Mechanical Mechanisms of Thrombosis in Intact Bent Microvessels of Rat Mesentery

Authors

Qin Liu, University of New York
David Mirc, University of Nevada, Las Vegas
Bingmei M. Fu, City University of New YorkFollow

Document Type

Article

Publication Date

8-28-2008

Publication Title

Journal of Biomechanics

Volume

41

Issue

12

First page number:

2726

Last page number:

2734

Abstract

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 μm 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°, 90° and 180°) 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° (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.

Keywords

Bent post-capillary venules; Low Reynolds number flow; Mesentery; Microcirculation; Rats; Shear (Mechanics); Reynolds number; Shear stress/rate; Shear stress/rate gradient; Strains and stresses; Thrombosis

Disciplines

Biomechanical Engineering | Biomedical Engineering and Bioengineering | Engineering | Mechanical Engineering

Language

English

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Liu, Q., Mirc, D., Fu, B. M. (2008). Mechanical Mechanisms of Thrombosis in Intact Bent Microvessels of Rat Mesentery. Journal of Biomechanics, 41(12), 2726-2734.