Prosthetic replacement of the tricuspid valve: Biological or mechanical?

Background. Incidence of tricuspid prosthesis replacement was 1.9% of all v alvular operations performed between Tune 6, 1966 and April 18, 1996. Many series report similar figures, but institutional experience is limited and the consensus on treatment modalities is lacking. Methods. One hundred tricuspid operations were performed on 83 patients (46 female). A primary operation was performed in 64 cases, 13 patients had on e previous operation, 4 patients had two previous operations, and 2 patient s had three previous operations. Seventeen patients required a tricuspid pr osthetic valve rereplacement. There were 2 emergent and 17 urgent operation s. The New York Heart Association class was IV in 13 patients (mean pulmona ry artery pressure, 41 mm Hg), III in 66 patients (mean pressure, 38 mm Hg) , and II in 21 patients. The most frequent operation was simultaneous repla cement of the mitral and tricuspid valve (41 patients). Seventy biological and 30 mechanical prostheses were used. Total follow-up time was 613 years, mean 7.4 years (median 4.2 years), with a maximum of 27.8 years, and was 9 2% complete. Results. Operative mortality was 24%. Survival was 0.54 (0.48 to 0.59, n = 39) at 5 years, 0.38 (0.32 to 0.44, n = 27) at 10 years, 0.31 (0.25 to 0.36 , n = 19) at 15 years, 0.29 (0.23 to 0.34, n = 11) at 20 years, and 0.17 (0 .098 to 0.26, n = 3) at 25 years. Early mortality was increased from higher New York Heart Association class (hazard ratio = 2.2), congenital disease (hazard ratio = 6.9), and valvuloplasty failure (hazard ratio = 4.3). The c onstant risk phase (4%/patient-year) after 2 years was enhanced by older op erative age (hazard ratio = 1.4). Prosthetic type had no independent effect . Biological prostheses were at risk for 300 years and had a reoperation in cidence of 4.7%/patient-year (14 events); mechanical prosthesis were at ris k for 137 years with a rate of 2.2%/patient-year (3 events) (p = 0.21). Thr ee valve thromboses were observed in old-design mechanical prosthesis. Biop rosthetic degeneration showed a steeper rate after 7 years. Conclusions. This study does not show a clear superiority of biological ver sus mechanical prostheses. In the long run survival with mechanical prosthe ses could be superior, given the high rate of bioprosthetic degeneration af ter 7 years. (C) 1998 by The Society of Thoracic Surgeons.