Hydrogel Balloon Assisted Intracranial Aneurysm Coiling Registry

This is a prospective, single arm, single center study of patients with ruptured or
unruptured saccular aneurysms that are embolized using MicroVention second-generation
hydrogel coils and undergo balloon remodeling with the MicroVention Scepter Occlusion
Balloon Catheter. Data for each patient will be collected 6 ± 3 months post-procedure for
the study.

Inclusion Criteria:

- Patient is 18-80 years of age.

- Patient has a documented, previously treated or untreated saccular intracranial
aneurysm, 4- 20 mm unruptured or ruptured, suitable for treatment with balloon
assisted coil embolization.

- Target aneurysm has a neck ≥4mm or the largest diameter to neck ratio of 2 or less.

- Patient has a Hunt and Hess Score of 3 or less.

- Patient has a premorbid mRS of 3 or less.

- Patient or patient's legally authorized representative has provided written informed
consent.

- Patient is willing to and can comply with study follow-up requirements.

Exclusion Criteria:

- Inability to obtain informed consent.

- Patient is <18 or >80 years of age.

- Target aneurysm is dissecting, fusiform, mycotic, or arteriovenous
malformation-related.

- Aneurysm that was treated previously with stent-assisted coiling.

- Implantation of the stent after the balloon-assisted coiling or combined stent and
balloon assisted coiling.

- Target aneurysm is deemed unsuitable for balloon-assisted coiling by the treating
physician prior to the procedure.

- Target aneurysm will be treated with a total coil length comprised of less than 80%
second generation MicroVention Hydrogel Coils.

- Balloon-assisted coiling will be performed using a balloon catheter other than the
MicroVention Scepter balloon (Scepter C, Scepter XC, any future Scepter
configurations).

- Patients in which the target aneurysm is planned not to be coiled in one procedure
(i.e. staged procedure).

- Patients with more than one aneurysm that requires treatment. (However, a second
small low risk aneurysm that does not require therapy may be allowed.)

- Patients with a life expectancy of ≤ 9 months.