Assessment of a novel stentless mitral valve using a pulsatile mitral valve simulator.

BACKGROUND AND AIM OF THE STUDY

The study aim was to develop a novel stentless mitral valve (SMV) and to evaluate its performance, using an original pulsatile simulator developed specifically to analyze the hydrodynamic function of the mitral valve.

METHODS

The SMV developed at the authors' institution consists of two major components: a large anterior leaflet with commissures, and a small posterior leaflet. The valve is formed by suturing the leaflets (made from bovine pericardium) to a flexible (Duran) ring. The SMV, constructed with a 27 mm flexible ring, was installed into the mitral valve simulator, after which the four papillary flaps of the two leaflets were sutured to artificial papillary muscles. The artificial ventricle was driven pneumatically at a pulse rate of 70 beats/min, with a systolic fraction of 35%. The mean flow, aortic pressure, and atrial pressure were adjusted to 4.5 1/min, 120/80 mmHg, and 10 mmHg, respectively. A 27 mm mechanical valve (MEV; St. Jude Medical Inc.) was employed as a control. The hydrodynamic performance of the SMV and MEV were investigated and compared. An echo-Doppler study was also performed.

RESULTS

The waveforms of the SMV and MEV showed a similar pattern. The mean transvalvular flow was 4.7 +/- 0.4 1/min for the SMV, and 3.55 +/- 0.13 1/min for the MEV (p < 0.001). Mitral regurgitation was 5.07 +/- 1.15 and 3.78 +/- 0.35 ml/beat, respectively (p < 0.05). Echocardiographic data indicated that the regurgitant jet towards the left atrial model was none or trivial for the SMV, and trivial for the MEV.

CONCLUSION

Within the environment of the mitral valve simulator, the novel SMV prepared from bovine pericardium demonstrated excellent performance characteristics, and may represent a potential future alternative for bioprosthetic stented mitral valves.