Supplementary Material for: Risk of Intracranial Hemorrhage after Endovascular Treatment for Acute Ischemic Stroke: Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Intracranial hemorrhage is a major complication of endovascular treatment in patients with acute ischemic stroke. Controlled clinical trials reported varied incidences of intracranial hemorrhage after endovascular treatment. This meta-analysis aimed to estimate whether endovascular treatment, compared with medical treatment, increases the risk of intracranial hemorrhage in patients with acute ischemic stroke. <b><i>Methods:</i></b> The current publications on endovascular treatment for acute ischemic stroke were systematically reviewed. Rates of intracranial hemorrhage after endovascular treatment for acute ischemic stroke reported in controlled clinical trials were pooled and analyzed. Random and fixed-effect models were used to pool the outcomes. For analyzing their individual risks, intracranial hemorrhages after endovascular treatment were classified as symptomatic and asymptomatic. <b><i>Results:</i></b> Eleven studies involving 1,499 patients with endovascular treatment and 1,320 patients with medical treatment were included. After pooling the data, the risk of any intracranial hemorrhage was significantly higher in patients with endovascular treatment than in patients with medical treatment (35.0 vs. 19.0%, OR = 2.55, 95% CI: 1.64-3.97, <i>p &lt; </i>0.00001). The risk of asymptomatic intracranial hemorrhage was also significantly higher in patients with endovascular treatment than in those with medical treatment (28 vs. 12%, OR = 3.16, 95% CI: 1.62-6.16, <i>p </i>&lt; 0.001). However, the risks of symptomatic intracranial hemorrhage were similar in patients with endovascular treatment and in those with medical treatment (5.6 vs. 5.2%, OR = 1.09, 95% CI: 0.79-1.50, <i>p</i> = 0.61). <b><i>Conclusion:</i></b> Although the risk of any intracranial hemorrhage may increase after endovascular treatment, the risk of symptomatic intracranial hemorrhage may remain similar as compared with medical treatment.