Urokinase Treatment for Aortic Thrombus in Preterm Infants

ABSTRACT

PURPOSE: Aortic thrombus is a rare but serious complication in neonates, usually associated with central vessel catheterization. Currently treatment of asymptomatic aortic thrombus in preterm infants is controversial. We evaluated effects of urokinase in preterm infants with aortic thrombi. METHODS: We studied 12 preterm infants in whom umbilical arterial catheterizations were performed and subsequently aortic thrombi were detected. In six patients bolus doses of urokinase 4, 400 IU/kg were injected, followed by continuous infusions of 4, 400 IU/kg/hr. The mean duration of urokinase use was 11 days (6-13 days). The other six patients who did not receive urokinase served as controls. The two groups were compared for changes in the size of thrombi. RESULTS: The initial sizes of aortic thrombi upon detection were similar, although the diagnoses were made earlier in urokinase group than in controls. The days to 50% reduction in size of thrombi were significantly shorter in urokinase group, as were the days to complete resolution. One infant in urokinase group and 2 infants in control group had persistent aortic thrombi up to 90 days of follow-up. Intracranial hemorrhage and disseminated intravascular coagulopathy were absent in all 12 cases. CONCLUSION: Urokinase administration could be an effective therapy for preterm neonates with aortic thrombi. It significantly reduces the size of the thrombus and shortens the days to complete resolution.