A rare heart defect characterized by complete lack of anatomical continuity between the transverse aortic arch and the descending thoracic aorta. AAI should be distinguished anatomically from atresia of the aortic arch where continuity between these segments is achieved by an imperforate fibrous strand of various lengths.

A hemangioma is a benign tumor characterized by blood-filled spaces lined by benign endothelial cells. A hemangioma characterized by large endothelial spaces (caverns) is called a cavernous hemangioma (in contrast to a hemangioma with small endothelial spaces, which is called capillary hemangioma).