[Long-term results of mitral valve regurgitation after surgical repair of incomplete atrioventricular septal defect].

Although the postoperative outcome in patients with incomplete atrioventricular septal defect (iAVSD) is excellent, deterioration of mitral valve regurgitation (MR) is still remained to be resolved. Therefore, this study was undertaken to compare surgical procedures for mitral cleft repair with their long-term results of MR. From 1991 to 1996, 52 patients underwent surgical repair of iAVSD. Age at operation ranged from 2 months to 62 years old with mean age of 14.2 years. Mean follow-up period was 8.6 +/- 4.4 years. All patients underwent patch closure of ostium primum defect. Two patients did not have cleft (Group A). Seven patients did not close the cleft at all (Group B), while 40 patients had the repair of valve by closing cleft near septal attachment only (Group C). The latest 3 patients had the complete closure of cleft from annulus to margin of leaflet where chorda is attached. MR was evaluated by echocardiography grading 0 to IV and regurgitation more than grade II was considered to be significant. In Group A, MR remained grade I. In Group B, MR was deteriorated in 5 patients (71%). Consequently, 6 patients (86%) had grade II or more regurgitation and 4 patients (57%) revealed grade III/IV regurgitation including one (14%) reoperation. In Group C, MR was deteriorated in 10 patients (55%). Consequently, 22 patients (86%) had grade II or more regurgitation and 5 patients (13%) had grade III/IV regurgitation including 3 (7.5%) reoperations. In Group D, no deterioration of MR was noted and all had grade I or less regurgitation. These results suggest that the closure of cleft near septal attachment is not sufficient to prevent MR in late phase and the complete closure of cleft from annulus to margin of leaflet, where chorda is attached, would be useful to prevent the deterioration of MR in late phase.