Anomalies of the atrioventricular septum, such as CAVSD or PAVSD, require surgical therapy, the former early in childhood and the latter electively before entering school. Primary repair is the treatment of choice. In the case of heart failure and/or moderate or severe LAVV incompetence, operative correction should be performed as early as possible. Otherwise, the operation should be carried out within the first 4-6 months of life. A two- stage approach-that is, PAB followed by later repair-is indicated in patients with heart failure, the absence of valve incompetence, a body weight <2500 g, the presence of coarctation or severe dysplastic LAVV, and/or a hypoplastic left ventricle. In the latter, quite rare group early decision making is required because a Fontan-type repair is hampered by the early development of pulmonary vascular disease. In our study, a two-stage repair permitted very good results even during a long-term observation period. For patients with PAVSD, operation should be completed between 2 and 4 years of age before entering school. For correction of CAVSD, we and many other surgeons prefer the two-patch technique, which permits more individual and precise repair of the common AV valve. In our more than 20 years' experience the function of the repaired AV valve has been remarkable; the rate for valve repair varies between 6% and 10% in patients with PAVSD. Valve replacement is rarely necessary, occurring in only 1.8% of patients after CAVSD correction and in 3.7% of patients after PAVSD correction. At the primary operation valve replacement is never indicated. The complication of complete AV block has become quite rare and is below 2%. Operative death varies between 1% and 5%. Risk factors include congestive heart failure, additional cardiovascular anomalies (e.g., coarctation), and pulmonary hypertension. In our more than 20 years' experience, >80% of patients with partial or common AV septal defects show normal development without medication, even after a two-stage approach.
