The purpose of this study is to evaluate the effectiveness, long-term safety and explore the safety and efficacy factors WILLIS™ intracranial stent graft system in clinical applications.

Intracranial aneurysm is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel.WILLIS® intracranial stent graft system is indicated for the treatment of intracranial aneurysms.

This study is a multi-center, prospective registration study.

Recruiting 100 specific patients to undergo a treatment with the WILLIS intracranial stent graft system, while giving the anti-platelet aggregation drugs and other medical therapy.

Patients enrolled will undergo a one-year follow-up.

Inclusion Criteria:

• Age over 18;
• Arterial wall defects conformed by imaging examination due to internal carotid artery, vertebral artery aneurysms or various causes;
• Target lesion vessel reference diameter 3.5-4.5mm;
• Investigators believe that the patient is suitable for the interventional therapy of WILLIS intracranial covered stent;
• Participate in the study voluntarily, accept follow up study and signed Informed Consent Form.

Exclusion Criteria:

• Existence of branch artery (eg anterior choroidal artery, posterior communicating artery, posterior inferior cerebellar artery, etc.) of target lesion which may cause severe neurological dysfunction after occlusion;
• No suitable vessel entrance, or diseased artery extremely tortuous;
• Coagulation disorders or serious heart, liver, kidney dysfunction or systemic infection, which not suitable for interventional treatment;
• Life expectancy <1 year;
• Contraindications to heparin, aspirin, clopidogrel, anesthesia, X-ray or contrast agents;
• Mental disorder