MODIFICATION OF DEVEGAS TRICUSPID ANNULOPLASTY FOR EXPERIMENTAL TRICUSPID REGURGITATION

We propose a new experimental model of tricuspid annular dilatation an d provide some modifications to De Vega's tricuspid annuloplasty to tr eat 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 circum ferentially around the tricuspid annulus and the suture ends were brou ght outside the heart through the right atrial wall. After cardiac res uscitation, the following hemodynamic variables were measured as prelo ad 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 con structed for three time periods: before annular dilatation (Control); after dilatation, but before external adjustment (Before); and after e xternal modification of the annulus (After). Following cardiac resusci tation, right atrial and ventricular pressures were significantly high er after annular dilatation, compared to control values. The preload-o utput curve was shifted to the right, and cardiac output could not be increased above 0.9 L/min. Once the extracardiac adjustment was accomp lished, these pressures were returned to control values, and the prelo ad-output relationship was returned to normal curve.