BACKGROUND AND AIMS OF THE STUDY
Cloth-covered Starr-Edwards ball valves were the first choice in prosthetic substitution at the authors' institution between June 1968 and March 1977. This study investigated, retrospectively, macroscopic aspects of the prostheses at reoperation.
METHODS
Among 59 survivors who underwent isolated aortic or mitral valve replacement, 12 required reoperation for valve dysfunction (five aortic valve replacements, seven mitral valve replacements). Reoperation was necessitated by valvular endocarditis, paravalvular leak, hemolysis, thromboembolism, orifice stenosis attributable to pannus, and inappropriate sizing related to growth and thrombus. The mean time to reoperation was 11.7 +/- 6.2 years after initial surgery (range: 2 years 4 months to 21 years 8 months).
RESULTS
Marked cloth wear was observed in all aortic prostheses, but only slight wear in mitral valves. Pannus formation was observed around the orifice in both aortic and mitral prostheses, but strut cloth was not extensively covered by autologous tissue. In mitral valves, strut cloth was only slightly worn and less loose than that of the aortic valve. These changes notably affected prosthetic valve function, the most significant problem in mitral prostheses being thrombus (four of seven valves).
CONCLUSIONS
Pannus formation and thrombus caused by the reaction of the patient's tissues remain major problems in the use of artificial valves, and require further work for their improvement.