Intraoperative fibrinolytic therapy: experimental evaluation

Percutaneous intra-arterial infusion of fibrinolytic agents has emerged as an alternative to embolectomy in selected patients with acute arterial occlusions. The combination of fibrinolytic therapy and embolectomy may be superior to either modality alone. This experiment was designed to determine safety and efficacy of intraoperative fibrinolytic therapy as an adjunct to catheter embolectomy. Forty hind limbs in 20 adult mongrel dogs were embolized with thrombus created in vitro. After 24 hours, bilateral transfemoral embolectomy was followed by intra-arterial, intraoperative infusion. Fifteen limbs (control) received 250 ml of saline solution during a 30-minute period; 25 limbs (experimental) received an arterial infusion of 60,000 units of streptokinase during a 30-minute period (SK 30'). In five limbs of each group, 500 units of heparin (H) was added. In five experimental limbs the streptokinase infusion time was increased to 60 minutes (SK 60'). Arteriograms and blood flow measurements were obtained before and after embolectomy (PE) and after infusion (PI); the results were compared. Improvement between the PE and PI angiograms was seen in 20% (3 of 15 dogs) of control subjects. In contrast, improvement after the infusion was evident in 100% (5 of 5 dogs) of dogs given SK plus H 30' (p less than 0.01), in 80% (12 of 15 dogs) of dogs given SK 30' (p less than 0.01), and in 20% (1 of 5 dogs) of dogs given SK 60'. A trend toward increased blood flow was noted in the experimental group. There were no intraoperative complications with hemostasis or postoperative bleeding (36-hour observation). We conclude that intraoperative fibrinolytic therapy in dogs is safe and effective as an adjunct to thromboembolectomy. A human clinical trial is recommended.