Congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries is a complex and rare cardiac malformation; the management of this defect should be based on the knowledge of anatomy, physiology, and natural history. It may present as an isolated defect but is frequently associated to other cardiac defects, such as ventricular septal defect, pulmonary stenosis, and Ebstein’s anomaly of the tricuspid valve. The morphologic left atrium is connected to the morphologically right ventricle across the tricuspid valve, and the latter is connected to the aorta; the morphologically right atrium connects to a left ventricle that is related to the pulmonary artery. Because of this double discordance, the systemic venous return is pumped to the lungs, while the pulmonary venous return is directed to the systemic circulation. Symptoms are produced not by the segmental arrangement of the cardiac components but by the presence of associated anomalies, and symptoms or complications of the defect may present early in infancy or later in adulthood. Surgical management of such an anomaly requires a highly dedicated team. It may include palliative and/or non-anatomic repair or anatomic repair. Anatomic repair is the preferred approach and usually consists of an atrial switch either by Senning or Mustard operations associated with an arterial switch operation, when there is no pulmonary stenosis, or with a Rastelli procedure in presence of right outflow tract obstruction. Physiologic repair by ventricular septal defect closure alone or in association with left ventricle-to-pulmonary artery conduit might be achieved in selected cases. In some cases, single-ventricle palliation with total cavo-pulmonary connections may be appropriate. Heart transplantation may be indicated in the presence of systemic ventricular failure. Surgical mortality after the anatomic repair should be expected to be below 10 %, with a 75 % freedom of reoperation rate at 10 years. Comparison between physiologic versus anatomic repair remains difficult because there is no long-term follow-up for the latter technique and because the surgical eras are drastically different. Congenitally corrected transposition, when associated with other cardiac defects, can be managed with anatomic repair with good results. Nevertheless, long-term outcome data demonstrating superiority of anatomic repair is lacking.