A Basilar Artery-Anterior Inferior Cerebellar Artery Aneurysm, Embolized By Guglielmi Detachable Coils: A Case Report.

We report a case of embolization of a downward aneurysm in the basilar artery-anterior inferior cerebellar artery bifurcation using Guglielmi detachable coil (GDC).A 68-year-old man complaining of a sudden headache was admitted. On admission his consciousness was clear and neurological examination showed no abnormalities. Computed tomography demonstrated subarachnoid hemorrhage (SAH). However, cerebral angiography (CAG) revealed no definite vascular lesion. CAG 6 days after onset revealed a downward aneurysm of 2.5 mm in diameter at the left anterior inferior cerebellar artery bifurcation. This aneurysm was embolized using GDC.We approached this lesion from the ipsilateral vertebral artery with a microcatheter shaped as an acute curve. However, the microcatheter was unstable when we pushed the GDC into the aneurysm. Therefore, caging was not carried out. Finally, we approached from the contralateral vertebral artery with a microcatheter shaped as a less acute curve and were able to pack 2 GDCs 10 (2 mm×1 cm) firmly into the aneurysm. A 6-day follow-up angiogram revealed no definite coil compaction.Approaching a basilar artery-anterior inferior cerebellar artery downward aneurysm from the contralateral vertebral artery was effective for embolization.