Anterior Mitral Leaflet Length: Predictor for Mitral Valve Repair in a Rheumatic Population

Background: The length and mobility of the anterior mitral leaflet (AML) are considered important for mitral valve reparability. In this study, we looked at AML length as a predictor of mitral valve reparability in a rheumatic population.

Methods: Between May and November 2008, 44 patients underwent mitral valve repair for pure mitral regurgitation, pure mitral stenosis, and mixed lesions. The mean age was 26.5 ± 10.4 years (range, 9 to 50; median 23.5), and 15 patients were less than 20 years old. There were 28 female patients. The mean body surface area was 1.37 ± 0.13 (range, 0.97 to 1.62). In all patients, we measured AML length at the A2 segment, both by transesophageal echocardiography and intraoperative direct measurement. These measurements were indexed to the body surface area.

Results: Thirty-five patients had successful repair. Nine patients underwent mitral valve replacement after failed repair. The AML lengths were significantly higher in the successful repair group as compared with the failed repair group (AML length measured by transesophageal echocardiography was 31.4 ± 4.9 mm versus 24.1 ± 2.2 mm, p = 0.001; AML length measured intraoperatively was 30.8 ± 4.4 mm versus 22.3 ± 1.5 mm, p = 0.001). An intraoperatively measured AML length of 26 mm or more predicts reparability with 97.1% sensitivity and 100% specificity. Transesophageal echocardiography can reliably judge AML length and can also predict reparability. Indexed AML lengths are an even stronger predictor of mitral valve reparability, especially in a pediatric population.

Conclusions: Indexed AML length is a strong predictor of mitral valve reparability. With a value of 18 mm/m(2) or more, repair can be accomplished in all cases.