Evaluation of Safety and Effectiveness of Stryker Surpass Evolve™ Flow Diverter System

Inclusion Criteria:

1. Age is ≥ 18 and ≤ 80 years
2. Has a single unruptured target intracranial aneurysm (IA) with the following characteristics:

1. Is located on the internal carotid artery (ICA) or its branches.
2. Has a neck ≥ 4 mm, dome to neck ratio ≤ 2.0, or no discernible neck
3. Aneurysm size is ≤ 12 mm (saccular or fusiform configuration)
3. Has a parent vessel diameter ≥ 1.75 mm and ≤ 5.0 mm at both the proximal and distal segments where the implant will be placed
4. Has multiple increased risk factors for intracranial (IA) aneurysm rupture, including but not limited to, aneurysm morphology, smoking, hypertension, diabetes, age, prior and/or family history of rupture, and/or history of subarachnoid hemorrhage that may result in a benefit risk profile of endovascular treatment that outweighs the risks of intracranial aneurysm rupture during the subject's expected lifetime if left untreated.

Exclusion Criteria:

1. Has an extradural target aneurysm
2. Has a target aneurysm in the posterior circulation
3. Perforator or branch vessel, inclusive of the posterior communicating artery, arises from the target aneurysm body or neck (branches or arteries must arise or connect from the parent vessel separate from the aneurysm or neck to not be excluded from study)
4. Has a true bifurcation aneurysm, defined as an aneurysm (saccular or non-saccular) located at a point of vessel bifurcation
5. Target aneurysm is unsuitable for flow diverter treatment
6. Has vessel characteristics, such as severe tortuosity (cICA Type IV), stenosis (\>70%), or morphology that would preclude safe endovascular access to the target aneurysm necessary for treatment with the study device
7. Received previous treatment of the target aneurysm or parent artery where it would interfere with the placement or proper apposition of the device
8. Has a medical contraindication to study or procedure related antiplatelet medications (aspirin, clopidogrel/Plavix, ticagrelor, and heparin), local or general anesthesia, or life-threatening allergy to contrast dye
9. Has a known severe allergy to nickel, chromium cobalt, tungsten or platinum.
10. Modified Rankin Score (mRS) assessment is ≥ 3 at preprocedure exam
11. Presence of unstable neurological deficit (i.e., worsening of clinical condition in the last 30 days)
12. Subarachnoid hemorrhage occurred within 30 days prior to enrollment
13. Major surgery (including previous intracranial implant) occurred within previous 30 days or is planned in the next 120 days after enrollment date
14. Has more than one IA that requires treatment within 12 months
15. Received previous intracranial implant associated with the symptomatic or vascular distribution within the past 12 weeks prior to treatment date
16. Chronic anticoagulation therapy is ongoing or known coagulopathy exists
17. Has other known serious concurrent medical conditions such as heart disease (e.g., unstable atrial fibrillation \[with or without pacemaker\], recent myocardial infarction \[\< 12 weeks ago\], symptomatic congestive heart failure, or carotid stenosis), kidney failure \[\>2.0mg/dl serum creatinine\], pulmonary disease, uncontrolled diabetes, progressive neurologic disorders, terminal cancer, vasculitis, high risk of ischemic stroke or recent stroke
18. Has acute life-threatening illness other than the neurological disease (e.g., acute kidney or heart failure) to be treated in this trial
19. Life expectancy is less than 5 years due to other illness or condition (in addition to an intracranial aneurysm)
20. Unable to complete study follow up due to dementia or psychiatric problem, substance abuse, or history of noncompliance with medical advice
21. Pregnancy at time of enrollment
22. Presence of intracranial mass (tumor, except meningioma, abscess, or other infection), non-treated arteriovenous malformation (AVM) in the territory of the target aneurysm
23. Evidence of active infection at the time of treatment
24. Enrollment in another trial involving an investigational product that could confound the outcomes of this trial