The Journal of Thoracic and Cardiovascular Surgery, Vol 77, 287-293, Copyright © 1979 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Experimental evaluation of aortic homograft valves mounted on flexible support frames and comparison with glutaraldehyde-treated porcine valves
PG Pohlner, FJ Thomson, E Hjelms and BG Barratt-Boyes
The durability of the aortic homograft valve, when mounted in a rigid
support frame, has been limited in some cases by aortic wall detachment
from the frame in the commissure buttress area. To investigate the effects
of frame flexibility, a stent was designed which was suitable for canine
aortic valves of selected sizes. Of the two materials tested, acetal
copolymer was found to be superior to polypropylene, as stents made from
the latter material were permanently deformed as a result of polymer creep
under the action of a cyclic load. Observations of a commercially available
glutaraldehyde-treated heterograft mounted on a polypropylene frame
indicated that stent flexibility was less important than had been suggested
in earlier reports. It is considered that the glutaraldehyde preservation
and the method of mounting this valve in the frame are major factors in
prolonging the life of the implant.
