Journal of JCIC

Our patient was a boy born at 33 weeks and 4 day’s gestation weighing 1174 g. Fetal ultrasound revealed a double-outlet right ventricle complicated by pulmonary artery stenosis. The patient’s oxygen saturation (SpO₂) at birth was in the low 90s, but Lipo-PGE1 was not administered as we deemed the hemodynamics ducts arteriosus-independent. Starting at 2 weeks of age, the patients SpO₂ gradually decreased to the low 80s after constriction of the arterial duct. Despite intravenous Lipo-PGE1 and supplemental oxygen, controlled ventilation was required to maintain the SpO₂. Although the precise anatomy of subvalvular stenosis was unclear on echocardiography, the patients was evaluated with animated three-dimensional images of the pulmonary artery from the right ventricular outflow tract by the creation of reconstructed images using PhyZiodynamics from the computed tomography date collected from the coronary artery evaluation. From the image, we identified mild subvalvular stenosis of the pulmonary artery. Consequently, we judged that percutaneous pulmonary valvuloplasty (PTPV) would be effective for hypoxemia, while pulmonary high flow would be unlikely as the small pulmonary valve ring could control the pulmonary blood flow. Following PTPV at 49 days of age using TMP PED balloon catheter (6 mm/2 cm), his arterial oxygen saturation increased from 80 to 98％, and he was weaned from the ventilator. Heart failure complicated by excessive pulmonary blood flow was not observed. He was able to wait until 75 days of age for systemic to pulmonary arterial shunt surgery, when his body weight reached 2.3 kg.