Long-term follow-up of Björk-Shiley mitral valve replacement. 10 years' experience

Retrospective analysis was made of 176 patients who received a Björk-Shiley mitral valve replacement in the period 1973 through 1982. Actuarial cumulative curves showed the 10-year and 5-year survival rates to be 79 +/- 3.4%. The functional status at follow-up was better than preoperatively in 77.1% of the patients. The hospital mortality was 9.1% and the late mortality was 3.6/100 patient years. Early complications included disc entrapment against the ventricular wall in three cases, wedging of chorda between disc and valve rim in two and posterior perforation of the left ventricle in three patients. There was no structural valve damage. Calculated per 100 patient years, the incidence of thromboembolism was 2.5, endocarditis 1.4 and prosthetic leak 1.8. One thrombosed valve was successfully replaced by a new prosthesis 11 years after the initial implantation. Jamming of the disc by tissue over-growth necessitated a new valve implantation in one case. The incidence of early valve-related complications was high, but the long-term results were comparable with those from other mechanical valves. One early complication--disc entrapment against the ventricular wall--may be avoided by use of a sufficiently small valve if the ventricle is small and thickened.