Background: Only individual cases or small series of neonatal thrombosis, treated with various drugs and dosages have been published. This report concerns 16 neonates treated with the same protocol.

Subjects: 16 neonates (renal venous thrombosis [n=7], renal arterial and/or aortic thrombosis [n=4], other venous thrombosis [n=4], limb arterial thrombosis [n=1]) over a 6 years period. Neonates with coagulation disorders, thrombopenia, hemorragic manifestations, or recent surgery were rejected.

Intervention: rt-PA was selected for its short half-life and less fibrinolysis activation. rt-PA infusion: 1 mg/kg over 3 hours was followed by heparin; additional infusions, up to 4, every 12-24 hours were administred if necessary.

Results: Efficacy was appraised by doppler ultrasonography. Flow restoration was complete in 8 patients, partial in 6, and absent in 2. No bleeding occured except in one patient included despite severe thrombopenia.

Conclusion: rt-PA for neonatal thrombosis is safe when exclusion criteria are observed. Failure of full flow restoration may be related to delayed therapy (5 cases) and could warrant trials with increased duration of rt-PA administration.