Comparative assessment of chordal preservation versus chordal resection in mitral valve replacement for mitral stenosis.

Mitral valve replacement with preserving all chordae tendineae in patients with mitral regurgitation has been proved to be beneficial for left ventricular performance in the postoperative period. To evaluate the effectiveness of this technique in patients with mitral stenosis a comparison of the hemodynamic and echocardiographic data between patients having operation with this technique (Group P, n = 15, mean age = 37.5 +/- 12 years), and those having operation with the conventional method of mitral valve replacement (Group C, n = 15, mean age = 39 +/- 10.4 years) was made. The study population was limited to patients who had no clinical evidence of coronary artery disease and if over 40 years of age had normal coronary artery anatomy on coronary arteriography; patients with no evidence of aortic stenosis and/or regurgitation; and patients who had pure mitral stenosis or mitral stenosis with slight regurgitation (Grade 2 or less) with a mean gradient across the mitral valve greater than 10 mmHg. Hemodynamic parameters improved in both groups after the operation. However, echocardiographic measurements obtained six months postoperatively revealed a significant decrease in left ventricular ejection fraction in Group C (61.33 +/- 9.29% preoperatively versus 53.2 +/- 10.3% postoperatively; p < 0.05). The difference between left ventricular ejection fraction diminution of the two groups was statistically significant (-0.71 +/- 6.28% in Group P versus -8.07 +/- 13.35% in Group C; p < 0.01). Left ventricular end systolic and end diastolic dimensions decreased in patients with preserved valves and increased in patients operated on with conventional method without reaching a statistical significance. Sizes of prosthetic valves inserted were in the same range and no significant differences were found in preoperative and postoperative comparison of the two groups in respect to effective mitral orifice area and transvalvular gradient. There were no evidence of prosthetic valve dysfunction and paravalvular leakage and no operative or late deaths. It is concluded that if it is suitable, mitral valve replacement with preservation of chordae tendineae is expected to have a beneficial effect on postoperative left ventricular performance in patients with mitral stenosis.