Aortic thrombosis diagnosed by ultrasound.

A neonate developed aortic thrombosis following catheterization of the umbilical artery. The thrombus was identified and followed up by ultrasonography. Fibrinolytic therapy led to the almost complete disappearance of the aortic thrombus but the child died of cerebral haemorrhage. Physicians should be alerted to the possibility of aortic thrombosis in neonates following umbilical arterial catheterization. Ultrasonography is an appropriate method for diagnosis and follow-up in these cases.