Vascular dilatation Congenital malformation of the great arteries Dilatation of the ductus arteriosus 2016-03-14T07:14:07Z Ductus arteriosus aneurysm has been observed in patients with connective tissue disorders like Marfan and Ehlers-Danlos syndrome and in patients with chromosomal syndromes (e.g. Williams, Larsen, aneuploidies). Aneurysm is considered a severe form of dilatation. UMLS:C0398357 Congenital ductus arteriosus aneurysm SNOMEDCT_US:233990006 Aneurysm of the ductus arteriosus Ductus arteriosus aneurysm (DAA) is a saccular dilatation of the ductus arteriosus. DAA can be either congenital or acquired (e.g. as a complication of surgical closure of a patent ductus arteriosus). Although the majority of patients with congenital DAA are asymptomatic and have a benign course, severe complications, such as rupture or thromboembolism, can occur. DAA is likely to emerge in the third trimester from the aortic junction of the DA, extending towards its pulmonary end. Ductus arteriosus aneurysm