1. Regarding the timing of surgery: Currently, most foreign scholars advocate radical surgery for TOF in infancy, i.e., around 6 months of age [1][2], and some even advocate surgery within 1 month [3], while domestic scholars tend to perform radical surgery around 1 year of age [4][5]. With a better understanding of the pathophysiology of TOF in infants and children, advances in preoperative diagnosis, anesthesia, extracorporeal circulation techniques, improved surgical techniques, and the availability of various special medical devices for infants and children with excellent performance, we believe that the age of surgery is no longer an important risk factor, and early radical treatment can prevent myocardial hypertrophy, increased collateral circulation, impaired pulmonary development, physical and mental retardation, and renal function caused by TOF further aggravation of impairment of renal function, etc. Hu Zhiwei, Department of Cardiac Surgery, Wuhan Union Medical College Hospital
2. Regarding the indications for radical surgery: McGoon index less than 1 and Nakata index less than 100 mm2/m2, the risk of radical surgery is significantly higher [1], and it has been reported in China [6] that left ventricular and pulmonary artery dysplasia can significantly increase the mortality after TOF, so the pulmonary artery index (PAI) >150 mm2/m2, McGoon index >1.5, left ventricular LVEDI >30 ml/m2 is still an important indication for radical TOF surgery. Two cases in this group also had severe dysplasia of the pulmonary artery and branches (McGoon index 0.7 in one case and 0.9 in the other) and poorly developed left ventricle, and died of severe hypovolemia after forced radical treatment. It has also been reported that preoperative diagnosis of poor pulmonary artery development and small left ventricular volume is not an absolute contraindication to surgery [7]. Therefore, we agree with the following criteria [8] as indications for palliative surgery for TOF: (1) McGoon index <1.0; (2) PAI <100 mm2/m2; and (3) combined right ventricular outflow tract coronary artery riding and other complex intracardiac malformations.