ABSTRACT
The authors report the case of a neonate presenting with a distended abdomen and shock from factor IX (F.IX) deficiency and intrahepatic bleeding. After resuscitation and treatment with recombinant F.IX through a central venous line, he developed superior vena cava, upper extremity, and intracerebral venous thrombosis resulting in superior vena cava syndrome and intrathalamic hemorrhage. He was treated with F.IX to achieve near-normal F.IX activity levels and with low-dose unfractionated heparin with clinical improvement. F.IX replacement on a subsequent admission was again complicated by upper venous system thrombosis and improved with low-dose heparin. The case illustrates an unusual presentation of hemophilia, life-threatening thrombotic complications associated with factor replacement, and a strategy for anticoagulant management in the setting of hemophilic bleeding.
