Operation for partial atrioventricular septal defect: A forty-year review

Background: We describe the long-term outcome of repair of partial atrioventricular septal defect by determining the rates of survival, reoperation, and occurrence of left atrioventricular valve regurgitation, left atrioventricular valve stenosis, left ventricular outflow tract obstruction, and arrhythmia. Methods: We studied 334 patients who underwent repair of partial atrioventricular septal defect before 1995. Results: The 30-day and 5-, 10-, 20-, and 40-year survival were 98%, 94%, 93%, 87%, and 76%, respectively. Closure of the left atrioventricular valve cleft (P = .03) and age less than 20 years at operation (P < .001) were associated with better survival. Reoperation was performed for 38 patients (11%). Repair of residual/recurrent left atrioventricular valve regurgitation or stenosis was the most common reason for reoperation. Left ventricular outflow tract obstruction occurred in 36 patients, and 7 patients underwent reoperation to relieve this obstruction. Supraventricular arrhythmias were observed in 58 patients (16%) after the operation. Supraventricular arrhythmias increased with increasing age at primary operation (P = .001). Complete atrioventricular block occurred in 9 patients (3%). Permanent pacemakers were implanted in 11 patients. Conclusions: Long-term survival after repair of partial atrioventricular septal defect is good. It is important to close the cleft in the left atrioventricular valve. Reoperation for persistent or recurrent left atrioventricular valve malfunction and relief of left ventricular outflow tract obstruction is necessary in approximately 11% of patients.