When   Friday, April 3, 2009   Time   2:00 PM - 3:00 PM  
Where   Technological Instit M 416 2145 Sheridan Rd.   map it
Audience   - Faculty/Staff - Student - Public
Contact   Molly E Scanlon   +1 847 491 5586  
Group   McCormick-Colloquia Engineering Sciences and Applied Mathematics

Applied Math Colloquium

Title: On the Mechanical and Biological Stability of Intracranial Aneurysms

Speaker: Professor Jay D. Humphrey, Texas A&M University

Abstract:

Intracranial aneurysms are focal dilatations of the arterial wall that usually occur in or near the circle of Willis, the primary network of arteries that supplies blood to the brain. Rupture of aneurysms having a saccular shape is the leading cause of spontaneous subarachnoid hemorrhage, which continues to cause high mortality and severe morbidity despite continued advances in neuroradiology and neurosurgery. Two longstanding clinical hypotheses have been that saccular aneurysms may enlarge or rupture because of either quasi-static (limit point) or dynamic (resonant) instabilities. Based on more appropriate nonlinear analyses, however, we have shown that such mechanical instabilities are highly unlikely [1]. This finding raises the question, therefore: What then causes aneurysmal enlargement and possible rupture?
 
In this presentation, we will review the computational findings that discount limit point instabilities under quasi-static increases in pressure and resonance under dynamic loading as possible mechanisms of enlargement of saccular aneurysms, and address the potential of biological growth and remodeling mechanisms as the key to the enlargement and possible rupture. In particular, we will present a new constrained mixture framework for understanding diverse cases of arterial adaptation and disease progression and highlight areas of future research motivated by diverse findings in arterial mechanobiology [2,3].
 
References
 
[1]        Humphrey JD (2002) Cardiovascular Solid Mechanics. Springer-Verlag, NY.
 
[2]        Baek S, Rajagopal KR, Humphrey JD (2006) ASME J Biomech Engr 128: 142-149.
 
[3]        Figueroa CA, Baek S, Taylor CA, Humphrey JD (2009) Comp Meth Appl Mech Engr (in press)