Study	Reason for exclusion
Compter 2015	The trial recruited 115 people with vertebral atherosclerotic stenosis, but only 16.5% of participants had intracranial vertebral stenosis, and we were unable to obtain detailed data for these participants.
Coward 2007	The trial enroled only 16 people with vertebral atherosclerosis, including the extracranial and intracranial artery, to compare ET versus best medical treatment. We were unable to obtain detailed data for the participants with ICAS.
Markus 2017	The trial recruited 179 people with vertebral atherosclerotic stenosis, but only 17.3% of participants had intracranial vertebral stenosis, and we were unable to obtain detailed data for these participants.

ET: endovascular therapy; ICAS: intracranial artery stenosis.