Micromechanics and Mathematical Modeling: An Inside Look at Bioprosthetic Valve Function
作者:
IVAN VESELY,
SLAVOMIR KRUCINSKI,
GORDON CAMPBELL,
期刊:
Journal of Cardiac Surgery
(WILEY Available online 1992)
卷期:
Volume 7,
issue 1
页码: 85-95
ISSN:0886-0440
年代: 1992
DOI:10.1111/j.1540-8191.1992.tb00779.x
出版商: Blackwell Publishing Ltd
关键词: bioprosthetic valves;micromechanics;shear;mathematical modeling;stent
数据来源: WILEY
摘要:
AbstractA major contributing factor in the degeneration of glutaraldehyde‐treated porcine xenograft bioprostheses is tearing of the valve cusps near their commissural attachment to the supporting stent. We have been examining aortic valves at the micromechanical level, and have developed several sensitive techniques to evaluate the biomechanical changes produced by the glutaraldehyde fixation process. Additionally, we have developed a mathematical modeling technique that simulates valve function during the entire cardiac cycle. Our micromechanical tests have shown that compressive buckling is common to all fixed tissues, occurs at physiological bending curvatures, and is likely to be the primary mode of mechanical failure of bioprosthetic valves. We have also shown that existing glutaraldehyde fixation techniques inhibit the natural internal shearing of the valve cusps, and disable the interaction of the fibrosa and the ventricularis. With our modeling technique, we have shown that flexural stresses are indeed concentrated near the valve commissures, and that appropriate modifications of the supporting stent can reduce flexural deformations. With these new, more revealing techniques at hand, prospective valve designs can be better evaluated prior to large scale animals and clinical testin
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