Definition: Pulmonary Atresia with Intact Ventricular Septum (PAIVS) is defined as atresia of one or more of the three main pulmonary arteries, the pulmonary valve, and the right and left bifurcations of the pulmonary artery, often with varying degrees of right ventricular and tricuspid valve dysplasia. The ventricular septum is intact and the aortic relationships are normal. Incidence: Pulmonary atresia with Intact Ventricular Septum (PAIVS) is a rare congenital heart disease with an incidence of 1% to 1.5% of congenital heart disease, with no gender differences. Clinical manifestations: Cyanosis appears at birth or shortly after birth in more than 90% of children and worsens progressively. The degree of cyanosis depends mainly on the blood flow to the lungs through the ductus arteriosus and other body-pulmonary artery traffic. If the ductus arteriosus is small and cyanosis is severe, survivors have pestle-like fingers (toes). Growth disorders are often associated with palpitations and shortness of breath after activity, but squatting is rare. If the body-lung traffic is large, cyanosis is mild and susceptible to respiratory infections, and heart failure can often occur early. If the arterial duct tends to close, the cyanosis is progressively worse. In severe cases, the partial pressure of arterial oxygen may drop to 20 mmHg and the oxygen saturation is only about 40%. Right heart failure is most often seen in patients with tricuspid valve closure insufficiency, with hepatomegaly, swelling, and apical rhythm. If the birth is normal, the child can usually develop better, with cyanosis, respiratory distress and metabolic acidosis after birth. Diagnosis: Diagnosis can be made by physical signs, chest radiograph, electrocardiogram, cardiac color ultrasound, CT, MRI, right heart catheterization and cardiography. Among them, CT and MRI can show the development of the pulmonary artery and the establishment of collateral circulation, and right heart catheterization and cardiography are the key to show the disease. Natural course: The natural prognosis of pulmonary atresia with an intact ventricular septum is poor, with 50% of children dying two weeks after birth and 85% dying six months after birth. The main causes of death are hypoxia and metabolic acidosis, which are particularly likely to occur after ductus arteriosus closure. The few patients who survive into childhood do so primarily through large atrial septal defects and patent ductus arteriosus, with very few children surviving into adulthood through a large extracardiac collateral circulation. Treatment: Surgical treatment is indicated upon diagnosis. Most surgical procedures are staged. Postnatal intravenous prostaglandin E1 is given to delay ductus arteriosus closure. The second stage is the establishment of a right ventricular to pulmonary artery flow channel at the age of 3 to 5 years to close the atrial traffic and extracardiac shunt. The survival rate of children undergoing palliative surgery in the neonatal period was 27% for pulmonary valvotomy alone, 30% for body-pulmonary shunt alone, and 79% for both procedures. The main factor in early surgical death is improper anastomotic size after bypass. After the first bypass, 25% required reoperation within one month because the anastomosis was too small. Secondly, myocardial coronary sinus traffic between the right ventricular cavity and the coronary artery, right ventricular hypertension, age and left ventricular function, were also factors for early death. The 3-year survival rate after palliative surgery without corrective surgery is 50% and the 5-year survival rate is less than 30%. The early mortality rate for radical surgery is 25%, and the main cause of death is left ventricular insufficiency. The main complication of applying an extracardiac tube with a valve is stenosis of the tube, which requires reoperation for replacement. Long-term survival of the child can restore cardiac function to class I-II.