Document Detail

Mechanical mechanisms of thrombosis in intact bent microvessels of rat mesentery.
MedLine Citation:
PMID:  18656200     Owner:  NLM     Status:  MEDLINE    
The hypothesis that thrombus can be induced by localized shear stresses/rates, such as in the bent/stretched microvessels, was tested both experimentally and computationally. Our newly designed in vivo experiments were performed on the microvessels (post-capillary venules, 20-50 microm diameter) of rat mesentery. These microvessels were bent/stretched with no/minimum injuries. In less than 60 min after the microvessels were bent/stretched, thrombi were formed in 19 out of 61 bent locations (31.1%). Interestingly, thrombi were found to be initiated at the inner wall of the curvature in these bent/stretched vessels. To investigate the mechanical mechanisms of thrombus induction, we performed a 3-D computational simulation using commercial software, FLUENT. To simulate the bending and stretching, we considered the vessels with different curvatures (0 degrees , 90 degrees and 180 degrees ) as well as different shaped cross-sections (circular and elliptic). Computational results demonstrated that the highest shear stress/rate and shear stress/rate gradient are located at the inner wall of the curved circular-shaped vessels. They are located at the two apexes of the wall with shorter axis for the 0 degrees (straight) elliptic-shaped vessel and towards the inner side when the vessels are bent. The differences of the shear stresses/rates and of the shear stress/rate gradients between the inner and outer walls become larger in more bent and elliptic-shaped microvessels. Comparison of our experimental and numerical simulation results suggests that the higher shear stress/rate and the higher shear stress/rate gradient at the inner wall are responsible for initiating the thrombosis in bent post-capillary venules.
Qin Liu; David Mirc; Bingmei M Fu
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2008-07-24
Journal Detail:
Title:  Journal of biomechanics     Volume:  41     ISSN:  0021-9290     ISO Abbreviation:  J Biomech     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-08-25     Completed Date:  2009-01-08     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0157375     Medline TA:  J Biomech     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2726-34     Citation Subset:  IM    
Department of Biomedical Engineering, The City College of the City University of New York, New York, NY 10031, USA.
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MeSH Terms
Biophysical Phenomena
Computer Simulation
Mesenteric Veins / physiopathology*
Models, Cardiovascular*
Rats, Sprague-Dawley
Stress, Mechanical
Torsion Abnormality / physiopathology*
Venous Thrombosis / physiopathology*
Venules / physiopathology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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