Drug-coated Balloon for Endovascular Treatment Versus Aggressive Medical Management in High-Risk Symptomatic Intracranial Atherosclerotic Stenosis

Inclusion Criteria: 1. Age 18-80 years old, regardless of gender 2. Patients with symptomatic ICAS caused by stenosis of a major intracranial artery (the degree of ischemic stroke with target vessel stenosis within 90 days before enrollment is required to be 70-99%, or the degree of transient ischemic attack with target vessel stenosis is required to be 80-99%), standardized drug management of at least one antithrombotic drug and/or vascular risk factors 3. DSA or CTA confirmed that the stenosis degree of one main intracranial artery (internal carotid artery C4-C7 segment, middle cerebral artery M1 segment, vertebral artery V4 segment and basilar artery) was between 70% and 99% (measured by WASID method), and was corresponding to the clinical symptoms. The normal diameter of the proximal end of the target lesion was ≥ 2mm, and the length of the target lesion was ≤ 15mm 4. If the target lesion is located in the anterior circulation system (C4-C7 of the internal carotid artery or M1 of the middle cerebral artery), it is required that there is hypoperfusion in the blood supply area of the target vessel (at least one of the following conditions is met): ①head CTP or PWI showed that CBF in the target vessel area decreased significantly (the lesion side decreased by more than 30% compared with the opposite side); ②Cerebral infarction with hemodynamic abnormalities confirmed by head CT or MRI (such as watershed infarction); ③ASITN/SIR collateral circulation score based on DSA\<3 points) 5. Those who voluntarily participated in the study and signed the informed consent Exclusion Criteria: 1. Serious calcification of target vessels, or serious distortion of target vessels or anatomical factors make it difficult for interventional instruments to be in place 2. Severe stenosis or occlusion of extracranial or intracranial vessels in series at the proximal or distal end of the target vessel 3. Major surgical operations have been performed in recent 3 weeks 4. Cerebral hemorrhage, massive cerebral infarction (the infarct area is greater than 50% of the middle cerebral artery supply area; cerebellar infarction: the infarct diameter is greater than 3cm) and myocardial infarction have occurred in the past three months 5. The target lesion has undergone stent implantation before 6. Intracranial artery stenosis caused by non atherosclerotic lesions, including but not limited to: arterial dissection, moyamoya disease, vasculitis, radiation vascular disease or fibromuscular dysplasia 7. mRS score ≥ 3 8. Patients with coagulation dysfunction 9. Those who cannot tolerate anesthesia and anticoagulant drugs, are contraindicated or allergic to surgical drugs (paclitaxel, heparin, contrast agent, aspirin, clopidogrel, etc.), and are allergic to surgical instruments or operating devices 10. Platelet (PLT\<90×109/L),hematocrit (\<30%), international normalized ratio (INR)\>1.5, uncontrollable severe hypertension (systolic blood pressure\>180mmHg or diastolic blood pressure\>110mmHg),severe liver injury (ALT or AST more than 3 times the normal value), severe renal function injury (creatinine\>3mg/dl,\>265μmol/L),and severe insufficiency of other important organs such as heart and lung 11. The subjects participated in other clinical trials and have not completed the follow-up or the researchers judged that the patients' compliance was poor and they were unable to complete the follow-up as required 12. Pregnant or lactating women, or those who plan to become pregnant within one year 13. The disease will cause difficulties in treatment and follow-up evaluation (such as dementia or mental disorders, cancer, infection, severe metabolic diseases), and it is speculated that the life expectancy of the participants is less than 3 years 14. Other cases that clinicians think should be excluded