Urokinase infusion restores function of thrombotically-occluded inferior vena cava apheresis catheters refractory to bolus urokinase therapy

Translumbar inferior vena cava catheters have been shown to be safe and effective in providing venous access for apheresis collection of peripheral blood stem cells for transplantation. Thrombotic occlusion of these catheters can limit their effectiveness for apheresis. While some of these occlusions respond to installation of the 5000 unit "Open-Cath^®" dose of urokinase, there are no guidelines for therapy of occluded catheters not responding to this treatment. We have performed low-dose urokinase infusion on 11 IVC apheresis catheters radiographically documented to be occluded by thrombus. These catheters had failed a mean of 1.5-5000 unit boluses of urokinase. Seven catheters underwent urokinase infusion at 40,000 units/ h for 12 h. All had complete restoration of catheter function and 6 had total dissolution of thrombus on post-therapy X-ray. Because of the initial success of the 12 h infusion, we treated 4 catheters with the same dose of urokinase for 6 h. All 4 had complete restoration of catheter function and 2 had total thrombus dissolution on X-ray. No bleeding complications were seen. For occluded IVC apheresis catheters, initial therapy should be the installation of at least one 5000 unit bolus of urokinase. For catheters not responding to this therapy, radiographic evaluation should be conducted. If thrombotic occlusion is found, a 40,000 unit/h infusion of urokinase for 6-12 h can safely salvage catheter function and allow continued apheresis.