HydroCoil Cerebral Aneurysm Treatment Trial

Inclusion Criteria: 1. Patient presenting with a ruptured or un-ruptured cerebral aneurysm appropriate for endovascular treatment as determined by the neurovascular team (neurosurgeon/neurointerventionalist) 2. The neurointerventionalist believes that the aneurysm can be safely treated with either Cerecyte or Hydrogel. 3. Patients between (and including) 21 and 90 years of age. 4. Patient HUNT AND HESS Grade 0-3. 5. Patient has given fully informed consent to endovascular coiling procedure. If patient cannot consent for themselves, appropriate written consent has been sought from their next of kin, or from appropriate power of attorney. 6. Aneurysm 5-20mm in maximum diameter. 7. Patient is willing and able to return for clinical evaluation and follow-up imaging evaluation (angiography or MRA) at both 6-months and 12-18 months after endovascular treatment. 8. The patient has not been previously randomized into this or another related ongoing trial. 9. The aneurysm has not previously been treated (by coiling or clipping). Exclusion Criteria: 1. Patient has more than one aneurysm requiring treatment in the current treatment session If a patient has multiple aneurysms, but only one will be treated at the time of enrollment, they are eligible for the trial. (Additional aneurysms may be treated at a later date, and may be treated with any coil type that the operator chooses). 2. Target aneurysm has had previous coil treatment or surgically clipped. 3. Patient has an H\&H score of 4 or 5 after subarachnoid hemorrhage (SAH). 4. Inability to obtain informed consent. 5. Medical or surgical co-morbidity such that the patient's life expectancy is less than 1 year. \-