Computational Modeling of the Mitral Heart Valve: From Mechanobiology to Surgical Repair

Date: April 5, 2018, 4:10 pm
Location: 105 Annenberg
Speaker: Michael Sacks, PhD, W. A. Moncrief, Jr. Simulation-Based Engineering Science Chair #1, Department of Biomedical Engineering, University of Texas at Austin

An essential element of the heart function, the mitral valve (MV) ensures proper directional blood flow between the left heart chambers. Over the past two decades, computational simulations have made marked advancements towards providing powerful predictive tools to improve treatments for MV diseases. However, several challenges remain in the development of robust means for the representation and simulation of MV function, especially in the long-term prediction of the post-repaired state. To address these issues, our group have developed state-of-the-art multi-scale geometric and finite element (FE) models of the MV. These models have quantified key anatomic features and, most importantly, critical resolution requirements for required accuracies for in-vivo simulation. Translation of these models to the in-vivo environment is complicated by the fact that while the annulus, leaflets, and papillary muscle (PM) tips geometries can be obtained in-vivo, the MV chordae tendonae are not currently imagable. I will thus also show how, building on our our in-depth knowledge of MV chordae tendonae structure and mechanics, we have addressed this problem by developing novel methodologies to developed functionally equivalent MV chordae tendonae networks. These methods then allow us to build complete MV models directly and completely from in-vivo rt-3DE images. We now have the means to generate MV specific FE models from the pre-repaired states and predict repaired states. I will then summarize our ongoing work on MV mechanobiology that will be used to develop novel MV leaflet tissue remodelling approaches, with a focus on cell-ECM coupling. This information will then used to predict post-repair states for long post-op time periods.

Michael Sacks

University of Texas at Austin

John Rogers Professor Michael Sacks is the W. A. "Tex" Moncrief, Jr. Simulation-Based Engineering Science Chair and a world authority on cardiovascular biomechanics. His research focuses on modeling and simulation on the mechanical behavior and function of the heart and native and replacement heart valves He is also active in the biomechanics of engineered tissues, and in understanding the in-vitro and in-vivo remodeling processes from a functional biomechanical perspective. Dr. Sacks is currently Professor of Biomedical Engineering and the director of the ICES Willerson Center for Cardiovascular Modeling and Simulation. His research includes multi-scale studies of cell/tissue/organ mechanical interactions in heart valves, including determining the local stress environment for heart valve interstitial cells. Recent research has included developing novel multi-scale models of the mitral and bioprosthetic heart valves, allowing long-term prediction of the post-repair state. He is also quite active in the development of cardiac models, in which ventricular myocardium is modeled to allow for the separation of the individual contributions of the myocyte and connective tissue networks, as well as the effects of myocardial compressibility.

Selected Recognitions: Fellow, American Society of Mechanical Engineers Fellow (Inaugural), Biomedical Engineering Society Fellow, American Institute for Medical and Biological Engineering Fellow, American Heart Association Van C. Mow Medal, American Society for Mechanical Engineers Bioengineering Division Chancellor's Distinguished Research Award, University of Pittsburgh Former Editor of the Journal of Biomechanical Engineering Education: Ph.D., Biomedical Engineering, University of Texas Southwestern Medical Center at Dallas M.S., Engineering Mechanics, Michigan State University B.S. Engineering Mechanics, Michigan State University.

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