Low-dose fibrinolytic therapy for recent lower extremity thromboembolism.

Low-dose catheter-directed fibrinolytic therapy (LDCF) using streptokinase (35) and urokinase (7) was performed on 42 separate occasions in 36 patients for recent lower extremity thromboembolic occlusion. Twenty-seven grafts and 15 native arteries were treated. Causes of occlusion were known in 32 instances: native artery proximal or distal occlusive disease or both (18 vessels); bypass graft stenosis (6); aneurysm (2); embolus (4); and postangiography thrombosis (2). Twenty-nine infusions were technically successful, and patients were clinically improved by 26 of the treatments. Twelve patients had unsuccessful infusions and six underwent subsequent amputation. In all patients, infusions longer than 12 hours resulted in prolonged thrombin times and lowered plasma fibrinogen concentrations; one infusion was discontinued due to a low fibrinogen concentration. Complications occurred on 17 occasions and included hemorrhage (6), distal embolization (3), compartment syndrome (1), retrograde thrombosis during infusion (5), hypotension (1), and systemic fibrinogenolysis (1). The cumulative success rate was 44% +/- 9% at 24 months. Late rethrombosis (five instances) was more common in patients who had inflow or outflow structural lesions not corrected following successful fibrinolysis. LDCF is a useful alternative to other methods of treatment for recent onset lower extremity thromboembolic occlusion. Structural vascular lesions uncovered by successful infusion should be corrected immediately after infusion to ensure long-term patency.