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Liu H, Sacks MS, Simonian NT, Gorman JH, Gorman RC. Simulated Effects of Acute Left Ventricular Myocardial Infarction on Mitral Regurgitation in an Ovine Model. J Biomech Eng 2024; 146:101009. [PMID: 38652602 DOI: 10.1115/1.4065376] [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: 04/30/2023] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
Ischemic mitral regurgitation (IMR) occurs from incomplete coaptation of the mitral valve (MV) after myocardial infarction (MI), typically worsened by continued remodeling of the left ventricular (LV). The importance of LV remodeling is clear as IMR is induced by the post-MI dual mechanisms of mitral annular dilation and leaflet tethering from papillary muscle (PM) distension via the MV chordae tendineae (MVCT). However, the detailed etiology of IMR remains poorly understood, in large part due to the complex interactions of the MV and the post-MI LV remodeling processes. Given the patient-specific anatomical complexities of the IMR disease processes, simulation-based approaches represent an ideal approach to improve our understanding of this deadly disease. However, development of patient-specific models of left ventricle-mitral valve (LV-MV) interactions in IMR are complicated by the substantial variability and complexity of the MR etiology itself, making it difficult to extract underlying mechanisms from clinical data alone. To address these shortcomings, we developed a detailed ovine LV-MV finite element (FE) model based on extant comprehensive ovine experimental data. First, an extant ovine LV FE model (Sci. Rep. 2021 Jun 29;11(1):13466) was extended to incorporate the MV using a high fidelity ovine in vivo derived MV leaflet geometry. As it is not currently possible to image the MVCT in vivo, a functionally equivalent MVCT network was developed to create the final LV-MV model. Interestingly, in pilot studies, the MV leaflet strains did not agree well with known in vivo MV leaflet strain fields. We then incorporated previously reported MV leaflet prestrains (J. Biomech. Eng. 2023 Nov 1;145(11):111002) in the simulations. The resulting LV-MV model produced excellent agreement with the known in vivo ovine MV leaflet strains and deformed shapes in the normal state. We then simulated the effects of regional acute infarctions of varying sizes and anatomical locations by shutting down the local myocardial contractility. The remaining healthy (noninfarcted) myocardium mechanical behaviors were maintained, but allowed to adjust their active contractile patterns to maintain the prescribed pressure-volume loop behaviors in the acute post-MI state. For all cases studied, the LV-MV simulation demonstrated excellent agreement with known LV and MV in vivo strains and MV regurgitation orifice areas. Infarct location was shown to play a critical role in resultant MV leaflet strain fields. Specifically, extensional deformations of the posterior leaflets occurred in the posterobasal and laterobasal infarcts, while compressive deformations of the anterior leaflet were observed in the anterobasal infarct. Moreover, the simulated posterobasal infarct induced the largest MV regurgitation orifice area, consistent with experimental observations. The present study is the first detailed LV-MV simulation that reveals the important role of MV leaflet prestrain and functionally equivalent MVCT for accurate predictions of LV-MV interactions. Importantly, the current study further underscored simulation-based methods in understanding MV function as an integral part of the LV.
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Affiliation(s)
- Hao Liu
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712
| | - Natalie T Simonian
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, University of Pennsylvania, Philadelphia, PA 19146-2701
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, University of Pennsylvania, Philadelphia, PA 19146-2701
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Zuo H, Feng W, Tang X, Li Z, Fan Y. The study of loading mode with in-vitro fatigue testing for mitral annuloplasty ring. J Biomech 2024; 166:112047. [PMID: 38484653 DOI: 10.1016/j.jbiomech.2024.112047] [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] [Received: 12/07/2023] [Revised: 02/23/2024] [Accepted: 03/07/2024] [Indexed: 04/13/2024]
Abstract
To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.
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Affiliation(s)
- Hui Zuo
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Wentao Feng
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
| | - Xiaolan Tang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Zhou Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
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Christierson L, Frieberg P, Lala T, Töger J, Liuba P, Revstedt J, Isaksson H, Hakacova N. Validation of fluid-structure interaction simulations of the opening phase of phantom mitral heart valves under physiologically inspired conditions. Comput Biol Med 2024; 171:108033. [PMID: 38430739 DOI: 10.1016/j.compbiomed.2024.108033] [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] [Received: 10/23/2023] [Revised: 12/22/2023] [Accepted: 01/26/2024] [Indexed: 03/05/2024]
Abstract
BACKGROUND AND OBJECTIVE Atrioventricular valve disease is a common cause of heart failure, and successful surgical or interventional outcomes are crucial. Patient-specific fluid-structure interaction (FSI) modeling may provide valuable insights into valve dynamics and guidance of valve repair strategies. However, lack of validation has kept FSI modeling from clinical implementation. Therefore, this study aims to validate FSI simulations against in vitro benchmarking data, based on clinically relevant parameters for evaluating heart valve disease. METHODS An FSI model that mimics the left heart was developed. The domain included a deformable mitral valve of different stiffnesses run with different inlet velocities. Five different cases were simulated and compared to in vitro data based on the pressure difference across the valve, the valve opening, and the velocity in the flow domain. RESULTS The simulations underestimate the pressure difference across the valve by 6.8-14 % compared to catheter measurements. Evaluation of the valve opening showed an underprediction of 5.4-7.3 % when compared to cine MRI, 2D Echo, and 3D Echo data. Additionally, the simulated velocity through the valve showed a 7.9-8.4 % underprediction in relation to Doppler Echo measurements. Qualitative assessment of the velocity profile in the ventricle and the streamlines of the flow in the domain showed good agreement of the flow behavior. CONCLUSIONS Parameters relevant to the diagnosis of heart valve disease estimated by FSI simulations showed good agreement when compared to in vitro benchmarking data, with differences small enough not to affect the grading of heart valve disease. The FSI model is thus deemed good enough for further development toward patient-specific cases.
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Affiliation(s)
- Lea Christierson
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden. Address: Barnhjärtcentrum mottagning, Skånes universitetssjukhus, Lasarettsgatan 48, 221 85, Lund, Sweden; Department of Biomedical Engineering, Lund University, Lund, Sweden. Address: Box 118, 221 00, Lund, Sweden.
| | - Petter Frieberg
- Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden. Address: Box 177, 221 00, Lund, Sweden
| | - Tania Lala
- Department of Biomedical Engineering, Lund University, Lund, Sweden. Address: Box 118, 221 00, Lund, Sweden; Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden. Address: Box 177, 221 00, Lund, Sweden
| | - Johannes Töger
- Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden. Address: Box 177, 221 00, Lund, Sweden
| | - Petru Liuba
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden. Address: Barnhjärtcentrum mottagning, Skånes universitetssjukhus, Lasarettsgatan 48, 221 85, Lund, Sweden
| | - Johan Revstedt
- Department of Energy Science, Lund University, Lund, Sweden. Address: Box 118, 221 00, Lund, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden. Address: Box 118, 221 00, Lund, Sweden
| | - Nina Hakacova
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden. Address: Barnhjärtcentrum mottagning, Skånes universitetssjukhus, Lasarettsgatan 48, 221 85, Lund, Sweden
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Fumagalli I, Pagani S, Vergara C, Dede’ L, Adebo DA, Del Greco M, Frontera A, Luciani GB, Pontone G, Scrofani R, Quarteroni A. The role of computational methods in cardiovascular medicine: a narrative review. Transl Pediatr 2024; 13:146-163. [PMID: 38323181 PMCID: PMC10839285 DOI: 10.21037/tp-23-184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 12/13/2023] [Indexed: 02/08/2024] Open
Abstract
Background and Objective Computational models of the cardiovascular system allow for a detailed and quantitative investigation of both physiological and pathological conditions, thanks to their ability to combine clinical-possibly patient-specific-data with physical knowledge of the processes underlying the heart function. These models have been increasingly employed in clinical practice to understand pathological mechanisms and their progression, design medical devices, support clinicians in improving therapies. Hinging upon a long-year experience in cardiovascular modeling, we have recently constructed a computational multi-physics and multi-scale integrated model of the heart for the investigation of its physiological function, the analysis of pathological conditions, and to support clinicians in both diagnosis and treatment planning. This narrative review aims to systematically discuss the role that such model had in addressing specific clinical questions, and how further impact of computational models on clinical practice are envisaged. Methods We developed computational models of the physical processes encompassed by the heart function (electrophysiology, electrical activation, force generation, mechanics, blood flow dynamics, valve dynamics, myocardial perfusion) and of their inherently strong coupling. To solve the equations of such models, we devised advanced numerical methods, implemented in a flexible and highly efficient software library. We also developed computational procedures for clinical data post-processing-like the reconstruction of the heart geometry and motion from diagnostic images-and for their integration into computational models. Key Content and Findings Our integrated computational model of the heart function provides non-invasive measures of indicators characterizing the heart function and dysfunctions, and sheds light on its underlying processes and their coupling. Moreover, thanks to the close collaboration with several clinical partners, we addressed specific clinical questions on pathological conditions, such as arrhythmias, ventricular dyssynchrony, hypertrophic cardiomyopathy, degeneration of prosthetic valves, and the way coronavirus disease 2019 (COVID-19) infection may affect the cardiac function. In multiple cases, we were also able to provide quantitative indications for treatment. Conclusions Computational models provide a quantitative and detailed tool to support clinicians in patient care, which can enhance the assessment of cardiac diseases, the prediction of the development of pathological conditions, and the planning of treatments and follow-up tests.
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Affiliation(s)
- Ivan Fumagalli
- MOX Laboratory, Department of Mathematics, Politecnico di Milano, Milan, Italy
| | - Stefano Pagani
- MOX Laboratory, Department of Mathematics, Politecnico di Milano, Milan, Italy
| | - Christian Vergara
- Laboratory of Biological Structures Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Milan, Italy
| | - Luca Dede’
- MOX Laboratory, Department of Mathematics, Politecnico di Milano, Milan, Italy
| | - Dilachew A. Adebo
- Children’s Heart Institute, Hermann Children’s Hospital, University of Texas Health Science Center, McGovern Medical School, Houston, TX, USA
| | - Maurizio Del Greco
- Department of Cardiology, S. Maria del Carmine Hospital, Rovereto, Italy
| | - Antonio Frontera
- Electrophysiology Department, De Gasperis Cardio Center, ASST Great Metropolitan Hospital Niguarda, Milan, Italy
| | | | - Gianluca Pontone
- Department of Perioperative Cardiology and Cardiovascular Imaging, Centro Cardiologico Monzino IRCSS, Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Roberto Scrofani
- Cardiovascular Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Alfio Quarteroni
- MOX Laboratory, Department of Mathematics, Politecnico di Milano, Milan, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Switzerland
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Khalili O, Asgari M. Fluid-structure interaction and structural simulation of high acceleration effects on surgical repaired human mitral valve biomechanics. Proc Inst Mech Eng H 2023; 237:1248-1260. [PMID: 37846647 DOI: 10.1177/09544119231200367] [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: 10/18/2023]
Abstract
Mitral valve dynamics depend on force stability in the mitral leaflets, the mitral annulus, the chordae tendineae, and the papillary muscles. In chordal rupture conditions, the proper function of the valve disrupts, causing mitral regurgitation, the most prevalent valvular disease. In this study, Structural and FSI frameworks were employed to study valve dynamics in healthy, pathologic, and repaired states. Anisotropic, non-linear, hyper-elastic material properties applied to tissues of the valve while the first-order Ogden model reflected the best compatibility with the empirical data. Hemodynamic blood pressure of the cardiovascular system is applied on the leaflets as uniform loads varying by time, and exposure to high acceleration loads imposed on models. Immersed boundary method used for simulation of fluid in a cardiac cycle. In comparison between healthy and pathologic models, stress values and chordal tensions are increased, by nearly threefold and twofold, respectively. Stress concentration on leaflets is reduced by 75% after performing a successful surgical repair on the pathological model. Crash acceleration loads led to more significant stress and chordae tension on models, by 27% and 23%, respectively. It is concluded that a more sophisticated model could lead to a better understanding of human heart valve biomechanics in various conditions. If a preoperative plan is developed based on these modeling methods, the requirement for multiple successive repairs would be eliminated, operative times are shortened, and patient outcomes are improved.
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Affiliation(s)
- Omid Khalili
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Masoud Asgari
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
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Laurence DW, Wang S, Xiao R, Qian J, Mir A, Burkhart HM, Holzapfel GA, Lee CH. An investigation of how specimen dimensions affect biaxial mechanical characterizations with CellScale BioTester and constitutive modeling of porcine tricuspid valve leaflets. J Biomech 2023; 160:111829. [PMID: 37826955 PMCID: PMC10995110 DOI: 10.1016/j.jbiomech.2023.111829] [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: 03/16/2023] [Revised: 08/19/2023] [Accepted: 10/03/2023] [Indexed: 10/14/2023]
Abstract
Biaxial mechanical characterizations are the accepted approach to determine the mechanical response of many biological soft tissues. Although several computational and experimental studies have examined how experimental factors (e.g., clamped vs. suture mounting) affect the acquired tissue mechanical behavior, little is known about the role of specimen dimensions in data acquisition and the subsequent modeling. In this study, we combined our established mechanical characterization framework with an iterative size-reduction protocol to test the hypothesis that specimen dimensions affect the observed mechanical behavior of biaxial characterizations. Our findings indicated that there were non-significant differences in the peak equibiaxial stretches of tricuspid valve leaflets across four specimen dimensions ranging from 4.5×4.5mm to 9 × 9mm. Further analyses revealed that there were significant differences in the low-tensile modulus of the circumferential tissue direction. These differences resulted in significantly different constitutive model parameters for the Tong-Fung model between different specimen dimensions of the posterior and septal leaflets. Overall, our findings demonstrate that specimen dimensions play an important role in experimental characterizations, but not necessarily in constitutive modeling of soft tissue mechanical behavior during biaxial testing with the commercial CellScale BioTester.
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Affiliation(s)
- Devin W Laurence
- Biomechanics and Biomaterials Design Laboratory, The University of Oklahoma, USA
| | - Shuodao Wang
- School of Mechanical and Aerospace Engineering, Oklahoma State University, USA
| | - Rui Xiao
- Department of Engineering Mechanics, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
| | - Jin Qian
- Department of Engineering Mechanics, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
| | - Arshid Mir
- Department of Pediatrics, University of Oklahoma Health Sciences Center, USA
| | - Harold M Burkhart
- Department of Surgery, University of Oklahoma Health Sciences Center, USA
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, Austria; Department of Structural Engineering, Norwegian University of Science and Technology, Norway
| | - Chung-Hao Lee
- Biomechanics and Biomaterials Design Laboratory, The University of Oklahoma, USA; Institute for Biomedical Engineering, Science and Technology, The University of Oklahoma, USA; Department of Bioengineering, The University of California, Riverside, USA.
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Simonian NT, Liu H, Vakamudi S, Pirwitz MJ, Pouch AM, Gorman JH, Gorman RC, Sacks MS. Patient-Specific Quantitative In-Vivo Assessment of Human Mitral Valve Leaflet Strain Before and After MitraClip Repair. Cardiovasc Eng Technol 2023; 14:677-693. [PMID: 37670097 DOI: 10.1007/s13239-023-00680-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 08/23/2023] [Indexed: 09/07/2023]
Abstract
PURPOSE Mitral regurgitation (MR) is a highly prevalent and deadly cardiac disease characterized by improper mitral valve (MV) leaflet coaptation. Among the plethora of available treatment strategies, the MitraClip is an especially safe option, but optimizing its long-term efficacy remains an urgent challenge. METHODS We applied our noninvasive image-based strain computation pipeline [1] to intraoperative transesophageal echocardiography datasets taken from ten patients undergoing MitraClip repair, spanning a range of MR etiologies and MitraClip configurations. We then analyzed MV leaflet strains before and after MitraClip implementation to develop a better understanding of (1) the pre-operative state of human regurgitant MV, and (2) the MitraClip's impact on the MV leaflet deformations. RESULTS The MV pre-operative strain fields were highly variable, underscoring both the heterogeneity of the MR in the patient population and the need for patient-specific treatment approaches. Similarly, there were no consistent overall post-operative strain patterns, although the average A2 segment radial strain difference between pre- and post-operative states was consistently positive. In contrast, the post-operative strain fields were better correlated to their respective pre-operative strain fields than to the inter-patient post-operative strain fields. This quantitative result implies that the patient specific pre-operative state of the MV guides its post-operative deformation, which suggests that the post-operative state can be predicted using pre-operative data-derived modelling alone. CONCLUSIONS The pre-operative MV leaflet strain patterns varied considerably across the range of MR disease states and after MitraClip repair. Despite large inter-patient heterogeneity, the post-operative deformation appears principally dictated by the pre-operative deformation state. This novel finding suggests that though the variation in MR functional state and MitraClip-induced deformation were substantial, the post-operative state can be predicted from the pre-operative data alone. This study suggests that, with use of larger patient cohort and corresponding long-term outcomes, quantitative predictive factors of MitraClip durability can be identified.
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Affiliation(s)
- Natalie T Simonian
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin , 201 East 24th St., Stop C0200, Austin, TX, 78712-1229, USA
| | - Hao Liu
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin , 201 East 24th St., Stop C0200, Austin, TX, 78712-1229, USA
| | - Sneha Vakamudi
- Ascension Texas Cardiovascular & Division of Cardiology, Department of Internal Medicine, Dell Medical School, University of Texas, Austin, TX, USA
| | - Mark J Pirwitz
- Ascension Texas Cardiovascular & Division of Cardiology, Department of Internal Medicine, Dell Medical School, University of Texas, Austin, TX, USA
| | - Alison M Pouch
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin , 201 East 24th St., Stop C0200, Austin, TX, 78712-1229, USA.
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Kim SM, Randall EB, Jezek F, Beard DA, Chesler NC. Computational modeling of ventricular-ventricular interactions suggest a role in clinical conditions involving heart failure. Front Physiol 2023; 14:1231688. [PMID: 37745253 PMCID: PMC10512181 DOI: 10.3389/fphys.2023.1231688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/09/2023] [Indexed: 09/26/2023] Open
Abstract
Introduction: The left (LV) and right (RV) ventricles are linked biologically, hemodynamically, and mechanically, a phenomenon known as ventricular interdependence. While LV function has long been known to impact RV function, the reverse is increasingly being realized to have clinical importance. Investigating ventricular interdependence clinically is challenging given the invasive measurements required, including biventricular catheterization, and confounding factors such as comorbidities, volume status, and other aspects of subject variability. Methods: Computational modeling allows investigation of mechanical and hemodynamic interactions in the absence of these confounding factors. Here, we use a threesegment biventricular heart model and simple circulatory system to investigate ventricular interdependence under conditions of systolic and diastolic dysfunction of the LV and RV in the presence of compensatory volume loading. We use the end-diastolic pressure-volume relationship, end-systolic pressure-volume relationship, Frank Starling curves, and cardiac power output as metrics. Results: The results demonstrate that LV systolic and diastolic dysfunction lead to RV compensation as indicated by increases in RV power. Additionally, RV systolic and diastolic dysfunction lead to impaired LV filling, interpretable as LV stiffening especially with volume loading to maintain systemic pressure. Discussion: These results suggest that a subset of patients with intact LV systolic function and diagnosed to have impaired LV diastolic function, categorized as heart failure with preserved ejection fraction (HFpEF), may in fact have primary RV failure. Application of this computational approach to clinical data sets, especially for HFpEF, may lead to improved diagnosis and treatment strategies and consequently improved outcomes.
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Affiliation(s)
- Salla M. Kim
- Department of Biomedical Engineering, Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, University of California Irvine, Irvine, CA, United States
| | - E. Benjamin Randall
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Filip Jezek
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
- Department of Pathological Physiology, First Faculty of Medicine, Charles University, Prague, Czechia
| | - Daniel A. Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Naomi C. Chesler
- Department of Biomedical Engineering, Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, University of California Irvine, Irvine, CA, United States
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Gaidulis G, Padala M. Computational Modeling of the Subject-Specific Effects of Annuloplasty Ring Sizing on the Mitral Valve to Repair Functional Mitral Regurgitation. Ann Biomed Eng 2023; 51:1984-2000. [PMID: 37344691 PMCID: PMC10826925 DOI: 10.1007/s10439-023-03219-9] [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: 12/21/2022] [Accepted: 04/21/2023] [Indexed: 06/23/2023]
Abstract
Surgical repair of functional mitral regurgitation (FMR) that occurs in nearly 60% of heart failure (HF) patients is currently performed with undersizing mitral annuloplasty (UMA), which lacks short- and long-term durability. Heterogeneity in valve geometry makes tailoring this repair to each patient challenging, and predictive models that can help with planning this surgery are lacking. In this study, we present a 3D echo-derived computational model, to enable subject-specific, pre-surgical planning of the repair. Three computational models of the mitral valve were created from 3D echo data obtained in three pigs with HF and FMR. An annuloplasty ring model in seven sizes was created, each ring was deployed, and post-repair valve closure was simulated. The results indicate that large annuloplasty rings (> 32 mm) were not effective in eliminating regurgitant gaps nor in restoring leaflet coaptation or reducing leaflet stresses and chordal tension. Smaller rings (≤ 32 mm) restored better systolic valve closure in all investigated cases,but excessive valve tethering and restricted motion of the leaflets were still present. This computational study demonstrates that for effective correction of FMR, the extent of annular reduction differs between subjects, and overly reducing the annulus has deleterious effects on the valve.
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Affiliation(s)
- Gediminas Gaidulis
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, USA
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, USA
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, USA.
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, USA.
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10
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Feng X, Liu Y, Kamensky D, McComb DW, Breuer CK, Sacks MS. Functional mechanical behavior of the murine pulmonary heart valve. Sci Rep 2023; 13:12852. [PMID: 37553466 PMCID: PMC10409802 DOI: 10.1038/s41598-023-40158-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: 05/11/2023] [Accepted: 08/05/2023] [Indexed: 08/10/2023] Open
Abstract
Genetically modified mouse models provide a versatile and efficient platform to extend our understanding of the underlying disease processes and evaluate potential treatments for congenital heart valve diseases. However, applications have been limited to the gene and molecular levels due to the small size of murine heart valves, which prohibits the use of standard mechanical evaluation and in vivo imaging methods. We have developed an integrated imaging/computational mechanics approach to evaluate, for the first time, the functional mechanical behavior of the murine pulmonary heart valve (mPV). We utilized extant mPV high resolution µCT images of 1-year-old healthy C57BL/6J mice, with mPVs loaded to 0, 10, 20 or 30 mmHg then chemically fixed to preserve their shape. Individual mPV leaflets and annular boundaries were segmented and key geometric quantities of interest defined and quantified. The resulting observed inter-valve variations were small and consistent at each TVP level. This allowed us to develop a high fidelity NURBS-based geometric model. From the resultant individual mPV geometries, we developed a mPV shape-evolving geometric model (SEGM) that accurately represented mPV shape changes as a continuous function of transvalvular pressure. The SEGM was then integrated into an isogeometric finite element based inverse model that estimated the individual leaflet and regional mPV mechanical behaviors. We demonstrated that the mPV leaflet mechanical behaviors were highly anisotropic and nonlinear, with substantial leaflet and regional variations. We also observed the presence of strong axial mechanical coupling, suggesting the important role of the underlying collagen fiber architecture in the mPV. When compared to larger mammalian species, the mPV exhibited substantially different mechanical behaviors. Thus, while qualitatively similar, the mPV exhibited important functional differences that will need to accounted for in murine heart valve studies. The results of this novel study will allow detailed murine tissue and organ level investigations of semi-lunar heart valve diseases.
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Affiliation(s)
- Xinzeng Feng
- Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yifei Liu
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, OH, 43210, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - David Kamensky
- Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, 92093, USA
| | - David W McComb
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, OH, 43210, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Christopher K Breuer
- Center for Regenerative Medicine, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, 43205, USA
- Department of Pediatric Surgery, Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Michael S Sacks
- Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
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11
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Didagelos M, Friderikos O, Ziakas A, David C, Sagris D, Pagiantza A, Karvounis H. Mitral valve geometrical echocardiographic analysis and 3D computational modeling of a normal mitral valve. Future Cardiol 2023; 19:453-467. [PMID: 37815033 DOI: 10.2217/fca-2021-0157] [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: 10/11/2023] Open
Abstract
Aim: This research aims to develop a consistent computational model of a normal mitral valve (MV) and describe mitral regurgitation (MR) geometry based on Carpentier's classification. Materials & methods: MV geometry was assessed by 2D transthoracic echocardiogram in 100 individuals. A 3D parametric geometric model of the MV was developed. A computational model of a normal MV was performed. Results: The simulation of the valve function was successfully accomplished and its kinematics was analyzed. Differences in geometry were revealed between normal and type III MR. Conclusion: 3D computational models of the normal MV can be constructed relying on standard measurements performed by 2D echocardiography. Certain geometrical differences exist among the normal and the most severe type of MR.
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Affiliation(s)
- Matthaios Didagelos
- 1st Cardiology Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636, Greece
| | - Orestis Friderikos
- Mechanical Engineering Department, International Hellenic University, Serres, 62124, Greece
| | - Antonios Ziakas
- 1st Cardiology Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636, Greece
| | - Constantine David
- Mechanical Engineering Department, International Hellenic University, Serres, 62124, Greece
| | - Dimitrios Sagris
- Mechanical Engineering Department, International Hellenic University, Serres, 62124, Greece
| | - Areti Pagiantza
- 1st Cardiology Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636, Greece
| | - Haralambos Karvounis
- 1st Cardiology Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636, Greece
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12
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Wu W, Ching S, Sabin P, Laurence DW, Maas SA, Lasso A, Weiss JA, Jolley MA. The effects of leaflet material properties on the simulated function of regurgitant mitral valves. J Mech Behav Biomed Mater 2023; 142:105858. [PMID: 37099920 PMCID: PMC10199327 DOI: 10.1016/j.jmbbm.2023.105858] [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: 02/09/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023]
Abstract
Advances in three-dimensional imaging provide the ability to construct and analyze finite element (FE) models to evaluate the biomechanical behavior and function of atrioventricular valves. However, while obtaining patient-specific valve geometry is now possible, non-invasive measurement of patient-specific leaflet material properties remains nearly impossible. Both valve geometry and tissue properties play a significant role in governing valve dynamics, leading to the central question of whether clinically relevant insights can be attained from FE analysis of atrioventricular valves without precise knowledge of tissue properties. As such we investigated (1) the influence of tissue extensibility and (2) the effects of constitutive model parameters and leaflet thickness on simulated valve function and mechanics. We compared metrics of valve function (e.g., leaflet coaptation and regurgitant orifice area) and mechanics (e.g., stress and strain) across one normal and three regurgitant mitral valve (MV) models with common mechanisms of regurgitation (annular dilation, leaflet prolapse, leaflet tethering) of both moderate and severe degree. We developed a novel fully-automated approach to accurately quantify regurgitant orifice areas of complex valve geometries. We found that the relative ordering of the mechanical and functional metrics was maintained across a group of valves using material properties up to 15% softer than the representative adult mitral constitutive model. Our findings suggest that FE simulations can be used to qualitatively compare how differences and alterations in valve structure affect relative atrioventricular valve function even in populations where material properties are not precisely known.
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Affiliation(s)
- Wensi Wu
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA; Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA
| | - Stephen Ching
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA
| | - Patricia Sabin
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA
| | - Devin W Laurence
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA; Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA
| | - Steve A Maas
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, UT, USA; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112, UT, USA
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, ON, Canada
| | - Jeffrey A Weiss
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, UT, USA; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112, UT, USA
| | - Matthew A Jolley
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA; Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, 19104, PA, USA.
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13
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van Kampen A, Morningstar JE, Goudot G, Ingels N, Wenk JF, Nagata Y, Yaghoubian KM, Norris RA, Borger MA, Melnitchouk S, Levine RA, Jensen MO. Utilization of Engineering Advances for Detailed Biomechanical Characterization of the Mitral-Ventricular Relationship to Optimize Repair Strategies: A Comprehensive Review. Bioengineering (Basel) 2023; 10:601. [PMID: 37237671 PMCID: PMC10215167 DOI: 10.3390/bioengineering10050601] [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: 04/17/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
The geometrical details and biomechanical relationships of the mitral valve-left ventricular apparatus are very complex and have posed as an area of research interest for decades. These characteristics play a major role in identifying and perfecting the optimal approaches to treat diseases of this system when the restoration of biomechanical and mechano-biological conditions becomes the main target. Over the years, engineering approaches have helped to revolutionize the field in this regard. Furthermore, advanced modelling modalities have contributed greatly to the development of novel devices and less invasive strategies. This article provides an overview and narrative of the evolution of mitral valve therapy with special focus on two diseases frequently encountered by cardiac surgeons and interventional cardiologists: ischemic and degenerative mitral regurgitation.
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Affiliation(s)
- Antonia van Kampen
- Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Leipzig Heart Centre, University Clinic of Cardiac Surgery, 02189 Leipzig, Germany
| | - Jordan E. Morningstar
- Department of Regenerative Medicine and Cell Biology, University of South Carolina, Charleston, SC 29425, USA
| | - Guillaume Goudot
- Cardiac Ultrasound Laboratory, Department of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Neil Ingels
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jonathan F. Wenk
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40508, USA;
| | - Yasufumi Nagata
- Cardiac Ultrasound Laboratory, Department of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Koushiar M. Yaghoubian
- Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Russell A. Norris
- Department of Regenerative Medicine and Cell Biology, University of South Carolina, Charleston, SC 29425, USA
| | - Michael A. Borger
- Leipzig Heart Centre, University Clinic of Cardiac Surgery, 02189 Leipzig, Germany
| | - Serguei Melnitchouk
- Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Robert A. Levine
- Cardiac Ultrasound Laboratory, Department of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Morten O. Jensen
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701, USA
- Department of Surgery, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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14
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Wu W, Ching S, Sabin P, Laurence DW, Maas SA, Lasso A, Weiss JA, Jolley MA. The Effects of leaflet material properties on the simulated function of regurgitant mitral valves. ARXIV 2023:arXiv:2302.04939v2. [PMID: 36798457 PMCID: PMC9934730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Advances in three-dimensional imaging provide the ability to construct and analyze finite element (FE) models to evaluate the biomechanical behavior and function of atrioventricular valves. However, while obtaining patient-specific valve geometry is now possible, non-invasive measurement of patient-specific leaflet material properties remains nearly impossible. Both valve geometry and tissue properties play a significant role in governing valve dynamics, leading to the central question of whether clinically relevant insights can be attained from FE analysis of atrioventricular valves without precise knowledge of tissue properties. As such we investigated 1) the influence of tissue extensibility and 2) the effects of constitutive model parameters and leaflet thickness on simulated valve function and mechanics. We compared metrics of valve function (e.g., leaflet coaptation and regurgitant orifice area) and mechanics (e.g., stress and strain) across one normal and three regurgitant mitral valve (MV) models with common mechanisms of regurgitation (annular dilation, leaflet prolapse, leaflet tethering) of both moderate and severe degree. We developed a novel fully-automated approach to accurately quantify regurgitant orifice areas of complex valve geometries. We found that the relative ordering of the mechanical and functional metrics was maintained across a group of valves using material properties up to 15% softer than the representative adult mitral constitutive model. Our findings suggest that FE simulations can be used to qualitatively compare how differences and alterations in valve structure affect relative atrioventricular valve function even in populations where material properties are not precisely known.
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Affiliation(s)
- Wensi Wu
- Department of Anesthesiology and Critical Care Medicine, Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Stephen Ching
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Patricia Sabin
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Devin W Laurence
- Department of Anesthesiology and Critical Care Medicine, Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Steve A Maas
- Department of Biomedical Engineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, ON
| | - Jeffrey A Weiss
- Department of Biomedical Engineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Matthew A Jolley
- Department of Anesthesiology and Critical Care Medicine, Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
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15
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Rego BV, Khalighi AH, Gorman JH, Gorman RC, Sacks MS. Simulation of Mitral Valve Plasticity in Response to Myocardial Infarction. Ann Biomed Eng 2023; 51:71-87. [PMID: 36030332 DOI: 10.1007/s10439-022-03043-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/01/2022] [Indexed: 01/13/2023]
Abstract
Left ventricular myocardial infarction (MI) has broad and debilitating effects on cardiac function. In many cases, MI leads to ischemic mitral regurgitation (IMR), a condition characterized by incompetency of the mitral valve (MV). IMR has many deleterious effects as well as a high mortality rate. While various clinical treatments for IMR exist, success of these procedures remains limited, in large part because IMR dramatically alters the geometry and function of the MV in ways that are currently not well understood. Previous investigations of post-MI MV remodeling have elucidated that MV tissues have a significant ability to undergo a form of permanent inelastic deformations in the first phase of the post-MI period. These changes appear to be attributable to the altered loading and boundary conditions on the MV itself, as opposed to an independent pathophysiological process. Mechanistically, these results suggest that the MV mostly responds passively to MI during the first 8 weeks post-MI by undergoing a permanent deformation. In the present study, we developed the first computational model of this post-MI MV remodeling process, which we term "mitral valve plasticity." Integrating methodologies and insights from previous studies of in vivo ovine MV function, image-based patient-specific model development, and post-MI MV adaptation, we constructed a representative geometric model of a pre-MI MV. We then performed finite element simulations of the entire MV apparatus under time-dependent boundary conditions and accounting for changes to material properties equivalent to those observed 0-8 weeks post-MI. Our results suggest that during this initial period of adaptation, the MV response to MI can be accurately modeled using a soft tissue plasticity approach, similar to permanent set frameworks that have been applied previously in the context of exogenously crosslinked tissues.
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Affiliation(s)
- Bruno V Rego
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Amir H Khalighi
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
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16
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Rego BV, Khalighi AH, Lai EK, Gorman RC, Gorman JH, Sacks MS. In vivo assessment of mitral valve leaflet remodelling following myocardial infarction. Sci Rep 2022; 12:18012. [PMID: 36289435 PMCID: PMC9606267 DOI: 10.1038/s41598-022-22790-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/19/2022] [Indexed: 01/24/2023] Open
Abstract
Each year, more than 40,000 people undergo mitral valve (MV) repair surgery domestically to treat regurgitation caused by myocardial infarction (MI). Although continual MV tissue remodelling following repair is believed to be a major contributor to regurgitation recurrence, the effects of the post-MI state on MV remodelling remain poorly understood. This lack of understanding limits our ability to predict the remodelling of the MV both post-MI and post-surgery to facilitate surgical planning. As a necessary first step, the present study was undertaken to noninvasively quantify the effects of MI on MV remodelling in terms of leaflet geometry and deformation. MI was induced in eight adult Dorset sheep, and real-time three-dimensional echocardiographic (rt-3DE) scans were collected pre-MI as well as at 0, 4, and 8 weeks post-MI. A previously validated image-based morphing pipeline was used to register corresponding open- and closed-state scans and extract local in-plane strains throughout the leaflet surface at systole. We determined that MI induced permanent changes in leaflet dimensions in the diastolic configuration, which increased with time to 4 weeks, then stabilised. MI substantially affected the systolic shape of the MV, and the range of stretch experienced by the MV leaflet at peak systole was substantially reduced when referred to the current time-point. Interestingly, when we referred the leaflet strains to the pre-MI configuration, the systolic strains remained very similar throughout the post-MI period. Overall, we observed that post-MI ventricular remodeling induced permanent changes in the MV leaflet shape. This predominantly affected the MV's diastolic configuration, leading in turn to a significant decrease in the range of stretch experienced by the leaflet when referenced to the current diastolic configuration. These findings are consistent with our previous work that demonstrated increased plastic (i.e. non-recoverable) leaflet deformations post-MI, that was completely accounted for by the associated changes in collagen fiber structure. Moreover, we demonstrated through noninvasive methods that the state of the MV leaflet can elucidate the progression and extent of MV adaptation following MI and is thus highly relevant to the design of current and novel patient specific minimally invasive surgical repair strategies.
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Affiliation(s)
- Bruno V. Rego
- grid.89336.370000 0004 1936 9924James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX USA
| | - Amir H. Khalighi
- grid.89336.370000 0004 1936 9924James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX USA
| | - Eric K. Lai
- grid.25879.310000 0004 1936 8972Gorman Cardiovascular Research Group, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Robert C. Gorman
- grid.25879.310000 0004 1936 8972Gorman Cardiovascular Research Group, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Joseph H. Gorman
- grid.25879.310000 0004 1936 8972Gorman Cardiovascular Research Group, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Michael S. Sacks
- grid.89336.370000 0004 1936 9924James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX USA
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Simonian NT, Liu H, Pouch AM, Gorman JH, Gorman RC, Sacks MS. Quantitative in vivo assessment of human mitral valve coaptation area after undersized ring annuloplasty repair for ischemic mitral regurgitation. JTCVS Tech 2022; 16:49-59. [PMID: 36510522 PMCID: PMC9735426 DOI: 10.1016/j.xjtc.2022.09.013] [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: 06/08/2022] [Revised: 08/29/2022] [Accepted: 09/13/2022] [Indexed: 11/08/2022] Open
Abstract
Objectives Long-term outcomes of mitral valve repair procedures to correct ischemic mitral regurgitation remain unpredictable, due to an incomplete understanding of the disease process and the inability to reliably quantify the coaptation zone using echocardiography. Our objective was to quantify patient-specific mitral valve coaptation behavior from clinical echocardiographic images obtained before and after repair to assess coaptation restoration and its relationship with long-term repair durability. Methods To circumvent the limitations of clinical imaging, we applied a simulation-based shape-matching technique that allowed high-fidelity reconstructions of the complete mitral valve in the systolic configuration. We then applied this method to an extant database of human regurgitant mitral valves before and after undersized ring annuloplasty to quantify the effect of the repair on mitral valve coaptation geometry. Results Our method was able to successfully resolve the coaptation zone into distinct contacting and redundant regions. Results indicated that in patients whose regurgitation recurred 6 months postrepair, both the contacting and redundant regions were larger immediately postrepair compared with patients with no recurrence (P < .05), even when normalized to account for generally larger recurrent valves. Conclusions Although increasing leaflet coaptation area is an intuitively obvious way to improve long-term repair durability, this study has implied that this may not be a reliable target for mitral valve repair. This study underscores the importance of a rigorous understanding of the consequences of repair techniques on mitral valve behavior, as well as a patient-specific approach to ischemic mitral regurgitation treatment within the context of mitral valve and left ventricle function.
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Key Words
- CMF, chordal mimicking force
- ED, end-diastolic
- ES, end-systolic
- FE, finite element
- IMR, ischemic mitral regurgitation
- LV, left ventricle
- MR, mitral regurgitation
- MV, mitral valve
- MVTa, mitral valve tenting area
- URA, undersized ring annuloplasty
- mitral valve imaging
- mitral valve mechanics
- mitral valve regurgitation
- mitral valve repair
- myocardial infarction
- rt-3DE, real-time 3-dimensional echocardiography
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Affiliation(s)
- Natalie T. Simonian
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, Tex
| | - Hao Liu
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, Tex
| | - Alison M. Pouch
- Departments of Radiology and Bioengineering, University of Pennsylvania, Philadelphia, Pa
| | - Joseph H. Gorman
- Department of Surgery, Smilow Center for Translational Research, Gorman Cardiovascular Research Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pa
| | - Robert C. Gorman
- Department of Surgery, Smilow Center for Translational Research, Gorman Cardiovascular Research Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pa
| | - Michael S. Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, Tex,Address for reprints: Michael S. Sacks, PhD, Department of Biomedical Engineering, The Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229.
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18
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Koivumäki JT, Hoffman J, Maleckar MM, Einevoll GT, Sundnes J. Computational cardiac physiology for new modelers: Origins, foundations, and future. Acta Physiol (Oxf) 2022; 236:e13865. [PMID: 35959512 DOI: 10.1111/apha.13865] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 01/29/2023]
Abstract
Mathematical models of the cardiovascular system have come a long way since they were first introduced in the early 19th century. Driven by a rapid development of experimental techniques, numerical methods, and computer hardware, detailed models that describe physical scales from the molecular level up to organs and organ systems have been derived and used for physiological research. Mathematical and computational models can be seen as condensed and quantitative formulations of extensive physiological knowledge and are used for formulating and testing hypotheses, interpreting and directing experimental research, and have contributed substantially to our understanding of cardiovascular physiology. However, in spite of the strengths of mathematics to precisely describe complex relationships and the obvious need for the mathematical and computational models to be informed by experimental data, there still exist considerable barriers between experimental and computational physiological research. In this review, we present a historical overview of the development of mathematical and computational models in cardiovascular physiology, including the current state of the art. We further argue why a tighter integration is needed between experimental and computational scientists in physiology, and point out important obstacles and challenges that must be overcome in order to fully realize the synergy of experimental and computational physiological research.
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Affiliation(s)
- Jussi T Koivumäki
- Faculty of Medicine and Health Technology, and Centre of Excellence in Body-on-Chip Research, Tampere University, Tampere, Finland
| | - Johan Hoffman
- Division of Computational Science and Technology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Mary M Maleckar
- Computational Physiology Department, Simula Research Laboratory, Oslo, Norway
| | - Gaute T Einevoll
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway.,Department of Physics, University of Oslo, Oslo, Norway.,Department of Physics, Norwegian University of Life Sciences, Ås, Norway
| | - Joakim Sundnes
- Computational Physiology Department, Simula Research Laboratory, Oslo, Norway
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19
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Wu W, Ching S, Maas SA, Lasso A, Sabin P, Weiss JA, Jolley MA. A Computational Framework for Atrioventricular Valve Modeling Using Open-Source Software. J Biomech Eng 2022; 144:101012. [PMID: 35510823 PMCID: PMC9254695 DOI: 10.1115/1.4054485] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/27/2022] [Indexed: 11/08/2022]
Abstract
Atrioventricular valve regurgitation is a significant cause of morbidity and mortality in patients with acquired and congenital cardiac valve disease. Image-derived computational modeling of atrioventricular valves has advanced substantially over the last decade and holds particular promise to inform valve repair in small and heterogeneous populations, which are less likely to be optimized through empiric clinical application. While an abundance of computational biomechanics studies has investigated mitral and tricuspid valve disease in adults, few studies have investigated its application to vulnerable pediatric and congenital heart populations. Further, to date, investigators have primarily relied upon a series of commercial applications that are neither designed for image-derived modeling of cardiac valves nor freely available to facilitate transparent and reproducible valve science. To address this deficiency, we aimed to build an open-source computational framework for the image-derived biomechanical analysis of atrioventricular valves. In the present work, we integrated an open-source valve modeling platform, SlicerHeart, and an open-source biomechanics finite element modeling software, FEBio, to facilitate image-derived atrioventricular valve model creation and finite element analysis. We present a detailed verification and sensitivity analysis to demonstrate the fidelity of this modeling in application to three-dimensional echocardiography-derived pediatric mitral and tricuspid valve models. Our analyses achieved an excellent agreement with those reported in the literature. As such, this evolving computational framework offers a promising initial foundation for future development and investigation of valve mechanics, in particular collaborative efforts targeting the development of improved repairs for children with congenital heart disease.
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Affiliation(s)
- Wensi Wu
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Stephen Ching
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Steve A Maas
- Department of Biomedical Engineering, Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Patricia Sabin
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Jeffrey A Weiss
- Department of Biomedical Engineering, Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Matthew A Jolley
- Department of Anesthesiology and Critical Care Medicine, Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
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20
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Lasso A, Herz C, Nam H, Cianciulli A, Pieper S, Drouin S, Pinter C, St-Onge S, Vigil C, Ching S, Sunderland K, Fichtinger G, Kikinis R, Jolley MA. SlicerHeart: An open-source computing platform for cardiac image analysis and modeling. Front Cardiovasc Med 2022; 9:886549. [PMID: 36148054 PMCID: PMC9485637 DOI: 10.3389/fcvm.2022.886549] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/08/2022] [Indexed: 11/25/2022] Open
Abstract
Cardiovascular disease is a significant cause of morbidity and mortality in the developed world. 3D imaging of the heart's structure is critical to the understanding and treatment of cardiovascular disease. However, open-source tools for image analysis of cardiac images, particularly 3D echocardiographic (3DE) data, are limited. We describe the rationale, development, implementation, and application of SlicerHeart, a cardiac-focused toolkit for image analysis built upon 3D Slicer, an open-source image computing platform. We designed and implemented multiple Python scripted modules within 3D Slicer to import, register, and view 3DE data, including new code to volume render and crop 3DE. In addition, we developed dedicated workflows for the modeling and quantitative analysis of multi-modality image-derived heart models, including heart valves. Finally, we created and integrated new functionality to facilitate the planning of cardiac interventions and surgery. We demonstrate application of SlicerHeart to a diverse range of cardiovascular modeling and simulation including volume rendering of 3DE images, mitral valve modeling, transcatheter device modeling, and planning of complex surgical intervention such as cardiac baffle creation. SlicerHeart is an evolving open-source image processing platform based on 3D Slicer initiated to support the investigation and treatment of congenital heart disease. The technology in SlicerHeart provides a robust foundation for 3D image-based investigation in cardiovascular medicine.
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Affiliation(s)
- Andras Lasso
- Laboratory for Percutaneous Surgery, School of Computing, Queen's University, Kingston, ON, Canada
| | - Christian Herz
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Hannah Nam
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Alana Cianciulli
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | | | - Simon Drouin
- Software and Information Technology Engineering, École de Technologie Supérieure, Montreal, QC, Canada
| | | | - Samuelle St-Onge
- Software and Information Technology Engineering, École de Technologie Supérieure, Montreal, QC, Canada
| | - Chad Vigil
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Stephen Ching
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Kyle Sunderland
- Laboratory for Percutaneous Surgery, School of Computing, Queen's University, Kingston, ON, Canada
| | - Gabor Fichtinger
- Laboratory for Percutaneous Surgery, School of Computing, Queen's University, Kingston, ON, Canada
| | - Ron Kikinis
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Matthew A. Jolley
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States,Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States,*Correspondence: Matthew A. Jolley
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21
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Nam HH, Herz C, Lasso A, Cianciulli A, Flynn M, Huang J, Wang Z, Paniagua B, Vicory J, Kabir S, Simpson J, Harrild D, Marx G, Cohen MS, Glatz AC, Jolley MA. Visualization and Quantification of the Unrepaired Complete Atrioventricular Canal Valve Using Open-Source Software. J Am Soc Echocardiogr 2022; 35:985-996.e11. [PMID: 35537615 PMCID: PMC9452462 DOI: 10.1016/j.echo.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/20/2022] [Accepted: 04/24/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Repair of complete atrioventricular canal (CAVC) is often complicated by residual left atrioventricular valve regurgitation. The structure of the mitral and tricuspid valves in biventricular hearts has previously been shown to be associated with valve dysfunction. However, the three-dimensional (3D) structure of the entire unrepaired CAVC valve has not been quantified. Understanding the 3D structure of the CAVC may inform optimized repair. METHODS Novel open-source work flows were created in SlicerHeart for the modeling and quantification of CAVC valves on the basis of 3D echocardiographic images. These methods were applied to model the annulus, leaflets, and papillary muscle (PM) structure of 35 patients (29 with trisomy 21) with CAVC using transthoracic 3D echocardiography. The mean leaflet and annular shapes were calculated and visualized using shape analysis. Metrics of the complete native CAVC valve structure were compared with those of normal mitral valves using the Mann-Whitney U test. Associations between CAVC structure and atrioventricular valve regurgitation were analyzed. RESULTS CAVC leaflet metrics varied throughout systole. Compared with normal mitral valves, the left CAVC PMs were more acutely angled in relation to the annular plane (P < .001). In addition, the anterolateral PM was laterally and inferiorly rotated in CAVC, while the posteromedial PM was more superiorly and laterally rotated, relative to normal mitral valves (P < .001). Lower native CAVC atrioventricular valve annular height and annular height-to-valve width ratio before repair were both associated with moderate or greater left atrioventricular valve regurgitation after repair (P < .01). CONCLUSIONS It is feasible to model and quantify 3D CAVC structure using 3D echocardiographic images. The results demonstrate significant variation in CAVC structure across the cohort and differences in annular, leaflet, and PM structure compared with the mitral valve. These tools may be used in future studies to catalyze future research intended to identify structural associations of valve dysfunction and to optimize repair in this vulnerable and complex population.
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Affiliation(s)
- Hannah H Nam
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Christian Herz
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, Ontario, Canada
| | - Alana Cianciulli
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Maura Flynn
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Jing Huang
- Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zi Wang
- Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | | | - Saleha Kabir
- Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom
| | - John Simpson
- Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom
| | - David Harrild
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts
| | - Gerald Marx
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts
| | - Meryl S Cohen
- Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Andrew C Glatz
- Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Matthew A Jolley
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
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22
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Vellguth K, Barbieri F, Reinthaler M, Kasner M, Landmesser U, Kuehne T, Hennemuth A, Walczak L, Goubergrits L. Effect of transcatheter edge-to-edge repair device position on diastolic hemodynamic parameters: An echocardiography-based simulation study. Front Cardiovasc Med 2022; 9:915074. [PMID: 36093164 PMCID: PMC9449143 DOI: 10.3389/fcvm.2022.915074] [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: 04/07/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundTranscatheter edge-to-edge repair (TEER) has developed from innovative technology to an established treatment strategy of mitral regurgitation (MR). The risk of iatrogenic mitral stenosis after TEER is, however, a critical factor in the conflict of interest between maximal reduction of MR and minimal impairment of left ventricular filling. We aim to investigate systematically the impact of device position on the post treatment hemodynamic outcome by involving the patient-specific segmentation of the diseased mitral valve.Materials and methodsTransesophageal echocardiographic image data of ten patients with severe MR (age: 57 ± 8 years, 20% female) were segmented and virtually treated with TEER at three positions by using a position based dynamics approach. Pre- and post-interventional patient geometries were preprocessed for computational fluid dynamics (CFD) and simulated at peak-diastole with patient-specific blood flow boundary conditions. Simulations were performed with boundary conditions mimicking rest and stress. The simulation results were compared with clinical data acquired for a cohort of 21 symptomatic MR patients (age: 79 ± 6 years, 43% female) treated with TEER.ResultsVirtual TEER reduces the mitral valve area (MVA) from 7.5 ± 1.6 to 2.6 ± 0.6 cm2. Central device positioning resulted in a 14% smaller MVA than eccentric device positions. Furthermore, residual MVA is better predictable for central than for eccentric device positions (R2 = 0.81 vs. R2 = 0.49). The MVA reduction led to significantly higher maximal diastolic velocities (pre: 0.9 ± 0.2 m/s, post: 2.0 ± 0.5 m/s) and pressure gradients (pre: 1.5 ± 0.6 mmHg, post: 16.3 ± 9 mmHg) in spite of a mean flow rate reduction by 23% due to reduced MR after the treatment. On average, velocities were 12% and pressure gradients were 25% higher with devices in central compared to lateral or medial positions.ConclusionVirtual TEER treatment combined with CFD is a promising tool for predicting individual morphometric and hemodynamic outcomes. Such a tool can potentially be used to support clinical decision making, procedure planning, and risk estimation to prevent post-procedural iatrogenic mitral stenosis.
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Affiliation(s)
- Katharina Vellguth
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- *Correspondence: Katharina Vellguth
| | - Fabian Barbieri
- Department of Cardiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Markus Reinthaler
- Department of Cardiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, Teltow, Germany
| | - Mario Kasner
- Department of Cardiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Ulf Landmesser
- Department of Cardiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Berlin, Germany
| | - Titus Kuehne
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Deutsches Herzzentrum der Charité—Medical Heart Center of Charité and German Heart Institute Berlin, Berlin, Germany
| | - Anja Hennemuth
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Fraunhofer MEVIS, Bremen, Germany
| | - Lars Walczak
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Fraunhofer MEVIS, Bremen, Germany
| | - Leonid Goubergrits
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Einstein Center Digital Future, Berlin, Germany
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23
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Cocchieri R, van de Wetering B, van Tuijl S, Mousavi I, Riezebos R, de Mol B. At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology. J Cardiovasc Dev Dis 2022; 9:jcdd9080261. [PMID: 36005425 PMCID: PMC9410306 DOI: 10.3390/jcdd9080261] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/15/2022] [Accepted: 08/09/2022] [Indexed: 11/26/2022] Open
Abstract
Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered.
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Affiliation(s)
- Riccardo Cocchieri
- Cardiothoracic Surgeon, OLVG Hospital, 1091 AC Amsterdam, The Netherlands
| | - Bertus van de Wetering
- Biomedical Engineer, LifeTec Group BV, 5611 ZS Eindhoven, The Netherlands
- Correspondence: (B.v.d.W.); (B.d.M.)
| | - Sjoerd van Tuijl
- Biomedical Engineer, LifeTec Group BV, 5611 ZS Eindhoven, The Netherlands
| | - Iman Mousavi
- Cardiothoracic Surgery Resident, OLVG Hospital, 1091 AC Amsterdam, The Netherlands
| | - Robert Riezebos
- Cardiologist, OLVG Hospital, 1091 AC Amsterdam, The Netherlands
| | - Bastian de Mol
- Department of Cardiothoracic Surgery, Amsterdam University Medical Center, 1105 AZ Amsterdam, The Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Correspondence: (B.v.d.W.); (B.d.M.)
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24
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Gaidulis G, Suresh KS, Xu D, Padala M. Patient-Specific Three-Dimensional Ultrasound Derived Computational Modeling of the Mitral Valve. Ann Biomed Eng 2022; 50:847-859. [PMID: 35380321 PMCID: PMC10826907 DOI: 10.1007/s10439-022-02960-x] [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: 12/27/2021] [Accepted: 03/27/2022] [Indexed: 11/01/2022]
Abstract
Several new techniques to repair the mitral valve affected by functional mitral regurgitation are in development. However, due to the heterogeneity of valve lesions between patients, predicting the outcomes of novel treatment approaches is challenging. We present a patient-specific, 3D ultrasound-derived computational model of the mitral valve for procedure planning, that faithfully mimics the pathological valve dynamics. 3D ultrasound images were obtained in three pigs induced with heart failure and which developed functional mitral regurgitation. For each case, images were segmented, and finite element model of mitral valve was constructed. Annular and papillary muscle dynamics were extracted and imposed as kinematic boundary conditions, and the chordae were pre-strained to induce valve tethering. Valve closure was simulated by applying physiologic transvalvular pressure on the leaflets. Agreement between simulation results and truth datasets was confirmed, with accurate location of regurgitation jets and coaptation defects. Inclusion of kinematic patient-specific boundary conditions was necessary to achieve these results, whereas use of idealized boundary conditions deviated from the truth dataset. Due to the impact of boundary conditions on the model, the effect of repair strategies on valve closure varied as well, indicating that our approach of using patient-specific boundary conditions for mitral valve modeling is valid.
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Affiliation(s)
- Gediminas Gaidulis
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, 380B Northyards Blvd NW, Atlanta, GA, 30313, USA
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Kirthana Sreerangathama Suresh
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, 380B Northyards Blvd NW, Atlanta, GA, 30313, USA
| | - Dongyang Xu
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, 380B Northyards Blvd NW, Atlanta, GA, 30313, USA
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, 380B Northyards Blvd NW, Atlanta, GA, 30313, USA.
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA, USA.
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25
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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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26
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Zhang W, Sommer G, Niestrawska JA, Holzapfel GA, Nordsletten D. The effects of viscoelasticity on residual strain in aortic soft tissues. Acta Biomater 2022; 140:398-411. [PMID: 34823042 DOI: 10.1016/j.actbio.2021.11.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 11/15/2022]
Abstract
Residual stress is thought to play a critical role in modulating stress distributions in soft biological tissues and in maintaining the mechanobiological stress environment of cells. Residual stresses in arteries and other tissues are classically assessed through opening angle experiments, which demonstrate the continuous release of residual stresses over hours. These results are then assessed through nonlinear biomechanical models to provide estimates of the residual stresses in the intact state. Although well studied, these analyses typically focus on hyperelastic material models despite significant evidence of viscoelastic phenomena over both short and long timescales. In this work, we extended the state-of-the-art structural tensor model for arterial tissues from Holzapfel and Ogden for fractional viscoelasticity. Models were tuned to capture consistent levels of hysteresis observed in biaxial experiments, while also minimizing the fractional viscoelastic weighting and opening angles to correctly capture opening angle dynamics. Results suggest that a substantial portion of the human abdominal aorta is viscoelastic, but exhibits a low fractional order (i.e. more elastically). Additionally, a significantly larger opening angle in the fully unloaded state is necessary to produce comparable hysteresis in biaxial testing. As a consequence, conventional estimates of residual stress using hyperelastic approaches over-estimate their viscoelastic counterparts by a factor of 2. Thus, a viscoelastic approach, such as the one illustrated in this study, in combination with an additional source of rate-controlled viscoelastic data is necessary to accurately analyze the residual stress distribution in soft biological tissues. STATEMENT OF SIGNIFICANCE: Residual stress plays a crucial role in achieving a homeostatic stress environment in soft biological tissues. However, the analysis of residual stress typically focuses on hyperelastic material models despite evidence of viscoelastic behavior. This work is the first attempt at analyzing the effects of viscoelasticity on residual stress. The application of viscoelasticity was crucial for producing realistic opening dynamics in arteries. The overall residual stresses were estimated to be 50% less than those from using hyperelastic material models, while the opening angles were projected to be 25% more than those measured after 16 hours, suggesting underestimated residual strain. This study highlights the importance viscoelasticity in the analysis of residual stress even in weakly dissipative materials like the human aorta.
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Affiliation(s)
- Will Zhang
- Department of Biomedical Engineering, University of Michigan, North Campus Research Center, Building 20, 2800 Plymouth Rd, Ann Arbor 48109, USA.
| | - Gerhard Sommer
- Institute of Biomechanics, Graz University of Technology, AT, Austria
| | - Justyna A Niestrawska
- Gottfried Schatz Research Center, Division of Macroscopic and Clinical Anatomy, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, AT, Austria; Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, NO, Norway
| | - David Nordsletten
- Division of Biomedical Engineering and Imaging Sciences, Department of Biomedical Engineering, King's College London, UK; Departments of Biomedical Engineering and Cardiac Surgery, University of Michigan, Ann Arbor, USA
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27
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Nam HH, Dinh PV, Lasso A, Herz C, Huang J, Posada A, Aly AH, Pouch AM, Kabir S, Simpson J, Glatz AC, Harrild DM, Marx G, Fichtinger G, Cohen MS, Jolley MA. Dynamic Annular Modeling of the Unrepaired Complete Atrioventricular Canal Annulus. Ann Thorac Surg 2022; 113:654-662. [PMID: 33359720 PMCID: PMC8219815 DOI: 10.1016/j.athoracsur.2020.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Repair of complete atrioventricular canal (CAVC) is often complicated by atrioventricular valve regurgitation, particularly of the left-sided valve. Understanding the 3-dimensional (3D) structure of the atrioventricular canal annulus before repair may help to inform optimized repair. However, the 3D shape and movement of the CAVC annulus has been neither quantified nor rigorously compared with a normal mitral valve annulus. METHODS The complete annuli of 43 patients with CAVC were modeled in 4 cardiac phases using transthoracic 3D echocardiograms and custom code. The annular structure was compared with the annuli of 20 normal pediatric mitral valves using 3D metrics and statistical shape analysis (Procrustes analysis). RESULTS The unrepaired CAVC annulus varied in shape significantly throughout the cardiac cycle. Procrustes analysis visually demonstrated that the average normalized CAVC annular shape is more planar than the normal mitral annulus. Quantitatively, the annular height-to-valve width ratio of the native left CAVC atrioventricular valve was significantly lower than that of a normal mitral valve in all systolic phases (P < .001). CONCLUSIONS The left half of the CAVC annulus is more planar than that of a normal mitral valve with an annular height-to-valve width ratio similar to dysfunctional mitral valves. Given the known importance of annular shape to mitral valve function, further exploration of the association of 3D structure to valve function in CAVC is warranted.
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Affiliation(s)
- Hannah H Nam
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Patrick V Dinh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, Ontario, Canada
| | - Christian Herz
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Jing Huang
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Adriana Posada
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Ahmed H Aly
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alison M Pouch
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Saleha Kabir
- Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom
| | - John Simpson
- Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom
| | - Andrew C Glatz
- Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - David M Harrild
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts
| | - Gerald Marx
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts
| | - Gabor Fichtinger
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Meryl S Cohen
- Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Matthew A Jolley
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
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28
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Dover CM, Goth W, Goodbrake C, Tunnell JW, Sacks MS. Simultaneous Wide-Field Planar Strain-Fiber Orientation Distribution Measurement Using Polarized Spatial Domain Imaging. Ann Biomed Eng 2022; 50:253-277. [PMID: 35084627 DOI: 10.1007/s10439-021-02889-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/04/2021] [Indexed: 11/26/2022]
Abstract
In the present study, we demonstrate that soft tissue fiber architectural maps captured using polarized spatial frequency domain imaging (pSFDI) can be utilized as an effective texture source for DIC-based planar surface strain analyses. Experimental planar biaxial mechanical studies were conducted using pericardium as the exemplar tissue, with simultaneous pSFDI measurements taken. From these measurements, the collagen fiber preferred direction [Formula: see text] was determined at the pixel level over the entire strain range using established methods ( https://doi.org/10.1007/s10439-019-02233-0 ). We then utilized these pixel-level [Formula: see text] maps as a texture source to quantify the deformation gradient tensor [Formula: see text] as a function of spatial position [Formula: see text] within the specimen at time t. Results indicted that that the pSFDI approach produced accurate deformation maps, as validated using both physical markers and conventional particle based method derived from the DIC analysis of the same specimens. We then extended the pSFDI technique to extract the fiber orientation distribution [Formula: see text] as a function of [Formula: see text] from the pSFDI intensity signal. This was accomplished by developing a calibration procedure to account for the optical behavior of the constituent fibers for the soft tissue being studied. We then demonstrated that the extracted [Formula: see text] was accurately computed in both the referential (i.e. unloaded) and deformed states. Moreover, we noted that the measured [Formula: see text] agreed well with affine kinematic deformation predictions. We also demonstrated this calibration approach could also be effectively used on electrospun biomaterials, underscoring the general utility of the approach. In a final step, using the ability to simultaneously quantify [Formula: see text] and [Formula: see text], we examined the effect of deformation and collagen structural measurements on the measurement region size. For pericardial tissues, we determined a critical length of [Formula: see text] 8 mm wherein the regional variations sufficiently dissipated. This result has immediate potential in the identification of optimal length scales for meso-scale strain measurement in soft tissues and fibrous biomaterials.
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Affiliation(s)
- Coinneach Mackenzie Dover
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, USA
| | - Will Goth
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Christian Goodbrake
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, USA
| | - James W Tunnell
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, The Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, USA.
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
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Herz C, Pace DF, Nam HH, Lasso A, Dinh P, Flynn M, Cianciulli A, Golland P, Jolley MA. Segmentation of Tricuspid Valve Leaflets From Transthoracic 3D Echocardiograms of Children With Hypoplastic Left Heart Syndrome Using Deep Learning. Front Cardiovasc Med 2021; 8:735587. [PMID: 34957233 PMCID: PMC8696083 DOI: 10.3389/fcvm.2021.735587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect in which the right ventricle and associated tricuspid valve (TV) alone support the circulation. TV failure is thus associated with heart failure, and the outcome of TV valve repair are currently poor. 3D echocardiography (3DE) can generate high-quality images of the valve, but segmentation is necessary for precise modeling and quantification. There is currently no robust methodology for rapid TV segmentation, limiting the clinical application of these technologies to this challenging population. We utilized a Fully Convolutional Network (FCN) to segment tricuspid valves from transthoracic 3DE. We trained on 133 3DE image-segmentation pairs and validated on 28 images. We then assessed the effect of varying inputs to the FCN using Mean Boundary Distance (MBD) and Dice Similarity Coefficient (DSC). The FCN with the input of an annular curve achieved a median DSC of 0.86 [IQR: 0.81-0.88] and MBD of 0.35 [0.23-0.4] mm for the merged segmentation and an average DSC of 0.77 [0.73-0.81] and MBD of 0.6 [0.44-0.74] mm for individual TV leaflet segmentation. The addition of commissural landmarks improved individual leaflet segmentation accuracy to an MBD of 0.38 [0.3-0.46] mm. FCN-based segmentation of the tricuspid valve from transthoracic 3DE is feasible and accurate. The addition of an annular curve and commissural landmarks improved the quality of the segmentations with MBD and DSC within the range of human inter-user variability. Fast and accurate FCN-based segmentation of the tricuspid valve in HLHS may enable rapid modeling and quantification, which in the future may inform surgical planning. We are now working to deploy this network for public use.
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Affiliation(s)
- Christian Herz
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
| | - Danielle F. Pace
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Hannah H. Nam
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
| | - Andras Lasso
- Laboratory for Percutaneous Surgery, Queen's University, Kingston, ON, Canada
| | - Patrick Dinh
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
| | - Maura Flynn
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
| | - Alana Cianciulli
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
| | - Polina Golland
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Matthew A. Jolley
- Children's Hospital of Philadelphia, Department of Anesthesia and Critical Care Medicine, Philadelphia, PA, United States
- Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States
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30
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Narang H, Rego BV, Khalighi AH, Aly A, Pouch AM, Gorman RC, Gorman Iii JH, Sacks MS. Pre-surgical Prediction of Ischemic Mitral Regurgitation Recurrence Using In Vivo Mitral Valve Leaflet Strains. Ann Biomed Eng 2021; 49:3711-3723. [PMID: 33837494 PMCID: PMC9134826 DOI: 10.1007/s10439-021-02772-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/27/2021] [Indexed: 10/21/2022]
Abstract
Ischemic mitral regurgitation (IMR) is a prevalent cardiac disease associated with substantial morbidity and mortality. Contemporary surgical treatments continue to have limited long-term success, in part due to the complex and multi-factorial nature of IMR. There is thus a need to better understand IMR etiology to guide optimal patient specific treatments. Herein, we applied our finite element-based shape-matching technique to non-invasively estimate peak systolic leaflet strains in human mitral valves (MVs) from in-vivo 3D echocardiographic images taken immediately prior to and post-annuloplasty repair. From a total of 21 MVs, we found statistically significant differences in pre-surgical MV size, shape, and deformation patterns between the with and without IMR recurrence patient groups at 6 months post-surgery. Recurrent MVs had significantly less compressive circumferential strains in the anterior commissure region compared to the recurrent MVs (p = 0.0223) and were significantly larger. A logistic regression analysis revealed that average pre-surgical circumferential leaflet strain in the Carpentier A1 region independently predicted 6-month recurrence of IMR (optimal cutoff value - 18%, p = 0.0362). Collectively, these results suggest greater disease progression in the recurrent group and underscore the highly patient-specific nature of IMR. Importantly, the ability to identify such factors pre-surgically could be used to guide optimal treatment methods to reduce post-surgical IMR recurrence.
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Affiliation(s)
- Harshita Narang
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Bruno V Rego
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Amir H Khalighi
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Ahmed Aly
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alison M Pouch
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph H Gorman Iii
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
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31
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Karakaya C, van Asten JGM, Ristori T, Sahlgren CM, Loerakker S. Mechano-regulated cell-cell signaling in the context of cardiovascular tissue engineering. Biomech Model Mechanobiol 2021; 21:5-54. [PMID: 34613528 PMCID: PMC8807458 DOI: 10.1007/s10237-021-01521-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/15/2021] [Indexed: 01/18/2023]
Abstract
Cardiovascular tissue engineering (CVTE) aims to create living tissues, with the ability to grow and remodel, as replacements for diseased blood vessels and heart valves. Despite promising results, the (long-term) functionality of these engineered tissues still needs improvement to reach broad clinical application. The functionality of native tissues is ensured by their specific mechanical properties directly arising from tissue organization. We therefore hypothesize that establishing a native-like tissue organization is vital to overcome the limitations of current CVTE approaches. To achieve this aim, a better understanding of the growth and remodeling (G&R) mechanisms of cardiovascular tissues is necessary. Cells are the main mediators of tissue G&R, and their behavior is strongly influenced by both mechanical stimuli and cell-cell signaling. An increasing number of signaling pathways has also been identified as mechanosensitive. As such, they may have a key underlying role in regulating the G&R of tissues in response to mechanical stimuli. A more detailed understanding of mechano-regulated cell-cell signaling may thus be crucial to advance CVTE, as it could inspire new methods to control tissue G&R and improve the organization and functionality of engineered tissues, thereby accelerating clinical translation. In this review, we discuss the organization and biomechanics of native cardiovascular tissues; recent CVTE studies emphasizing the obtained engineered tissue organization; and the interplay between mechanical stimuli, cell behavior, and cell-cell signaling. In addition, we review past contributions of computational models in understanding and predicting mechano-regulated tissue G&R and cell-cell signaling to highlight their potential role in future CVTE strategies.
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Affiliation(s)
- Cansu Karakaya
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Jordy G M van Asten
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Tommaso Ristori
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands.,Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Cecilia M Sahlgren
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands.,Faculty of Science and Engineering, Biosciences, Åbo Akademi, Turku, Finland
| | - Sandra Loerakker
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands. .,Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands.
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32
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Adventures in Heart Valve Function A Personal Thank You to Dr. Ajit P. Yoganathan. Cardiovasc Eng Technol 2021; 12:651-653. [PMID: 34145557 DOI: 10.1007/s13239-021-00555-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 06/07/2021] [Indexed: 01/19/2023]
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33
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Panicheva D, Villard PF, Hammer PE, Perrin D, Berger MO. Automatic extraction of the mitral valve chordae geometry for biomechanical simulation. Int J Comput Assist Radiol Surg 2021; 16:709-720. [PMID: 33978895 DOI: 10.1007/s11548-021-02368-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/06/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE Mitral valve computational models are widely studied in the literature. They can be used for preoperative planning or anatomical understanding. Manual extraction of the valve geometry on medical images is tedious and requires special training, while automatic segmentation is still an open problem. METHODS We propose here a fully automatic pipeline to extract the valve chordae architecture compatible with a computational model. First, an initial segmentation is obtained by sub-mesh topology analysis and RANSAC-like model-fitting procedure. Then, the chordal structure is optimized with respect to objective functions based on mechanical, anatomical, and image-based considerations. RESULTS The approach has been validated on 5 micro-CT scans with a graph-based metric and has shown an [Formula: see text] accuracy rate. The method has also been tested within a structural simulation of the mitral valve closed state. CONCLUSION Our results show that the chordae architecture resulting from our algorithm can give results similar to experienced users while providing an equivalent biomechanical simulation.
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Affiliation(s)
| | - Pierre-Frédéric Villard
- CNRS, Inria, LORIA, Université de Lorraine, Nancy, France. .,Harvard School of Engineering and Applied Sciences, Cambridge, MA, USA.
| | | | - Douglas Perrin
- Harvard School of Engineering and Applied Sciences, Cambridge, MA, USA.,Harvard Medical School, Boston, MA, USA
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34
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Ooms JF, Wang DD, Rajani R, Redwood S, Little SH, Chuang ML, Popma JJ, Dahle G, Pfeiffer M, Kanda B, Minet M, Hirsch A, Budde RP, De Jaegere PP, Prendergast B, O'Neill W, Van Mieghem NM. Computed Tomography-Derived 3D Modeling to Guide Sizing and Planning of Transcatheter Mitral Valve Interventions. JACC Cardiovasc Imaging 2021; 14:1644-1658. [PMID: 33744155 DOI: 10.1016/j.jcmg.2020.12.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/16/2020] [Accepted: 12/23/2020] [Indexed: 12/16/2022]
Abstract
A plethora of catheter-based strategies have been developed to treat mitral valve disease. Evolving 3-dimensional (3D) multidetector computed tomography (MDCT) technology can accurately reconstruct the mitral valve by means of 3-dimensional computational modeling (3DCM) to allow virtual implantation of catheter-based devices. 3D printing complements computational modeling and offers implanting physician teams the opportunity to evaluate devices in life-size replicas of patient-specific cardiac anatomy. MDCT-derived 3D computational and 3D-printed modeling provides unprecedented insights to facilitate hands-on procedural planning, device training, and retrospective procedural evaluation. This overview summarizes current concepts and provides insight into the application of MDCT-derived 3DCM and 3D printing for the planning of transcatheter mitral valve replacement and closure of paravalvular leaks. Additionally, future directions in the development of 3DCM will be discussed.
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Affiliation(s)
- Joris F Ooms
- Department of Interventional Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Dee Dee Wang
- Center for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan, USA
| | - Ronak Rajani
- Department of Cardiology, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Simon Redwood
- Cardiovascular Division, King's College London British Heart Foundation Centre of Excellence, The Rayne Institute, St. Thomas' Hospital Campus, London, United Kingdom
| | - Stephen H Little
- Department of Cardiology, Houston Methodist Hospital, Houston, Texas, USA
| | - Michael L Chuang
- Cardiovascular Division, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Jeffrey J Popma
- Cardiovascular Division, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Gry Dahle
- Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Michael Pfeiffer
- Division of Cardiology, Penn State Heart and Vascular Institute, Hershey, Pennsylvania, USA
| | - Brinder Kanda
- Stroobants Cardiovascular Center, Lynchburg, Virginia, USA
| | | | - Alexander Hirsch
- Department of Interventional Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, the Netherlands; Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Ricardo P Budde
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Peter P De Jaegere
- Department of Interventional Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Bernard Prendergast
- Department of Cardiology, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - William O'Neill
- Center for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan, USA
| | - Nicolas M Van Mieghem
- Department of Interventional Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, the Netherlands.
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35
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Ristori T, Sjöqvist M, Sahlgren CM. Ex Vivo Models to Decipher the Molecular Mechanisms of Genetic Notch Cardiovascular Disorders. Tissue Eng Part C Methods 2021; 27:167-176. [PMID: 33403934 PMCID: PMC7984653 DOI: 10.1089/ten.tec.2020.0327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/04/2020] [Indexed: 12/13/2022] Open
Abstract
Notch is an evolutionary, conserved, cell-cell signaling pathway that is central to several biological processes, from tissue morphogenesis to homeostasis. It is therefore not surprising that several genetic mutations of Notch components cause inherited human diseases, especially cardiovascular disorders. Despite numerous efforts, current in vivo models are still insufficient to unravel the underlying mechanisms of these pathologies, hindering the development of utmost needed medical therapies. In this perspective review, we discuss the limitations of current murine models and outline how the combination of microphysiological systems (MPSs) and targeted computational models can lead to breakthroughs in this field. In particular, while MPSs enable the experimentation on human cells in controlled and physiological environments, in silico models can provide a versatile tool to translate the in vitro findings to the more complex in vivo setting. As a showcase example, we focus on Notch-related cardiovascular diseases, such as Alagille syndrome, Adams-Oliver syndrome, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Impact statement In this review, a comprehensive overview of the limitations of current in vivo models of genetic Notch cardiovascular diseases is provided, followed by a discussion over the potential of microphysiological systems and computational models in overcoming these limitations and in potentiating drug testing and modeling of these pathologies.
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Affiliation(s)
- Tommaso Ristori
- Department of Biomedical Engineering, Technical University of Eindhoven, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Marika Sjöqvist
- Faculty of Science and Engineering, Biosciences, Åbo Akademi University, Turku, Finland
- Turku Bioscience Centre, Åbo Akademi University and University of Turku, Turku, Finland
| | - Cecilia M. Sahlgren
- Department of Biomedical Engineering, Technical University of Eindhoven, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands
- Faculty of Science and Engineering, Biosciences, Åbo Akademi University, Turku, Finland
- Turku Bioscience Centre, Åbo Akademi University and University of Turku, Turku, Finland
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36
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Loerakker S, Ristori T. Computational modeling for cardiovascular tissue engineering: the importance of including cell behavior in growth and remodeling algorithms. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2020; 15:1-9. [PMID: 33997580 PMCID: PMC8105589 DOI: 10.1016/j.cobme.2019.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Understanding cardiovascular growth and remodeling (G&R) is fundamental for designing robust cardiovascular tissue engineering strategies, which enable synthetic or biological scaffolds to transform into healthy living tissues after implantation. Computational modeling, particularly when integrated with experimental research, is key for advancing our understanding, predicting the in vivo evolution of engineered tissues, and efficiently optimizing scaffold designs. As cells are ultimately the drivers of G&R and known to change their behavior in response to mechanical cues, increasing efforts are currently undertaken to capture (mechano-mediated) cell behavior in computational models. In this selective review, we highlight some recent examples that are relevant in the context of cardiovascular tissue engineering and discuss the current and future biological and computational challenges for modeling cell-mediated G&R.
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Affiliation(s)
- Sandra Loerakker
- Department of Biomedical Engineering, Eindhoven University of Technology, Groene Loper Building 15, 5612 AP, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Groene Loper Building 7, 5612 AJ, Eindhoven, the Netherlands
| | - Tommaso Ristori
- Department of Biomedical Engineering, Eindhoven University of Technology, Groene Loper Building 15, 5612 AP, Eindhoven, the Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, Groene Loper Building 7, 5612 AJ, Eindhoven, the Netherlands
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37
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Ayoub S, Howsmon DP, Lee CH, Sacks MS. On the role of predicted in vivo mitral valve interstitial cell deformation on its biosynthetic behavior. Biomech Model Mechanobiol 2020; 20:135-144. [PMID: 32761471 DOI: 10.1007/s10237-020-01373-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/28/2020] [Indexed: 02/06/2023]
Abstract
Ischemic mitral regurgitation (IMR), a frequent complication of myocardial infarction, is characterized by regurgitation of blood from the left ventricle back into the left atrium. Physical interventions via surgery or less-invasive techniques are the only available therapies for IMR, with valve repair via undersized ring annuloplasty (URA) generally preferred over valve replacement. However, recurrence of IMR after URA occurs frequently and is attributed to continued remodeling of the MV and infarct region of the left ventricle. The mitral valve interstitial cells (MVICs) that maintain the tissue integrity of the MV leaflets are highly mechanosensitive, and altered loading post-URA is thought to lead to aberrant MVIC-directed tissue remodeling. Although studies have investigated aspects of mechanically directed VIC activation and remodeling potential, there remains a substantial disconnect between organ-level biomechanics and cell-level phenomena. Herein, we utilized an extant multiscale computational model of the MV that linked MVIC to organ-level MV biomechanical behaviors to simulate changes in MVIC deformation following URA. A planar biaxial bioreactor system was then used to cyclically stretch explanted MV leaflet tissue, emulating the in vivo changes in loading following URA. This simulation-directed experimental investigation revealed that post-URA deformations resulted in decreased MVIC activation and collagen mass fraction. These results are consistent with the hypothesis that URA failures post-IMR are due, in part, to reduced MVIC-mediated maintenance of the MV leaflet tissue resulting from a reduction in physical stimuli required for leaflet tissue homeostasis. Such information can inform the development of novel URA strategies with improved durability.
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Affiliation(s)
- Salma Ayoub
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, USA
| | - Daniel P Howsmon
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, USA
| | - Chung-Hao Lee
- School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, USA.
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Caballero A, Mao W, McKay R, Hahn RT, Sun W. A Comprehensive Engineering Analysis of Left Heart Dynamics After MitraClip in a Functional Mitral Regurgitation Patient. Front Physiol 2020; 11:432. [PMID: 32457650 PMCID: PMC7221026 DOI: 10.3389/fphys.2020.00432] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 04/08/2020] [Indexed: 12/14/2022] Open
Abstract
Percutaneous edge-to-edge mitral valve (MV) repair using MitraClip has been recently established as a treatment option for patients with heart failure and functional mitral regurgitation (MR), which significantly expands the number of patients that can be treated with this device. This study aimed to quantify the morphologic, hemodynamic and structural changes, and evaluate the biomechanical interaction between the MitraClip and the left heart (LH) complex of a heart failure patient with functional MR using a fluid-structure interaction (FSI) modeling framework. MitraClip implantation using lateral, central and double clip positions, as well as combined annuloplasty procedures were simulated in a patient-specific LH model that integrates detailed anatomic structures, incorporates age- and gender-matched non-linear elastic material properties, and accounts for mitral chordae tethering. Our results showed that antero-posterior distance, mitral annulus spherecity index, anatomic regurgitant orifice area, and anatomic opening orifice area decreased by up to 28, 39, 52, and 71%, respectively, when compared to the pre-clip model. MitraClip implantation immediately decreased the MR severity and improved the hemodynamic profile, but imposed a non-physiologic configuration and loading on the mitral apparatus, with anterior and posterior leaflet stress significantly increasing up to 210 and 145% during diastole, respectively. For this patient case, while implanting a combined central clip and ring resulted in the highest reduction in the regurgitant volume (46%), this configuration also led to mitral stenosis. Patient-specific computer simulations as used here can be a powerful tool to examine the complex device-host biomechanical interaction, and may be useful to guide device positioning for potential favorable clinical outcomes.
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Affiliation(s)
- Andrés Caballero
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Wenbin Mao
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Raymond McKay
- Division of Cardiology, The Hartford Hospital, Hartford, CT, United States
| | - Rebecca T. Hahn
- Division of Cardiology, Columbia University Medical Center, New York, NY, United States
| | - Wei Sun
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
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Howsmon DP, Rego BV, Castillero E, Ayoub S, Khalighi AH, Gorman RC, Gorman JH, Ferrari G, Sacks MS. Mitral valve leaflet response to ischaemic mitral regurgitation: from gene expression to tissue remodelling. J R Soc Interface 2020; 17:20200098. [PMID: 32370692 PMCID: PMC7276554 DOI: 10.1098/rsif.2020.0098] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/07/2020] [Indexed: 02/06/2023] Open
Abstract
Ischaemic mitral regurgitation (IMR), a frequent complication following myocardial infarction (MI), leads to higher mortality and poor clinical prognosis if untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post MI, and this remodelling increases both the severity of IMR and the occurrence of MV repair failures. However, the mechanisms of extracellular matrix maintenance and modulation by MV interstitial cells (MVICs) and their impact on MV leaflet tissue integrity and repair failure remain largely unknown. Herein, we sought to elucidate the multiscale behaviour of IMR-induced MV remodelling using an established ovine model. Leaflet tissue at eight weeks post MI exhibited significant permanent plastic radial deformation, eliminating mechanical anisotropy, accompanied by altered leaflet composition. Interestingly, no changes in effective collagen fibre modulus were observed, with MVICs slightly rounder, at eight weeks post MI. RNA sequencing indicated that YAP-induced genes were elevated at four weeks post MI, indicating elevated mechanotransduction. Genes related to extracellular matrix organization were downregulated at four weeks post MI when IMR occurred. Transcriptomic changes returned to baseline by eight weeks post MI. This multiscale study suggests that IMR induces plastic deformation of the MV with no functional damage to the collagen fibres, providing crucial information for computational simulations of the MV in IMR.
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Affiliation(s)
- Daniel P. Howsmon
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Bruno V. Rego
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Estibaliz Castillero
- Department of Surgery, Columbia University Irving Medical Center, New York, NY, USA
| | - Salma Ayoub
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Amir H. Khalighi
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Robert C. Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph H. Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Giovanni Ferrari
- Department of Surgery, Columbia University Irving Medical Center, New York, NY, USA
| | - Michael S. Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
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Pre-Operative Modeling of Transcatheter Mitral Valve Replacement in a Surgical Heart Valve Bioprosthesis. PROSTHESIS 2020. [DOI: 10.3390/prosthesis2010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Obstruction of the left ventricular outflow tract (LVOT) is a common complication of transcatheter mitral valve replacement (TMVR). This procedure can determine an elongation of an LVOT (namely, the neo-LVOT), ultimately portending hemodynamic impairment and patient death. This study aimed to understand the biomechanical implications of LVOT obstruction in a patient who underwent TMVR using a transcatheter heart valve (THV) to repair a failed bioprosthetic heart valve. We first reconstructed the heart anatomy and the bioprosthetic heart valve to virtually implant a computer-aided-design (CAD) model of THV and evaluate the neo-LVOT area. A numerical simulation of THV deployment was then developed to assess the anchorage of the THV to the bioprosthetic heart valve as well as the resulting Von Mises stress at the mitral annulus and the contract pressure among implanted bioprostheses. Quantification of neo-LVOT and THV deployment may facilitate more accurate predictions of the LVOT obstruction in TMVR and help clinicians in the optimal choice of the THV size.
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Caballero A, Mao W, McKay R, Sun W. Transapical mitral valve repair with neochordae implantation: FSI analysis of neochordae number and complexity of leaflet prolapse. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3297. [PMID: 31833663 DOI: 10.1002/cnm.3297] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 11/05/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
Transapical mitral valve repair with neochordae implantation is a relatively new minimally invasive technique to treat primary mitral regurgitation. Quantifying the complex biomechanical interaction and interdependence between the left heart structures and the neochordae during this procedure is technically challenging. The aim of this parametric computational study is to investigate the immediate effects of neochordae number and complexity of leaflet prolapse on restoring physiologic left heart dynamics after optimal transapical neochordae repair procedures. Neochordae implantation using three and four sutures was modeled under three clinically relevant prolapse conditions: isolated P2, multi-scallop P2/P3, and multi-scallop P2/P1. A fluid-structure interaction (FSI) modeling framework was used to evaluate the left heart dynamics under baseline, prerepair, and postrepair states. Despite immediate restoration of leaflet coaptation and no residual mitral regurgitation in all postrepair models, the average and peak stresses in the repaired scallop(s) increased >40% and >100%, respectively, compared with the baseline state. Additionally, anterior mitral leaflet marginal chordae tension increased >30%, while posterior mitral leaflet chordae tension decreased at least 30%. No marked differences in hemodynamic performance, in native and neochordae forces, and in leaflet stress were found when implanting three or four sutures. We report, to our knowledge, the first set of time-dependent in silico FSI human neochordae tension measurements during transapical neochordae repair. This work represents a further step towards an improved understanding of the biomechanical outcomes of minimally invasive mitral valve repair procedures.
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Affiliation(s)
- Andrés Caballero
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
| | - Wenbin Mao
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
| | - Raymond McKay
- Division of Cardiology, The Hartford Hospital, Hartford, Connecticut
| | - Wei Sun
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
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Some Effects of Different Constitutive Laws on FSI Simulation for the Mitral Valve. Sci Rep 2019; 9:12753. [PMID: 31484963 PMCID: PMC6726639 DOI: 10.1038/s41598-019-49161-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022] Open
Abstract
In this paper, three different constitutive laws for mitral leaflets and two laws for chordae tendineae are selected to study their effects on mitral valve dynamics with fluid-structure interaction. We first fit these three mitral leaflet constitutive laws and two chordae tendineae laws with experimental data. The fluid-structure interaction is implemented in an immersed boundary framework with finite element extension for solid, that is the hybrid immersed boundary/finite element(IB/FE) method. We specifically compare the fluid-structure results of different constitutive laws since fluid-structure interaction is the physiological loading environment. This allows us to look at the peak jet velocity, the closure regurgitation volume, and the orifice area. Our numerical results show that different constitutive laws can affect mitral valve dynamics, such as the transvalvular flow rate, closure regurgitation and the orifice area, while the differences in fiber strain and stress are insignificant because all leaflet constitutive laws are fitted to the same set of experimental data. In addition, when an exponential constitutive law of chordae tendineae is used, a lower closure regurgitation flow is observed compared to that of a linear material model. In conclusion, combining numerical dynamic simulations and static experimental tests, we are able to identify suitable constitutive laws for dynamic behaviour of mitral leaflets and chordae under physiological conditions.
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