A model system for mapping vascular responses to complex hemodynamics at arterial bifurcations in vivo.
OBJECTIVE
Cerebral aneurysms are preferentially located at arterial bifurcation apices with complex hemodynamics. To understand disease mechanisms associated with aneurysm initiation, we attempted to establish a causal relationship between local hemodynamics and vascular responses.


METHODS
Arterial bifurcations were surgically created from native common carotid arteries in two dogs, angiographically imaged 2 weeks and 2 months later, and then excised. We characterized local morphological changes in response to specifically manipulated hemodynamics. Computational fluid dynamics simulations were performed on the in vivo images and results mapped onto histological images.


RESULTS
Local flow conditions, such as high wall shear stress and high wall shear stress gradient, were found to be associated with vascular changes, including an intimal pad in the flow impingement region and a "groove" bearing the characteristics of an early aneurysm.


CONCLUSIONS
This novel method of histohemodynamic micromapping reveals a direct correlation between an altered hemodynamic microenvironment and vascular responses consistent with aneurysm development.
Meng
Hui
H
Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA. huimeng@buffalo.edu
Swartz
Daniel D
DD
Wang
Zhijie
Z
Hoi
Yiemeng
Y
Kolega
John
J
Metaxa
Eleni M
EM
Szymanski
Michael P
MP
Yamamoto
Junichi
J
Sauvageau
Eric
E
Levy
Elad I
EI
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D017536:Carotid Artery, Common / Q000502:physiology*; D003198:Computer Simulation; D004285:Dogs; D004548:Elasticity; D005260:Female; D021621:Imaging, Three-Dimensional / Q000379:methods*; D066298:In Vitro Techniques; D008955:Models, Cardiovascular; D033081:Shear Strength; D013314:Stress, Mechanical