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 underwent mitral valve repair for mitral regurgitation (MR). The etiology of mitral insufficiency was prolapse, dilated annulus, and ischemic. 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), coaptation length index (CL/MVd) were measured by the 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 index, only CLI have a statistically significant negative correlation with the degree of residual MR. Conclusion: The mitral valve ring annuloplasty produce the morphologic change of mitral apparatus, especially the increase of CLI, which may be one of the main factors in regulation of regurgitation.