Abstract: Objective  To explore the effects of different urokinase thrombolysis methods on the four-year patency rate of tunneled-cuffed catheters (TCC).  Methods  Clinical data of the 96 patients undergoing maintenance hemodialysis using TCC in the Blood Purification Center of Guangdong Provincial People's Hospital from June 2021 to May 2024 were retrospectively analyzed. According to the method of urokinase thrombolysis therapy when the patients first showed insufficient flow or embolism in TCC, they were divided into two groups: the lock-tube thrombolysis group and the pre-hemodialysis intravenous bolus thrombolysis group. In the lock-tube thrombolysis group, each side of the catheter was configured with 1 ml of normal saline + 125,000 units of urokinase + 1 ml (6,250 units) of heparin sodium, and locked according to the lumen volume. In the pre-hemodialysis intravenous bolus thrombolysis group, each side of the catheter was treated with 10 ml of normal saline + 125,000 units of urokinase, and pumped in at a constant speed of 30-60 minutes with a constant speed pump before hemodialysis. The four-year secondary patency rate of TCC was observed in the two groups.  Results  We collected the data of urokinase thrombolysis therapies for TCC in 96 patients, including 11 cases (14.5%) in the pre-hemodialysis intravenous bolus thrombolysis group and 85 cases (85.5%) in the lock-tube thrombolysis group. COX univariate Kaplan-Meier survival analysis showed that there was no statistically significant difference in the four-year secondary patency rate of TCC between the two groups (HR=0.333, 95% CI: 0.044～2.530, P=0.239). The one-year, two-year, three-year, and four-year secondary patency rates of TCC were 90.9%, 72.7%, 54.5%, and 27.3% respectively in the pre-hemodialysis intravenous bolus thrombolysis group, and were 64.7%, 42.4%, 22.4%, and 15.3% respectively in the lock-tube thrombolysis group.  Conclusion  There is no significant difference in the secondary patency rate between the lock-tube thrombolysis group and the pre-hemodialysis intravenous bolus thrombolysis group. Survival curve analysis shows that the pre-hemodialysis intravenous bolus thrombolysis method using 10 ml of normal saline+125,000 units of urokinase has a tendency of better secondary patency rate of TCC, but no statistical significance existed between the two groups probably due to insufficient sample size. Further verification of this hypothesis requires prospective research in the future.

Key words: Tunneled-cuffed central venous catheter, Urokinase thrombolysis, Urokinase lock-tube, Secondary patency rate