Urokinase efficacy in the restoration of hemodialysis catheter function.

Thrombus formation is a common cause of hemodialysis catheter malfunction. When thrombus or fibrin sheath restrict the flow of blood through one or both lumens, the catheter may need to be replaced. A less invasive, potentially lower cost option may be the instillation of low dose urokinase to degrade fibrin and restore catheter function. This study examines the efficacy of urokinase in improving blood flow and maintaining catheter patency. In a one-year period, urokinase was utilized in 25 dual lumen hemodialysis catheters (20 temporary, five permanent) in 22 patients. Blood flow and arterial and venous pressures were monitored before and after instillation. Urokinase administration successfully restored function in 20 catheters (80%). Paired t-tests demonstrated a significant improvement in blood flow and arterial pressure (p < 0.01) following urokinase. Catheter patency was extended for a mean of 18.0 days (range 0-90 days). The cost effectiveness of urokinase was evaluated in terms of direct costs, such as the cost of urokinase or materials to replace catheters, and indirect costs such as nursing and physician time and delays in dialysis scheduling. The results of this study suggest that judicious use of urokinase is a cost-effective, non-invasive method of restoring blood flow and extending patency in hemodialysis catheters.