Discussion Following Chapters 35–39
Maini asked Wildevuur how important the biodegradability of the urethane structure was because the final composition quoted was 95% polyurethane, 5% lactide, which he imagined would take a fair amount of time to degrade. Wildevuur replied that he did not know if degradation was very important to promote the elastin growth. Polyurethane is non-degradable and has approximately the same compliance as the other materials, and tests were going on to see if there were differences in elastin growth. Ethicon had made biodegradable vascular grafts as well and they were not able to show any elastin in their non-elastic one. He thought that as long as the material could function naturally then elastin would be developed. It was not clear how important biodegradation was in addition to elasticity. Lindsay asked Wildevuur if there was any difference in the endothelialisation rate and specifically the prostacyclin generation with the time of biodegradation. Wildevuur believed this not to be true but could not prove it. Indium-labelled studies by other investigators have shown that long velour aorta grafts will still remain platelet adherent after one year but if endothelial seeding techniques are used on those types of grafts there is no platelet adherence after 6 weeks. This is probably related to the
KeywordsSaphenous Vein Vascular Graft Skeleton Structure Dacron Graft Polyurethane Segment
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