Document Detail


Effects of mechanical fatigue on the bending properties of the porcine bioprosthetic heart valve.
MedLine Citation:
PMID:  9952009     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mechanisms underlying the failure of porcine bioprosthetic aortic heart valves are not well understood. One possible explanation is that delaminations of the layered leaflet structure occur through flexion, leading to calcification and further delaminations, and finally resulting in valve failure. We investigated the changes in flexural rigidity of the belly of aortic valve cusps subjected to accelerated durability testing. We used three-point bending wherein a load was applied to the center of each specimen by a thin stainless steel bar calibrated to a known load-displacement relationship. Ten circumferential and 15 radial specimens from valves fatigued to 0, 50, 100, and 200 million cycles were flexed both with and against the curvature of the cusp. Linear beam theory was applied as a means to compare the relative bending stiffness between groups. Although specimens aligned to the circumferential direction were stiffer when bent against the cuspal curvature, the radial oriented specimens exhibited no bending directional dependence. Both the radial and circumferential specimens experienced a significant decrease in the bending stiffness with an increased number of accelerated test cycles. Overall, our results suggest that it is the fibrosa that experiences the greatest loss of stiffness with mechanically induced fatigue damage.
Authors:
D C Gloeckner; K L Billiar; M S Sacks
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  ASAIO journal (American Society for Artificial Internal Organs : 1992)     Volume:  45     ISSN:  1058-2916     ISO Abbreviation:  ASAIO J.     Publication Date:    1999 Jan-Feb
Date Detail:
Created Date:  1999-04-13     Completed Date:  1999-04-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9204109     Medline TA:  ASAIO J     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  59-63     Citation Subset:  IM    
Affiliation:
Department of Biomedical Engineering, University of Miami, Florida, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Bioprosthesis*
Elasticity
Heart Valve Prosthesis*
Models, Cardiovascular
Prosthesis Design
Prosthesis Failure
Stress, Mechanical
Swine

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


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