Efficacy and safety of heparin anticoagulation for neonatal renal vein thrombosis.

Purpose: We report on the safety and efficacy of heparin anticoagulation for the treatment of neonatal renal vein thrombosis.

Patients and methods: Six consecutive, prospectively identified, critically ill neonates with renal vein thrombosis were studied. Diagnosis of renal vein thrombosis was based on history and examination and confirmed with renal ultrasound. All neonates were treated with continuous i.v. heparin titrated to achieve a therapeutic whole blood clotting time and/or APTT.

Results: Renal vein thrombosis was bilateral for three of six neonates. Heparin infusion rates varied from 8 to 40 U/kg/h and were administered for 7-14 days. Two neonates developed hemorrhagic complications; one had disseminated intravascular coagulation but did not hemorrhage until heparin toxicity ensued, and another was well until an umbilical catheter was removed while he was therapeutically heparinized. Renal outcome at 3 months to 6 years showed hypertension in one neonate, atrophic kidneys in two, and both hypertension and an atrophic kidney in one.

Conclusions: Bleeding was a significant complication of heparin therapy for neonatal renal vein thrombosis. Renal dysfunction was not prevented in four of six neonates treated with heparin. Alternative approaches to titrate heparin, alternative anticoagulants, or fibrinolytic therapy should be considered as therapy for neonatal renal vein thrombosis.