Right ventricular outflow tract is a cardiac disorder whose typical symptoms include cyanosis, dyspnea and hypoxic episodes, and squatting. Related symptoms include dyspnea, cyanosis, systolic tremor, cardiogenic dyspnea, and blood hypoxia. The most common primary symptoms of tetralogy of Fallot are cyanosis and blood hypoxia. The time to presentation and severity of clinical symptoms depend on the degree of right ventricular outflow tract obstruction and the amount of blood flow in the pulmonary circulation. In the majority of cases, cyanosis begins only after the closure of the ductus arteriosus in the first weeks or months of life and progressively worsens. However, if the degree of right ventricular outflow tract obstruction is severe, such as pulmonary atresia, diffuse dysplasia of the outflow tract, and multiple severe stenoses of the funnel, pulmonary annulus, and pulmonary valves, cyanosis is present at birth. In cases with mild right ventricular outflow tract obstruction and low right-to-left blood shunt, cyanosis is mild, and left-to-right blood shunt at the level of the ventricle may not be cyanotic if it is predominantly left-to-right. Cyanosis worsens with eating, crying, and activity, and dyspnea occurs. Children prefer to adopt the squatting position. Squatting reduces venous return flow to the lower extremities and increases the resistance of the circulation, which increases pulmonary blood flow, increases arterial oxygen saturation, and reduces cyanosis and dyspnea. The only effective treatment for tetralogy of Fallot is surgical intervention to increase pulmonary blood flow and improve hypoxia or radical surgery for intracardiac malformations. more than 40 years ago, the surgical treatment for tetralogy of Fallot was to perform a body-pulmonary shunt in order to alleviate hypoxia, improve symptoms, and prolong life expectancy. After the introduction of extracorporeal endocardial direct visualization surgery into the clinical application, the radical treatment of tetralogy of Fallot has gradually replaced the palliative body-pulmonary bypass, and the therapeutic effect has been improving, but the opinion on the use of staged surgery, i.e., shunt surgery, followed by radical surgery or one-stage radical surgery for infants and young children is not yet unanimous. It is suggested that patients with tetralogy of Fallot who have obvious clinical symptoms should undergo one-stage radical surgery regardless of their age, so as to avoid the risk of undergoing two surgeries. Early surgery also prevents right ventricular hypertrophy and outflow tract stenosis from worsening. Another group of surgeons believe that the operative mortality rate of radical surgery in the first 3 months of life is 25-67%, which is much higher than that of body-pulmonary bypass, and that the operative mortality rate of radical surgery is significantly lower when delayed to 1-2 years of age, so they advocate staged surgery. body-pulmonary bypass is performed in cases between 6 months and 1 year of age, and then a second radical surgery is performed when the patient grows up. With the accumulation of clinical experience, the mortality rate of radical surgery has been reduced and the therapeutic efficacy has been improved, and the current tendency is to formulate the surgical plan according to the patient’s age and the patho-anatomical morphology of the lesion. The mortality rate of radical surgery is higher in infants and young children, so the age of surgery is preferred to be more than 6 months. infants under 6 months of age who are in serious condition and need urgent surgical treatment should be operated with palliative body-pulmonary bypass first. However, if the right ventricular outflow tract obstruction is characterized by funnel stenosis on angiography, the pulmonary valve annulus and pulmonary artery are well developed, and recurrent hypoxic episodes occur due to spasm of the funnel, then cardiac glycosides and other medications may be given, and radical surgery may be performed when the patient is older than 6 months old.Selective right ventriculography in patients younger than 6 months old reveals that the right ventricular outflow tract or the stenosis of the pulmonary artery is characterized by diffuse dysplasia of the funnel, pulmonary valve annulus stenosis and pulmonary artery stenosis. In patients under 6 months of age with selective right ventriculography showing right ventricular outflow tract or pulmonary stenosis of diffuse funnel dysplasia, pulmonary annular stenosis, pulmonary trunk or branch stenosis requiring suture enlargement across the annulus, palliative bypass is preferred because of the high mortality rate of radical surgery, which can be performed when the patient is old enough to be treated with a palliative shunt.