Purpose: Thrombotic complications in nephrotic syndrome due to renal loss of antithrombin III (AT III) are well known. With this case report, we want to demonstrate the possibility of achieving the lysis of such a thrombosis in the neonatal period with low-dose rt-PA.
Patients and methods: We treated a 10-day-old newborn who had congenital nephrotic syndrome, who developed a caval thrombosis during the first days of his life. After a trial of heparin (up to 20 IU/kg/hour) over a period of 24 hours and treatment with AT III (2 x 250 IU/day) proved to be ineffective, we started systemic thrombolytic therapy with rt-PA. An initial bolus of 0.4 mg/kg during 1 hour was followed by an infusion of 0.5 mg/kg/d rt-PA over a period of 36 hours. Low-dose heparin (5 IU/kg/hour) was given simultaneously. Complete clot dissolution could be achieved this way. No adverse effects were observed, including no clinical signs of bleeding.
Conclusion: It seems that low-dose rt-PA treatment is safe and effective in dissoluting large caval thromboses in neonates.