Angioplasty and Stenting for Patients With Symptomatic Intracranial Atherosclerosis

Inclusion Criteria: * Patients aged from 18 to 70 years. * Complaints of a Symptomatic ICAS: a history of recurrent transient ischemic attacks or an ischemic stroke within 1 year owing to a 70%-99% stenosis in an internal carotid artery, middle cerebral artery, vertebral artery, or basilar artery. * A length ≤ 15mm of a stenosis in the target vessel and a vessel size \>2.5mm. * Hypoperfusion in the territory of the target vessels, which is determined by CT or MRI in 14 days before stenting. * CT or MRI scans show no massive cerebral infarction (beyond half of the territory of middle cerebral artery (MCA)), intracranial hemorrhage, epidural or sub-dural hemorrhage, and intracranial brain tumor. * Patients who understand the purpose of the study and have provided informed consent. Exclusion Criteria: * Not able to receive general anesthesia. * Not able to receive angiographic assessment. * A stenosis \>50% in an extracranial carotid or vertebral artery on the ipsilateral side. * Infarctions due to the perforators occlusion (determined by MRI scan), which is defined as basal ganglia or brainstem/thalamus infarction related with middle cerebral artery or basilar artery stenosis. * A high risk (leading to a stroke or death) to deliver the stent to the lesion. * A previous stent or angioplasty in the target lesion. * Progressive neurological signs within 24 hours before enrolment * Any haemorrhagic infarct within 14 days before enrolment * The presence of a cardiac source of embolus * Thrombolytic therapy within 24 hours before enrollment * Presence of intraluminal thrombus proximal to or at the target lesion * Myocardial infarction within previous 30 days * Non-atherosclerotic lesions: arterial dissection, moya-moya disease; vasculitic disease; herpes zoster, varicella zoster or other viral vasculopathy; neurosyphilis; any other intracranial infection; any intracranial stenosis associated with cerebrospinal fluid pleocytosis; radiation-induced vasculopathy; fibromuscular dysplasia; sickle cell disease; neurofibromatosis; benign angiopathy of central nervous system; postpartum angiopathy; suspected vasospastic process, and suspected recanalized embolus. * Known contraindications for aspirin and clopidogrel treatment. * An modified Rankin scale≥3. * With a childbearing potential or a positive pregnancy test in 1 week before enrolment.