Animal model of acute pulmonary thromboembolism treated by local recirculation of streptokinase through the lung.

Massive acute pulmonary thromboembolism has a high mortality within the first few hours. Surgical intervention can remove only larger thrombi. Systemic fibrinolytic administration requires many hours for adequate treatment. We describe an anesthetized dog model of acute, massive, disseminated pulmonary thromboembolism achieved by injection of 1.7 ml/kg of 1-hour-old thrombi directly into the pulmonary artery. The emboli were lysed with 50,000 IU streptokinase recirculated for 20 minutes through the isolated pulmonary vascular bed by use of a roller pump while the systemic bed was supported by conventional cardiopulmonary bypass. On reestablishing natural circulation all hemodynamic parameters returned to preembolism values. Success of lysis was histologically confirmed. Perfusion of the pulmonary vascular bed without inclusion of streptokinase in the perfusate worsened the hemodynamic state of the animals compared with an untreated nonperfused control group.