Although intravenous thrombolysis increases the probability of a good
functional outcome in carefully selected patients with acute ischemic
stroke, a substantial proportion of patients who receive thrombolysis do not
have a good outcome. Several recent trials of mechanical thrombectomy appear
to indicate that this treatment may be superior to thrombolysis. We
therefore conducted a systematic review and meta-analysis to evaluate the
clinical effectiveness and safety of new-generation mechanical thrombectomy
devices with intravenous thrombolysis (if eligible) compared with
intravenous thrombolysis (if eligible) in patients with acute ischemic
stroke caused by a proximal intracranial occlusion. We systematically
searched seven databases for randomized controlled trials published between
January 2005 and March 2015 comparing stent retrievers or thromboaspiration
devices with best medical therapy (with or without intravenous thrombolysis)
in adults with acute ischemic stroke. We assessed risk of bias and overall
quality of the included trials. We combined the data using a fixed or random
effects meta-analysis, where appropriate. We identified 1579 studies; of
these, we evaluated 122 full-text papers and included five randomized
control trials (n=1287). Compared with patients treated medically, patients
who received mechanical thrombectomy were more likely to be functionally
independent as measured by a modified Rankin score of 0-2 (odds ratio, 2.39;
95% confidence interval, 1.88-3.04; I2=0%). This finding was
robust to subgroup analysis. Mortality and symptomatic intracerebral
hemorrhage were not significantly different between the two groups.
Mechanical thrombectomy significantly improves functional independence in
appropriately selected patients with acute ischemic stroke.