Safety and Efficacy of Endovascular Treatment of Intracranial Aneurysms With Surpass Elite With GUARDian Flow Diverter (GUARD)

Inclusion Criteria:

1. Age is ≥18 and ≤80 years at the time of consent

2. Has a single unruptured target intracranial aneurysm (IA) of any size with thefollowing characteristics:

3. Is located on the internal carotid artery or its branches

4. Has a wide neck (wide neck typically defined as neck width ≥ 4 millimeter (mm),or dome to neck ratio ≤ 2.0) or no discernible neck

5. Aneurysm is either saccular or fusiform in nature

6. Has a parent vessel diameter ≥ 3.0 mm to ≤ 6.0 mm at the largest diameter

7. There is documented risk-benefit of endovascular treatment that outweighs the risksof intracranial aneurysm rupture during the subject's expected lifetime if leftuntreated.

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, arisesfrom the target aneurysm body or neck (branches or arteries must arise or connectfrom the parent vessel separate from the aneurysm or neck to not be excluded fromtrial)

4. Has a true bifurcation aneurysm, defined as an aneurysm (saccular or non-saccular)located at a point of vessel bifurcation

5. Has vessel characteristics, such as severe tortuosity (cavernous Internal CarotidArtery (cICA) Type IV1), stenosis (>70%), or morphology that would preclude safeendovascular access or proper deployment of the trial device to the target aneurysm

6. Received previous treatment for the target aneurysm or parent artery where it wouldinterfere with the placement or proper apposition of the device

7. Has a medical contraindication to trial or procedure related antiplateletmedications (aspirin, clopidogrel/Plavix, ticagrelor, and heparin), local or generalanesthesia, or life-threatening allergy to contrast dye

8. Has a known severe allergy to nickel, chromium cobalt, tungsten, or platinum

9. Patients with heparin hypersensitivity, including patients with a previous incidentof Heparin-Induced Thrombocytopenia (HIT).

10. Modified Rankin Score (mRS) assessment is ≥ 3 at pre-procedure exam

11. Presence of unstable neurological deficit (i.e., worsening of clinical condition inthe last 30 days prior to the index procedure)

12. Subarachnoid hemorrhage occurred within 30 days prior to the index procedure

13. Major surgery (including previous intracranial implant) either occurred within 30days prior to the index procedure date or is planned to occur within 120 daysfollowing the index procedure date

14. Has more than one intracranial aneurysm (IA) that requires treatment within 12months after the index procedure

15. Received previous intracranial implant associated with the symptomatic or vasculardistribution within the past 84 days prior to treatment date

16. Chronic anticoagulation therapy is ongoing or known coagulopathy exists

17. Has atrial fibrillation with or without pacemaker.

18. Has other known serious concurrent medical conditions such as cardiovascular disease (including recent myocardial infarction [<12 weeks], symptomatic congestive heartfailure, or carotid stenosis), kidney failure (>2.0 mg/dl serum creatinine),pulmonary disease, uncontrolled diabetes, progressive neurologic disorders, terminalcancer, vasculitis, high risk of ischemic stroke or recent stroke

19. Has acute life-threatening illness (e.g., acute kidney or heart failure) other thanthe neurological disease to be treated in this trial

20. Evidence of active infection at the time of treatment

21. Life expectancy is less than 5 years due to other illness or condition (in additionto an intracranial aneurysm)

22. Unable to comply with the trial follow up requirements due to conditions such asdementia or psychiatric problems, active substance abuse, or history ofnon-compliance with medical advice, as determined by the investigator

23. Pregnant or breast- feeding women or women who wish to become pregnant during thelength of trial participation

24. Presence of intracranial mass (tumor, except meningioma, abscess, or otherinfection), non-treated arteriovenous malformation (AVM) in the territory of thetarget aneurysm

25. Enrollment in another study involving an investigational product that could confoundthe outcomes of this trial