Left-Sided Atrioventricular Valve Regurgitation After the Repair of Complete Atrioventricular Septal Defect

This study aimed to investigate left-sided atrioventricular valve outcome after the repair of complete atrioventricular septal defect from single-institutional retrospective chart review. From 1998 to 2022, 55 patients with complete atrioventricular septal defect and balanced 2 ventricles underwent biventricular repair. Median age and weight at repair were 5.5 months old [interquartile range, 3.4-9.1] and 4.6 kg [3.9-5.9]. Analyzed possible risk factors were Rastelli classification, low birth weight < 2.5 kg, preterm < 37 weeks, proceeding pulmonary artery banding, Down syndrome, persistent left superior vena cava, tetralogy of Fallot, early surgical era < 2010, preoperative left-sided atrioventricular valve regurgitation > mild, modified single-patch repair, small left mural leaflet, and complete left-sided atrioventricular valve cleft closure. No patients underwent left-sided atrioventricular valve replacement at the timing of repair. No patient required subsequent single ventricular conversion. The median follow-up period in survivors was 11.0 years. The survival rate at 15 years from repair was 96.4%. Freedom from moderate or greater left-sided atrioventricular valve regurgitation rate at 10 years was 58.4%. After elimination of 3 patients undergone complete closure then experienced tone of closed cleft, complete cleft closure was significant inhibitor for moderate or greater left-sided atrioventricular valve regurgitation (p = 0.034, Odds ratio: 0.36, 95% Confidence intervals: 0.14-0.93). Twelve patients underwent 15 reoperations for left-sided atrioventricular valve. All 4 patients who developed left-sided atrioventricular valve stenosis and backward pulmonary hypertension required prosthetic valve replacement. Incomplete cleft closure was the only risk factor for significant postoperative left-sided atrioventricular valve regurgitation. Already small left-sided atrioventricular valve by previous repair developed significant regurgitation, it is no longer repairable therefore required to be replaced.