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Park MH, Zhu Y, Imbrie-Moore AM, Wang H, Marin-Cuartas M, Paulsen MJ, Woo YJ. Heart Valve Biomechanics: The Frontiers of Modeling Modalities and the Expansive Capabilities of Ex Vivo Heart Simulation. Front Cardiovasc Med 2021; 8:673689. [PMID: 34307492 PMCID: PMC8295480 DOI: 10.3389/fcvm.2021.673689] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/17/2021] [Indexed: 01/05/2023] Open
Abstract
The field of heart valve biomechanics is a rapidly expanding, highly clinically relevant area of research. While most valvular pathologies are rooted in biomechanical changes, the technologies for studying these pathologies and identifying treatments have largely been limited. Nonetheless, significant advancements are underway to better understand the biomechanics of heart valves, pathologies, and interventional therapeutics, and these advancements have largely been driven by crucial in silico, ex vivo, and in vivo modeling technologies. These modalities represent cutting-edge abilities for generating novel insights regarding native, disease, and repair physiologies, and each has unique advantages and limitations for advancing study in this field. In particular, novel ex vivo modeling technologies represent an especially promising class of translatable research that leverages the advantages from both in silico and in vivo modeling to provide deep quantitative and qualitative insights on valvular biomechanics. The frontiers of this work are being discovered by innovative research groups that have used creative, interdisciplinary approaches toward recapitulating in vivo physiology, changing the landscape of clinical understanding and practice for cardiovascular surgery and medicine.
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Affiliation(s)
- Matthew H Park
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Yuanjia Zhu
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Annabel M Imbrie-Moore
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Hanjay Wang
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States
| | - Mateo Marin-Cuartas
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,University Department of Cardiac Surgery, Leipzig Heart Center, Leipzig, Germany
| | - Michael J Paulsen
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States
| | - Y Joseph Woo
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Bioengineering, Stanford University, Stanford, CA, United States
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2
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Kheradvar A, Vannan MA, Dasi LP, Pedrizzetti G. The effect of aortic root anatomy and vortex flow induced shear stress on the aortic valve leaflets. Eur Heart J Cardiovasc Imaging 2021; 22:995-997. [PMID: 33758910 DOI: 10.1093/ehjci/jeab031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Arash Kheradvar
- Edwards Lifesciences Center for Advanced Cardiovascular Technology, Department of Biomedical Enginnering, University of California, Irvine, CA, USA
| | - Mani A Vannan
- Marcus Heart Valve Center, Piedmont Heart Institute, Atlanta, GA, USA
| | - Lakshmi P Dasi
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Gianni Pedrizzetti
- Department of Engineering and Architecture, University of Trieste, Trieste, Italy
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3
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Hayashi H, Itatani K, Akiyama K, Zhao Y, Kurlansky P, DeRoo S, Sanchez J, Ferrari G, Yuzefpolskaya M, Colombo PC, Takeda K, Wu IY, Kainuma A, Takayama H. Influence of aneurysmal aortic root geometry on mechanical stress to the aortic valve leaflet. Eur Heart J Cardiovasc Imaging 2021; 22:986-994. [PMID: 33611382 DOI: 10.1093/ehjci/jeab006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 01/08/2021] [Indexed: 01/16/2023] Open
Abstract
AIMS While mechanical stress caused by blood flow, e.g. wall shear stress (WSS), and related parameters, e.g. oscillatory shear index (OSI), are increasingly being recognized as key moderators of various cardiovascular diseases, studies on valves have been limited because of a lack of appropriate imaging modalities. We investigated the influence of aortic root geometry on WSS and OSI on the aortic valve (AV) leaflet. METHODS AND RESULTS We applied our novel approach of intraoperative epi-aortic echocardiogram to measure the haemodynamic parameters of WSS and OSI on the AV leaflet. Thirty-six patients were included, which included those who underwent valve-sparing aortic root replacement (VSARR) with no significant aortic regurgitation (n = 17) and coronary artery bypass graft (CABG) with normal AV (n = 19). At baseline, those who underwent VSARR had a higher systolic WSS (0.52 ± 0.12 vs. 0.32 ± 0.08 Pa, respectively, P < 0.001) and a higher OSI (0.37 ± 0.06 vs. 0.29 ± 0.04, respectively, P < 0.001) on the aortic side of the AV leaflet than those who underwent CABG. Multivariate regression analysis revealed that the size of the sinus of Valsalva had a significant association with WSS and OSI. Following VSARR, WSS and OSI values decreased significantly compared with the baseline values (WSS: 0.29 ± 0.12 Pa, P < 0.001; OSI: 0.26 ± 0.09, P < 0.001), and became comparable to the values in those who underwent CABG (WSS, P = 0.42; OSI, P = 0.15). CONCLUSIONS Mechanical stress on the AV gets altered in correlation with the size of the aortic root. An aneurysmal aortic root may expose the leaflet to abnormal fluid dynamics. The VSARR procedure appeared to reduce these abnormalities.
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Affiliation(s)
- Hideyuki Hayashi
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Keiichi Itatani
- Department of Cardiovascular Surgery, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Koichi Akiyama
- Department of Anesthesiology, Yodogawa Christian Hospital, 1 Chome-7-50, Kunijima, Higashiyodogawa Ward, Osaka, 533-0024, Japan
| | - Yanling Zhao
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Paul Kurlansky
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Scott DeRoo
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Joseph Sanchez
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Giovanni Ferrari
- Department of Surgery and Biomedical Engineering, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Melana Yuzefpolskaya
- Division of Cardiology, Department of Medicine, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Paolo C Colombo
- Division of Cardiology, Department of Medicine, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Koji Takeda
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Isaac Y Wu
- Department of Anesthesiology, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Atsushi Kainuma
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
| | - Hiroo Takayama
- Division of Cardiothoracic Surgery, Department of Surgery, New York-Presbyterian Hospital, Columbia University Medical Center, 707 Fort Washington Avenue, New York, NY 10032, USA
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4
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Johnson EL, Wu MCH, Xu F, Wiese NM, Rajanna MR, Herrema AJ, Ganapathysubramanian B, Hughes TJR, Sacks MS, Hsu MC. Thinner biological tissues induce leaflet flutter in aortic heart valve replacements. Proc Natl Acad Sci U S A 2020; 117:19007-19016. [PMID: 32709744 PMCID: PMC7431095 DOI: 10.1073/pnas.2002821117] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Valvular heart disease has recently become an increasing public health concern due to the high prevalence of valve degeneration in aging populations. For patients with severely impacted aortic valves that require replacement, catheter-based bioprosthetic valve deployment offers a minimally invasive treatment option that eliminates many of the risks associated with surgical valve replacement. Although recent percutaneous device advancements have incorporated thinner, more flexible biological tissues to streamline safer deployment through catheters, the impact of such tissues in the complex, mechanically demanding, and highly dynamic valvular system remains poorly understood. The present work utilized a validated computational fluid-structure interaction approach to isolate the behavior of thinner, more compliant aortic valve tissues in a physiologically realistic system. This computational study identified and quantified significant leaflet flutter induced by the use of thinner tissues that initiated blood flow disturbances and oscillatory leaflet strains. The aortic flow and valvular dynamics associated with these thinner valvular tissues have not been previously identified and provide essential information that can significantly advance fundamental knowledge about the cardiac system and support future medical device innovation. Considering the risks associated with such observed flutter phenomena, including blood damage and accelerated leaflet deterioration, this study demonstrates the potentially serious impact of introducing thinner, more flexible tissues into the cardiac system.
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Affiliation(s)
- Emily L Johnson
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | - Michael C H Wu
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | - Fei Xu
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | - Nelson M Wiese
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | - Manoj R Rajanna
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | - Austin J Herrema
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011
| | | | - Thomas J R Hughes
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX 78712;
| | - Michael S Sacks
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX 78712;
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712
| | - Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011;
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5
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Shar JA, Liu J, Atkins SK, Sucosky P. Letter by Shar et al Regarding Article, “Low and Oscillatory Wall Shear Stress Is Not Related to Aortic Dilation in Patients With Bicuspid Aortic Valve: A Time-Resolved 3-Dimensional Phase-Contrast Magnetic Resonance Imaging Study”. Arterioscler Thromb Vasc Biol 2020; 40:e114-e115. [DOI: 10.1161/atvbaha.120.314049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Jason A. Shar
- From the Department of Mechanical and Materials Engineering, Wright State University, Russ Engineering Center, Dayton, OH (J.A.S., J.L., P.S.)
| | - Janet Liu
- From the Department of Mechanical and Materials Engineering, Wright State University, Russ Engineering Center, Dayton, OH (J.A.S., J.L., P.S.)
| | - Samantha K. Atkins
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (S.K.A.)
| | - Philippe Sucosky
- From the Department of Mechanical and Materials Engineering, Wright State University, Russ Engineering Center, Dayton, OH (J.A.S., J.L., P.S.)
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6
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Hayashi H, Akiyama K, Itatani K, DeRoo S, Sanchez J, Ferrari G, Colombo PC, Takeda K, Wu IY, Kainuma A, Takayama H. A novel in vivo assessment of fluid dynamics on aortic valve leaflet using epi-aortic echocardiogram. Echocardiography 2020; 37:323-330. [PMID: 32003907 DOI: 10.1111/echo.14596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/27/2019] [Accepted: 01/07/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Mechanical stress caused by blood flow, such as wall shear stress (WSS) and its related parameters, is key moderator of endothelial degeneration. However, an in vivo method to measure WSS on heart valves has not been developed. METHODS We developed a novel approach, based on vector flow mapping using intraoperative epi-aortic echocardiogram, to measure WSS and oscillatory shear index (OSI) on the aortic valve. We prospectively enrolled 15 patients with normal valves, who underwent coronary artery bypass graft. RESULTS Systolic WSS on the ventricularis (2.40 ± 0.44 Pa [1.45-3.00 Pa]) was higher than systolic WSS on the fibrosa (0.33 ± 0.08 Pa [0.14-0.47 Pa], P < .001) and diastolic WSS on the ventricularis (0.18 ± 0.07 Pa [0.04-0.28 Pa], P < .001). Oscillatory shear index on the fibrosa was higher than on the ventricularis (0.29 ± 0.04 [0.24-0.36] vs 0.05 ± 0.03 [0.01-0.12], P < .001). A pilot study involving two patients with severe aortic regurgitation showed significantly different values in fluid dynamics. CONCLUSION Vector flow mapping method using intraoperative epi-aortic echocardiogram is an effective way of measuring WSS and OSI on normal aortic leaflet in vivo, allowing for better understanding of the pathophysiology of aortic valve diseases.
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Affiliation(s)
- Hideyuki Hayashi
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - Koichi Akiyama
- Department of Anesthesiology, Yodogawa Christian Hospital, Osaka, Japan
| | - Keiichi Itatani
- Department of Cardiovascular Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Scott DeRoo
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - Joseph Sanchez
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - Giovanni Ferrari
- Department of Surgery and Biomedical Engineering, Columbia University Medical, New York, NY, USA
| | - Paolo C Colombo
- Division of Cardiology, Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - Koji Takeda
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - Isaac Y Wu
- Department of Anesthesiology, Columbia University Medical Center, New York, NY, USA
| | - Atsushi Kainuma
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - Hiroo Takayama
- Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA
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7
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Wu MCH, Muchowski HM, Johnson EL, Rajanna MR, Hsu MC. Immersogeometric fluid-structure interaction modeling and simulation of transcatheter aortic valve replacement. COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2019; 357:112556. [PMID: 32831419 PMCID: PMC7442159 DOI: 10.1016/j.cma.2019.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The transcatheter aortic valve replacement (TAVR) has emerged as a minimally invasive alternative to surgical treatments of valvular heart disease. TAVR offers many advantages, however, the safe anchoring of the transcatheter heart valve (THV) in the patients anatomy is key to a successful procedure. In this paper, we develop and apply a novel immersogeometric fluid-structure interaction (FSI) framework for the modeling and simulation of the TAVR procedure to study the anchoring ability of the THV. To account for physiological realism, methods are proposed to model and couple the main components of the system, including the arterial wall, blood flow, valve leaflets, skirt, and frame. The THV is first crimped and deployed into an idealized ascending aorta. During the FSI simulation, the radial outward force and friction force between the aortic wall and the THV frame are examined over the entire cardiac cycle. The ratio between these two forces is computed and compared with the experimentally estimated coefficient of friction to study the likelihood of valve migration.
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Affiliation(s)
- Michael C. H. Wu
- Department of Mechanical Engineering, Iowa State University, 2043 Black Engineering, Ames, Iowa 50011, USA
- School of Engineering, Brown University, 184 Hope Street, Providence, Rhode Island 02912, USA
| | - Heather M. Muchowski
- Department of Mechanical Engineering, Iowa State University, 2043 Black Engineering, Ames, Iowa 50011, USA
- Department of Mathematics, Iowa State University, 396 Carver Hall, Ames, Iowa 50011, USA
| | - Emily L. Johnson
- Department of Mechanical Engineering, Iowa State University, 2043 Black Engineering, Ames, Iowa 50011, USA
| | - Manoj R. Rajanna
- Department of Mechanical Engineering, Iowa State University, 2043 Black Engineering, Ames, Iowa 50011, USA
| | - Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, 2043 Black Engineering, Ames, Iowa 50011, USA
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8
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Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional–printed heart simulator. J Thorac Cardiovasc Surg 2019; 158:392-403. [DOI: 10.1016/j.jtcvs.2018.10.145] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/07/2018] [Accepted: 10/19/2018] [Indexed: 12/24/2022]
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9
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Kaufman JL. Invited commentary. J Vasc Surg 2019; 69:452-453. [PMID: 30683194 DOI: 10.1016/j.jvs.2018.05.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 05/30/2018] [Indexed: 10/27/2022]
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10
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Wu MCH, Zakerzadeh R, Kamensky D, Kiendl J, Sacks MS, Hsu MC. An anisotropic constitutive model for immersogeometric fluid-structure interaction analysis of bioprosthetic heart valves. J Biomech 2018; 74:23-31. [PMID: 29735263 DOI: 10.1016/j.jbiomech.2018.04.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/25/2018] [Accepted: 04/04/2018] [Indexed: 12/01/2022]
Abstract
This paper considers an anisotropic hyperelastic soft tissue model, originally proposed for native valve tissue and referred to herein as the Lee-Sacks model, in an isogeometric thin shell analysis framework that can be readily combined with immersogeometric fluid-structure interaction (FSI) analysis for high-fidelity simulations of bioprosthetic heart valves (BHVs) interacting with blood flow. We find that the Lee-Sacks model is well-suited to reproduce the anisotropic stress-strain behavior of the cross-linked bovine pericardial tissues that are commonly used in BHVs. An automated procedure for parameter selection leads to an instance of the Lee-Sacks model that matches biaxial stress-strain data from the literature more closely, over a wider range of strains, than other soft tissue models. The relative simplicity of the Lee-Sacks model is attractive for computationally-demanding applications such as FSI analysis and we use the model to demonstrate how the presence and direction of material anisotropy affect the FSI dynamics of BHV leaflets.
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Affiliation(s)
- Michael C H Wu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Rana Zakerzadeh
- Willerson Center for Cardiovascular Modeling and Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - David Kamensky
- Department of Structural Engineering, University of California, San Diego, 9500 Gilman Drive, Mail Code 0085, La Jolla, CA 92093, USA
| | - Josef Kiendl
- Department of Marine Technology, Norwegian University of Science and Technology, O. Nielsens veg 10, 7052 Trondheim, Norway
| | - Michael S Sacks
- Willerson Center for Cardiovascular Modeling and Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA.
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11
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Xu F, Morganti S, Zakerzadeh R, Kamensky D, Auricchio F, Reali A, Hughes TJ, Sacks MS, Hsu MC. A framework for designing patient-specific bioprosthetic heart valves using immersogeometric fluid-structure interaction analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2938. [PMID: 29119728 PMCID: PMC5893448 DOI: 10.1002/cnm.2938] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/08/2017] [Accepted: 10/22/2017] [Indexed: 05/07/2023]
Abstract
Numerous studies have suggested that medical image derived computational mechanics models could be developed to reduce mortality and morbidity due to cardiovascular diseases by allowing for patient-specific surgical planning and customized medical device design. In this work, we present a novel framework for designing prosthetic heart valves using a parametric design platform and immersogeometric fluid-structure interaction (FSI) analysis. We parameterize the leaflet geometry using several key design parameters. This allows for generating various perturbations of the leaflet design for the patient-specific aortic root reconstructed from the medical image data. Each design is analyzed using our hybrid arbitrary Lagrangian-Eulerian/immersogeometric FSI methodology, which allows us to efficiently simulate the coupling of the deforming aortic root, the parametrically designed prosthetic valves, and the surrounding blood flow under physiological conditions. A parametric study is performed to investigate the influence of the geometry on heart valve performance, indicated by the effective orifice area and the coaptation area. Finally, the FSI simulation result of a design that balances effective orifice area and coaptation area reasonably well is compared with patient-specific phase contrast magnetic resonance imaging data to demonstrate the qualitative similarity of the flow patterns in the ascending aorta.
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Affiliation(s)
- Fei Xu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Simone Morganti
- Department of Electrical, Computer, and Biomedical Engineering, University of Pavia, via Ferrata 3, 27100, Pavia Italy
| | - Rana Zakerzadeh
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - David Kamensky
- Department of Structural Engineering, University of California, San Diego, 9500 Gilman Drive, Mail Code 0085 La Jolla, CA 92093, USA
| | - Ferdinando Auricchio
- Department of Civil Engineering and Architecture, University of Pavia, via Ferrata 3, 27100, Pavia, Italy
| | - Alessandro Reali
- Department of Civil Engineering and Architecture, University of Pavia, via Ferrata 3, 27100, Pavia, Italy
| | - Thomas J.R. Hughes
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Michael S. Sacks
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
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12
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Wang ZC, Yuan Q, Zhu HW, Shen BS, Tang D. Computational Modeling for Fluid–Structure Interaction of Bioprosthetic Heart Valve with Different Suture Density: Comparison with Dynamic Structure Simulation. INT J PATTERN RECOGN 2017. [DOI: 10.1142/s0218001417570075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this paper, a parametric geometry model based on elliptic and conic surfaces was developed for bioprosthetic heart valve (BHV) simulation. The valve material was modeled by a hyperelastic nonlinear anisotropic solid model. Different suture densities could be substituted by various bonded points between artery vessel and the leaflets as boundary conditions in the computational modeling. Besides these two assumptions that dynamic structure (DS) and fluid–structure interaction (FSI) both shared, the latter need incompressible viscous Newton fluid model to depict bloodstream passing through the BHV. Immersed boundary (IB) method was introduced to solve the FSI simulation. In addition, the DS analysis applied transvalvular pressure on the valve while FSI had left ventricular pressure on fluid inlet as initials. There was inconsistency between the moments of the maximum deformation and the maximum loading in both simulations. Although a similar trend of deformation lagging the load was viewed, the extent of delay in FSI was much smaller compared with that in DS simulation. The deformed profiles in cross-sectional views were shown in one picture to illustrate different dynamic responses caused by distinct assumptions. Percent of open area at the moments when the maximum deformation occurred was defined to show which calculation achieved better approximation for precise hemodynamics. Fixed point was given as boundaries between BHV and artery in the modeling part. Calculations showed that the more the fixed points in this bonded contact, the lower the principal stress was. The maximum shear stress showed a different trend. It had a different trend. Stress concentration in the conjunction area made it high-risk to be teared. Different suture densities had significant impaction in FSI simulations. With that analysis our work achieved a more comprehensive simulation to describe true hemodynamics of a BHV implanted in artery. The artery vessel had particular dynamic response under such assumptions, gradient existed in the maximum principal stress distribution diagram, from inner wall through which blood passing to the outer wall. Results showed a large suture density was suggested in BHV implantation.
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Affiliation(s)
- Z. C. Wang
- School of Mechanical Engineering Shandong University, Key Laboratory of High-efficiency and Clean Mechanical Manufacture, (Shandong University) Ministry of Education, Jinan, P. R. China
| | - Q. Yuan
- School of Mechanical Engineering Shandong University, Key Laboratory of High-efficiency and Clean Mechanical Manufacture, (Shandong University) Ministry of Education, Jinan, P. R. China
| | - H. W. Zhu
- School of Mechanical Engineering Shandong University, Key Laboratory of High-efficiency and Clean Mechanical Manufacture, (Shandong University) Ministry of Education, Jinan, P. R. China
| | - B. S. Shen
- School of Mechanical Engineering Shandong University, Key Laboratory of High-efficiency and Clean Mechanical Manufacture, (Shandong University) Ministry of Education, Jinan, P. R. China
| | - D. Tang
- School of Mechanical Engineering Shandong University, Key Laboratory of High-efficiency and Clean Mechanical Manufacture, (Shandong University) Ministry of Education, Jinan, P. R. China
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13
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The effects of positioning of transcatheter aortic valves on fluid dynamics of the aortic root. ASAIO J 2015; 60:545-552. [PMID: 25010918 DOI: 10.1097/mat.0000000000000107] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Transcatheter aortic valve implantation is a novel treatment for severe aortic valve stenosis. Due to the recent use of this technology and the procedural variability, there is very little data that quantify the hemodynamic consequences of variations in valve placement. Changes in aortic wall stresses and fluid retention in the sinuses of Valsalva can have a significant effect on the clinical response a patient has to the procedure. By comprehensively characterizing complex flow in the sinuses of Valsalva using digital particle image velocimetry and an advanced heart-flow simulator, various positions of a deployed transcatheter valve with respect to a bioprosthetic aortic valve (valve-in-valve) were tested in vitro. Displacements of the transcatheter valve were axial and directed below the simulated native valve annulus. It was determined that for both blood residence time and aortic Reynolds stresses, it is optimal to have the annulus of the transcatheter valve deployed as close to the aortic valve annulus as possible.
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Hsu MC, Kamensky D, Xu F, Kiendl J, Wang C, Wu MCH, Mineroff J, Reali A, Bazilevs Y, Sacks MS. Dynamic and fluid-structure interaction simulations of bioprosthetic heart valves using parametric design with T-splines and Fung-type material models. COMPUTATIONAL MECHANICS 2015; 55:1211-1225. [PMID: 26392645 PMCID: PMC4574293 DOI: 10.1007/s00466-015-1166-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This paper builds on a recently developed immersogeometric fluid-structure interaction (FSI) methodology for bioprosthetic heart valve (BHV) modeling and simulation. It enhances the proposed framework in the areas of geometry design and constitutive modeling. With these enhancements, BHV FSI simulations may be performed with greater levels of automation, robustness and physical realism. In addition, the paper presents a comparison between FSI analysis and standalone structural dynamics simulation driven by prescribed transvalvular pressure, the latter being a more common modeling choice for this class of problems. The FSI computation achieved better physiological realism in predicting the valve leaflet deformation than its standalone structural dynamics counterpart.
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Affiliation(s)
- Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - David Kamensky
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Fei Xu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Josef Kiendl
- Department of Civil Engineering and Architecture, University of Pavia, via Ferrata 3, 27100 Pavia, Italy
| | - Chenglong Wang
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Michael C. H. Wu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Joshua Mineroff
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - Alessandro Reali
- Department of Civil Engineering and Architecture, University of Pavia, via Ferrata 3, 27100 Pavia, Italy
| | - Yuri Bazilevs
- Department of Structural Engineering, University of California, San Diego, 9500 Gilman Drive, Mail Code 0085, La Jolla, CA 92093, USA
| | - Michael S. Sacks
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
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Coronary Flow Impacts Aortic Leaflet Mechanics and Aortic Sinus Hemodynamics. Ann Biomed Eng 2015; 43:2231-41. [PMID: 25636598 DOI: 10.1007/s10439-015-1260-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/17/2015] [Indexed: 12/29/2022]
Abstract
Mechanical stresses on aortic valve leaflets are well-known mediators for initiating processes leading to calcific aortic valve disease. Given that non-coronary leaflets calcify first, it may be hypothesized that coronary flow originating from the ostia significantly influences aortic leaflet mechanics and sinus hemodynamics. High resolution time-resolved particle image velocimetry (PIV) measurements were conducted to map the spatiotemporal characteristics of aortic sinus blood flow and leaflet motion with and without physiological coronary flow in a well-controlled in vitro setup. The in vitro setup consists of a porcine aortic valve mounted in a physiological aorta sinus chamber with dynamically controlled coronary resistance to emulate physiological coronary flow. Results were analyzed using qualitative streak plots illustrating the spatiotemporal complexity of blood flow patterns, and quantitative velocity vector and shear stress contour plots to show differences in the mechanical environments between the coronary and non-coronary sinuses. It is shown that the presence of coronary flow pulls the classical sinus vorticity deeper into the sinus and increases flow velocity near the leaflet base. This creates a beneficial increase in shear stress and washout near the leaflet that is not seen in the non-coronary sinus. Further, leaflet opens approximately 10% farther into the sinus with coronary flow case indicating superior valve opening area. The presence of coronary flow significantly improves leaflet mechanics and sinus hemodynamics in a manner that would reduce low wall shear stress conditions while improving washout at the base of the leaflet.
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Abstract
During every heartbeat, cardiac valves open and close coordinately to control the unidirectional flow of blood. In this dynamically challenging environment, resident valve cells actively maintain homeostasis, but the signalling between cells and their microenvironment is complex. When homeostasis is disrupted and the valve opening obstructed, haemodynamic profiles can be altered and lead to impaired cardiac function. Currently, late stages of cardiac valve diseases are treated surgically, because no drug therapies exist to reverse or halt disease progression. Consequently, investigators have sought to understand the molecular and cellular mechanisms of valvular diseases using in vitro cell culture systems and biomaterial scaffolds that can mimic the extracellular microenvironment. In this Review, we describe how signals in the extracellular matrix regulate valve cell function. We propose that the cellular context is a critical factor when studying the molecular basis of valvular diseases in vitro, and one should consider how the surrounding matrix might influence cell signalling and functional outcomes in the valve. Investigators need to build a systems-level understanding of the complex signalling network involved in valve regulation, to facilitate drug target identification and promote in situ or ex vivo heart valve regeneration.
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Hsu MC, Kamensky D, Bazilevs Y, Sacks MS, Hughes TJR. Fluid-structure interaction analysis of bioprosthetic heart valves: Significance of arterial wall deformation. COMPUTATIONAL MECHANICS 2014; 54:1055-1071. [PMID: 25580046 PMCID: PMC4286305 DOI: 10.1007/s00466-014-1059-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We propose a framework that combines variational immersed-boundary and arbitrary Lagrangian-Eulerian (ALE) methods for fluid-structure interaction (FSI) simulation of a bioprosthetic heart valve implanted in an artery that is allowed to deform in the model. We find that the variational immersed-boundary method for FSI remains robust and effective for heart valve analysis when the background fluid mesh undergoes deformations corresponding to the expansion and contraction of the elastic artery. Furthermore, the computations presented in this work show that the arterial wall deformation contributes significantly to the realism of the simulation results, leading to flow rates and valve motions that more closely resemble those observed in practice.
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Affiliation(s)
- Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011, USA
| | - David Kamensky
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Yuri Bazilevs
- Department of Structural Engineering, University of California, San Diego, 9500 Gilman Drive, Mail Code 0085, La Jolla, CA 92093, USA
| | - Michael S Sacks
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
| | - Thomas J R Hughes
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712, USA
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Jackson MS, Igo SR, Lindsey TE, Maragiannis D, Chin KE, Autry K, Schutt R, Shah DJ, Valsecchi P, Kline WB, Little SH. Development of a Multi-modality Compatible Flow Loop System for the Functional Assessment of Mitral Valve Prostheses. Cardiovasc Eng Technol 2014. [DOI: 10.1007/s13239-014-0177-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Yap CH, Saikrishnan N, Tamilselvan G, Vasilyev N, Yoganathan AP. The congenital bicuspid aortic valve can experience high-frequency unsteady shear stresses on its leaflet surface. Am J Physiol Heart Circ Physiol 2012; 303:H721-31. [PMID: 22821994 DOI: 10.1152/ajpheart.00829.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The bicuspid aortic valve (BAV) is a common congenital malformation of the aortic valve (AV) affecting 1% to 2% of the population. The BAV is predisposed to early degenerative calcification of valve leaflets, and BAV patients constitute 50% of AV stenosis patients. Although evidence shows that genetic defects can play a role in calcification of the BAV leaflets, we hypothesize that drastic changes in the mechanical environment of the BAV elicit pathological responses from the valve and might be concurrently responsible for early calcification. An in vitro model of the BAV was constructed by surgically manipulating a native trileaflet porcine AV. The BAV valve model and a trileaflet AV (TAV) model were tested in an in vitro pulsatile flow loop mimicking physiological hemodynamics. Laser Doppler velocimetry was used to make measurements of fluid shear stresses on the leaflet of the valve models using previously established methodologies. Furthermore, particle image velocimetry was used to visualize the flow fields downstream of the valves and in the sinuses. In the BAV model, flow near the leaflets and fluid shear stresses on the leaflets were much more unsteady than for the TAV model, most likely due to the moderate stenosis in the BAV and the skewed forward flow jet that collided with the aorta wall. This additional unsteadiness occurred during mid- to late-systole and was composed of cycle-to-cycle magnitude variability as well as high-frequency fluctuations about the mean shear stress. It has been demonstrated that the BAV geometry can lead to unsteady shear stresses under physiological flow and pressure conditions. Such altered shear stresses could play a role in accelerated calcification in BAVs.
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Affiliation(s)
- Choon Hwai Yap
- Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology, Atlanta, USA
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Yap CH, Saikrishnan N, Yoganathan AP. Experimental measurement of dynamic fluid shear stress on the ventricular surface of the aortic valve leaflet. Biomech Model Mechanobiol 2011; 11:231-44. [PMID: 21465260 DOI: 10.1007/s10237-011-0306-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 03/21/2011] [Indexed: 12/20/2022]
Abstract
Aortic valve (AV) calcification is a highly prevalent disease with serious impact on mortality and morbidity. The exact causes and mechanisms of AV calcification are unclear, although previous studies suggest that mechanical forces play a role. It has been clinically demonstrated that calcification preferentially occurs on the aortic surface of the AV. This is hypothesized to be due to differences in the mechanical environments on the two sides of the valve. It is thus necessary to characterize fluid shear forces acting on both sides of the leaflet to test this hypothesis. The current study is one of two studies characterizing dynamic shear stress on both sides of the AV leaflets. In the current study, shear stresses on the ventricular surface of the AV leaflets were measured experimentally on two prosthetic AV models with transparent leaflets in an in vitro pulsatile flow loop using two-component Laser Doppler Velocimetry (LDV). Experimental measurements were utilized to validate a theoretical model of AV ventricular surface shear stress based on the Womersley profile in a straight tube, with corrections for the opening angle of the valve leaflets. This theoretical model was applied to in vivo data based on MRI-derived volumetric flow rates and valve dimension obtained from the literature. Experimental results showed that ventricular surface shear stress was dominated by the streamwise component. The systolic shear stress waveform resembled a half-sinusoid during systole and peaks at 64-71 dyn/cm(2), and reversed in direction at the end of systole for 15-25 ms, and reached a significant negative magnitude of 40-51 dyn/cm(2). Shear stresses from the theoretical model applied to in vivo data showed that shear stresses peaked at 77-92 dyn/cm(2) and reversed in direction for substantial period of time (108-110 ms) during late systole with peak negative shear stress of 35-38 dyn/cm(2).
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Affiliation(s)
- Choon Hwai Yap
- Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332-0535, USA
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