OBJECTIVETo investigate the efficacy and safety of percutaneous radiofrequency perforation and valvuloplasty in infants with pulmonary atresia with intact ventricular septum (PA/IVS).

METHODSFour infants (body weight 4 - 10 kg) aged 11 months, 9 months, 12 days and 9 months old, respectively, were hospitalized for dyspnea and cyanosis. All patients had a continuous murmur in the left second intercostal space. Doppler echocardiogram showed membranous pulmonary atresia with intact ventricular septum. Right ventriculogram showed a tripartite right ventricle, vasiform infundibulum, and membranous pulmonary valve atresia without ventriculocoronary connections. Descending thoracic aortogram showed good-sized confluent pulmonary arteries being filled from a ductus arteriosus. All the patients were taken up for radiofrequency perforation followed by a balloon dilatation. A 6F Judkins right coronary guiding catheter was positioned in the right ventricular outflow tract and under the atretic pulmonary valve membrane. The radiofrequency perforation catheter along with coaxial injectable catheter was then passed through the right coronary guiding catheter, using it as the guide to the imperforate membrane. The proximal end of the radiofrequency perforation catheter was then connected to radiofrequency generator. After the cusps of pulmonary valve were perforated, the coaxial injectable catheter was moved into the main pulmonary artery. A tiny floppy-tipped coronary guidewire was then passed through the coaxial injectable catheter into the main pulmonary artery and directed through the patent ductus arteriosus into the descending thoracic aorta or directed into pulmonary arteriola. Thereafter, serial balloon dilation catheters were introduced across the pulmonary valve, and dilations were sequentially performed with increasing balloon diameters. The balloon was dilated until the concave of the balloons disappeared. The radiofrequency energy (5 to 8 W) was delivered for 2 to 5 seconds once, but commonly twice, to perforate the valves. After a predilation with a 3 mm x 20 mm to 5 mm x 20 mm balloon at 6 - 14 atm pressure, the valve was subsequently dilated with 10 mm x 30 mm to 14 mm x 30 mm balloon once or twice. The duration of procedures was 120 to 150 min and exposure time was 25.4 to 43.9 min.

RESULTSThe primary procedure was successful in all the infants except one who died early of cardiac perforation with tamponade. After a follow-up period ranging from 2 to 8 months (mean 4.3 m), the remaining 3 survivors achieved complete biventricular circulation. Two of them were awaiting occlusion of the patent ductus arteriosus and 1 needed right ventricular outflow tract reconstruction because of infundibular obstruction.

CONCLUSIONPA/IVS consists of 0.7% to 3.1% of congenital heart defects. 85% of the untreated patients die within half a year. Surgical repair for the infants with PA/IVS is associated with a high mortality. In carefully selected patients with PA/IVS, radiofrequency perforation and balloon dilatation of the pulmonary valve is feasible and may represent a new alternative to surgery due to its low mortality and avoidance of cardiopulmonary bypass.