PRET: Patients Prone to Recurrence After Endovascular Treatment

Inclusion Criteria:

- All patients presenting at least one aneurysm 'prone to recurrence after endovascular
treatment' (PRET), defined for the sake of this study as:

- PRET-1: One ruptured or unruptured aneurysm, never treated, with a dimension
≥10mm (longest axis, including thrombosed portions of large or giant aneurysms);
for ruptured lesions, patients should be in WFNS grade I, II or III.

- PRET-2: an Aneurysm presenting a major recurrence after previous coiling; and
judged by the neurovascular team to require elective treatment.

- The anatomy of the lesion is such that endovascular treatment is possible with both
types of coils (not necessarily certain or probable)

- The endovascular physician is content to use either type of coils (platinum or
hydrogel-coated coils) but no other type of coils

- Patient is 18 or older

- Life expectancy is more than 2 years

Exclusion Criteria:

- Presence of other aneurysms requiring treatment during the same session

- Patients with associated cerebral arteriovenous malformations

- When parent vessel occlusion, without simultaneous endosaccular coiling of the
aneurysm, is the primary intent of the procedure

- Any absolute contraindication to endovascular treatment, angiography, or anaesthesia
such as severe allergies to contrast or medications