ABSTRACT
The saccular or fusiform dilatation of the ductus arteriosus is called aneurysm (DAA). It is diagnosed in the second trimester during a structural ultrasound. Even though the reported incidence is 2.2%, it remains infrequent, because it is not searched routinely. The pathogenesis is uncertain, resulting from an increase on the circulating blood volume thus in the cardiac afterload, associated to a thinning of the vessel wall, for an inadequate intima development. Ductus arteriosus aneurysm can be classified according by their diameter as small (<7 mm.) and large (> or =8 mm). The smaller commonly closes spontaneously in 70% of the cases, unlike the larger one, they are associate in a greater number of complications, such as thrombosis, embolism, infection, compression effects of adjacent structures and spontaneous rupture. The absence of spontaneous closure, according to the symptoms and possible complications, a neonatal surgical closure should be considered. We report a case of a 35-year-old patient, diagnose on the 35 week pregnancy, a ductus arteriosus aneurysm by ultrasound with an image of the three vessels performed communicating, saccular dilatation of 7-8 mm. and a turbulent Doppler flow.
