Title:

Better Biomechanical Design for Stenting Arteries

Speaker:

Dr. James E. Moore

Affiliation:

Texas A&M University

When:

Tuesday, March 30, 2010 at 11:00:00 AM   Add to Calendar

Where:

IBB Building, Room 1128

Host:

David Ku
david.ku@me.gatech.edu

Abstract

While stents have revolutionized the treatment of atherosclerosis, they still suffer clinical failures due to restenosis. We have analyzed the biomechanical interaction of stents with the artery wall from both the fluid mechanics and solid mechanics points of view. These studies incorporate a variety of approaches, including computational modeling and in vitro experimentation. These studies indicate that there are certain design features that contribute to a potentially bad biomechanical environment, which in turn leads to additional intimal hyperplasia and eventually restenosis. Our results indicate that inclusion of biodegradable features in stents can minimize some of these deleterious effects. The concept of biodegradable stents dates back at least to 1990, yet no designs are approved for the US market. This is in part due to the challenges associated with designing a structure that provides an appropriate amount of support to the artery wall for a sufficient period. Material models for the polymers typically used in medical applications are insufficient for this design challenge. We have developed a new class of material models that accounts for the effects of cyclic strain in accelerating degradation. These models were implemented in a finite element modeling package and applied to representative stent designs. The results indicate that some parts of the stent degrade faster than others, depending on the stent design. Non-uniform biodegradation could lead to dangerous embolous development from non-degraded pieces breaking off of the main structure. This new class of material models, if coupled with appropriate experimental data on material behavior under cyclic loading, provides the opportunity to predict where and when a biodegradable stent begins to lose structural integrity. It should also be possible to design stents for more uniform degradation profiles.

Biography

Dr. Moore was born in Toccoa, Georgia. He received his Bachelor of Mechanical Engineering in 1987, his Master of Science in Mechanical Engineering in 1988 and his Ph.D. in 1991, all from Georgia Institute of Technology. He had postdoctoral training at the Swiss Institute of Technology at Lausanne, 1991 – 1994. From 1994-2003 Dr. Moore served as a professor of Mechanical and Biomedical Engineering, Florida International University; he joined Texas A&M University in July 2003. Dr. Moore’s speciality is Cardiovascular Biomechanics, Stents, Implantable Devices, and Atherosclerosis. His research is concerned with the role of biomechanics (blood flow patterns and artery wall stress) in the formation and treatment of arterial diseases. Along with his funding from the National Institutes of Health, Dr. Moore has received four patents and co-founded two startup companies. He has established new courses in biofluid mechanics and entrepreneurial issues for biomedical engineers at Texas A&M.