Surgery of the Complete Atrioventricular Canal: Relationship between Age at Operation, Mitral Regurgitation, Size of the Ventricular Septum Defect, Additional Malformations and Early Postoperative Outcome

Abstract
The perioperative risk after repair of the complete atrioventricular canal is reported to be low provided there is a balanced relationship of both ventricles, and elevated pulmonary vascular resistance has been demonstrated to be reversible. However, some pre- and perioperative conditions may adversely affect early postoperative outcome. A consecutive series of 42 patients (mean age 8.5 months, 34/42, 81%, with trisomy 21) operated between 1994 and 1998 was analyzed prospectively for pre- and perioperative risk factors. Echocardiography alone was performed in 35 patients whereas cardiac catheterization was performed in 7 patients aged more than 18 months to confirm operability. Additional malformations were found in 20 patients. Early mortality was 2.3% (1/42), and postoperatively a low cardiac output was observed in 25 patients (59%); NO inhalation was used in 12 patients. Only the size of the ventricular septal defect (> than the diameter of the aortic annulus) could be identified as a predictor of adverse postoperative outcome in multivariate analysis. The presence of associated intracardiac malformations showed a trend to increased perioperative risk in multivariate analysis. Early results after repair of the complete atrioventricular canal are excellent. Survival, postoperative morbidity and normalization of pulmonary artery pressure can be related to the size of the ventricular septal defect. Continuous monitoring of the pulmonary artery pressure (with consequent NO application when indicated) is probably responsible for the low perioperative risk encountered in this series, despite the high incidence of postoperative pulmonary artery hypertension.