Modification of De Vega's tricuspid annuloplasty for experimental tricuspid regurgitation

We propose a new experimental model of tricuspid annular dilatation and provide some modifications to De Vega's tricuspid annuloplasty to treat this condition. Tricuspid annular dilatation was done by creating ten 1.5-mm incisions around the circumference of the tricuspid annulus. The annulus became significantly dilated from 7.6 cm to 9.4 cm (p < 0.01). After dilatation, 2-0 polypropylene stitches were placed circumferentially around the tricuspid annulus and the suture ends were brought outside the heart through the right atrial wall. After cardiac resuscitation, the following hemodynamic variables were measured as preload was increased incrementally: mean right atrial pressure, v wave of atrial pressure, right ventricular end-diastolic pressure, and cardiac output. Measurements were obtained and preload-output curves were constructed for three time periods: before annular dilatation (Control); after dilatation, but before external adjustment (Before); and after external modification of the annulus (After). Following cardiac resuscitation, right atrial and ventricular pressures were significantly higher after annular dilatation, compared to control values. The preload-output curve was shifted to the right, and cardiac output could not be increased above 0.9 L/min. Once the extracardiac adjustment was accomplished, these pressures were returned to control values, and the preload-output relationship was returned to normal curve.