RÉSUMÉ
Although pulmonary valvular stenosis with intact ventricular septum is a common congenital abnormality, critical pulmonary stenosis of its severe form in the neonate is rare and highly fatal. With the development of percutaneous balloon valvuloplasty, surgical treatment is even more rare. This report is on a 2 day old male neonate with a critical pulmonary stenosis with intact ventricular septum who suffered from severe cyanosis and hypoxemia. Oxygen was inhalated and Prostaglandin E1 was infused initially and then arterial PO2 was increased from 19 mmHg to 54 mmHg. Percutaneous balloon valvuloplasty was attemped; however, the guidewire could not pass through the stenotic pulmonary valve, and during the procedure right ventricular perforation was suspected due to the presence of dye in the pericardial space. Emergency transarterial pulmonary valvotomy was performed using normothermic cardiopulmonary bypass. Postoperatively, the patient was in fair condition in the ICU and presently is in good condition at 6 months postoperative follow up.