There is inadequate evidence to draw strong conclusions on the efficacy or safety of the drug interventions included in this review. There is some low quality evidence from a meta-analysis of two studies investigating urokinase (various strengths) and some very low evidence from two single studies investigating alteplase 2 mg/2 mL that suggest that these two drug interventions may be effective in treating withdrawal or total occlusion of CVC lumens caused by thrombosis. Further high quality, sufficiently powered research is still required to look at the efficacy and safety of urokinase, alteplase and other chemical, surgical and drug interventions for treating CVC lumen occlusion. Research studies which exclusively include child participants are especially warranted.
Low-dose urokinase infusions to treat fibrinous obstruction of venous access devices in cancer patients.
This study was undertaken to determine the role of low-dose urokinase infusions in treating fibrinous occlusions of venous access devices (VADs) in cancer patients.
                Forty-two patients with VAD occlusions refractory to routine urokinase instillations were documented by x-ray (cathetergram) to have fibrin sleeves at the catheter tips. They were randomized to receive infusions of either urokinase (40,000 U/h) or urokinase with heparin (320 U/h) through their catheters. After 1, 3, 6, and 12 hours of treatment, the function of the VADs was reassessed. Whenever the obstruction had been relieved, the infusion was stopped and a repeat cathetergram was performed. The status of the unoccluded catheters was followed to determine the longevity of the restored function.
                Twenty-one catheters were treated with urokinase alone and 21 with the combination of urokinase and heparin. In each group, 16 VADs opened within 12 hours of treatment and five did not. By actuarial analysis, the probability was only 0.28 that a reopened catheter would reocclude within 6 months.
                Low-dose urokinase infusions can restore function to the majority of catheters occluded by fibrin sleeves. Adding heparin to the urokinase does not enhance the efficacy of the infusions. The restored function often persists until the VADs are removed.