Safety and Performance of the Penumbra Liberty Stent in the Treatment of Wide-Neck, Saccular, Intracranial Aneurysms

Inclusion Criteria: * Patient from 18 to 85 years old * A symptomatic unruptured saccular intracranial aneurysm with a neck ≥4mm (or a dome to neck ratio \<2) and a parent vessel diameter between 2.5 to 5.0 mm (inclusive) in both the anterior and posterior circulation of the brain, that is amenable to stent-assisted coiling. "Symptomatic" is defined as any neurological symptoms attributed to the target aneurysm. * Life expectancy \>6 months * Signed Informed Consent Exclusion Criteria: * Aneurysm with branches from the aneurysm base * Rapidly growing aneurysm * Daughter aneurysm * Aneurysm with partial or complex calcifications * Females who are nursing, pregnant or intend to become pregnant during the study. Females of child-bearing potential must have a urinary pregnancy test within 7 days of enrollment and use an approved highly efficient contraceptive method during the study * Multiple untreated cerebral aneurysms at study entry * Recent history of stroke, TIA, subarachnoid hemorrhage, intracranial hemorrhage, or major surgery within one month of enrollment * Previous brain surgery or irradiation of the target treatment territory that would, in the opinion of the investigator, interfere with the treatment of the target aneurysm * Admission platelet \<150,000 or any known hemorrhagic diathesis, coagulation deficiency, or on oral anticoagulant therapy * Underlying unstable Coronary Artery Disease, cardiac insufficiency or Myocardial Infarction * Contraindication to angiography such as elevated creatinine or known allergy to angiographic contrast * Contraindication to CT and/or MRI scans * Known allergy to the metal component of the Penumbra Liberty Stent System * Evidence of active infection (WBC \>10x109/L) * Any medical conditions that will not allow the necessary follow-up for this study (e.g., pre-existing neurological or psychiatric diseases) * Current substance-abuse/illicit drug use * Angiographic evidence of an arterial stenosis proximal to the target lesion that could prevent device deployment * Contraindications to study medications (heparin, aspirin, clopidogrel, and radiographic contrasts) * Patients unable to sign Informed Consent due to the emergency conditions of the intervention