Pivotal Study of the Silk Vista Baby Flow Diverters in the Treatment of Unruptured Intracranial Aneurysms (PIONEER)

1. Age 22 to ≤ 80 years old
2. Participant has a single target unruptured intracranial aneurysm (IA) originating from a parent vessel of 1.5 mm to 3.4mm in diameter located at or distal to the ICA terminus or in SVB-amenable anterior or posterior anatomy
3. Participant has a target saccular or fusiform IA with an aneurysm neck ≥ 4mm or a dome to neck ratio \<2
4. Participant has a target IA that is ≤ 12 mm
5. Participant meets one or more risk factors for IA rupture, such as age (≤70); hypertension; cigarette smoking; use of sympathomimetic drugs; Japanese or Finnish ancestry; history of prior aneurysmal subarachnoid hemorrhage (aSAH); familial intracranial aneurysms or SAH; clinical or radiological mass effect; reduced quality of life due to fear of rupture; IA size, location, and morphology (yielding 1 point or greater score per UIATS scale); documented growth of IA on serial imaging; presence of multiple IAs; and presence of concurrent pathology
6. Participant has pre-procedure (obtained up to 14 days prior to the procedure day) PRU value between 60-200
7. Participant or a legally authorized representative (LAR) provides written informed consent using the IRB/REB-approved consent form and agrees to comply with protocol follow-up and requirements

Exclusion Criteria:

1. Target aneurysm is unsuitable for flow diverter treatment
2. Subject requires more than one flow diverter for target aneurysm treatment
3. Has vessel characteristics, such as severe tortuosity, stenosis, atherosclerotic disease, or morphology that would preclude safe endovascular access to the target aneurysm necessary for treatment with the study device
4. Received previous treatment of the target aneurysm or parent artery where it would interfere with the placement or proper apposition of the device
5. Has a medical contraindication to study or procedure-related antiplatelet/anticoagulation medications (e.g., aspirin, clopidogrel/Plavix, ticagrelor, Prasugrel, Gp IIb/IIIa inhibitors, heparin, etc.), local or general anesthesia, or life-threatening allergy to contrast dye
6. Has a known severe allergy to nickel, titanium or platinum
7. Modified Rankin Score (mRS) assessment is ≥ 3 at screening or pre-procedure mRS could not be assessed
8. The health of the participant or the validity of the study outcomes (e.g., high risk of neurologic events, worsening of clinical condition in the last 30 days) may be compromised by the participant's enrollment
9. Subarachnoid hemorrhage occurred within 30 days prior to enrollment
10. Intracranial parenchymal hemorrhage occurred within 60 days prior to enrollment
11. Major surgery (including previous intracranial implant) occurred within previous 30 days or is planned in the next 120 days after treatment date
12. Has more than one IA that requires treatment within 120 days of treatment date
13. Received previous intracranial implant associated with the symptomatic or vascular distribution within the past 12 weeks prior to treatment date
14. Requires adjunctive coiling during SVB procedure
15. Chronic anticoagulation therapy is ongoing or known coagulopathy exists
16. Has other known serious concurrent medical conditions such as active bacterial infection, heart disease (including atrial fibrillation, pacemaker, recent myocardial infarction [\< 12 weeks], symptomatic congestive heart failure, or carotid stenosis), kidney failure (e.g., >2.0mg/dl serum creatinine) or any other non-neurological disease-related acute life threatening illness to be treated in this trial, pulmonary disease, uncontrolled diabetes, progressive neurologic disorders, cancer requiring active treatment (e.g., chemotherapy, etc.) or on palliative care, vasculitis, high risk of ischemic stroke or recent stroke (within 30 days)
17. Life expectancy is less than 5 years due to other illness or condition (in addition to an intracranial aneurysm)
18. Unable to complete study follow-up due to dementia or psychiatric disorder, substance abuse, or history of noncompliance with medical advice
19. Women who are pregnant or nursing at the time of enrollment or women who wish to become pregnant during the length of study participation
20. Presence of intracranial mass (tumor, except meningioma that doesn't require surgery for 1 year) or non-treated arteriovenous malformation (AVM) in the territory of the target aneurysm
21. Participation in any other investigational study which can influence collection of valid data under this study