Thirty-two patients with acute and subacute limb-threatening peripheral arterial ischaemia were treated with low dose intra-arterial streptokinase infusions. The mean duration of infusion was 38 h. Six patients developed pericatheter thrombosis and two had distal embolization of fragments of thrombus but in all cases these responded to repositioning the catheter and continuing the infusion. Five patients developed groin haematomata and in three of these there was evidence of a systemic fibrinolytic effect from the streptokinase with plasma fibrinogen reduced below 1 g/l. The most serious complication was perforation of the popliteal and tibial arteries which occurred on two occasions and required cessation of the infusion. Twenty-two patients (69 per cent) achieved limb salvage, eight (25 per cent) suffered a major amputation and two (6 per cent) died. The outcome was not related to the site, nature or duration of the arterial occlusion but patients with loss of sensation or paralysis of the affected limb were significantly less likely to obtain limb salvage (P = 0.001). For occlusions greater than 30 cm in length a new technique was used where the thrombus was lysed from distal to proximal in short lengths by gradual catheter withdrawal. This was successful in five out of six cases. Low dose intra-arterial streptokinase has been confirmed as an effective, relatively safe method of treatment in recent arterial ischaemia and can be recommended in situations where the results of surgery may not be favourable. In particular, patients with arterial thromboses and no distal run-off, distal and late arterial emboli, thrombosed popliteal aneurysms and patients after a failed embolectomy, have all been shown to respond to thrombolytic therapy with intra-arterial streptokinase.
