Clinical course after arterial switch operation

This thesis reports on the outcome of patients with transposition of the great arteries (TGA) and surgical correction by the arterial switch operation (ASO). In our histological study, diffuse interstitial myocardial fibrosis was already found in uncorrected TGA newborns in the systemic right ventricle as well as in the subpulmonary left ventricle, suggesting that myocardial remodeling in TGA may already occur at the fetal stage. The ASO is nowadays associated with low mortality and therefore the attention is directed towards long-term sequelae. We demonstrated in adult TGA-ASO patients that coronary high-risk features, including acute coronary take-off angle and interarterial course were frequently found. However, the need for late coronary re-interventions appeared to be low. Furthermore, an ongoing dilatation of the neo-aortic root was observed. The clinical course of TGA-ASO patients is characterized by an ongoing need for re-interventions for right ventricular outflow tract (RVOT) obstruction, neo-aortic root dilatation or neo-aortic valve regurgitation. In patients with either a catheter or surgical RVOT re-intervention a significantly worse clinical performance was found compared to patients without previous RVOT re-intervention. The need for re-interventions indicates a strict lifelong surveillance in TGA-ASO, also during adulthood.