Evaluation of the Mitral Valve Leaflet Morphology After Mitral Valve Reconstruction with a Concept “Coaptation Length Index”

BACKGROUND: In clinical settings, information on morphology of mitral valve leaflet after mitral valve reconstruction is limited. METHODS: Between January 1996 and June 2000, 36 patients underwent mitral valve repair for mitral regurgitation (MR). The etiology of mitral insufficiency was prolapse, dilated annulus, and ischemia. Ring annuloplasty was performed in all cases. Mitral valve short-axis dimension (MVd), vertical distance between annular line and closing point (Vd), coaptation length (CL), and coaptation length index (CLI) were measured by two-dimensional transesophageal echocardiography for the present 11 cases. RESULTS: In 11 cases, residual MR, using a scale from 0 to 4, was 0 in 5 patients, 1 in 4 patients, 2 in 2 patients whose etiology of regurgitation was cardiomyopathy. MVd and Vd decreased significantly (38.7+/- 6.2 to 27.0 +/- 5.6 mm, 10.1 +/- 7.7 to 6.5 +/- 4.6 mm, respectively). CL and CLI increased significantly (6.4 +/- 2.4 to 11.6 +/- 4.6 mm, 0.16 +/- 0.06 to 0.44 +/- 0.21, respectively). Among those indices, only CLI has a statistically significant negative correlation with the degree of residual MR. CONCLUSION: Mitral valve ring annuloplasty produces the morphologic change of the mitral apparatus, especially increase of CLI, which may be one of the main factors in regulation of regurgitation.