Long-term results of repair of incomplete persistent atrioventricular canal.

We evaluated the late results following repair of otherwise anatomically uncomplicated incomplete persistent atrioventricular canal in 39 consecutive operative survivors who underwent operation at our institution prior to 1976. Average follow-up was 12 years. Postoperative cardiac catheterization was performed in 35 patients (90%) at an average of 11 months after operation. Seven (20%) had residual mitral regurgitation with elevated mean pulmonary arterial wedge of left atrial pressures with abnormal v waves. Regurgitation was mild to moderate (pulmonary artery wedge or left atrial pressure 12 to 15 mm Hg) in five and severe (pulmonary artery wedge pressure over 20 mm Hg) in two patients. Clinically significant arrhythmias including complete heart block, sudden death, nodal rhythm, and chronic atrial fibrillation occurred in seven patients (18%). Two patients have required reoperation for mitral regurgitation. Five have clinically recognizable mild-to-moderate mitral regurgitation controlled with medical management; 25 patients are asymptomatic at current evaluation. Estimated actuarial survival rate at 13 years is 88% +/- 6%, with an actuarial survival free of reoperation of 82% +/- 6%. However, actuarial survival free of any late complication including late death, reoperation, serious arrhythmia, or mitral regurgitation is only 52% +/- 10% at 13 years.