In Situ Thrombolysis for Late Occlusion of Suprafemoral Prosthetic Grafts

Low-dose urokinase was used to obtain in situ thrombolysis in the treatment of 20 late occlusions of suprafemoral prosthetic grafts in 19 patients. Aortofemoral or aortobifemoral bypasses with occlusion of one limb had been performed in nine patients, direct iliofemoral bypasses in six, crossover iliofemoral bypasses in two, and axillofemoral bypasses in three. Sixteen of the grafts were polytetrafluoroethylene and four were Dacron. Vascular surgery had been performed on an average of 3 years earlier. Thrombolysis was initiated on an average of 3 days after onset of occlusion. The protocol called for penetration of the thrombus with a 5 F catheter inserted through a brachial (12 cases) or femoral (eight cases) route. After initial injection of 2500 units of urokinase a continuous infusion of urokinase was begun at a dose of 2500 units/hr and heparin at 100 units/kg/12 hr. Clinical, biochemical (fibrinogen and activated cephalin time every 6 hours), and arteriographic surveillance was carried out every 12 hours with progressive mobilization of the catheter until complete clearance of the artery. Clearance was achieved in all cases. Anteroposterior and occasionally lateral arteriograms with the hip joint in flexion were obtained. An organic cause amenable to treatment was found in 16 cases, including distal or proximal lesions (two and 10 cases, respectively) and elongation/kinking (four cases). Endoluminal angioplasty, stenting, or endarterectomy (six cases) and conventional procedures (10 cases) were also performed. After treatment of the cause of thrombosis no further rethrombosis of the graft was observed (mean follow-up 26 months, range 3 to 50 months). The morbidity rate was 15% and was essentially due to thrombosis or hematoma at the sites of puncture of the brachial artery. No deaths occurred. The analysis of our experience shows that in situ thrombolysis with low-dose urokinase is efficacious. Furthermore, this technique also demonstrates the cause of occlusion, which then can be treated as appropriate.