AcoArt VI / Vertebral Artery Ostium Stenosis in China

Inclusion Criteria: * aged between 18 and 80 years old * symptomatic VAO stenosis refractory to AMM (aggressive medical management) * etiology of VAOS was atherosclerosis * the diameter of the normal segment of the artery beyond the stenosis between 3mm and 5mm * Target lesion has stenosis ≥ 70% evidenced by angiography * Score on the modified Rankin scale ≤ 3 * NIHSS≤ 6 * Patients have signed informed consent Exclusion Criteria: * In-stent restenosis in vertebral artery * Severe calcified lesion or residual stenosis ≥30% after predilatation or flow-limiting dissection * Tortuous or variable vessels * distal serial stenosis or distal vascular dysplasia of the stenosis segment * Non-atherosclerotic arterial stenosis * Non-vertebral artery stenosis caused TIA or stroke * intracranial stent implantation within 12 months * Intracranial hemorrhage occurred within 3 months * Obvious thrombosis in brain vessel, or have received thrombolytic therapy 24 hours before procedure * Active bleeding or coagulation disorders * Serious liver/kidney damage, not suitable for routine surgical treatment * Myocardial infarction or extensive cerebral infarction occurred within 2 weeks * Uncontrolled high blood pressure * Complicated intracranial tumor, cerebral arteriovenous malformation, or intracranial aneurysm * Potential sources of cardiogenic thrombosis, such as mitral stenosis, atrial septal defect, aorta or mitral valve replacement, left atrial myxoma, etc * Life expectancy shorter than 1…