Test in vitro of silicone rubber heart-valve poppets for lipid absorption
Carmen, R.; Kahn, P.
Jaami Journal of the Association for the Advancement of Medical Instrumentation 3(1 Part 1): 14-17
1969
ISSN/ISBN: 0004-5446 PMID: 5293906 Document Number: 5837
Silicone rubber balls that had changed in vivo were analyzed for the amount and type of absorbed blood lipids. Lipid content ranged from 0.1 to 16.0 wt and correlated well with implantation time for a limited number of balls from mitral prostheses. A part of the absorbed material was free, simple lipid. By continuously circulating a saline solution containing these simple lipids through a conduit holding silicone rubber balls, it was possible to generally duplicate the in vivo changes in vitro. Lipid absorption in vitro was independent of fluid velocity. The affinity of silicone rubber for lipid increased with degree of cure. A theory accounting for this phenomenon is presented and experiments testing its validity are described. Increasing the fi ller content of silicone rubber markedly decreases lipid absorption. Of eight alternate elastomers tested, only fluorosilicone was promising. Elastomers normally considered oil and fat resistant, such as nitrite and neoprene, performed very poorly. The results of extensive testing of the fluorosilicone material are presented.
Document emailed within 1 workday
