Subtemporal suboccipital transpetrosal transsigmoidal approach to aneurysm of the basilar artery fenestration.

The aneurysm arising from the lower third of a basilar artery fenestration is a rare event. The traditional suboccipital or subtentorial transtentorial or transoral approach to this vascular malformation can be problematic. We report the case of a 52-year-old woman who suffered a Grade 4 subarachnoid hemorrhage from an aneurysm located at a fenestration of the proximal third of the basilar artery. This aneurysm was successfully clipped through a left subtemporal suboccipital translabyrinthine transsigmoidal approach. In the aneurysms of the proximal third of the basilar artery the transpetrosal approach with its variants (translabyrinthine and transsigmoidal) related to patient's clinical condition can be useful with undoubted advantages.