ObjectiveTo analyze the risk factors and re-intervention strategies for mid- and long-term residual after arterial switch operation (ASO). MethodsThe clinical data of children with complex congenital heart disease who underwent ASO surgery in Shanghai Children’s Medical Center from January 2006 to June 2022 were retrospectively collected, and the factors for mid- and long-term residual after ASO were analyzed. ResultsA total of 952 children undergoing ASO were enrolled in this study, including 654 males and 298 females with an average age of 102.9±90.1 d and weight of 4.6±1.6 kg. There were 421 patients with D-transposition of the great arteries with intact ventricular septum (D-TGA/IVS), 357 patients with D-transposition of the great arteries with ventricular septal defect (D-TGA/VSD), and 174 patients with right ventricle double outlet combined with inferior pulmonary artery absence (Taussig-Bing malformation). Eighty-nine patients died early after the surgery, the mortality rate was 9.3%. The 746 surviving children were regularly followed up after the surgery (follow-up rate 86.4%), with a median follow-up time of 79.4 (12.0-188.0) months. During the follow-up, 53 children underwent surgical re-intervention due to residual, including 33 males and 20 females, with a median age of 62.5 (17.0-214.0) months. The median surgical weight was 19.0 (8.2-86.0) kg, and the mean time of re-intervention was 28.0-170.0 (77.5±45.4) months after the ASO. Residual problems included common trunk and branch stenosis of the pulmonary artery in 34 patients, right outflow tract stenosis in 11 patients, left outflow tract stenosis in 6 patients, aortic arch restenosis in 5 patients, aortic insufficiency in 5 patients, residual shunt of ventricular septal defect in 2 patients, and tricuspid valve insufficiency in 1 patient. Two patients died early after the re-intervention because of acute left heart failure, and the mortality rate was 3.8% (2/53). The mean follow-up time of the surviving children was 52.4±28.6 months, and no mid- and long-term death occurred. Two patients underwent the third operations due to pulmonary restenosis. The multivariate analysis result showed that combined aortic arch surgery and early postoperative right ventricular outlet tract (RVOT) velocity>3 m/s were independent risk factors for mid- and long-term residual after ASO. ConclusionASO is an ideal surgical method for the treatment of D-TGA/IVS, D-TGA/VSD and Taussig-Bing malformations. Combined aortic arch surgery and early postoperative RVOT velocity>3 m/s are independent risk factors for mid- and long-term residual after ASO.