Feasibility of continuous, catheter-directed thrombolysis using low-dose urokinase in combination with low molecular-weight heparin for acute iliofemoral venous thrombosis in patients at risk of bleeding.

The present study aimed to examine the feasibility of catheter-directed thrombolysis (CDT) using continuous infusion of low-dose urokinase in combination with low molecular weight heparin (LMWH) for acute iliofemoral venous thrombosis. This retrospective analysis included patients with symptomatic acute iliofemoral venous thrombosis who received CDT using continuous infusion of low-dose urokinase in combination with LMWH within the past four years. Urokinase was administered at 1×104 U/h and 2×104 U/h in patients at high-risk and low-risk of bleeding, respectively. Measurements included urokinase dosage, duration, clinical outcomes and CDT-related complications. A total of 46 patients were included (high-risk, n=17; low-risk, n=29). In the high-risk patients, 64.7% experienced dissolution of ≥50% thrombi after a median CDT duration of 8 days (range, 6-10 days) and median total urokinase dose of 1.92×106 units (range, 1.44-2.4×106 units). In the low-risk patients, 82.8% achieved dissolution of ≥50% thrombi after a median CDT duration of 7 days (range, 4-10 days) and a median total urokinase dose of 3.36×106 units (range, 1.92-4.80×106 units). Remission of clinical symptoms after CDT was achieved in 15 (88.2%) and 28 (96.6%) cases in high-risk and low-risk patients, respectively. No treatment-associated pulmonary embolism or major bleeding was observed. Three (6.5%) subjects (high-risk, n=1; low-risk, n=2) experienced minor bleeding. In conclusion, continuous infusion of low-dose urokinase via CDT in combination with LMWH is effective and safe for acute iliofemoral venous thrombosis in patients with one or more risk factor for bleeding.