Popliteal aneurysms identified by intra-arterial streptokinase: a changing pattern of presentation. Five patients presenting with chronic or subacute leg ischaemia due to thrombosed popliteal artery aneurysm are described. Only one of these aneurysms was diagnosed before intra-arterial streptokinase infusion, which successfully lysed the thrombus in all cases. One aneurysm had been symptomatic for 5 years and another for 2 years. Popliteal aneurysm may well be underdiagnosed as a cause of chronic leg ischaemia. 