Double aortic arch: postnatal obliteration of the left aortic arch. Is arterial duct closure responsible?

We present a case of double aortic arch with a predominant right and a double arterial duct detected by echocardiogram in a 28-week gestation foetus. The first evaluation revealed that both arches were perfused; the 1-month postnatal echocardiogram showed the closure of both arterial ducts and the partial obliteration of the left aortic arch between the left subclavian artery and the dorsal aorta. In our case, the postnatal obliteration of the left arch in a double aortic arch was probably due to the closure of the left-sided arterial duct.