Post Approval Study - Evaluate the Long-Term Safety and Effectiveness of the WEB Device

Key Inclusion Criteria: * Patient must be ≥ 18 at the time of screening * Patient must have a single ruptured or unruptured IA requiring treatment * Patient must sign and date an IRN approved written informed consent prior to initiation of any study procedures Key Exclusion Criteria: * Patient has an IA with characteristics unsuitable for endovascular treatment * Patient has conditions placing them at high risk for ischemic stroke or has exhibited ischemic symptoms such as transient ischemic attacks, minor strokes, or stroke-in-evolution within the prior 30 days * Patient has had an SAH from a non-index IA or other intracranial hemorrhage within 90 days * Patient index IA was previously treated * Patient is pregnant