The proposed study is a multi-center single arm retrospective and prospective data collection, of patients treated with the LVIS device of specific sizes of 3.5mm, 4.0mm, 4.5mm, 5.5mm with up to 5 years follow-up. Information collected during the study will be standardized across centers to include pre-treatment baseline characteristics of patients including aneurysm(s) symptoms, procedural information, prespecified clinical safety events of interest, and follow-up imaging, clinical visits or telephone calls.

Inclusion Criteria:

The following criteria match the FDA-approved indications for use per PMA (P170013)

• Subjects treated with the LVIS® Device in accordance with currently approved indications for use;
• Treatment of wide-necked (neck ≥ 4mm or dome to neck ratio < 2) intracranial saccular aneurysm arising from a parent vessel with a diameter ≥ 2.0 mm and ≤ 4.5 mm who underwent treatment with LVIS device of researched sizes within the last 5 years.

(Device models: 212517-LVIS, 212525-LVIS, 213015-LVIS, 213025-LVIS, 213041-LVIS, 214035-LVIS, 214049-LVIS; 212912-LVIS, 212917-LVIS, 212922-LVIS, 212928-LVIS, and 212931-LVIS);

• Availability of Medical Health Records;

• Subject whose age is ≥ 18;

• Appropriate or Waived Consent:

  1. For retrospective review: Local Institutional Review Board approves the research as exempt, allowing an all-inclusive retrospective examination of medical records documenting treatments using the study devices and available clinical and imaging follow up;
  2. For prospective follow up: Subject or his/her Legally Authorized Representative consents to participation in the study follow up visits up to 5 years, and provides a signed informed consent form as applicable;.

Exclusion Criteria:

• Subjects not treated according to the currently approved indications for use

The study population conforms to currently approved Indications for Use: Subjects with wide-necked (neck ≥ 4 mm or dome to neck ratio < 2) intracranial, saccular aneurysms arising from a parent vessel with a diameter ≥ 2.0 mm and ≤ 4.5 mm who underwent treatment with LVIS device since approval in the local geography of researched sizes.