BACKGROUND: The optimal management of patients with symptomatic isolated internal carotid artery (ICA) occlusion is unknown. We aimed to assess whether endovascular treatment (EVT) compared with standard medical care was associated with improved functional outcomes in patients with acute symptomatic isolated intracranial ICA occlusion without involvement of the middle or anterior cerebral artery, that is, ICA-I occlusion. Additionally, we aimed to compare ICA-I with ICA-L/T occlusion, which involves themiddle and anterior cerebral artery, respectively.

METHODS: We analyzed data from the highly effective reperfusion evaluated in multiple endovascular stroke trials (HERMES) collaboration, which performed an individual patient data meta-analysis of 7 randomized controlled trials conducted between 2010 and 2017 assessing the benefit of EVT compared to medical management in patients with anterior circulation large vessel occlusion. We assessed the association between EVT and 90-day good functional outcome (modified Rankin scale scores 0-2), National Institutes of Health Stroke Scale scores at 24 hours, symptomatic intracranial hemorrhage rates and mortality in patients with ICA-I and ICA-L/T occlusion.

RESULTS: We included 442 patients with intracranial ICA occlusion, of whom 38 (8.6%) had ICA-I occlusion. In the ICA-I group, the median age [interquartile range] was 69.5 [61.7-79.5] years, 42.1% were male, and median baseline National Institutes of Health Stroke Scale was 17 [15-20]. Compared with standard medical care alone, EVT resulted in higher good outcome rates in patients with ICA-I (42.9% versus 25%; P=0.296) and ICA-L/T occlusion (32.5% versus 14.4%; P<0.001), and significant improvement in National Institutes of Health Stroke Scale scores at 24 hours. Mortality and symptomatic intracranial hemorrhage rates were similar between the treatment groups for both occlusion types.

CONCLUSIONS: A minority of patients with intracranial carotid occlusion presented with ICA-I occlusion in the HERMES population. EVT in patients with ICA-I occlusion and moderate-to-severe deficit was safe and tended to be similarly effective as compared to patients with ICA-L/T occlusion.