Abstract
Background
Most disabling strokes are due to blockage of a large artery in the brain by a blood clot. Prompt removal of the clot with intra-arterial thrombolytic drugs or mechanical devices, or both, can restore blood flow before major brain damage has occurred, leading to improved recovery. However, these so-called percutaneous vascular interventions can cause bleeding in the brain.
Objectives
To assess the safety and efficacy of percutaneous vascular interventions in patients with acute ischaemic stroke.
Search methods
We searched the Trials Registers of the Cochrane Stroke Group and Cochrane Peripheral Vascular Diseases Group (last searched May 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 5), MEDLINE (1980 to May 2010), EMBASE (1980 to May 2010) and eight additional databases. We also searched trials registers, screened reference lists, contacted researchers and equipment manufacturers, and handsearched journals and conference proceedings.
Selection criteria
Randomised, controlled and unconfounded trials of any percutaneous vascular intervention compared with control in patients with definite ischaemic stroke.
Data collection and analysis
Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We obtained both published and unpublished data if available
Main results
We included four trials involving 350 patients. Not all trials contributed data to each outcome. The trials tested either intra-arterial urokinase or recombinant pro-urokinase versus an open control. One trial used guidewire-mediated clot disruption in some patients randomised to the intervention group. Most data came from trials that started treatment up to six hours after stroke; one small trial started treatment up to a median of 12.5 hours after stroke. Most data came from trials of middle cerebral artery territory infarction. Compared with non-thrombolytic standard medical treatment, the intervention administered up to six hours after ischaemic stroke significantly increased the proportion of patients with favourable outcome (modified Rankin 0 to 2) three months after stroke (relative risk (RR) 1.47, 95% confidence interval (CI) 1.07 to 2.02). The intervention also significantly increased the risk of symptomatic intracranial haemorrhage within 24 hours of treatment (RR 3.85, 95% CI 0.91 to 16.36). There was no significant heterogeneity between the included trials.
Authors’ conclusions
Overall, intervention results in a significant increase in the proportion of patients with a favourable outcome, despite a significant increase in intracranial haemorrhage. Further trials are needed to confirm or refute these findings and, given the cost and practical difficulties, to establish whether percutaneous techniques are feasible and cost effective in wider clinical practice.
Plain language summary
Percutaneous vascular interventions for acute ischaemic stroke
The majority of disabling strokes are due to blockage of a large artery in the brain by a blood clot. For these patients, the most intuitive means of treatment is removal of the blockage by either injecting clot-dissolving (thrombolytic) drugs directly into the clot or removal of the clot using a mechanical device, or both. Prompt treatment can restore blood flow before major brain damage has occurred, leading to a good recovery. However, these treatments can also cause bleeding in the brain with poorer outcomes. This review of four trials involving 350 participants indicated that this form of treatment can remove large artery blood clots and improve the chances of good recovery despite an increased risk of bleeding in the brain. Long term risk of death is unaffected. However, it is still not clear what the time window is within which treatment is beneficial, what types of arterial blockage are most likely to respond, whether mechanical devices are effective, and whether any of these treatments are better than standard intravenous thrombolytic drugs. More information is needed from forthcoming randomised trials to answer these questions.
