Use of tissue type plasminogen activator in neonates: case reports and review of the literature.

Recombinant tissue type plasminogen activator (rt-PA) has been used successfully in neonates for resolution of thrombotic processes, both arterial and venous. We report on 2 neonates with vena cava inferior thrombosis and with biochemical evidence of liver dysfunction in whom rt-PA treatment had to be interrupted because of significant bleeding tendency, without complete resolution of the thrombus. Therapy failure may be due to the age of the thrombus and the systemic way of administration, bypassing the site of the thrombus by collateral circulation. Impaired liver function may result in decreased degradation of rt-PA with prolonged effect and higher risk for bleeding complications. We suggest that lower doses should be administered in these patients.