The primary objective of this trial is to evaluate the safety and efficacy of SINOMED IS- DES in patients with symptomatic intracranial atherosclerotic stenosis.

This study is a prospective, multicenter, objective performance criteria clinical trial to evaluate the safety and efficacy of intracranial self-expanding drug stent system in the treatment of symptomatic intracranial atherosclerotic stenosis. A total of 128 patients are planned to be included. The primary endpoint is the incidence of In-stent restenosis at 6 months after operation (ISR is defined as stenosis greater than 50% within or immediately adjacent (within 5 mm) to the implanted stents and absolute luminal loss greater than 20% at 6 months follow-up imaging.). All patients will have clinical follow-up during intraoperative, 30 days, 6 months, 1 year.

Inclusion Criteria:

1. 30 to 75 years of age;
2. Patients with symptomatic intracranial atherosclerotic stenosis who failed antiplatelet therapy or poor collateral circulation compensation or hypoperfusion in the territory of the culprit artery;
3. Digital Subtraction Angiography(DSA) showed 70% to 99% stenosis in target intracranial artery
4. The target lesion was in the internal carotid artery (intracranial segment), middle cerebral artery, vertebral artery (intracranial segment), basilar artery, and it was a single lesion that required surgical treatment;
5. The target lesion reference diameter must be visually estimated to be ≥2.0 mm and <4.5mm in diameter, and lesion length of ≤34 mm;
6. mRS < 3;
7. The onset of the latest transient ischemic attack (TIA) was not limited or ischemic stroke occurred within 2 weeks prior to stenting procedure;
8. Willingness to participate in this clinical trial and signing the consent form, and be able to complete the corresponding inspections, follow-ups, etc. according to the requirements of the clinical protocol during the clinical trial.

Exclusion Criteria:

1. The target vessels was complete occlusion;
2. >70% stenosis observed at the intracranial large-vessel distal to the target vessel or >70% stenosis observed at the intracranial/extracranial large-vessel proximal to the target vessel;
3. Preoperative magnetic resonance only showed perforating infarction in the target lesion area;
4. Preoperative CT or MRI showed that there was hemorrhage transformation after infarction in the target vessel area, or a history of primary cerebral hemorrhage, or a history of subarachnoid, subdural and epidural hemorrhage within 30 days before operation, or there was no treatment Chronic subdural hematoma ≥5mm;
5. Hospitalized surgical treatment within 30 days before operation, or planned hospitalized surgical treatment within 6 months after surgery;
6. CT showed Severe calcified lesions;
7. Previously received endovascular treatment or surgical intervention at the target vessel (except for patients with simple balloon dilatation);
8. Non-atherosclerosis lesions;
9. Patients with potential sources of cardiac embolism (such as atrial fibrillation, left ventricular thrombosis, myocardial infarction within 6 weeks);
10. Concomitant intracranial tumor, aneurysm or intracranial arteriovenous malformation;
11. Known hypersensitivity to aspirin, heparin, clopidogrel, rapamycin (sirolimus), lactic acid polymer, poly-n-butyl methacrylate, nickel-titanium alloy, or contraindications to anesthetics and contrast agents;
12. Hemoglobin <100g/L, platelet count <100*109/L, International normalized ratio (INR) >1.5 (irreversible) or uncorrectable hemorrhagic factors;
13. Uncontrollable severe hypertension (systolic blood pressure>180mmHg or diastolic blood pressure>110mmHg)；
14. Known liver or renal insufficiency (ALT> 3x upper limit or AST > 3x upper limit, Serum creatinine>250μmol/L);
15. Life expectancy < 1 year;
16. Pregnant/lactating female patients;
17. Patients with cognitive impairment or mental diseases (except for those with cognitive impairment due to arterial stenosis);
18. Patients who were participated in other clinical trials within 3 months or participating in other clinical trials who had not yet reached the primary clinical endpoint;
19. Inapplicable for intravascular stenting treatment as per investigators judgment.