This clinical research study is designed to determine safety and effectiveness of the Surpass Flow Diverter (Surpass System), an investigational device developed to treat wide-neck, large or giant intracranial aneurysms. An intracranial aneurysm is a bulge in the wall of a blood vessel in the brain. The bulge is caused by a weakening of the vessel wall. If left untreated, the bulge may continue to grow larger and ultimately the vessel may break open (rupture), resulting in serious bleeding into or around the brain. The information collected from this study will be used to evaluate how well patients do when treated with the Surpass System both immediately after treatment of an aneurysm and over a long period of time (5 years).

The objective of this study is to determine safety and effectiveness of the Surpass Flow Diverter (Surpass System) in the endovascular treatment of large or giant wide-necked intracranial aneurysms in the internal carotid artery up to the terminus. The Surpass Flow Diverter is an intracranial implant designed to be placed in a parent artery so as to divert blood flow away from an aneurysm. Use of the Surpass System may be associated with a decrease in neurological death or ipsilateral stroke in patients with large or giant wide-neck aneurysms. In a given patient, the Surpass System will be deemed effective if treatment results in complete occlusion of their aneurysm without clinically significant stenosis of the parent artery, or requires retreatment of the aneurysm through 12 months.

Inclusion Criteria:

• Age 19 to 80 years
• Subject or legal representative is willing and able to give informed consent
• Subject has a single targeted intracranial aneurysm
• Subject agrees to return to the treating Investigator for all scheduled follow up visits and is capable of returning to the hospital for follow up

Exclusion Criteria:

• Known allergy or contraindication to aspirin, clopidogrel/Plavix, heparin, local or general anesthesia
• Known history of life threatening allergy to contrast dye
• Known allergy to nickel, chromium cobalt, tungsten or platinum
• Subject has documented resistance to clopidogrel/Plavix
• Major surgery within previous 30 days or planned in the next 120 days after enrollment date
• Previous intracranial implant associated with the symptomatic distribution within the past 12 weeks prior to treatment date
• Stenting, angioplasty, or endarterectomy of an extracranial (carotid or vertebral artery) or intracranial artery within 30 days prior to treatment date
• Any previous stenting of parent artery at or proximal to the aneurysm where it would interfere with the placement and proper apposition of the device
• Any previous coiling where it would interfere with the placement and proper apposition of the device
• Platelet count less than 100,000 cells/mm3 or known platelet dysfunction
• More than one intracranial aneurysm (IA) that requires treatment within 12 months
• Asymptomatic extradural aneurysms requiring treatment
• Contraindication to CT scan or MRI
• Severe neurological deficit that renders the subject incapable of living independently
• Unstable neurological deficit (i.e., worsening of clinical condition in the last 30 days)
• Evidence of active infection at the time of treatment
• Dementia or psychiatric problem that prevents the patient from completing required follow up
• Co-morbid conditions that may limit survival to less than 24 months
• Serum creatinine greater or equal to 2.5 mg/dL
• Female subjects who are pregnant or planning to become pregnant within the study period
• Subject with anatomy not appropriate for endovascular treatment due to severe intracranial vessel tortuosity or stenosis
• Extra-cranial stenosis or parent vessel with stenosis greater than 50% in the area proximal to the aneurysm
• Other known serious concurrent medical conditions
• History of intracranial vasospasm not responsive to medical therapy
• Subject with an intracranial mass, or is undergoing radiation therapy for carcinoma or sarcoma of the head or neck region
• Subject has a history of bleeding diathesis or coagulopathy, international normalized ratio (INR) greater than 1.5, or will refuse blood transfusions
• Subject had a subarachnoid hemorrhage within 30 days prior to the enrollment date
• Subject has a non-treated arteriovenous malformation (AVM) in the territory of the target aneurysm
• Inability to understand the study or a history of non-compliance with medical advice
• Current use of illicit substance
• Enrollment in another trial involving an investigational product
• Subject has a need for long-term use of anticoagulants (i.e., Warfarin, Dabigatran)

There is no plan to make IPD information available to other researchers. Blinded study data by mITT and Roll-in cohorts may be made available to SCENT researchers post publication of the primary study results.