Atrioventricular Canal Defects.

Atrioventricular (AV) canal defects should be diagnosed by means of echocardiography. Infants with complete AV canal defects should undergo intracardiac surgical repair before pulmonary vascular obstructive disease develops, preferably before 6 months of age. Repair of partial AV canal defects or primum atrial septal defects can be postponed until 18 to 36 months of age if the patient does not have pulmonary hypertension or growth failure. The one- and two-patch techniques can both provide excellent results with a low mortality rate in repair of complete AV canal defects. Repair of the cleft mitral valve at the time of initial surgery is advised to preserve long-term mitral valve function. Tetralogy of Fallot with AV canal defect can also be repaired but at an older age and with a greater incidence of reoperation. Unbalanced AV canal defects associated with a hypoplastic ventricle may necessitate initial pulmonary artery banding and a subsequent decision about the suitability of two-ventricle repair. If ventricular septation is unsuitable, a single-ventricle path is chosen. Bidi-rectional cavopulmonary anastomosis and, eventually, the Fontan procedure are used.