Successful thrombolysis of neonatal bilateral renal vein thrombosis originating in the IVC

We describe a case of inferior vena cava thrombosis (IVC) leading to bilateral renal vein thrombosis and renal failure in a neonate, which was successfully treated by thrombolysis. A male neonate, born at term by vaginal delivery (Apgar score 9–10–10) and weighing 4210 g at birth after a normal pregnancy, presented at 9 days of age due to failure to thrive and gross haematuria. At admission the child weighed 4200 g and appeared to be dehydrated. He was anuric with a serum creatinine of 222 μmol/L (reference 14–37 μmol/L), severe metabolic acidosis and respiratory difficulties. He had a palpable abdominal mass on the left side of the abdomen. Ultrasound examination showed enlarged hyperechogenic kidneys, especially on the left side. The renal veins and IVC could not be visualised. Magnetic resonance (MR) angiography revealed thrombosis of the IVC from the bifurcation up to the hepatic veins (Fig. 1a, b) and extending into both renal veins. There was no evidence of adrenal haemorrhage. Treatment with warfarin (Waran; Nycomed, Zurich, Switzerland) was initiated (Fig. 1c), and systemic lowmolecular weight heparin (LMWH) (dalteparin sodium, Fragmin; Pfizer, New York, NY). The dose was adjusted by following levels of anti-Factor Xa geared at 0.5–1.0 kIE/L. Because the ultrasound did not show any change in the size of the thrombus, warfarin was discontinued, and local fibrinolysis was initiated [1, 2]. An angio-catheter was inserted into the occluding thrombus in the IVC, and continuous infusion of recombinant tissue plasminogen activator (rt-PA) (Actilyse; Boehringer, Ingelheim, Germany) was administered at 0.1 mg/kg/hour. The rt-PA treatment was monitored by an analysis of plasma fibrinogen levels. Systemic LMWH was continued in order to prevent thromboembolism, and fresh frozen plasma was infused daily. Cranial ultrasound was performed daily due to the risk of intracranial haemorrhage. Three days after the patient had been admitted, systemic LMWH was switched to unfractionated heparin (LEO Pharma, Ballerup, Denmark) infusion because the level of anti-FXa was too low. The dose of unfractionated heparin was monitored by activated clotting time targeted at 180–200 s. Local rt-PA treatment was discontinued due to excessive bleeding from the peritoneal dialysis catheter insertion site. Pediatr Nephrol (2009) 24:2069–2071 DOI 10.1007/s00467-009-1172-3