[Surgical treatment for mitral regurgitation associated with secundum atrial septal defect]

We reviewed 25 patients who underwent a mitral valvuloplasty, from 1984 to 1996, for mitral regurgitation (MR) associated with atrial septal defect (ASD). Mean grade of MR was 2.3 +/- 0.7. The locations of mitral valve lesion were as follows; Postero-medial side of the anterior leaflet (AML) (11 patients: 44%), posteromedial side to center of the AML (7 patients: 28%), whole of the AML (5 patients: 20%), center of the AML (1 patient: 4%), posteromedial side of the posterior leaflet (PML) (1 patient: 4%). In summary, the mitral valve lesion was located in the AML in 96% patients and were seen in the postero-medial side of 96% patients. Mitral valve repair was performed as follows; chordae shortening only (3 patients: 12%), chordae shortening + Kay's annuloplasty (9 patients: 36%), Kay's anuloplasty (10 patients: 40%), using artificial chordae only (1 patient: 4%), using artificial chordae + Kay's annuloplasty (1 patient: 4%), using artificial chordae + ring annuloplasty (1 patient: 4%). In 24 patients, the grade of MR was less than 2/4 in the early postoperative period. In one patient, the grade of 3/4 MR was still remained. Reoperation were required in 2 patients, because of gradual increase of MR, 9 years and 10 years after the initial operation, respectively. In another patient, the grade 3/4 MR recurrently occurred at 6 months after the operation. He has been well maintained medically. In all 4 patients who had more than the grade 3/4 MR postoperatively, the annuloplasty was performed with Kay's method and the cause of MR was poor coaptation around the center of the AML. The mitral valve lesion associated with ASD seemed to be the dislocation of the AML which cause the discrepancy of the coaptation zone between both leaflets, without any prominent prolapse and chordae elongation. We put a particular emphasis on that the mitral valve repair should be performed with the recognition of the etiology of the mitral valve lesion. Especially, if the lesion extends around the center of the AML, sufficient coaptation area of both leaflets at the center of the AML should be obtained by anuloplasty.