New Covered Stent (Willis) for the Endovascular Reconstruction of Intracranial Vessel Wall Defects Registry

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