Aortic levopositions without ventricular inversion.

A multi-center series of aortic levoposition (aorta anterior and to the left of the pulmonary artery) without ventricular inversion is presented and analyzed from an anatomical viewpoint. All the cases are exceptions to the 'loop rule' and amount to 0.9% of the total number or cases reviewed. A combined study of our own cases and those reported in the literature is presented. There is a high incidence of anomalies (malrotations, juxtaposition of the atrial appendages, atrioventricular valve anomalies, ventricular septal defects, pulmonary outflow tract obstructions and abnormal conal types) which may be related to the primary cause of the aortic levoposition, suggesting that they may form part of a new syndrome of diagnostic and surgical importance. In some cases, absence of coronary sinus was noted without asplenia or left superior vena cava draining into the left atrium. The major coronary artery pattern in cases of antomically corrected malposition with two well-developed ventricles was similar to that seen with ventricular inversion. Most of these cases can be helped surgically provided accurate and detailed preoperative evaluation and operative assessment and treatment is carried out.