Intraoperative evaluation of mitral valve regurgitation and repair by transesophageal echocardiography: Incidence and significance of systolic anterior motion

Objectives. This study was designed to delineate the utility and results of intraoperative transesophageal echocardiography in the evaluation of patients undergoing mural valve repair for mitral regurgitation. Background. Mitral valve reconstruction offers many advantages over prosthetic valve replacement. Intraoperative assessment of valve competence after repair is vital to the effectiveness of this procedure. Methods. Intraoperative transesophageal echocardiography was performed in 143 patients undergoing mitral valve repair over a period of 23 months, Before and after repair, the functional morphology of the mitral apparatus was defined by twodimensional echocardiography; Doppler color flow imaging was used to clarify the mechanism of mitral regurgitation and to semiquantitate its severity. Results. There was significant improvement in the mean mitral regurgitation grade by composite intraoperative transesophageal echocardiography after valve repair (3.6 ± 0.8 to 0.7 ± 0.7; p < 0.00001). Excellent results from initial repair with grade ≤ 1 residual mitral regurgitation were observed in 88.1% of patients. Significant residual mitral regurgitation (grade ≥ 3) was identified in 11 patients (7.7%); 5 underwent prosthetic valve replacement, 5 had revision of the initial repair and 1 patient had observation only. Of the 100 patients with a myxomatous mitral valve, the risk of grade ≥ 3 mitral regurgitation after initial repair was 1.7% in patients with isolated posterior leaflet disease compared with 22.5% in patients with anterior or bileaflet disease. Severe systolic anterior motion of the mitral apparatus causing grade 2 to 4 mitral regurgitation was present in 13 patients (9.1%) after cardiopulmonary bypass. In 8 patients (5.6%), systolic anterior motion resolved immediately with correction of hyperdynamic hemodynamic status, resulting in grade ≤ 1 residual mitral regurgitation without further operative intervention. Transthoracic echocardiography before hospital discharge demonstrated grade ≤ 1 residual mitral regurgitation in 86.4% of 132 patients studied. A significant discrepancy (> 1 grade) in residual mitral regurgitation by predischarge transthoracic versus intraoperative transesophageal echocardiography was noted in 17 patients (12.9%). Conclusions. Transesophageal echocardiography is a valuable adjunct in the intraoperative assessment of mitral valve repair.