PURPOSE:To compare central dialysis catheter patency rates after stripping procedures with those after urokinase (UK) infusion. MATERIALS AND METHODS:Fifty-seven tunneled catheters with either (i) flow rates less than 250 mL/min and established baseline flow rates > or = 300 mL/min or (ii) flow rates 50 mL/min less than higher established baseline flows were prospectively randomized to undergo stripping procedures (n = 28) or UK infusion (n = 29) at 30,000 U/h via each port concurrently, for a total 250,000 U. Success and patency were determined by dialysis at normal flow rates (> or = 300 mL/min) or at the previously established higher baseline rate. Flow rates were monitored weekly. Primary patency ended with catheter malfunction or removal. Kaplan-Meier survival analysis was used to construct survival curves. RESULTS:In the stripping group, initial clinical success was 89% (25 of 28). The 15-, 30-, and 45-day primary patency rates were 75% (n = 20), 52% (n = 13), and 35% (n = 8), respectively. The median duration of additional function was 32 days (95% CI: 18-48 d). In the UK group, initial clinical success was 97% (28 of 29). The 15-, 30-, and 45-day primary patency rates were 86% (n = 21), 63% (n = 13), and 48% (n = 9), respectively. The median duration of additional patency was 42 days (95% CI: 22-153 d). The Wilcoxon test for equality detected no significant difference in the survival curves for the two treatment groups (P = .236). CONCLUSION:There is no significant difference in time to primary patency between the two methods. Both allow temporary catheter salvage in most patients.