Congenital Aorto-Cardiac Connections (CACC) Revisited: Introduction of a Novel Anatomic-therapeutic Classification

Abnormal congenital aorto-cardiac communications (CACC) are a heterogeneous constellation of anomalies that provide an abnormal connection between the aorta and other cardiac chambers or structures, including the atria, ventricles, the main pulmonary artery, and the coronary sinus. The current terminology of CACC has significant errors and shortcomings including inconsistent and interchangeable use of terms of fistula and tunnel and lack of an inclusive classification with practical information on therapeutic management. The aims of this study were threefold: firstly, to perform a concise narrative review of congenital pathologic connections between the aortic root and cardiac chambers which include rupture of congenital sinus of Valsalva aneurysm, aorto-left ventricular and less commonly right ventricular tunnels, coronary cameral fistulas, and aorto-atrial communications; secondly, to investigate the differentiating features of the so-called aorta right atrial tunnel (ARAT), with and without coronary artery take-off from the tunnel, and coronary cameral fistula (CCF) by applying a differential diagnostic assistance toolbox to two groups of patients with ARAT and CCF; and lastly, to propose a practical and inclusive anatomic-therapeutic classification for CACCs. The two main cornerstones of the proposed classification are the type of the connector between the aorta and cardiac chamber (hole versus passage) and the nature of the connecting passage ( anatomic versus extra-anatomic). We classified CACCs into three types. Depending on the intramural versus extramural course of the extra-anatomic connecting passage, type 3 is further subdivided into type 3A and type 3B.