Vortex Dynamics in a Carotid Artery Bifurcation and Implications for Cardiovascular Disease

Michael W. Plesniak, PhD
Professor and Chair
George Washington University

Abstract: Cardiovascular diseases are among the leading causes of death in the United States and world-wide. While it is recognized that low wall-shear-stresses trigger atherosclerotic plaque formation, e.g., in the internal carotid artery sinus, there is limited understanding of why plaques form only in certain patients. In this seminar I will discuss a typical ‘disease-prone’ carotid artery bifurcation geometry and its associated pathological wall-shear-stresses compared to a ‘healthy’ bifurcation geometry, as determined from patient-averaged clinical data. I will further highlight the potential role of three-dimensional vortical structures in atherosclerotic plaque formation by identifying vortical structures, following their evolution, and linking them to the wall-shear-stress-distributions known to contribute to disease onset. In this study physiological pulsatile flow computational fluid dynamics simulations were performed on ‘healthy’ and ‘disease-prone’ carotid artery bifurcation models. Both artery models were developed based on clinical risk estimations and patient-averaged anatomical features. Geometry and flow effects are investigated separately by simulating a third, hybrid model with the healthy geometry, but imposed disease-prone flow conditions. These findings imply that a long lifespan of the internal carotid artery sinus hairpin vortical structure has a physiologically beneficial role by maintaining local wall-shear-stresses at higher, healthier levels. The deterioration of this beneficial vortical structure, which occurs under disease-prone flow conditions, is expected to play a significant role in promoting atherosclerotic plaques.

Biography: Dr. Michael W. Plesniak is Professor and Chair of the Department of Mechanical & Aerospace Engineering at the George Washington University, with a secondary appointment in the Department of Biomedical Engineering. Prof. Plesniak is the Director of GW’s Center for Biomimetics and Bioinspired Engineering. He was formerly Professor of Mechanical Engineering at Purdue University and Eugene Kleiner Professor for Innovation in Mechanical Engineering at Polytechnic University in Brooklyn, NY. He served as the Director of the Fluid Dynamics & Hydraulics program at the National Science Foundation from 2002-2006. Prof. Plesniak earned his Ph.D. degree from Stanford University, and his M.S. and B.S degrees from the Illinois Institute of Technology; all in Mechanical Engineering. Dr. Plesniak is a Fellow of AIAA, ASME, the American Physical Society (APS), the American Society of Thermal & Fluids Engineers (ASTFE), the American Institute for Medical and Biological Engineering (AIMBE), the Association for the Advancement of Science (AAAS) and the Washington Academy of Sciences. He has authored over three hundred refereed archival publications, conference papers and presentations, and has presented numerous invited seminars and keynote addresses. His research group is currently studying the pulsatile flows, physics of phonation, cardiovascular flows and tissue engineering. Prof. Plesniak was a recipient of the 2018 Washington Academy of Sciences Distinguished Career in Engineering Award, 2017 ASME Fluids Engineering Award, and the 2011 NASA DC Space Grant Consortium’s Outstanding STEM Faculty Award, awarded to faculty that make an outstanding contribution to STEM that goes above and beyond the classroom. Dr. Plesniak was also named the American Institute for Aeronautics and Astronautics, National Capital Section Engineer of the Year 2010-2011.