A systematic review of the clinical effectiveness of emergency endovascular therapy using mechanical thrombectomy in acute ischaemic stroke: implications for service delivery.

backgroundTwelve randomised controlled trials (RCTs) comparing mechanical thrombectomy against traditional treatment options for patients experiencing acute ischaemic stroke (AIS) have been published.

aimsTo evaluate whether this technology is more effective and/or safer than traditional treatment options and to assess the potential for implementation of this technology as a treatment strategy for acute ischaemic stroke in Ireland.

methodsRCTs published up to February 2017 were included. Meta-analysis was performed for two primary (mortality at 90 days, mRS at 90 days) and four secondary outcomes. Cumulative meta-analysis was used to investigate the point at which a consistent treatment effect was observed for outcomes that had a statistically significant pooled effect.

resultsMechanical thrombectomy was associated with higher likelihood of being independent (mRS, p < 0.01; Barthel index, p < 0.01) at 90 days post-AIS (p < 0.001). Cumulative meta-analysis demonstrated a consistent treatment effect in favour of mechanical thrombectomy after each trial was added to the analysis. There was no evidence of a difference in mortality rates (p = 0.21) or rates of SICH (p = 0.71) between patients randomised to intervention and control arms. Although the intervention appears to be associated with higher rates of any cerebral haemorrhage (p < 0.01) and recurrent ischaemic stroke (p = 0.03), considerable uncertainty remains as to these treatment effects.

conclusionsThe trials published most recently have acted as a 'watershed' for mechanical thrombectomy, and while there are significant caveats, the data suggests that mechanical thrombectomy needs to be factored into the planning and delivery of services for the management of patients with acute ischaemic stroke in Ireland.