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

Abstract

Objective: This study was designed to delineate the utility and results of intraoperative transesophageal echocardiography in the evaluation of patients undergoing mitral 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 two-dimensional 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 less than 0.00001). Excellent results from initial repair with grade less than or equal to 1 residual mitral regurgitation were observed in 88.1% of patients. Significant residual mitral regurgitation (grade greater than or equal to 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 greater than or equal to 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 less than or equal to 1 residual mitral regurgitation without further operative intervention. Transthoracic echocardiography before hospital discharge demonstrated grade less than or equal to 1 residual mitral regurgitation in 86.4% of 132 patients studied. A significant discrepancy (greater than 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.