Intraarterial thrombolysis and the role of intensive care in acute ischaemic stroke

Thrombolytics have the potential to reduce disability of acute ischaemic stroke patients without increasing mortality, if patients are carefully selected. Per 1000 patients treated 110-150 less will be disabled. Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) given within 3 hours after stroke onset has been shown to reduce the rate of long-term-disability significantly. The clinical benefit of intraarterial thrombolysis in acute stroke patients with M1 or M2 occlusion of the middle cerebral artery, when performed up to six hours of symptom onset, has recently been proved in a randomised trial. In addition, several case series indicate that intraarterial thrombolysis and intravenous thrombolysis can be administered safely in clinical practice and improve clinical outcome when the occluded vessel is recanalised. In acute stroke due to basilar artery occlusion intraarterial thrombolysis is a therapeutic option at longer time intervals in specialist stroke centres. Several series of patients with basilar artery occlusion suggest that intraarterial thrombolysis has the potential to enhance the chances of basilar artery recanalisation and improve clinical outcome. In some of these studies, using various thrombolytic agents and intervals to treatment, an association between vessel recanalisation and clinical outcome was described. The percentage of patients with a favourable functional clinical outcome is more than 50% when early recanalisation of the basilar artery can be achieved and very low when the artery remains occluded. To date, no randomised controlled trial has compared intraarterial thrombolysis and intravenous thrombolysis. Intraarterial thrombolysis has several advantages: arteriography assesses the complete vessel status and collateral circulation.The thrombolytic medication can be applied directly into the thrombus. Vessel recanalisation as well as reocclusion are visualised directly, and in the case of rapid recanalisation, the infusion of the thrombolytic drug can be stopped before the maximum dose is applied. If pharmacological thrombolysis cannot be achieved, mechanical recanalisation procedures like thrombus perforation, thrombaspiration or percutaneous transluminal angioplasty are alternative or adjunctive strategies. In addition, mechanical recanalisation can sometimes be timesaving and achieved within a few minutes and faster than pharmacological reopening of the vessel. Limitations of intraarterial thrombolysis include the potential risk of arteriography, the time delay due to diagnostic arteriography and that it can only be applied at institutions with an experienced interventional neuroradiology team. Bleeding represents a hazard as with intravenous thrombolysis. Another major advantage of intraarterial thrombolysis is the extended time window up 6 hours compared to the 3 hours of intravenous thrombolysis. Therefore, intraarterial thrombolysis increases the number of patients who are eligible for thrombolysis. Nevertheless, campaigns and protocols for early referral to stroke centres and a standardised treatment algorithm are urgently needed. Educational programs for both the physicians and the public have the potential to increase the percentage of patients admitted to stroke centres within the time window for thrombolysis.