“…Experimentally it has been shown that the plasminogen activators, streptokinase and urokinase, accelerate resolution of pulmonary emboli in animals (Browse and James, 1964;Genton and Wolf, 1967a). Angiographic improvement has also been documented after thrombolytic therapy in patients with severe pulmonary embolism (Hirsh et al, 1967;Sasahara et al, 1967;Sautter et al, 1967;Tow et al, 1967). However, further investigations are required before the place of thrombolytic therapy in the management of acute major pulmonary embolism can be clearly defined.…”