Forty-two patients received urokinase (40,000u/hr) through their venous access devices (VADs) to relieve obstruction caused by a fibrin sheath. Twenty-one of these also received heparin (320u/hr) with the urokinase. In each group 16 VADs opened within 12 hours of treatment. By actual analysis the probability was only 0.28 that a reopened catheter would reocclude within 6 months. The results have been published (Journal of Clinical Oncology 1997; 15:2709-2714) and the study terminated.
