Long-term echocardiographic follow-up of patients with a tricuspid bioprosthesis. To clarify the long-term results of bioprosthetic valve function in the tricuspid position, 29 consecutive patients who underwent tricuspid valve replacement (TVR) were evaluated. There were 20 girls/women and 9 boys/men, with ages ranging from 6 to 61 years (mean 41.4 years). The bioprosthetic valves included Hancock in 2, and Carpentier-Edwards in 27. The follow-up period ranged from 32 to 145 months (mean 89 months). Regurgitant flow of the tricuspid bioprosthesis was studied by color Doppler echocardiography. Peak velocity (Vp) and pressure half time (PHT) were measured by continuous wave Doppler echocardiography. Operative mortality was 13.7% (4/29), with the actuarial survival rate, including operative deaths, 75% at 10 years. Valve thrombosis developed in one patient 4 years after TVR. Color Doppler showed regurgitation in 7 of the 20 patients who were completely followed up, but they were all asymptomatic and required no special intervention. Cusp tear or calcification requiring reoperation was not observed in this study, including 8 patients younger than 35 years of age. The Vp was significantly slower, and PHT was significantly prolonged, in the tricuspid rather than the mitral position. These data demonstrate that bioprosthetic valves in the tricuspid position can be used safely. Doppler examination should be performed taking these different flow dynamics into account. 