The study is designed to evaluate the safety and effectiveness of ENTERPRISE 2 vascular reconstruction device and delivery system (hereinafter referred to as ENTERPRISE 2) to facilitate endovascular coil embolization of intracranial aneurysms.

This is a prospective, multicenter, single-arm observational study, in which enrolled patients will be implanted with the ENTERPRISE 2 for evaluation of safety and effectiveness of ENTERPRISE 2 in real-world applications.

The study population will consist of 164 patients with ruptured or unruptured intracranial aneurysms and a parent vessel diameter of ≥2.5 mm and ≤4 mm. All patients will be implanted with the study device.

The enrolled patients will be followed at 30 days, 180 days, 1 year, 2 years, 3 years, 4 years and 5 years post procedure.

The primary endpoint is the incidence of aneurysm recanalization (at 180 days) evaluated through digital subtraction angiography (DSA). Secondary effectiveness endpoints include incidence of aneurysm recanalization (at 1 year), successful stent/coil placement rate (immediately post procedure), aneurysm occlusion (immediately post procedure, at 180 days and 1 year), incidence of retreatment (at 30 and 180 days, and 1, 2, 3, 4 and 5 years). Safety evaluation include: incidence of disabling stroke or neurological death (at 180 days and 1 year), incidence of in-stent thrombosis (at 180 days and 1 year), and incidence of in-stent stenosis (at 180 days and 1 year). Exploratory endpoints include stent wall apposition performance (intra-procedure), first-time deployment success rate (intra-procedure) and duration of stent deployment (intra-procedure).

Inclusion Criteria:

1. Patient (or his/her legal representative) understands the nature of the procedure and provides voluntary written informed consent for the use of his/her peri-procedural and follow-up data;
2. Aged between 18 years and 80 years of age the time of consent;
3. Patient has been diagnosed with ruptured (Hunt-Hess Grade I-III) or unruptured intracranial aneurysm and requires the endovascular treatment;
4. Parent vessel with a diameter of ≥2.5 mm and ≤4 mm;
5. Patient is willing to return to the investigational site for the post-procedure follow-up evaluations.

Exclusion Criteria:

1. Severe co-morbidity associated with a life-expectancy of less than twelve months as determined by the investigator;
2. Poor clinical condition with modified Rankin Scale (mRS) score ≥4;
3. Having prior or potential severe allergic reaction to contrast medium;
4. Known allergies to any of the device components, including Enterprise 2 and PROWLER® SELECT™ Plus Infusion Catheter;
5. Angiogram demonstrating that the aneurysm is not appropriate for endovascular treatment (i.e. severe intracranial vessel tortuosity, stenosis, intracranial vasospasm not responsive to medical therapy);
6. Arteriovenous malformation (AVM) in the territory of the target aneurysm;
7. Unsuitable for the antithrombotic and/or anticoagulant therapies;
8. Implantation of an intracranial stent associated with aneurysm or symptom distribution within 12 weeks prior to signature of Informed Consent Form;
9. Implantation of a carotid stent associated with aneurysm or symptom distribution within 12 weeks prior to signature of Informed Consent Form;
10. Evidence of active infection;
11. Pregnant or lactating women;
12. Having participated in clinical studies of other investigational drugs or devices within 30 days prior to signature of Informed Consent Form, excluding epidemiological studies of observational nature or natural history or not involving intervention;
13. Pre-planned staged procedure of target aneurysms.

This study will be conducted in patients with unruptured or ruptured intracranial aneurysm with a parent vessel diameter of ≥2.5 mm and ≤4 mm.

Johnson & Johnson Medical Device Companies have an agreement with the Yale Open Data Access (YODA) Project to serve as the independent review panel for evaluation of requests for clinical study reports and participant level data from investigators and physicians for scientific research that will advance medical knowledge and public health. Requests for access to the study data can be submitted through the YODA Project site at http://yoda.yale.edu.