics (SPH). In order to further enhance its clinical relevance, this study employs a patient-specific vascular geometry and presents a successful validation against traditional finite volume method and 4D magnetic resonance imaging (MRI) data. The results have demonstrated that SPH is ideally suited to simulate the heart valve function due to its Lagrangian description of motion, which is a favourable feature for FSI. In addition, a novel methodology for the estimation of the wall shear stress (WSS) and other related haemodynamic parameters have been proposed from the SPH perspective. Finally, a detailed comparison of the haemodynamic parameters has been carried out for both native and mechanical aortic valve, with a particular emphasis on the clinical risks associated with the mechanical valve.
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Affiliation(s)
- Sumanta Laha
- School of Engineering, University of Manchester, Manchester, M13 9PL, UK
- Department of Mechanical Engineering, IIT Kharagpur, Kharagpur, 721302, India
| | - Georgios Fourtakas
- School of Engineering, University of Manchester, Manchester, M13 9PL, UK
| | - Prasanta K Das
- Department of Mechanical Engineering, IIT Kharagpur, Kharagpur, 721302, India
| | - Amir Keshmiri
- School of Engineering, University of Manchester, Manchester, M13 9PL, UK.
- Manchester University NHS Foundation Trust, Manchester, M13 9PL, UK.
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6
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D'Souza GA, Rinaldi JE, Meki M, Crusan A, Richardson E, Shinnar M, Herbertson LH. Using a Mock Circulatory Loop as a Regulatory Science Tool to Simulate Different Heart Failure Conditions. J Biomech Eng 2024; 146:011004. [PMID: 37831143 DOI: 10.1115/1.4063746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023]
Abstract
Mechanical circulatory support (MCS) device therapy is one of the primary treatment options for end-stage heart failure (HF), whereby a mechanical pump is integrated with the failing heart to maintain adequate tissue perfusion. The ISO 14708-5:2020 standard prescribes generic guidelines for nonclinical device evaluation and system performance testing of MCS devices using a mock circulatory loop (MCL). However, the utility of MCLs in premarket regulatory submissions of MCS devices is ambiguous, and the specific disease states that the device is intended to treat are not usually simulated. Hence, we aim to outline the potential of MCLs as a valuable regulatory science tool for characterizing MCS device systems by adequately representing target clinical-use HF conditions on the bench. Target pathophysiologic hemodynamics of HF conditions (i.e., cardiogenic shock (CS), left ventricular (LV) hypertrophy secondary to hypertension, and coronary artery disease), along with a healthy adult at rest and a healthy adult during exercise are provided as recommended test conditions. The conditions are characterized based on LV, aorta, and left atrium pressures using recommended cardiac hemodynamic indices such as systolic, diastolic, and mean arterial pressure, mean cardiac output (CO), cardiac cycle time, and systemic vascular resistance. This study is a first step toward standardizing MCLs to generate well-defined target HF conditions used to evaluate MCS devices.
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Affiliation(s)
- Gavin A D'Souza
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Jean E Rinaldi
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Moustafa Meki
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Annabelle Crusan
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Eric Richardson
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Meir Shinnar
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Luke H Herbertson
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
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7
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Contarino C, Chifari F, D'Souza GA, Herbertson LH. Validation of a Multiscale Computational Model Using a Mock Circulatory Loop to Simulate Cardiogenic Shock. ASAIO J 2023; 69:e502-e512. [PMID: 37923315 DOI: 10.1097/mat.0000000000002062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023] Open
Abstract
The objectives of this study are to characterize the hemodynamics of cardiogenic shock (CS) through a computational model validated using a mock circulatory loop (MCL) and to perform sensitivity analysis and uncertainty propagation studies after the American Society of Mechanical Engineers (ASME) Validation and Verification (V&V) guidelines. The uncertainties in cardiac cycle time ( ), total resistance ( ), and total volume ( ) were quantified in the MCL and propagated in the computational model. Both models were used to quantify the pressure in the left atrium, aorta (Ao), and left ventricle (LV), along with the flow through the aortic valve, reaching a good agreement. The results suggest that 1) is the main source of uncertainty in the variables under study, 2) showed its greatest impact on the uncertainty of Ao hemodynamics, and 3) mostly affected the uncertainty of LV pressure and Ao flow at the late-systolic phase. Comparison of uncertainty levels in the computational and experimental results was used to infer the presence of additional contributing factors that were not captured and propagated during a first analysis. Future work will expand upon this study to analyze the impact of mechanical circulatory support devices, such as ventricular assist devices, under CS conditions.
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Affiliation(s)
- Christian Contarino
- From the Research and Development, Computational Life Inc., Wilmington, Delaware
| | - Francesco Chifari
- From the Research and Development, Computational Life Inc., Wilmington, Delaware
| | - Gavin A D'Souza
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland
| | - Luke H Herbertson
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland
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Langenaeken T, Vanoppen A, Janssens F, Tanghe L, Verbrugghe P, Rega F, Meuris B. DOACs in the Anticoagulation of Mechanical Valves: A Systematic Review and Future Perspectives. J Clin Med 2023; 12:4984. [PMID: 37568386 PMCID: PMC10419922 DOI: 10.3390/jcm12154984] [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: 06/15/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
Valvular heart disease is a common disease often necessitating valve replacement. Mechanical heart valves (MHVs) are often used in younger patients because of their longer durability. Their main disadvantage is the need for lifelong anticoagulation. Warfarin is considered a standard treatment, but it is far from perfect. Direct oral anticoagulants (DOACs) are a new and more patient-friendly alternative to warfarin when anticoagulation is required, but have not yet been approved for the indication of mechanical valves. EVIDENCE ACQUISITION A literature search of Pubmed, Embase, Web of Science (Core Collection), and Cochrane Library (from inception to May 2023) was performed using a search string that was well defined and not modified during the study. An extensive overview of the search terms used in each database can be found in the Appendix. Only prospective clinical trials were included in this review. A total of 10 publications were included in this review. RELEVANCE TO CLINICAL PRACTICE This systematic review summarizes the different types of DOACs and their possible use in the anticoagulation of mechanical valves. We aim to propose future directions in anticoagulation research for mechanical valves. CONCLUSIONS DOAC use in MHVs has been halted due to the failure of both dabigatran and apixaban in two major clinical trials. However, rivaroxaban was successful in two small clinical trials. Ample research is still needed to explore new valve designs as well as new anticoagulation targets.
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Affiliation(s)
- Tom Langenaeken
- Department of Cardiac Surgery, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium (B.M.)
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9
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Zhou J, Li Y, Li T, Tian X, Xiong Y, Chen Y. Analysis of the Effect of Thickness on the Performance of Polymeric Heart Valves. J Funct Biomater 2023; 14:309. [PMID: 37367273 DOI: 10.3390/jfb14060309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/17/2023] [Accepted: 05/26/2023] [Indexed: 06/28/2023] Open
Abstract
Polymeric heart valves (PHVs) are a promising and more affordable alternative to mechanical heart valves (MHVs) and bioprosthetic heart valves (BHVs). Materials with good durability and biocompatibility used for PHVs have always been the research focus in the field of prosthetic heart valves for many years, and leaflet thickness is a major design parameter for PHVs. The study aims to discuss the relationship between material properties and valve thickness, provided that the basic functions of PHVs are qualified. The fluid-structure interaction (FSI) approach was employed to obtain a more reliable solution of the effective orifice area (EOA), regurgitant fraction (RF), and stress and strain distribution of the valves with different thicknesses under three materials: Carbothane PC-3585A, xSIBS and SIBS-CNTs. This study demonstrates that the smaller elastic modulus of Carbothane PC-3585A allowed for a thicker valve (>0.3 mm) to be produced, while for materials with an elastic modulus higher than that of xSIBS (2.8 MPa), a thickness less than 0.2 mm would be a good attempt to meet the RF standard. What is more, when the elastic modulus is higher than 23.9 MPa, the thickness of the PHV is recommended to be 0.l-0.15 mm. Reducing the RF is one of the directions of PHV optimization in the future. Reducing the thickness and improving other design parameters are reliable means to reduce the RF for materials with high and low elastic modulus, respectively.
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Affiliation(s)
- Jingyuan Zhou
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Yijing Li
- College of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Tao Li
- College of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Xiaobao Tian
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Yan Xiong
- College of Mechanical Engineering, Sichuan University, Chengdu 610065, China
| | - Yu Chen
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
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10
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Nowak M, Divo E, Adamczyk WP. Multiscale model for blood flow after a bileaflet artificial aortic valve implantation. Comput Biol Med 2023; 158:106805. [PMID: 37019010 DOI: 10.1016/j.compbiomed.2023.106805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/15/2023] [Accepted: 03/20/2023] [Indexed: 04/05/2023]
Abstract
Cardiovascular diseases are the leading cause of mortality in the world, mainly due to atherosclerosis and its consequences. The article presents the numerical model of the blood flow through artificial aortic valve. The overset mesh approach was applied to simulate the valve leaflets motion and to realize the moving mesh, in the aortic arch and the main branches of cardiovascular system. To capture the cardiac system's response and the effect of vessel compliance on the outlet pressure, the lumped parameter model has been also included within the solution procedure. Three different turbulence modeling approaches were used and compared - the laminar, k-ϵ and k-ω model. The simulation results were also compared with the model excluding the moving valve geometry and the importance of the lumped parameter model for the outlet boundary condition was analyzed. Proposed numerical model and protocol was found as suitable for performing the virtual operations on the real patient vasculature geometry. The time-efficient turbulence model and overall solving procedure allows to support the clinicians in making decisions about the patient treatment and to predict the results of the future surgery.
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11
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Ponnaluri SV, Sacks MS, Manning KB. The Accelerated Transcatheter Heart Valve Testing Environment: Loading, Motion, and Fluid Dynamics. J Biomech Eng 2023; 145:031005. [PMID: 36416296 PMCID: PMC9791666 DOI: 10.1115/1.4056291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/24/2022]
Abstract
Transcatheter aortic valve replacements (TAVRs) are an increasingly common treatment for aortic valve disease due to their minimally invasive delivery. As TAVR designs require thinner leaflets to facilitate catheter-based delivery, they experience greater leaflet operational stresses and potentially greater durability issues than conventional surgical valves. Yet, our understanding of TAVR durability remains largely unexplored. Currently, preclinical TAVR durability is evaluated within an ISO:5840 compliant accelerated wear tester (AWT) up to a required 200 × 106 cycles, corresponding to approximately five years in vivo. While AWTs use high cycle frequencies (10-20 Hz) to achieve realistic timeframes, the resulting valve loading behaviors and fluid dynamics are not representative of the in vivo environment and thus may not accurately predict failure mechanisms. Despite the importance of fatigue and failure predictions for replacement heart valves, surprisingly, little quantitative information exists on the dynamic AWT environment. To better understand this environment, we examined frequency and diastolic period effects for the first time using high-speed enface imaging and particle image velocimetry to quantify valve motion and flow, respectively, using a Durapulse™ AWT at frequencies of 10, 15, and 20 Hz. Regardless of operating condition, no waveform achieved a physiologically relevant transvalvular loading pressure, despite having an ISO compliant geometric orifice area (GOA) and waveform. General fluid mechanics were consistent with in vivo but the AWT geometry developed secondary flow structures, which could impact mechanical loading. Therefore, the nonphysiologic loading and variability induced by changes in operating condition must be carefully regulated to ensure physiologically relevant fatigue.
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Affiliation(s)
- Sailahari V. Ponnaluri
- Department of Biomedical Engineering, The Pennsylvania State University, 122 Chemical and Biomedical Engineering Building, University Park, PA 16802
| | - Michael S. Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering Sciences, University of Texas, Austin, TX 78712; Department of Biomedical Engineering, University of Texas, Austin, TX 78712
| | - Keefe B. Manning
- Department of Biomedical Engineering, The Pennsylvania State University, 122 Chemical and Biomedical Engineering Building, University Park, PA 16802; Department of Surgery, Penn State Hershey Medical Center, Hershey, PA 17033
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12
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Patient-Specific Immersed Finite Element-Difference Model of Transcatheter Aortic Valve Replacement. Ann Biomed Eng 2023; 51:103-116. [PMID: 36264408 PMCID: PMC9832092 DOI: 10.1007/s10439-022-03047-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/03/2022] [Indexed: 01/28/2023]
Abstract
Transcatheter aortic valve replacement (TAVR) first received FDA approval for high-risk surgical patients in 2011 and has been approved for low-risk surgical patients since 2019. It is now the most common type of aortic valve replacement, and its use continues to accelerate. Computer modeling and simulation (CM&S) is a tool to aid in TAVR device design, regulatory approval, and indication in patient-specific care. This study introduces a computational fluid-structure interaction (FSI) model of TAVR with Medtronic's CoreValve Evolut R device using the immersed finite element-difference (IFED) method. We perform dynamic simulations of crimping and deployment of the Evolut R, as well as device behavior across the cardiac cycle in a patient-specific aortic root anatomy reconstructed from computed tomography (CT) image data. These IFED simulations, which incorporate biomechanics models fit to experimental tensile test data, automatically capture the contact within the device and between the self-expanding stent and native anatomy. Further, we apply realistic driving and loading conditions based on clinical measurements of human ventricular and aortic pressures and flow rates to demonstrate that our Evolut R model supports a physiological diastolic pressure load and provides informative clinical performance predictions.
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13
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Mann M, Qavi I, Zhang N, Tan G. Engineers in Medicine: Foster Innovation by Traversing Boundaries. Crit Rev Biomed Eng 2023; 51:19-32. [PMID: 37551906 DOI: 10.1615/critrevbiomedeng.2023047838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Engineers play a critical role in the advancement of biomedical science and the development of diagnostic and therapeutic technologies for human well-being. The complexity of medical problems requires the synthesis of diverse knowledge systems and clinical experiences to develop solutions. Therefore, engineers in the healthcare and biomedical industries are interdisciplinary by nature to innovate technical tools in sophisticated clinical settings. In academia, engineering is usually divided into disciplines with dominant characteristics. Since biomedical engineering has been established as an independent curriculum, the term "biomedical engineers" often refers to the population from a specific discipline. In fact, engineers who contribute to medical and healthcare innovations cover a broad range of engineering majors, including electrical engineering, mechanical engineering, chemical engineering, industrial engineering, and computer sciences. This paper provides a comprehensive review of the contributions of different engineering professions to the development of innovative biomedical solutions. We use the term "engineers in medicine" to refer to all talents who integrate the body of engineering knowledge and biological sciences to advance healthcare systems.
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Affiliation(s)
- Monikka Mann
- Department of Industrial, Manufacturing and Systems Engineering, Texas Tech University, Lubbock, TX, USA
| | - Imtiaz Qavi
- Department of Industrial, Manufacturing and Systems Engineering, Texas Tech University, Lubbock, TX, USA
| | - Nan Zhang
- Department of Industrial, Manufacturing and Systems Engineering, Texas Tech University, Lubbock, TX, USA
| | - George Tan
- Department of Industrial, Manufacturing and Systems Engineering, Texas Tech University, Lubbock, TX, USA
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14
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Brunel L, Williams ZA, Yastrebov K, Robinson BM, Wise IK, Paterson HS, Bannon PG. Splitting the anterior mitral leaflet impairs left ventricular function in an ovine model. EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY : OFFICIAL JOURNAL OF THE EUROPEAN ASSOCIATION FOR CARDIO-THORACIC SURGERY 2022; 63:6849520. [PMID: 36440952 DOI: 10.1093/ejcts/ezac539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/01/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES During mitral valve replacement, the anterior mitral leaflet is usually resected or modified. Anterior leaflet splitting seems the least disruptive modification. Reattachment of the modified leaflet to the annulus reduces the annulopapillary distance. The goal of this study was to quantify the acute effects on left ventricular function of splitting the anterior mitral leaflet and shortening the annulopapillary distance. METHODS In 6 adult sheep, a wire was placed around the anterior leaflet and exteriorized through the left ventricular wall to enable splitting the leaflet in the beating heart. Releasable snares to reduce annulopapillary distance were likewise positioned and exteriorized. A mechanical mitral prosthesis was inserted to prevent mitral incompetence during external manipulations of the native valve. Instantaneous changes in left ventricular function were recorded before and after shortening the annulopapillary distance, then before and after splitting the anterior leaflet. RESULTS After splitting the anterior leaflet, preload recruitable stroke work, stroke work, stroke volume, cardiac output, left ventricular end systolic pressure and mean pressure were significantly decreased by 26%, 23%, 12%, 9%, 15% and 11%, respectively. Shortening the annulopapillary distance was associated with significant decreases in the end systolic pressure volume relationship, preload recruitable stroke work, stroke work and left ventricular end systolic pressure by 67%, 33%, 15% and 13%, respectively. Shortening the annulopapillary distance after splitting the leaflet had no significant effect. CONCLUSIONS Splitting the anterior mitral leaflet acutely impaired left ventricular contractility and haemodynamics in an ovine model. Shortening the annulopapillary distance after leaflet splitting did not further impair left ventricular function.
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Affiliation(s)
| | - Zoe A Williams
- DVC Research Portfolio, The University of Sydney, NSW, Australia
| | - Konstantin Yastrebov
- Prince of Wales Medical School, Faculty of Medicine and Health, The University of New South Wales, NSW, Australia
| | - Benjamin M Robinson
- Institute of Academic Surgery and Baird Institute for Applied Heart and Lung Surgery, Camperdown, NSW, Australia
| | - Innes K Wise
- Department of Laboratory Animal Services, The University of Sydney, NSW, Australia
| | - Hugh S Paterson
- Central Clinical School-Surgery, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Paul G Bannon
- Institute of Academic Surgery and Baird Institute for Applied Heart and Lung Surgery, Camperdown, NSW, Australia.,Central Clinical School-Surgery, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
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15
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Comparison of performance of self-expanding and balloon-expandable transcatheter aortic valves. JTCVS OPEN 2022; 10:128-139. [PMID: 36004225 PMCID: PMC9390782 DOI: 10.1016/j.xjon.2022.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/20/2022] [Accepted: 04/12/2022] [Indexed: 11/23/2022]
Abstract
Objective Methods Results Conclusions
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16
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Liu X, Zhang W, Ye P, Luo Q, Chang Z. Fluid-Structure Interaction Analysis on the Influence of the Aortic Valve Stent Leaflet Structure in Hemodynamics. Front Physiol 2022; 13:904453. [PMID: 35634139 PMCID: PMC9136298 DOI: 10.3389/fphys.2022.904453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
Transcatheter aortic valve replacement (TAVR) is a minimally invasive surgical treatment for heart valve disease. At present, personalized TAVR valves are not available for some patients. This study adopts the fluid-structure interaction (FSI) model of the research object that has a three-disc leaflet form and structural design in the valve leaflet area. The valve opening shape, orifice area, stress-strain, and distribution of hemodynamic flow and pressure were compared under the condition of equal contact area between valve and blood. The FSI method was used to simulate the complex three dimensional characteristics of the flow field more accurately around the valve after TAVR stent implantation. Three personalized stent systems were established to study the performance of the leaflet design based on computational fluid dynamics. By comparing the different leaflet geometries, the maximum stress on leaflets and stents of model B was relatively reduced, which effectively improved the reliability of the stent design. Such valve design also causes the opening area of the valve leaflet to increase and the low-velocity area of the flow field to decrease during the working process of the valve, thus reducing the possibility of thrombosis. These findings can underpin breakthroughs in product design, and provide important theoretical support and technical guidance for clinical research.
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17
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Asadi H, Hedayat M, Borazjani I. The Effects of Implantation Orientation of a Bileaflet Mechanical Heart Valve in an Anatomic Left Ventricle-Aorta Configuration. J Biomech Eng 2022; 144:1140397. [PMID: 35466356 DOI: 10.1115/1.4054411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Indexed: 11/08/2022]
Abstract
We have performed three-dimensional high-resolution numerical simulations of a bi-leaflet mechanical heart valve (BMHV) implanted at different orientations in an anatomic left ventricle-aorta obtained from magnetic resonance imaging (MRI) of a volunteer. The thoroughly validated overset curvilinear-immersed boundary (overset-CURVIB) fluid-structure interaction (FSI) flow solver is used in which the aorta and LV are discretized with boundary-conforming and non-conforming curvilinear grids, respectively. The motion of the LV wall is prescribed based on a lumped parameter model while the motion of the leaflets are calculated using a strong coupled FSI algorithm enhanced with Aitken convergence technique. We carried out simulations for three valve orientations, which differ from each other by 45 degrees and compared the leaflet motion and flow field for multiple cycles. Our results show reproducible and relatively symmetrical opening for all valve orientations. The presence of small-scale vortical structures after peak systole, cause significant cycle-to-cycle variations in valve kinematics during the closing phase for all valve orientations. Furthermore, our results show that valve orientation does not have a significant effect on the distribution of viscous shear stress in the ascending aorta. Additionally, two different mathematical activation models including linear level of activation and Soares model are used to quantify the platelet activation in the ascending aorta. The results show that the valve orientation does not significantly affect (less than 8%) the total platelet activation in the ascending aorta.
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Affiliation(s)
- Hossein Asadi
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Mohammadali Hedayat
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Iman Borazjani
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843, USA
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Wang Z, Dasi LP, Hatoum H. Controlling the Flow Separation in Heart Valves Using Vortex Generators. Ann Biomed Eng 2022; 50:914-928. [PMID: 35415767 DOI: 10.1007/s10439-022-02966-5] [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: 11/17/2021] [Accepted: 04/06/2022] [Indexed: 11/25/2022]
Abstract
A comprehensive computational study is performed to investigate the effectiveness of vortex generators (VGs) applied to mechanical bi-leaflet heart valves. Co-rotating and counter-rotating VG configurations are compared to a control valve without VGs. Detailed flow fields are obtained and used to elucidate the underlying flow physics. It was found that VGs reduce flow separation over the leaflets and hence reduce the Reynolds shear stress (RSS) in the vicinity regions of heart valve. The co-rotating VG configuration demonstrates a better performance compared with the counter-rotating configuration in terms of the RSS, turbulent kinetic energy production and velocity distributions, especially in the peripheral jet flows. The fraction of blood damage in the co-rotating configuration shows a 4.7% reduction in comparison to the control case, while a 3.7% increase is observed in the counter-rotating configuration. The passive flow control technique of applying co-rotating VG illustrates a great potential to help mitigate the hemodynamic factors leading to potential blood damage risk.
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Affiliation(s)
- Zhenyu Wang
- Simulation Innovation and Modeling Center (SIMCenter), The Ohio State University, Columbus, OH, USA.,Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - Lakshmi Prasad Dasi
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Hoda Hatoum
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, USA. .,Health Research Institute, Center of Biocomputing and Digital Health and Institute of Computing and Cybernetics, Michigan Technological University, Houghton, MI, USA.
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19
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Computational Methods for Fluid-Structure Interaction Simulation of Heart Valves in Patient-Specific Left Heart Anatomies. FLUIDS 2022. [DOI: 10.3390/fluids7030094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Given the complexity of human left heart anatomy and valvular structures, the fluid–structure interaction (FSI) simulation of native and prosthetic valves poses a significant challenge for numerical methods. In this review, recent numerical advancements for both fluid and structural solvers for heart valves in patient-specific left hearts are systematically considered, emphasizing the numerical treatments of blood flow and valve surfaces, which are the most critical aspects for accurate simulations. Numerical methods for hemodynamics are considered under both the continuum and discrete (particle) approaches. The numerical treatments for the structural dynamics of aortic/mitral valves and FSI coupling methods between the solid Ωs and fluid domain Ωf are also reviewed. Future work toward more advanced patient-specific simulations is also discussed, including the fusion of high-fidelity simulation within vivo measurements and physics-based digital twining based on data analytics and machine learning techniques.
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20
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Hatoum H, Ahn S, Lilly S, Maureira P, Crestanello J, Thourani VH, Dasi LP. Flow dynamics of surgical and transcatheter aortic valves: Past to present. JTCVS OPEN 2022; 9:43-56. [PMID: 36003460 PMCID: PMC9390780 DOI: 10.1016/j.xjon.2022.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 01/12/2022] [Indexed: 11/15/2022]
Affiliation(s)
- Hoda Hatoum
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Mich
- Health Research Institute, Center of Biocomputing and Digital Health and Institute of Computing and Cybernetics, Michigan Technological University, Houghton, Mich
- Center of Biocomputing and Digital Health, Michigan Technological University, Houghton, Mich
- Address for reprints: Hoda Hatoum, PhD, Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr, Houghton, MI 49931.
| | - Sunyoung Ahn
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Mich
| | - Scott Lilly
- Division of Cardiovascular Medicine, The Ohio State University, Columbus, Ohio
| | - Pablo Maureira
- Department of Cardiovascular Surgery, CHU de Nancy, Nancy, France
| | - Juan Crestanello
- Department of Cardiovascular Surgery, Mayo Clinic, Rochester, Minn
| | - Vinod H. Thourani
- Department of Cardiovascular Surgery, Marcus Valve Center, Piedmont Heart Institute, Atlanta, Ga
| | - Lakshmi Prasad Dasi
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
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21
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Vogl BJ, El Shaer A, Crestanello JA, Alkhouli M, Hatoum H. Flow dynamics in the sinus and downstream of third and fourth generation balloon expandable transcatheter aortic valves. J Mech Behav Biomed Mater 2022; 127:105092. [DOI: 10.1016/j.jmbbm.2022.105092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/27/2021] [Accepted: 01/12/2022] [Indexed: 10/19/2022]
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22
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Assessment Parameters for Arrayed Pulse Wave Analysis and Application in Hypertensive Disorders. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:6652028. [PMID: 35222674 PMCID: PMC8872656 DOI: 10.1155/2022/6652028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/20/2022] [Indexed: 11/18/2022]
Abstract
Study on the objectivity of pulse diagnosis is inseparable from the instruments to obtain the pulse waves. The single-pulse diagnostic instrument is relatively mature in acquiring and analysing pulse waves, but the pulse information captured by single-pulse diagnostic instrument is limited. The sensor arrays can simulate rich sense of the doctor's fingers and catch multipoint and multiparameter array signals. How to analyse the acquired array signals is still a major problem in the objective research of pulse diagnosis. The goal of this study was to establish methods for analysing arrayed pulse waves and preliminarily apply them in hypertensive disorders. While a sensor array can be used for the real-time monitoring of twelve pulse wave channels, for each subject in this study, only the pulse wave signals of the left hand at the “guan” location were obtained. We calculated the average pulse wave (APW) per channel over a thirty-second interval. The most representative pulse wave (MRPW) and the APW were matched by their correlation coefficient (CC). The features of the MRPW and the features that corresponded to the array pulse volume (APV) parameters were identified manually. Finally, a clinical trial was conducted to detect these feature performance indicators in patients with hypertensive disorders. The independent-samples t-tests and the Mann–Whitney U-tests were performed to assess the differences in these pulse parameters between the healthy and hypertensive groups. We found that the radial passage (RP) APVh1, APVh3, APVh4, APVh3/h1 (P < 0.01), and APVh4/h1 (P < 0.05) were significantly higher in the hypertensive group than in the healthy group; the intermediate passage (IP) APVh4, APVh3/h1 (P < 0.05), and APVh4/h1 (P < 0.01) and the mean APVh3, APVh3/h1 (P < 0.05), and APVh4/h1 (P < 0.01) were significantly higher in the hypertensive group than in the healthy group, and the ulnar passage (UP) APVh4/h1 (P < 0.05) was clearly elevated in the hypertensive group. These results provide a preliminary validation of this novel approach for determining the APV by arrayed pulse wave analysis. In conclusion, we identified effective indicators of hypertensive vascular function. Traditional Chinese medicine (TCM) pulses comprise multidimensional information, and a sensor array could provide a better indication of TCM pulse characteristics. In this study, the validation of the arrayed pulse wave analysis demonstrates that the APV can reliably mirror TCM pulse characteristics.
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Tasca G, Sturla F, Jaworek M, Giese D, Menicanti L, Vismara R, Lombardi M, Redaelli A. In vitro four-dimensional flow magnetic resonance analysis of the effect of pericardial valve design on aortic flow. J Med Eng Technol 2022; 46:209-219. [DOI: 10.1080/03091902.2022.2026505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Giordano Tasca
- Cardiac Surgery Department, Heart Health Center, King Saud Medical City, Riyadh, Kingdom of Saudi Arabia
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Francesco Sturla
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Michal Jaworek
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | | | - Lorenzo Menicanti
- Cardiac Surgery Department, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Riccardo Vismara
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Massimo Lombardi
- Multimodality Cardiac Imaging, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
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24
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Park J, Wu Z, Steiner PR, Zhu B, Zhang JXJ. Heart-on-Chip for Combined Cellular Dynamics Measurements and Computational Modeling Towards Clinical Applications. Ann Biomed Eng 2022; 50:111-137. [PMID: 35039976 DOI: 10.1007/s10439-022-02902-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/01/2022] [Indexed: 12/24/2022]
Abstract
Organ-on-chip or micro-engineered three-dimensional cellular or tissue models are increasingly implemented in the study of cardiovascular pathophysiology as alternatives to traditional in vitro cell culture. Drug induced cardiotoxicity is a key issue in drug development pipelines, but the current in vitro and in vivo studies suffer from inter-species differences, high costs, and lack of reliability and accuracy in predicting cardiotoxicity. Microfluidic heart-on-chip devices can impose a paradigm shift to the current tools. They can not only recapitulate cardiac tissue level functionality and the communication between cells and extracellular matrices but also allow higher throughput studies conducive to drug screening especially with their added functionalities or sensors that extract disease-specific phenotypic, genotypic, and electrophysiological information in real-time. Such electrical and mechanical components can tailor the electrophysiology and mechanobiology of the experiment to better mimic the in vivo condition as well. Recent advancements and challenges are reviewed in the fabrication, functionalization and sensor assisted mechanical and electrophysiological measurements, numerical and computational modeling of cardiomyocytes' behavior, and the clinical applications in drug screening and disease modeling. This review concludes with the current challenges and perspectives on the future of such organ-on-chip platforms.
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Affiliation(s)
- Jiyoon Park
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Ziqian Wu
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Paul R Steiner
- Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, Lebanon, NH, 03766, USA
| | - Bo Zhu
- Computer Science Department, Dartmouth College, Hanover, NH, 03755, USA
| | - John X J Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA. .,Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, Lebanon, NH, 03766, USA.
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25
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Manivasagam VK, Sabino RM, Kantam P, Popat KC. Surface modification strategies to improve titanium hemocompatibility: a comprehensive review. MATERIALS ADVANCES 2021; 2:5824-5842. [PMID: 34671743 PMCID: PMC8451052 DOI: 10.1039/d1ma00367d] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/27/2021] [Indexed: 05/31/2023]
Abstract
Titanium and its alloys are widely used in different biomaterial applications due to their remarkable mechanical properties and bio-inertness. However, titanium-based materials still face some challenges, with an emphasis on hemocompatibility. Blood-contacting devices such as stents, heart valves, and circulatory devices are prone to thrombus formation, restenosis, and inflammation due to inappropriate blood-implant surface interactions. After implantation, when blood encounters these implant surfaces, a series of reactions takes place, such as protein adsorption, platelet adhesion and activation, and white blood cell complex formation as a defense mechanism. Currently, patients are prescribed anticoagulant drugs to prevent blood clotting, but these drugs can weaken their immune system and cause profound bleeding during injury. Extensive research has been done to modify the surface properties of titanium to enhance its hemocompatibility. Results have shown that the modification of surface morphology, roughness, and chemistry has been effective in reducing thrombus formation. The main focus of this review is to analyze and understand the different modification techniques on titanium-based surfaces to enhance hemocompatibility and, consequently, recognize the unresolved challenges and propose scopes for future research.
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Affiliation(s)
| | - Roberta M Sabino
- School of Advanced Materials Discovery, Colorado State University Fort Collins CO USA
| | - Prem Kantam
- Department of Mechanical Engineering, Colorado State University Fort Collins CO USA
| | - Ketul C Popat
- Department of Mechanical Engineering, Colorado State University Fort Collins CO USA
- School of Advanced Materials Discovery, Colorado State University Fort Collins CO USA
- School of Biomedical Engineering, Colorado State University Fort Collins CO USA
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26
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Schaller T, Scharfschwerdt M, Schubert K, Prinz C, Lembke U, Sievers HH. Aortic valve replacement in sheep with a novel trileaflet mechanical heart valve prosthesis without anticoagulation. JTCVS OPEN 2021; 7:76-88. [PMID: 36003713 PMCID: PMC9390555 DOI: 10.1016/j.xjon.2021.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/21/2021] [Indexed: 11/14/2022]
Abstract
Background Even after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation. Methods Four female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep. Results Mean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls. Conclusions The preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events.
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Bui HT, Khair N, Yeats B, Gooden S, James SP, Dasi LP. Transcatheter Heart Valves: A Biomaterials Perspective. Adv Healthc Mater 2021; 10:e2100115. [PMID: 34038627 DOI: 10.1002/adhm.202100115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/23/2021] [Indexed: 11/11/2022]
Abstract
Heart valve disease is prevalent throughout the world, and the number of heart valve replacements is expected to increase rapidly in the coming years. Transcatheter heart valve replacement (THVR) provides a safe and minimally invasive means for heart valve replacement in high-risk patients. The latest clinical data demonstrates that THVR is a practical solution for low-risk patients. Despite these promising results, there is no long-term (>20 years) durability data on transcatheter heart valves (THVs), raising concerns about material degeneration and long-term performance. This review presents a detailed account of the materials development for THVRs. It provides a brief overview of THVR, the native valve properties, the criteria for an ideal THV, and how these devices are tested. A comprehensive review of materials and their applications in THVR, including how these materials are fabricated, prepared, and assembled into THVs is presented, followed by a discussion of current and future THVR biomaterial trends. The field of THVR is proliferating, and this review serves as a guide for understanding the development of THVs from a materials science and engineering perspective.
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Affiliation(s)
- Hieu T. Bui
- Department of Biomedical Engineering Georgia Institute of Technology 387 Technology Cir NW Atlanta GA 30313 USA
| | - Nipa Khair
- School of Advanced Materials Discovery Colorado State University 700 Meridian Ave Fort Collins CO 80523 USA
| | - Breandan Yeats
- Department of Biomedical Engineering Georgia Institute of Technology 387 Technology Cir NW Atlanta GA 30313 USA
| | - Shelley Gooden
- Department of Biomedical Engineering Georgia Institute of Technology 387 Technology Cir NW Atlanta GA 30313 USA
| | - Susan P. James
- School of Advanced Materials Discovery Colorado State University 700 Meridian Ave Fort Collins CO 80523 USA
| | - Lakshmi Prasad Dasi
- Department of Biomedical Engineering Georgia Institute of Technology 387 Technology Cir NW Atlanta GA 30313 USA
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El-Sabawi B, Guerrero ME, Eleid MF, Nkomo VT, Pislaru SV, Rihal CS. Hemolysis after transcatheter mitral valve replacement in degenerated bioprostheses, annuloplasty rings, and mitral annular calcification: Incidence, patient characteristics, and clinical outcomes. Catheter Cardiovasc Interv 2021; 98:776-785. [PMID: 34057272 DOI: 10.1002/ccd.29779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/20/2021] [Accepted: 05/09/2021] [Indexed: 01/07/2023]
Abstract
OBJECTIVES To determine the incidence, characteristics, and outcomes of patients with hemolysis after transcatheter mitral valve replacement (TMVR). BACKGROUND Hemolysis is an increasingly recognized complication of TMVR. Clinical outcomes and optimal management for patients with hemolysis after TMVR are unclear. METHODS Patients that underwent mitral valve-in-valve (MViV), valve-in-ring (MViR), and valve-in-mitral annular calcification (ViMAC) at a single center were retrospectively assessed. RESULTS A total of 101 patients had TMVR, including 69 with MViV, 14 with MViR, and 18 with ViMAC. ViMAC patients had an increased frequency of mild or greater paravalvular leak (PVL) (ViMAC, 72.2%; MViR, 14.3%; MViV, 13.0%; p < .001). Hemolysis occurred in eight patients and was more common after ViMAC (ViMAC, 33.3%; MViR, 7.1%; MViV, 1.5%; p < .001). This required transfusion in five (ViMAC, 4; MViV, 1) and was associated with acute kidney injury in five with ViMAC. Among the ViMAC patients, four had transcatheter re-intervention to treat hemolysis with resolution of anemia in three and mild residual anemia in one with persistent mild PVL. The two ViMAC patients without re-intervention had persistent anemia and died within 6 months. Both MViV and MViR patients with hemolysis did not have PVL but had turbulent flow from left ventricular outflow tract narrowing and their hemolysis was self-limited. CONCLUSIONS Hemolysis occurs with greater frequency and increased clinical severity after ViMAC as compared to MViV or MViR and is likely related to increased incidence of PVL. These findings demonstrate the need to investigate novel strategies that can reduce the burden of hemolysis with ViMAC.
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Affiliation(s)
| | - Mayra E Guerrero
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Mackram F Eleid
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Vuyisile T Nkomo
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Sorin V Pislaru
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Charanjit S Rihal
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Arakawa K, Giorgio-Serchi F, Mochiyama H. Snap Pump: A Snap-Through Mechanism for a Pulsatile Pump. IEEE Robot Autom Lett 2021. [DOI: 10.1109/lra.2021.3052416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Hatoum H, Askegaard G, Iyer R, Prasad Dasi L. Atrial and ventricular flows across a transcatheter mitral valve. Interact Cardiovasc Thorac Surg 2021; 33:1-9. [PMID: 33674829 DOI: 10.1093/icvts/ivab032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 11/20/2020] [Accepted: 01/10/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The objective of this study was to evaluate the haemodynamic performance of transcatheter mitral valve replacement (TMVR) Implant with a focus on turbulence and washout adjacent to the ventricular surface of the leaflets. TMVR holds the promise of treating a large spectrum of mitral valve diseases. However, the haemodynamic performance and flow dynamics of such replacements are not fully understood. METHODS A tri-leaflet biopsrosthetic TMVR represented by Caisson implant of size 36A was implanted in the mitral position of a left heart simulator pulse duplicating system under physiological conditions. The 36A implant covers an anterior-posterior range of 26-32 mm and a commissure-to-commissure range of 30-36 mm. Transmitral pressure gradient, effective orifice area and regurgitant fraction were calculated. Particle image velocimetry was performed to evaluate turbulence in 2 perpendicular planes (Reynolds and viscous shear stresses, respectively). Additionally, dye experiments were performed to visualize washout. RESULTS Transmitral pressure gradient was 1.29 ± 0.27 mmHg and effective orifice area was 2.96 ± 0.28 cm2. Regurgitant fraction was 14.13 ± 0.08%. Total washout was 4.27 cardiac cycles. Largest viscous shear stress reaches 3.7 Pa and 2.4 Pa in ventricle and atrium, respectively. Reynolds shear stress in the atrial side was <10 Pa. In the ventricular side, the largest Reynolds shear stress reached ∼35 Pa. CONCLUSIONS TMVR leads to favourable haemodynamics with low degree of turbulence combined with fast washout around the leaflets indicating promising potential for freedom from blood damage potential and thrombosis corroborated by initial clinical studies as part of the valves's Early Feasibility Study.
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Affiliation(s)
- Hoda Hatoum
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, USA
| | | | - Ramji Iyer
- R&D Department, LivaNova PLC, Maple Grove, MN, USA
| | - Lakshmi Prasad Dasi
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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31
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Transcatheter Heart Valve Downstream Fluid Dynamics in an Accelerated Evaluation Environment. Ann Biomed Eng 2021; 49:2170-2182. [PMID: 33638029 DOI: 10.1007/s10439-021-02751-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 02/12/2021] [Indexed: 10/22/2022]
Abstract
Transcatheter aortic valve replacements (TAVRs) provide minimally invasive delivery of bioprosthetic heart valves (BHVs) for the treatment of aortic valve disease. While surgical BHVs show efficacy for 8-10 years, long-term TAVR durability remains unknown. Pre-clinical testing evaluates BHV durability in an ISO:5840 compliant accelerated wear tester (AWT), yet, the design and development of AWTs and their accuracy in predicting in vivo performance, is unclear. As a result of limited knowledge on AWT environment and BHV loading, durability assessment of candidate valves remains fundamentally empirical. For the first time, high-speed particle image velocimetry quantified an ISO:5840 compliant downstream AWT velocity field, Reynolds stresses, and turbulence intensity. TAVR enface imaging quantified the orifice area and estimated the flow rate. When valve area and flow rate were at their maximum during peak systole (1.49 cm2 and 16.05 L/min, respectively), central jet velocity, Reynolds normal and shear stress, and turbulence intensity grew to 0.50 m/s, 265.1 Pa, 124.6 Pa, and 37.3%, respectively. During diastole, unique AWT recirculation produced retrograde flow and the directional changes created eddies. These novel AWT findings demonstrated a substantially reduced valve fully loaded period and pressure not matching in vivo or in vitro studies, despite the comparable fluid environment and TAVR motion.
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Multiscale Characterization of Isotropic Pyrolytic Carbon Used for Mechanical Heart Valve Production. Processes (Basel) 2021. [DOI: 10.3390/pr9020338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Usage of pyrolytic carbon (PyC) to produce mechanical heart valves (MHVs) has led to heart valve replacement being a very successful procedure. Thus, the mechanical properties of employed materials for MHV production are fundamental to obtain the required characteristics of biocompatibility and wear resistance. In this study, two deposition methods of PyC were compared through a multiscale approach, performing three-point bending tests and nanoindentation tests. Adopted deposition processes produced materials that were slightly different. Significant differences were found at the characteristic scale lengths of the deposited layers. Setting changes of the deposition process permitted obtaining PyC characterized by a more uniform microstructure, conferring to the bulk material superior mechanical properties.
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Proper Orthogonal Decomposition Analysis of the Flow Downstream of a Dysfunctional Bileaflet Mechanical Aortic Valve. Cardiovasc Eng Technol 2021; 12:286-299. [PMID: 33469847 DOI: 10.1007/s13239-021-00519-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/02/2021] [Indexed: 12/14/2022]
Abstract
PURPOSE Aortic valve replacement remains the only viable solution for symptomatic patients with severe aortic valve stenosis. Despite their improved design and long history of successful operation, bileaflet mechanical heart valves are still associated with post-operative complications leading to valve dysfunction. Thus, the flow dynamics can be highly disturbed downstream of the dysfunctional valve. METHODS In this in vitro study, the flow dynamics downstream of healthy and dysfunctional bileaflet mechanical heart valves have been investigated using particle image velocimetry measurements. Proper orthogonal decomposition of the velocity field has been performed in order to explore the coherent flow features in the ascending aorta in the presence of a dysfunctional bileaflet mechanical heart valve. RESULTS The ability of proper orthogonal decomposition derived metrics to differentiate between heathy and dysfunctional cases is reported. Moreover, reduced-order modeling using proper orthogonal decomposition is thoroughly investigated not only for the velocity field but also for higher order flow characteristics such as time average wall shear stress, oscillatory shear index and viscous energy dissipation. CONCLUSION Considering these results, proper orthogonal decomposition can provide a rapid binary classifier to evaluate if the bileaflet mechanical valve deviates from its normal operating conditions. Moreover, the study shows that the size of the reduced-order model depends on which flow parameter is required to be reconstructed.
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Schiavone NK, Elkins CJ, McElhinney DB, Eaton JK, Marsden AL. In Vitro Assessment of Right Ventricular Outflow Tract Anatomy and Valve Orientation Effects on Bioprosthetic Pulmonary Valve Hemodynamics. Cardiovasc Eng Technol 2021; 12:215-231. [PMID: 33452649 DOI: 10.1007/s13239-020-00507-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
PURPOSE The congenital heart defect Tetralogy of Fallot (ToF) affects 1 in 2500 newborns annually in the US and typically requires surgical repair of the right ventricular outflow tract (RVOT) early in life, with variations in surgical technique leading to large disparities in RVOT anatomy among patients. Subsequently, often in adolescence or early adulthood, patients usually require surgical placement of a xenograft or allograft pulmonary valve prosthesis. Valve longevity is highly variable for reasons that remain poorly understood. METHODS This work aims to assess the performance of bioprosthetic pulmonary valves in vitro using two 3D printed geometries: an idealized case based on healthy subjects aged 11 to 13 years and a diseased case with a 150% dilation in vessel diameter downstream of the valve. Each geometry was studied with two valve orientations: one with a valve leaflet opening posterior, which is the native pulmonary valve position, and one with a valve leaflet opening anterior. RESULTS Full three-dimensional, three-component, phase-averaged velocity fields were obtained in the physiological models using 4D flow MRI. Flow features, particularly vortex formation and reversed flow regions, differed significantly between the RVOT geometries and valve orientations. Pronounced asymmetry in streamwise velocity was present in all cases, while the diseased geometry produced additional asymmetry in radial flows. Quantitative integral metrics demonstrated increased secondary flow strength and recirculation in the rotated orientation for the diseased geometry. CONCLUSIONS The compound effects of geometry and orientation on bioprosthetic valve hemodynamics illustrated in this study could have a crucial impact on long-term valve performance.
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Affiliation(s)
| | | | | | - John K Eaton
- Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Alison L Marsden
- Pediatrics and Bioengineering, Stanford University, Stanford, CA, USA.
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Yu Z, Tan J, Wang S. Enhanced discrete phase model for multiphase flow simulation of blood flow with high shear stress. Sci Prog 2021; 104:368504211008064. [PMID: 33788651 PMCID: PMC10358624 DOI: 10.1177/00368504211008064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Shear stress is often present in the blood flow within blood-contacting devices, which is the leading cause of hemolysis. However, the simulation method for blood flow with shear stress is still not perfect, especially the multiphase flow model and experimental verification. In this regard, this study proposes an enhanced discrete phase model for multiphase flow simulation of blood flow with shear stress. This simulation is based on the discrete phase model (DPM). According to the multiphase flow characteristics of blood, a virtual mass force model and a pressure gradient influence model are added to the calculation of cell particle motion. In the experimental verification, nozzle models were designed to simulate the flow with shear stress, varying the degree of shear stress through different nozzle sizes. The microscopic flow was measured by the Particle Image Velocimetry (PIV) experimental method. The comparison of the turbulence models and the verification of the simulation accuracy were carried out based on the experimental results. The result demonstrates that the simulation effect of the SST k-ω model is better than other standard turbulence models. Accuracy analysis proves that the simulation results are accurate and can capture the movement of cell-level particles in the flow with shear stress. The results of the research are conducive to obtaining accurate and comprehensive analysis results in the equipment development phase.
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Affiliation(s)
- Zheqin Yu
- College of Energy and Power Engineering, Changsha University of Science & Technology, Hunan, China
- College of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan, China
| | - Jianping Tan
- College of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan, China
| | - Shuai Wang
- College of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan, China
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36
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In vitro calcification studies on bioprosthetic and decellularized heart valves under quasi-physiological flow conditions. Biodes Manuf 2020. [DOI: 10.1007/s42242-020-00110-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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37
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Chung JJ, Im H, Kim SH, Park JW, Jung Y. Toward Biomimetic Scaffolds for Tissue Engineering: 3D Printing Techniques in Regenerative Medicine. Front Bioeng Biotechnol 2020; 8:586406. [PMID: 33251199 PMCID: PMC7671964 DOI: 10.3389/fbioe.2020.586406] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/05/2020] [Indexed: 12/21/2022] Open
Abstract
Three-dimensional (3D) printing technology allows fabricating complex and precise structures by stacking materials layer by layer. The fabrication method has a strong potential in the regenerative medicine field to produce customizable and defect-fillable scaffolds for tissue regeneration. Plus, biocompatible materials, bioactive molecules, and cells can be printed together or separately to enhance scaffolds, which can save patients who suffer from shortage of transplantable organs. There are various 3D printing techniques that depend on the types of materials, or inks, used. Here, different types of organs (bone, cartilage, heart valve, liver, and skin) that are aided by 3D printed scaffolds and printing methods that are applied in the biomedical fields are reviewed.
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Affiliation(s)
- Justin J. Chung
- Center for Biomaterials, Korea Institute of Science and Technology, Seoul, South Korea
| | - Heejung Im
- Center for Biomaterials, Korea Institute of Science and Technology, Seoul, South Korea
| | - Soo Hyun Kim
- Center for Biomaterials, Korea Institute of Science and Technology, Seoul, South Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, South Korea
| | - Jong Woong Park
- Department of Orthopedic Surgery, Korea University Anam Hospital, Seoul, South Korea
| | - Youngmee Jung
- Center for Biomaterials, Korea Institute of Science and Technology, Seoul, South Korea
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, South Korea
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38
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Giles TX, Bennett J, Stone CE, Gendreau JL, Abraham M, Mammis A. Characterizing Complications of Intracranial Responsive Neurostimulation Devices for Epilepsy Through a Retrospective Analysis of the Federal MAUDE Database. Neuromodulation 2020; 25:263-270. [PMID: 32881224 DOI: 10.1111/ner.13259] [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: 05/19/2020] [Revised: 07/03/2020] [Accepted: 07/27/2020] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Responsive neurostimulation is an innovative modality in the treatment of medication-refractory epilepsy for patients who are not suitable candidates for surgical intervention. While being a potentially life-changing treatment option for many individuals with epilepsy, little is known about the system's complications aside from its performance in initial clinical trials. Therefore, the goal of this study was to characterize all reported complications of the RNS system made to the Food & Drug Administration since its approval. MATERIALS AND METHODS The Manufacturer and User Facility Device Experience (MAUDE) database was queried for entries reported under "implanted brain stimulator for epilepsy" through the dates of November 1, 2013 to March 1, 2020. After correction of duplicate entries, each was sorted into complication types based on the entries' narrative descriptions. RESULTS The searched yielded 241 unique complication events. The most common complications were attributed to infections (40%) and lead breaks (12%). Other reported complications included poor wound healing (10%) and intrinsic device failure (7%). Focal neurological deficits were found in 2%. Over half (67%) of the reported complications required return to the operating room for revision or explant. The remainder of the adverse events were self-resolved or treated with either medication or software adjustment. CONCLUSIONS Future research endeavors should attempt to optimize the implantable device for preventing infections. The data of complications provided by this review will also aid physicians in providing the most accurate informed consent for patients when deciding to undergo implantation with the responsive neurostimulation system.
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Affiliation(s)
- Tyler Xavier Giles
- School of Medicine, Mercer University School of Medicine, Macon, GA, USA
| | - Josiah Bennett
- School of Medicine, Mercer University School of Medicine, Macon, GA, USA
| | | | | | - Mickey Abraham
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Antonios Mammis
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, NJ, USA
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Hemodynamic Performance of Dysfunctional Prosthetic Heart Valve with the Concomitant Presence of Subaortic Stenosis: In Silico Study. Bioengineering (Basel) 2020; 7:bioengineering7030090. [PMID: 32784661 PMCID: PMC7552677 DOI: 10.3390/bioengineering7030090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/29/2020] [Accepted: 08/06/2020] [Indexed: 01/09/2023] Open
Abstract
The prosthetic heart valve is vulnerable to dysfunction after surgery, thus a frequent assessment is required. Doppler electrocardiography and its quantitative parameters are commonly used to assess the performance of the prosthetic heart valves and provide detailed information on the interaction between the heart chambers and related prosthetic valves, allowing early detection of complications. However, in the case of the presence of subaortic stenosis, the accuracy of Doppler has not been fully investigated in previous studies and guidelines. Therefore, it is important to evaluate the accuracy of the parameters in such cases to get early detection, and a proper treatment plan for the patient, at the right time. In the current study, a CFD simulation was performed for the blood flow through a Bileaflet Mechanical Heart Valve (BMHV) with concomitant obstruction in the Left Ventricle Outflow Tract (LVOT). The current study explores the impact of the presence of the subaortic on flow patterns. It also investigates the accuracy of (BMHV) evaluation using Doppler parameters, as proposed in the American Society of Echocardiography (ASE) guidelines.
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40
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Zakko J, Blum KM, Drews JD, Wu YL, Hatoum H, Russell M, Gooden S, Heitkemper M, Conroy O, Kelly J, Carey S, Sacks M, Texter K, Ragsdale E, Strainic J, Bocks M, Wang Y, Dasi LP, Armstrong AK, Breuer C. Development of Tissue Engineered Heart Valves for Percutaneous Transcatheter Delivery in a Fetal Ovine Model. JACC Basic Transl Sci 2020; 5:815-828. [PMID: 32875171 PMCID: PMC7452327 DOI: 10.1016/j.jacbts.2020.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023]
Abstract
A fully biodegradable fetal valve was developed using a zinc-aluminum alloy stent and electrospun PCL leaflets. In vitro evaluation of the valve was performed with accelerated degradation, mechanical, and flow loop testing, and the valve showed trivial stenosis and trivial regurgitation. A large animal model was used for percutaneous delivery of the valve to the fetal pulmonary annulus. Following implantation, the valve had no stenosis or regurgitation by echocardiography, and the fetal sheep matured and was delivered at term with the tissue-engineered valve.
This multidisciplinary work shows the feasibility of replacing the fetal pulmonary valve with a percutaneous, transcatheter, fully biodegradable tissue-engineered heart valve (TEHV), which was studied in vitro through accelerated degradation, mechanical, and hemodynamic testing and in vivo by implantation into a fetal lamb. The TEHV exhibited only trivial stenosis and regurgitation in vitro and no stenosis in vivo by echocardiogram. Following implantation, the fetus matured and was delivered at term. Replacing a stenotic fetal valve with a functional TEHV has the potential to interrupt the development of single-ventricle heart disease by restoring proper flow through the heart.
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Key Words
- EOA, effective orifice area
- MPA, main pulmonary artery
- Mn, molecular size
- Mw, molecular weight
- NOI, normalized orientation index
- PCL, polycaprolactone
- PDI, polydispersity index
- PG, pressure gradient
- RF, regurgitant fraction
- RV, right ventricular/ventricle
- SEM, scanning electron microscopy
- TEHV, tissue-engineered heart valve
- congenital heart disease
- tissue-engineered heart valve
- transcatheter heart valve
- translational medicine
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Affiliation(s)
- Jason Zakko
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Department of Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Kevin M Blum
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Department of Biomedical Engineering, Ohio State University, Columbus, Ohio
| | - Joseph D Drews
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Department of Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Yen-Lin Wu
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York
| | - Hoda Hatoum
- Coulter Department of Biomedical Engineering, Georgia Tech, Atlanta, Georgia
| | - Madeleine Russell
- Oden Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas
| | - Shelley Gooden
- Coulter Department of Biomedical Engineering, Georgia Tech, Atlanta, Georgia
| | - Megan Heitkemper
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Department of Biomedical Engineering, Ohio State University, Columbus, Ohio
| | - Olivia Conroy
- Oden Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas
| | - John Kelly
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Heart Center, Nationwide Children's Hospital, Columbus, Ohio
| | - Stacey Carey
- Heart Center, Nationwide Children's Hospital, Columbus, Ohio
| | - Michael Sacks
- Oden Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas
| | - Karen Texter
- Heart Center, Nationwide Children's Hospital, Columbus, Ohio
| | - Ellie Ragsdale
- Department of OB/GYN-Maternal Fetal Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - James Strainic
- Department of Pediatric Cardiology, University Hospitals Rainbow Babies and Children's Hospital, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Martin Bocks
- University Hospitals Rainbow Babies and Children's Hospital, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Yadong Wang
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York
| | - Lakshmi Prasad Dasi
- Coulter Department of Biomedical Engineering, Georgia Tech, Atlanta, Georgia
| | | | - Christopher Breuer
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.,Department of Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
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Kim W, Choi H, Kweon J, Yang DH, Kim YH. Effects of pannus formation on the flow around a bileaflet mechanical heart valve. PLoS One 2020; 15:e0234341. [PMID: 32530931 PMCID: PMC7292405 DOI: 10.1371/journal.pone.0234341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/23/2020] [Indexed: 11/19/2022] Open
Abstract
Some patients with a bileaflet mechanical heart valve (BMHV) show significant increases in the transvalvular pressure drop and abnormal leaflet motion due to a pannus (an abnormal fibrovascular tissue) formed on the ventricular side, even in the absence of physical contact between the pannus and leaflets. We investigate the effects of the pannus shape (circular or semi-circular ring), implantation location and height on the leaflet motion, flow structure and transvalvular pressure drop using numerical simulations. The valve model considered resembles a 25 mm masters HP valve. The mean systolic pressure drop is significantly increased with increasing pannus height, irrespective of its implantation orientation. Near the peak inflow rate, the flow behind the pannus becomes highly turbulent, and the transvalvular pressure drop is markedly increased by the pannus. At the end of valve opening and the start of valve closing, oscillatory motions of the leaflets occur due to periodic shedding of vortex rings behind the pannus, and their amplitudes become large with increasing pannus height. When the pannus shape is asymmetric (e.g., a semi-circular ring) and its height reaches about 0.1D (D (= 25 mm) is the diameter of an aorta), abnormal leaflet motions occur: two leaflets move asymmetrically, and valve closing is delayed in time or incomplete, which increases the regurgitation volume. The peak energy loss coefficients due to panni are obtained from simulation data and compared with those predicted by a one-dimensional model. The comparison indicates that the one-dimensional model is applicable for the BMHV with and without pannus.
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Affiliation(s)
- Woojin Kim
- Department of Mechanical Engineering, Seoul National University, Seoul, Korea
| | - Haecheon Choi
- Department of Mechanical Engineering, Seoul National University, Seoul, Korea
- Institute of Advanced Machines and Design, Seoul National University, Seoul, Korea
- * E-mail:
| | - Jihoon Kweon
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Dong Hyun Yang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Young-Hak Kim
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
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de Oliveira DMC, Abdullah N, Green NC, Espino DM. Biomechanical Assessment of Bicuspid Aortic Valve Phenotypes: A Fluid-Structure Interaction Modelling Approach. Cardiovasc Eng Technol 2020; 11:431-447. [PMID: 32519086 DOI: 10.1007/s13239-020-00469-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/04/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE Bicuspid aortic valve (BAV) is a congenital heart malformation with phenotypic heterogeneity. There is no prior computational study that assesses the haemodynamic and valve mechanics associated with BAV type 2 against a healthy tricuspid aortic valve (TAV) and other BAV categories. METHODS A proof-of-concept study incorporating three-dimensional fluid-structure interaction (FSI) models with idealised geometries (one TAV and six BAVs, namely type 0 with lateral and anterior-posterior orientations, type 1 with R-L, N-R and N-L leaflet fusion and type 2) has been developed. Transient physiological boundary conditions have been applied and simulations were run using an Arbitrary Lagrangian-Eulerian formulation. RESULTS Our results showed the presence of abnormal haemodynamics in the aorta and abnormal valve mechanics: type 0 BAVs yielded the best haemodynamical and mechanical outcomes, but cusp stress distribution varied with valve orifice orientation, which can be linked to different cusp calcification location onset; type 1 BAVs gave rise to similar haemodynamics and valve mechanics, regardless of raphe position, but this position altered the location of abnormal haemodynamic features; finally, type 2 BAV constricted the majority of blood flow, exhibiting the most damaging haemodynamic and mechanical repercussions when compared to other BAV phenotypes. CONCLUSION The findings of this proof-of-concept work suggest that there are specific differences across haemodynamics and valve mechanics associated with BAV phenotypes, which may be critical to subsequent processes associated with their pathophysiology processes.
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Affiliation(s)
- Diana M C de Oliveira
- Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Nazirul Abdullah
- Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK
| | - Naomi C Green
- Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK
| | - Daniel M Espino
- Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK
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Hatoum H, Gooden S, Heitkemper M, Blum KM, Zakko J, Bocks M, Yi T, Wu YL, Wang Y, Breuer CK, Dasi LP. Fetal Transcatheter Trileaflet Heart Valve Hemodynamics: Implications of Scaling on Valve Mechanics and Turbulence. Ann Biomed Eng 2020; 48:1683-1693. [PMID: 32052320 PMCID: PMC7286783 DOI: 10.1007/s10439-020-02475-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 02/05/2020] [Indexed: 01/09/2023]
Abstract
The scarcity of data available on the best approach for pulmonary fetal valve replacement or implantation necessitate an investigation on whether practices using adult transcatheter valves could be translated to fetal applications. The objective of this study is to evaluate the hemodynamic characteristics and the turbulent properties of a fetal sized trileaflet transcatheter pulmonary valve in comparison with an adult balloon-expandable valve in order to assess the possibility of designing valves for fetal applications using dynamic similarity. A 6 mm fetal trileaflet valve and a 26 mm SAPIEN 3 valve were assessed in a pulse duplicator. Particle image velocimetry was performed. Pressure gradient (ΔP), effective orifice area (EOA), regurgitant fractions (RF), pinwheeling indices (PI) and turbulent stresses were evaluated. ΔP was 8.56 ± 0.139 and 7.76 ± 0.083 mmHg with fetal valve and SAPIEN respectively (p < 0.0001); EOA was 0.10 ± 0.0007 and 2.1 ± 0.025 cm2 with fetal valve and SAPIEN respectively (p < 0.0001); RF with the fetal valve was 2.35 ± 1.99% and with SAPIEN 10.92 ± 0.11% (p < 0.0001); PI with fetal valve was 0.404 ± 0.01 and with SAPIEN 0.37 ± 0.07; The flow regime with the fetal valve was turbulent and Reynolds numbers reached about 7000 while those with the SAPIEN reached about 20,000 at peak velocity. Turbulent stresses were significantly higher with fetal valve compared with SAPIEN. Instantaneous viscous shear stresses with fetal valve were 5.8 times higher than those obtained with SAPIEN and Reynolds shear stresses were 2.5 times higher during peak systole. The fetal valve implantation leads to a turbulent flow (specific to this particular type and design of valve) regime unlike what is expected of a small valve with different flow properties compared to adult valves.
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Affiliation(s)
- Hoda Hatoum
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 387 Technology Circle NW, Atlanta, GA, 30313, USA
| | - Shelley Gooden
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 387 Technology Circle NW, Atlanta, GA, 30313, USA
| | - Megan Heitkemper
- Center for Regenerative Medicine, Tissue Engineering Program, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Kevin M Blum
- Center for Regenerative Medicine, Tissue Engineering Program, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Jason Zakko
- Center for Regenerative Medicine, Tissue Engineering Program, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Martin Bocks
- Case Western Reserve University School of Medicine, UH Rainbow Babies & Children's Hospital, Cleveland, OH, USA
| | - Tai Yi
- Center for Regenerative Medicine, Tissue Engineering Program, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Yen-Lin Wu
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Yadong Wang
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Christopher K Breuer
- Center for Regenerative Medicine, Tissue Engineering Program, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Lakshmi Prasad Dasi
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 387 Technology Circle NW, Atlanta, GA, 30313, USA.
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44
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Lee JH, Rygg AD, Kolahdouz EM, Rossi S, Retta SM, Duraiswamy N, Scotten LN, Craven BA, Griffith BE. Fluid-Structure Interaction Models of Bioprosthetic Heart Valve Dynamics in an Experimental Pulse Duplicator. Ann Biomed Eng 2020; 48:1475-1490. [PMID: 32034607 PMCID: PMC7154025 DOI: 10.1007/s10439-020-02466-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 12/18/2019] [Indexed: 12/15/2022]
Abstract
Computer modeling and simulation is a powerful tool for assessing the performance of medical devices such as bioprosthetic heart valves (BHVs) that promises to accelerate device design and regulation. This study describes work to develop dynamic computer models of BHVs in the aortic test section of an experimental pulse-duplicator platform that is used in academia, industry, and regulatory agencies to assess BHV performance. These computational models are based on a hyperelastic finite element extension of the immersed boundary method for fluid-structure interaction (FSI). We focus on porcine tissue and bovine pericardial BHVs, which are commonly used in surgical valve replacement. We compare our numerical simulations to experimental data from two similar pulse duplicators, including a commercial ViVitro system and a custom platform related to the ViVitro pulse duplicator. Excellent agreement is demonstrated between the computational and experimental results for bulk flow rates, pressures, valve open areas, and the timing of valve opening and closure in conditions commonly used to assess BHV performance. In addition, reasonable agreement is demonstrated for quantitative measures of leaflet kinematics under these same conditions. This work represents a step towards the experimental validation of this FSI modeling platform for evaluating BHVs.
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Affiliation(s)
- Jae H Lee
- Department of Mathematics, University of North Carolina, Chapel Hill, NC, USA
| | - Alex D Rygg
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA
| | - Ebrahim M Kolahdouz
- Department of Mathematics, University of North Carolina, Chapel Hill, NC, USA
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA
| | - Simone Rossi
- Department of Mathematics, University of North Carolina, Chapel Hill, NC, USA
| | - Stephen M Retta
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA
| | - Nandini Duraiswamy
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA
| | | | - Brent A Craven
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA
| | - Boyce E Griffith
- Departments of Mathematics, Applied Physical Sciences, and Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA.
- Carolina Center for Interdisciplinary Applied Mathematics, University of North Carolina, Chapel Hill, NC, USA.
- Computational Medicine Program, University of North Carolina, Chapel Hill, NC, USA.
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA.
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45
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YU ZHEQIN, TAN JIANPIN, WANG SHUAI. MODIFICATION OF THE SPALART–ALLMARAS MODEL FOR HEMOLYTIC SHEAR FLOW SIMULATION WITH PIV EXPERIMENT. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519420500025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hemolysis in blood-contacting devices severely affects the health of users, and computation fluid dynamics (CFD) simulation is a crucial method for hemolysis analysis. Medical equipment has high requirements for simulation accuracy. Modification of the turbulence model is one of the most effective ways to improve efficiency. In this study, we designed nozzle models to simulate hemolytic shear flow, varying the degree of shear flow through different nozzle orifice sizes. The study acquires microscopic flow results through Particle Image Velocimetry (PIV) experiments, and the Sparlart–Allmaras (S–A) model was modified based on the experimental results. In the study, we obtained the influence characteristics of the model coefficients on the simulation results and completed the accuracy correction. The results showed that the model coefficient [Formula: see text] has the most significant effect on the simulation results. Correcting [Formula: see text] to about 200% of the standard value can significantly improve the simulation accuracy, and the high shear flow intensity corresponds to a slightly lower correction value. The model modification eliminates the simulation error in the high-speed area, and the comparison results show that it is superior to the standard turbulence model.
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Affiliation(s)
- ZHEQIN YU
- School of Mechanical and Electrical Engineering, Central South University, Hunan 410083, P. R. China
| | - JIANPIN TAN
- School of Mechanical and Electrical Engineering, Central South University, Hunan 410083, P. R. China
| | - SHUAI WANG
- School of Mechanical and Electrical Engineering, Central South University, Hunan 410083, P. R. China
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46
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Ghosh RP, Marom G, Bianchi M, D'souza K, Zietak W, Bluestein D. Numerical evaluation of transcatheter aortic valve performance during heart beating and its post-deployment fluid-structure interaction analysis. Biomech Model Mechanobiol 2020; 19:1725-1740. [PMID: 32095912 DOI: 10.1007/s10237-020-01304-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 02/02/2020] [Indexed: 01/11/2023]
Abstract
Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure that provides an effective alternative to open-heart surgical valve replacement for treating advanced calcific aortic valve disease patients. However, complications, such as valve durability, device migration, paravalvular leakage (PVL), and thrombogenicity may lead to increased overall post-TAVR morbidity and mortality. A series of numerical studies involving a self-expandable TAVR valve were performed to evaluate these complications. Structural studies were performed with finite element (FE) analysis, followed by computational fluid dynamics (CFD) simulations, and fluid-structure interaction (FSI) analysis. The FE analysis was utilized to study the effect of TAVR valve implantation depth on valve anchorage in the Living Heart Human Model, which is capable of simulating beating heart during repeated cardiac cycles. The TAVR deployment cases where no valve migration was observed were then used to calculate the post-deployment thrombogenic potential via CFD simulations. FSI analysis followed to further assess the post-deployment TAVR hemodynamic performance for different implantation depths. The deployed valves PVL, geometric and effective orifice areas, and the leaflets structural and flow stress magnitudes were compared to determine the device optimal landing zone. The combined structural and hemodynamic analysis indicated that with the TAVR valve deployed at an aft ventricle position an optimal performance was achieved in the specific anatomy studied. Given the TAVR's rapid expansion to younger lower-risk patients, the comprehensive numerical methodology proposed here can potentially be used as a predictive tool for both procedural planning and valve design optimization to minimize the reported complications.
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Affiliation(s)
- Ram P Ghosh
- Department of Biomedical Engineering, Health Sciences Center T08-050, Stony Brook University, Stony Brook, NY, 11794-8084, USA
| | - Gil Marom
- School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Matteo Bianchi
- Department of Biomedical Engineering, Health Sciences Center T08-050, Stony Brook University, Stony Brook, NY, 11794-8084, USA
| | - Karl D'souza
- Dassault Systèmes SIMULIA Corp, Johnston, RI, 02919, USA
| | - Wojtek Zietak
- Capvidia NV, Research Park Haasrode, Technologielaan 3, 3001, Leuven, Belgium
| | - Danny Bluestein
- Department of Biomedical Engineering, Health Sciences Center T08-050, Stony Brook University, Stony Brook, NY, 11794-8084, USA.
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47
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Medical Device Failure—Implant Retrieval, Evaluation, and Failure Analysis. Biomater Sci 2020. [DOI: 10.1016/b978-0-12-816137-1.00096-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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48
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Li RL, Russ J, Paschalides C, Ferrari G, Waisman H, Kysar JW, Kalfa D. Mechanical considerations for polymeric heart valve development: Biomechanics, materials, design and manufacturing. Biomaterials 2019; 225:119493. [PMID: 31569017 PMCID: PMC6948849 DOI: 10.1016/j.biomaterials.2019.119493] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/21/2019] [Accepted: 09/11/2019] [Indexed: 01/12/2023]
Abstract
The native human heart valve leaflet contains a layered microstructure comprising a hierarchical arrangement of collagen, elastin, proteoglycans and various cell types. Here, we review the various experimental methods that have been employed to probe this intricate microstructure and which attempt to elucidate the mechanisms that govern the leaflet's mechanical properties. These methods include uniaxial, biaxial, and flexural tests, coupled with microstructural characterization techniques such as small angle X-ray scattering (SAXS), small angle light scattering (SALS), and polarized light microscopy. These experiments have revealed complex elastic and viscoelastic mechanisms that are highly directional and dependent upon loading conditions and biochemistry. Of all engineering materials, polymers and polymer-based composites are best able to mimic the tissue-level mechanical behavior of the native leaflet. This similarity to native tissue permits the fabrication of polymeric valves with physiological flow patterns, reducing the risk of thrombosis compared to mechanical valves and in some cases surpassing the in vivo durability of bioprosthetic valves. Earlier work on polymeric valves simply assumed the mechanical properties of the polymer material to be linear elastic, while more recent studies have considered the full hyperelastic stress-strain response. These material models have been incorporated into computational models for the optimization of valve geometry, with the goal of minimizing internal stresses and improving durability. The latter portion of this review recounts these developments in polymeric heart valves, with a focus on mechanical testing of polymers, valve geometry, and manufacturing methods.
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Affiliation(s)
- Richard L Li
- Department of Mechanical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 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
| | - Jonathan Russ
- Department of Civil Engineering and Engineering Mechanics, Fu Foundation School of Engineering and Applied Science, Columbia University, New York, NY, USA
| | - Costas Paschalides
- Department of Mechanical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, New York, NY, USA
| | - Giovanni Ferrari
- Department of Surgery and Biomedical Engineering, Columbia University Medical Center, New York, NY, USA
| | - Haim Waisman
- Department of Civil Engineering and Engineering Mechanics, Fu Foundation School of Engineering and Applied Science, Columbia University, New York, NY, USA
| | - Jeffrey W Kysar
- Department of Mechanical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 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.
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49
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Wium E, Jordaan CJ, Botes L, Smit FE. Alternative mechanical heart valves for the developing world. Asian Cardiovasc Thorac Ann 2019; 28:431-443. [PMID: 31752500 DOI: 10.1177/0218492319891255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Due to the prevalence of rheumatic heart disease in the developing world, mechanical heart valves in the younger patient population remain the prostheses of choice if repair is not feasible. Despite their durability, mechanical valves are burdened by coagulation and thromboembolism. Modern design tools can be utilized during the design process of mechanical valves, which allow a more systematic design approach and more detailed analysis of the blood flow through and around valves. These tools include computer-aided design, manufacturing, and engineering, such as computational fluid dynamics and finite element analysis, modern manufacturing techniques such as additive manufacturing, and sophisticated in-vitro and in-vivo tests. Following this systematic approach, a poppet valve was redesigned and the results demonstrate the benefits of the method. More organized flow patterns and fewer complex fluid structures were observed. The alternative trileaflet valve design has also been identified as a potential solution and, if a similar design approach is adopted, it could lead to the development of an improved mechanical heart valve in the future. It is imperative that researchers in developing countries continue their search for a mechanical heart valve with a reduced thromboembolic risk, requiring less or no anticoagulation.
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Affiliation(s)
- Elsmari Wium
- Robert WM Frater Cardiovascular Research Centre, Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa.,Department of Mechanical and Mechatronic Engineering, Faculty of Engineering, Stellenbosch University, Stellenbosch, South Africa
| | - Christiaan Johannes Jordaan
- Robert WM Frater Cardiovascular Research Centre, Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
| | - Lezelle Botes
- Department of Health Sciences, Central University of Technology, Bloemfontein, South Africa
| | - Francis Edwin Smit
- Robert WM Frater Cardiovascular Research Centre, Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
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50
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Mirvakili N, Di Labbio G, Saleh W, Kadem L. Flow characteristics in a model of a left ventricle in the presence of a dysfunctional mitral mechanical heart valve. J Vis (Tokyo) 2019. [DOI: 10.1007/s12650-019-00611-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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