Endovascular treatment of AICA flow dependent aneurysms. A report of three cases and review of the literature

Abstract

Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare, accounting for less than 1% of all cerebral aneurysms. To our knowledge 34 flow-related cases including the present study have been reported in the literature. Three patients harbouring four flow dependent aneurysms were referred to our institution. Two patients presented with subarachnoid hemorrhage, one presented with cerebellar manifestations. They were all treated by endovascular embolization of the aneurysm as well as the parent artery using liquid embolic material. Two cases were embolized using NBCA, Onyx was used in the third case. No bleeding or rebleeding were encountered during the follow-up period which ranged from five to nine months. One patient developed facial palsy, cerebellar symptoms and sensorineural hearing loss. The remaining two cases did not develop any post treatment neurological complications. Endovascular management of flow-dependent AICA aneurysms by parent artery occlusion is feasible and efficient in terms of rebleeding prevention. Post embolization neurological complications are unpredictable. This depends upon the adequacy of collaterals from other cerebellar arteries.

Figure 1

A) Oblique view angiography shows an AICA aneurysm proximal to a cerebellar AVM. B) The Onyx cast fills the aneurysm sac and part of the AVM. C) Pre-treatment MRI T2-weighted image shows the compressing effect of the venous channel over the fourth ventricle. D) MRI T2-weighted image 6 months post-embolization shows the relative improvement of the fourth ventricle compression.

Figure 2

A) MRI Flair image shows subarachnoid blood in the sylvian fissure with associated temporo-parieto-occipital infarction. B) Conventional angiography oblique view shows severe vasospasm in the whole posterior circulation. C) Post embolization CT shows the aneurysm sac filled with embolising cast.

Figure 3

A) CT shows subarachnoid hemorrhage at the prepontine cistern. B) Early arterial phase angiography shows 2 AICA aneurysms. C) Selective microcatheter angiography shows the aneurysms proximal to the infratentorial AVM. D) MRI Flair image shows infarction at the brachium pontis.