Technique and results of "low-dose" infusion.

The results of 125 urokinase (UK) infusions in 108 patients were analyzed. Results showed total clot lysis in 61% of patients, partial lysis in 24%, and no lysis in 15%. Predictably, patients with acute occlusions had the highest incidence of complete clot lysis. However, clots older than 3 weeks had a surprisingly high lysis rate of 57%. None of the patients had a fibrinogen level below 100 mg/dL. Overall incidence of bleeding (major and minor) was 15%; patients having the most severe bleeding were on concomitant anticoagulation. We conclude that UK is a safe and effective therapeutic option in patients with acute and chronic obstruction. Significant bleeding episodes are uncommon during UK therapy and are related primarily to ongoing anticoagulation.