All explanted prostheses were examined radiologically, grossly and histologically, by one author (J.B.).
The 40 bioprosthetic valves were explanted from 19 (47.5%) women and 21 (52.5%) men.
Nineteen (47.5%) of the explanted bioprostheses were of the Hancock variety (Medtronic Heart Valve Division, Irvine, Calif), 13 (32.5%) were Ionescu-Shiley valves (Shiley Heart Valve Research Center, Irvine, Calif), and 8 (20%) were Carpentier-Edwards bioprostheses (Baxter Healthcare Corporation, now Edwards Life Sciences, Irvine, Calif; Figure 1).
The only valve that did not show evidence of SVD was a Hancock valve that had been in place for 2 years (the shortest duration in this series) and was explanted because of severe pannus-causing valvular stenosis.
Pannus was present on 39 (97.5%) of the explanted specimens.
The explanted device was a conduit with a Carpentier-Edwards porcine bioprosthesis that had been in place for 12 years.
Evidence of thrombi (generally small) was discovered in 11 (27.5%) of the explanted valves.
Nineteen (47.5%) of the explanted pulmonary valves were in conduits.
In the younger age group, 11 (57.9%) of the explanted valves showed severe and diffuse calcification as did 11 (52.4%) of the valves in the older age group.
The 40 explanted valves in this series had a relatively long period of bioprosthesis survival (14.3 [+ or -] 5.2 years) in a fairly young patient population.
We found pannus almost universally (97.5%) in our cases, with severe pannus present in 87.5% of these explanted valves.
Another interesting finding in this series of explanted valves is their low incidence of cusp tears, considering the longevity of the valves and the high incidence of other features of structural deterioration.