BME Graduate Seminar - Dr. Victor Barocas

Roy J. Carver Department of Biomedical Engineering Graduate Seminar (BME:5010)

Victor Barocas, PhD
Professor of Biomedical Engineering
University of Minnesota

Multiscale, Multidirectional Mechanics of Ascending Thoracic Aortic Aneurysm

Asending thoracic aortic aneurysms (ATAAs) present a considerable therapeutic and intellectual challenge. Often undiagnosed or discovered serendipitously, ATAAs are largely asymptomatic until a catastrophic event. In addition, open repair surgery is not without risk, so there is considerable potential benefit to be gained from improved methods to predict vessel failure. In pursuing better tools, however, we must face a number of challenges and consider certain factors unique to the ATAA among blood vessels. As a general rule, ATAAs do not rupture (i.e., split the vessel along a theta-facing plane) but rather dissect (i.e., delaminate the vessel along an r-facing plane). In a non-biological setting, such a failure mode would be associate with shear or torsion of the construct. Is shear important in the ATAA? How does the microstructure of the ATAA affect its behavior? Our group seeks to address these questions via a combination of ex vivo tissue mechanics experiments and multiscale computational studies. In addition, there is the question of how the aneurysm forms and grows. The concept of tensional homeostasis has been successful in numerous vascular remodeling studies, and it is appealing, but it is clearly a simplification of what is happening in the cell and the extracellular matrix. The seminar will discuss our recent exploration of different approaches to modeling remodeling at the microstructural scale.