Balloon-expandable DES for ICAS Registry Study (BDES-ICAS Registry)

Inclusion Criteria: 1. Age ≥ 18 years. 2. According to clinical and angiographic evidence, symptomatic intracranial arteries stenosis within 3 months include vertebral artery V4 segment or internal carotid artery C2-C7 segment, and the degree of diseased arterial stenosis is between 70%\~99% (WASID method). 3. Patients have more than 1 episode of symptoms including stroke or transient ischemia attack (TIA) after intensive medical treatment (including antiplatelet therapy, antihypertensive, hypoglycemic and lipid-lowering treatments). 4. Patients have at least 1 risk factor for intracranial atherosclerosis, including previous or existing hypertension, hyperlipidemia, diabetes mellitus, smoking, alcohol consumption, obesity, underlying heart disease, family history of atherosclerotic vascular disease, hyperhomocysteinemia and so on. 5. Baseline mRS score ≤3. 6. Patient or guardian signs informed consent. Exclusion Criteria: 1. Patients who cannot receive dual antiplatelet therapy due to existing diseases or with server coagulation dysfunction, uncontrolled serious infections, serious systemic diseases, uncontrollable hypertension and other conditions are not suitable for surgery. 2. Patients with aneurysm that cannot be treated in advance or at the same time or are not suitable for surgery. 3. Gastrointestinal disease with active bleeding. 4. Myocardial infarction or massive cerebral infarction within 2 weeks. 5. Patients with known severe allergies or contraindications to heparin, rapamycin, anesthesia and contrast media. 6. Life expectancy \<12 months. 7. According to the judgement of the investigator, other situations that are not suitable for enrollment.