Contour Neurovascular System™ ContiNued Access Investigational Device EXempTion (IDE) Trial (NEXT Trial)

Inclusion criteria

• Patient is 18-75 years of age at the time of screening.
• Patient has a single ruptured or unruptured IA requiring treatment. If the patient has an additional IA requiring treatment, the additional IA must not require treatment within 60 days after the index procedure.
• The target IA must have the following characteristics:
• Saccular morphology
• Located at a bifurcation in the anterior or posterior circulation
• Aneurysm neck diameter between 2 and 10 mm and aneurysm equatorial diameter between 2 and 10.5 mm
• Wide-necked, defined as neck size ≥ 4 mm or a dome/neck ratio \< 2
• Patient may be treated with Contour without the use of additional implanted devices.
• Patient is able to comply with all aspects of the screening, evaluation, treatment, and the post-procedure follow-up schedule.
• Patient or legally authorized representative has signed and dated an institutional review board (IRB)/Ethics Committee (EC)-approved written informed consent prior to initiation of any study procedures. FOR PATIENTS WITH UNRUPTURED ANEURYSM
• Patient meets the criteria outlined in the "Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms" as published by the AHA/ASA\^6 FOR PATIENTS WITH RUPTURED ANEURYSM
• Patient meets the criteria outlined in the "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage: A Guideline for Healthcare Professionals from the American Heart Association/American Stroke Association" as published by the AHA/ASA.\^6
• Patient must be neurologically stable with Hunt \& Hess Score of I, II or III. (\^6: 6 https://www.ahajournals.org/doi/full/10.1161/STR.0000000000000070)

Exclusion criteria

• Anatomy or physiology considered unsuitable for endovascular treatment with the Contour device by the implanting physician and/or the Patient Selection Committee
• Target IA contains other devices/implants (e.g., coils) that could interfere with the correct placement of the Contour device
• Subject has a known, untreatable hypersensitivity to contrast dye, iodine, or any component of the treatment device.
• Contraindication to anticoagulants or anti-platelet medications
• Stenosis of the target IA's parent vessel is \>50%
• Anticoagulation medications (e.g., warfarin) that cannot be discontinued
• Acute / chronic renal failure (unless on dialysis) or creatinine \> 2.00 mg/dl or \> 182 μmol/L
• Vascular disease or other vascular anomaly that precluded the necessary access to the aneurysm for use of the study device.
• Clinical, angiographic or computed tomography (CT) evidence of vasospasm, vasculitis, an intracranial tumor (except small meningioma) or any other intracranial vascular malformations on presentation.
• Conditions placing them at high risk for ischemic stroke or had exhibited ischemic symptoms such as transient ischemic attacks, minor strokes, or stroke-in-evolution within the prior 60-days.
• Any circulatory, neurovascular, cardiovascular, or neurologic conditions that can result in unstable neurological symptoms (e.g., multiple sclerosis, established seizure disorder).
• Modified Rankin Scale (mRS) score ≥ 2 prior to presentation or rupture (as applicable).
• Subarachnoid hemorrhage (SAH) from a non-index aneurysm or any other intracranial hemorrhage within 90 days.
• Physical, neurologic or psychiatric conditions which precluded his/her ability to comply with all aspects of the screening, evaluation, treatment, and the post-procedure follow-up schedule.
• Pregnant, breastfeeding or planning pregnancy in the next 2 years
• Subject is enrolled in another device or drug study in which participation could confound study results.
• Life expectancy of less than 2 years due to an illness or condition other than the index intracranial aneurysm.