ISSN:
1573-9686
Keywords:
Cerebral aneurysms
;
Birefringence
;
Collagen organization
;
Tissue mechanics
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Abstract The aneurysm wall, which must withstand arterial blood pressure, is composed of layered collagen. Wall strength is related to both collagen fiber strength and orientation. When the aneurysm enlarges, the amount and organization of the collagen fibers change, potentially increasing the risk of rupture. We studied the directional organization and molecular strength of the collagen fibers layer by layer across the walls of four aneurysms in order to measure their mechanical integrity. The technique incorporates the birefringent properties of collagen, enabling us to use linearly polarized light for measuring the orientation of the fibers, and the Sénarmont compensator to measure the birefringence and thus mechanical strength. Intact aneurysms were obtained at autopsy, fixed at physiological pressure, sectioned at 4 μm, and stained with 0.05% picrosirius red. By combining birefringence and orientation data we estimated tensile strength as a function of direction on the aneurysmal wall. The average breaking strength of the wall ranged from 0.73 to 1.9 MPa. Comparing the weakest to the strongest direction, the breaking strength varied by a factor of up to 2×, implying a significant degree of mechanical anisotropy. © 2000 Biomedical Engineering Society. PAC00: 8719Rr, 8719Uv, 8764Rr
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1114/1.292
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