Successful atrioventricular valve repair improves long-term outcomes in children with unbalanced atrioventricular septal defect

Background: Atrioventricular valve regurgitation is a significant cause of morbidity and mortality in patients with unbalanced atrioventricular septal defect. However, knowledge of the outcomes of atrioventricular valve repair in children with unbalanced atrioventricular septal defect and univentricular physiology is limited. Methods: We conducted a retrospective review of all patients with unbalanced atrioventricular septal defect treated with single-ventricle palliation who underwent atrioventricular valve surgery at The Royal Children's Hospital. Results: Between 1976 and 2016, 139 children with unbalanced atrioventricular septal defect underwent single-ventricle palliation, of whom 31.7% (44/139) required atrioventricular valve surgery. Repair of the atrioventricular valve was attempted in 97.7% (43/44) of patients, of whom 4.7% (2/43) were converted to replacement during the initial operation. Replacement of the atrioventricular valve without attempted repair was performed in 2.3% (1/44) of patients. Early mortality was 18.2% (8/44). Freedom from death or transplantation at 10 years was 66.0% (95% confidence interval, 49.1-78.5) and at 20 years was 53.3% (95% confidence interval, 32.1-70.6). In multivariable analysis, significant predischarge atrioventricular valve regurgitation (hazard ratio, 6.4; P=.002), age less than 1 year (hazard ratio, 8.3; P=.01), and repair before stage II palliation (hazard ratio, 3.4; P=.04) were associated with death. Freedom from reoperation at 10 years was 61.9% (95% confidence interval, 41.9-76.8) and at 20 years was 56.3% (95% confidence interval, 35.3-72.8). Moderate or greater atrioventricular valve regurgitation at discharge was associated with an increased risk of reoperation (hazard ratio, 1.8; P=.03). Of transplant-free survivors, atrioventricular valve regurgitation was less than moderate in 60.0% (15/25) at the most recent follow-up. Conclusions: Atrioventricular valve surgery in patients with unbalanced atrioventricular septal defect is associated with substantial mortality and a high rate of reoperation. Successful atrioventricular valve repair is associated with better survival and freedom from reoperation.