Severe aortic thrombosis in the neonate--successful treatment with low-molecular-weight heparin: two case reports and review of the literature.

Small- to moderate-sized aortic thrombi in the sick newborn are frequently demonstrated, however, severe aortic thrombosis is rarely encountered. We report two newborn infants presenting with signs of decreased lower limb perfusion shortly after birth. An occlusive infrarenal aortic thrombus was demonstrated in both infants by ultrasound. No predisposing condition for thrombosis could be found in the first infant; in the second, an umbilical arterial catheter was the likely cause. The infants were successfully treated with low-molecular-weight heparin. In both infants resolution of the thrombus was observed by ultrasound. No complications of treatment were encountered. The clinical spectrum of neonatal aortic thrombosis and treatment options are reviewed.