Intra-arterial streptokinase infusion in acute lower limb ischaemia

Atraumatic acute upper limb ischemia: a series of 64 patients in a Middle East tertiary vascular center and literature review

This paper documents the various causes of upper limb ischemia in a series of 64 Egyptian patients presenting to a tertiary referral center over a 4-year period and offers a diagnostic dissertation and review of the pertinent literature. Atraumatic upper limb ischemia is an uncommon entity. It has a broad etiology with diverse management pathways. Nineteen patients presented with severe and immediate limb-threatening ischemia. These patients underwent immediate surgical exploration: an embolus was diagnosed in 15 and thrombosis in 4. Twenty-eight patients presented with ischemia of lesser severity, allowing preoperative angiography. Of these 28 patients, 6 had an embolus, 14 had thrombosis, 4 had thoracic outlet syndrome, the remainder had miscellaneous causes. Fifteen patients had upper limb ischemia secondary to arteritis, and 2 patients with dissection of the ascending thoracic aorta presented with upper limb ischemia. Forty-seven patients underwent a surgical procedure, with a morbidity rate of 21% and mortality rate of 19%. Patients presenting with upper limb ischemia tend to have significant co-existing disease. Management of upper limb ischemia requires preoperative and/or peroperative angiography with careful application of vascular surgical expertise.

Lysis-assisted angioplasty in the treatment of lower-limb arterial thrombosis

This study examined the results in 30 patients treated with lysis-assisted angioplasty and compared them with the results of 30 patients with simple stenotic disease treated by angioplasty alone. One patient died on the day of treatment with lysis-assisted angioplasty from arterial perforation and haemorrhage. Of the remaining 29 patients 16 (55 per cent) were symptomatically improved and 13 had early reocclusion. Six patients developed major complications (two deaths, two major haemorrhage, two cerebrovascular accident). The late results were comparable to those for patients undergoing angioplasty alone. The best outcome was obtained in patients with proximal disease (P < 0.01); poor run-off or critical ischaemia did not preclude a good outcome.

Thrombolysis in acute lower limb ischaemia

For the past three decades balloon embolectomy has been the treatment of choice for acute lower limb occlusion. However, although usually successful in emboli, results are often disappointing in thrombotic atherosclerotic vessels. Attempted dissolution of the clot is accordingly attractive, and has theoretically been possible since the introduction of streptokinase in 1933. This was initially used intravenously, with variable success rates, although intraarterial administration is currently the method of choice. Later thrombolytic drugs such as tissue plasminogen activator, urokinase and anistreplase have been introduced. Lysis time has also been increased by using pharmaco-mechanical methods of administration such as pulsed spray catheters, which could increase the usefulness of thrombolysis in patients with rapidly progressive neurological signs where currently surgical embolectomy would be advocated. Several newer drugs with theoretical advantages over older drugs such as single-chain urokinase-type plasminogen activator or K1K2PU are currently undergoing trials. The role of thrombolysis as an adjunct to surgical embolectomy is also promising, though again requires further trials. There is still no consensus as to which patients are best suited to thrombolysis, nor an optimum drug or method of administration. However, there seems no doubt that thrombolysis will be increasingly used in the management of peripheral limb ischaemia, though requiring a team approach between surgeons, radiologists and haematologists.

Acute limb deterioration during intra-arterial thrombolysis

Approximately 12 per cent of limbs undergoing intra-arterial thrombolysis (IAT) develop distal embolism or extension of thrombus during the procedure. These are usually of little clinical consequence and can be treated by increasing the rate of administration of the lytic agent. However, in some patients the clinical condition of the limb deteriorates rapidly. In an attempt to define the incidence of acute limb deterioration during IAT, information was collected from five centres in the UK with experience of the technique. A total of 866 treatments were recorded, with 20 limbs (2.3 per cent) undergoing acute deterioration. This complication was more common during the treatment of thrombosed popliteal aneurysm than during that of emboli or thrombosed atheromatous arteries or grafts (P < 0.001). The amputation rate associated with the complication was high, and operative intervention provided better results than continuation of lysis.

Early results and 1-year follow-up after intra-arterial thrombolysis

Intra-arterial thrombolysis (IAT) was used as first-line treatment for 100 occlusions causing acute, subacute or chronic ischaemia. Streptokinase was used in 90 cases and tissue plasminogen activator in the remaining ten. Complete lysis, as determined radiologically, was achieved in 55 per cent of cases and partial lysis in 20 per cent. Lysis was more effective the earlier it was used. Major complications occurred in seven cases: five patients suffered major haemorrhage, two of whom died, and two had haemorrhagic cerebrovascular accidents. Of the patients with complete or partial clearance of thrombosis, 19 had no underlying apparent cause, 23 underwent angioplasty and 15 had an operation. The 1-year patency rate following complete lysis was 58 per cent. The 1-year patency rate after successful treatment commencing within 1 week of symptoms starting was 71 per cent, compared with 36 per cent for later treatment. Aortofemoral bifurcation grafts were cleared in three of five cases and all remain patent. Eight popliteal aneurysms were demonstrated by IAT and were ligated and bypassed; all these grafts remained patent at follow-up. IAT is less effective in chronic than acute occlusion. It should be reserved for patients in whom the occlusion is of short duration or for those with a thrombosed aortofemoral bifurcation graft or popliteal aneurysm.

Choice of agent for peripheral thrombolysis

Evidence has been accumulating that tissue plasminogen activator (tPA) is a more rapid and effective agent than streptokinase for peripheral thrombolysis. Twenty-three patients with acute limb-threatening ischaemia treated with tPA (0.5 mg h-1) over 15 months were compared with 20 consecutive patients previously receiving streptokinase (5000-10,000 units h-1). There were no major differences between the rates of complete and partial lysis (61 per cent for tPA versus 65 per cent for streptokinase) or limb salvage (65 versus 55 per cent respectively). Complication rates were also similar. It was not possible to show that tPA, an agent ten times more expensive than streptokinase, was superior for peripheral thrombolysis.