A comparative study between glutaraldehyde-preserved aortic and pulmonary heterograft valves in the tricuspid position in dogs.

Morphological observations have been presented on 10 metaperiodate-glutaraldehyde-preserved aortic heterograft valves and 5 pulmonary heterograft valves implanted into the tricuspid position for periods ranging from 7 to 183 days. It is recognized that there was a relatively minimal histological change in pulmonary valves. However, calcification of implanted aortic cusps was observed in 20% (2 out of 10) of cases and high incidence of thrombus formation on aortic cusps was recognized, although there were none on pulmonary cusps. It seems reasonable to presume that the high incidence of thrombus formation on the aortic valves is primarily due to the decreased pliability and stiffness of the cusps. It is concluded that the pulmonary valves rather than the aortic valves are recommended for tricuspid valve replacement.