Mitral valve replacement with small-sized tilting-disc mechanical prostheses may lead to moderate stenosis.

BACKGROUND

Analyzing the hemodynamics of small-sized tilting-disc mechanical prostheses implanted in the mitral position.

EXPERIMENTAL

DESIGN

this is a retrospective study. The mean follow-up of patients was 114+/-27 months (range 68-152 months).

SETTING

departments of Cardiovascular Surgery and Cardiology in a general community hospital Patients: this study includes 9 survivors of 17 patients undergoing mitral valve replacement with this type of device between May, 1982 and July, 1991.

INTERVENTIONS: all subjects underwent mitral valve replacement with size 25 mm Sorin tilting-disc mechanical prostheses.

MEASURES: all patients underwent transthoracic echocardiography. Five consenting patients also underwent transoesophageal echocardiography. The following parameters were measured: peak gradient, mean gradient, peak velocity, mean velocity, pressure half-time and Doppler area.

RESULTS

The ejection fraction was 50% or more in all patients. The following mean results were obtained: peak gradient: 17.4+/-2.5 mmHg; mean gradient: 8.2+/-0.6 mmHg; peak velocity: 2.1+/-0.1 m/sec; mean velocity: 1.43+/-0.06 m/sec; pressure half-time: 135.9+/-29.7 msec; Doppler area: 1.7+/-0.3 cm2.

CONCLUSIONS

Valve replacement with Sorin 25 mm tilting-disc mechanical prostheses appears to originate a moderate degree of mitral stenosis and, therefore, we do not recommend their use if at all possible.