Creation of a communication between the left and right atrium to decompress the left ventricle can be life-saving after corrective surgery in some patients with congenital heart disease and small left ventricle. After adaptation of the left ventricle, surgical closure of this anastomosis becomes mandatory. We report four patients (2.9 to 8.2 kg) where non-surgical, transcatheter-closure was performed in the first year of life using the Rashkind-PDA-Occluder System (USCI). In a newborn with d-transposition of the great arteries (2.9 kg), in a patient with atrial septal defect (5.1 kg), and in a patient with tetralogy of Fallot with atrial septal defect (4.9 kg) atrial septal defects were not completely closed during correction because of left-ventricular dysfunction. Five to 12 days postoperatively transcatheter closure was performed utilizing the 8F-Rashkind-PDA-Occluder System in the first two patients (2.9 kg and 4.9 kg) and by use of the 11F-Rashkind-PDA-Occluder System in the third patient (4.9 kg). In the patient with supracardiac total anomalous pulmonary venous drainage via a vertical vein, the vertical vein was not closed during surgical correction at the age of 2 months. Transcatheter closure was performed 6 months later using the 11F-Rashkind-PDA-Occluder-System. It is concluded that small, defined atrial septal defects can be closed, even in newborns, using the Rashkind-PDA-Occluder System (USCI) and, furthermore, that large vessels, even without luminal narrowing can be occluded completely. Thus, this combined "surgical-interventional approach" is not limited by age and could reduce the risk of surgical correction in patients with congenital heart disease and small left ventricle.