Objectives: We reviewed our 28 years of experience of arterial switch operation (ASO) for transposition of the great arteries to investigate late sequelae of this procedure.
Methods: 387 patients who underwent ASO from 1984 to 2010 were included in this retrospective study. The longitudinal data were estimated by the Kaplan-Meier method and compared using a log-rank test. Risk factors for late sequelae were analysed by the multivariable Cox proportional hazards model.
Results: The mean follow-up time was 10.0 years. There were 13 early deaths and 17 late deaths. All late deaths were within 1 year, except for three patients. Actuarial survival was 92.2 and 91.6% at 10 and 20 years, respectively. Sixty-six patients (17.1%) had developed pulmonary stenosis (PS) and 29 patients (7.5%) had developed moderate or more aortic insufficiency (AI) during follow-up. Selective coronary angiography was performed in 210 patients (54.3%) at 9.6 ± 5.1 years after ASO. Left main tract occlusion was found in 2 patients (2/210; 1.0%) and hypoplastic left coronary artery was found in 10 patients (10/210; 4.8%). Among these 12 patients, 8 patients were asymptomatic. Re-operation was performed in 76 patients (19.6%), pulmonary artery plasty for PS in 58 patients (15.0%), aortic valve replacement for AI including two Bentall operations in 9 patients (2.3%) and others. Freedom from re-operation was 78.2 and 62.8% at 10 and 20 years, respectively. The risk factor for PS was the use of equine pericardium for reconstruction (P < 0.0001). Factors associated with moderate or more AI was the presence of left ventricular outflow tract obstruction (P = 0.004). There were no risk factors for late coronary lesions. Three hundred and forty surviving patients (340/357; 95.2%) were in NYHA functional class I. Treadmill test, which was performed on 217 patients (56.1%) at 14.3 ± 5.4 years after ASO, revealed that the maximum heart rate was 97.5 ± 7.6% of normal and peak oxygen consumption was 105.2 ± 20.5% of normal.
Conclusions: ASO was performed with satisfactory results in the overall survival and functional status. PS was the main reason for re-operation. Coronary lesions can appear late without any symptoms. Benefits of ASO can be achieved by long-term follow-ups of PS, AI and coronary lesions.