A Case of a Successfully Clipped Saccular Aneurysm Arising from a Fenestration at the Vertebrobasilar Junction

-Usefulness of Removal of the Petrosal Ridge with Monitoring by a X-Ray Image Intensifier-

Abstract

A 39-year-old man, with a saccular aneurysm arising from the proximal end of a fenestration at the vertebrobasilar junction is presented. Considering the location, posterosuperior projection of the aneurysm, and the relationships between the aneurysm and its surrounding structures, we selected a subtemporal transpetrosal approach with resection of a part of the petrosal ridge anterosuperior to the internal auditory foramen. The aneurysm was completely clipped without difficulty. The patient had temporal abducens palsy and facial hypesthesia postoperatively, but he eventually recovered completely and returned to his previous job. Aneurysms at the fenestration of the basilar artery are rare. A total of 52 cases have been reported and most were operated on via the suboccipital approach. We emphasize that the subtemporal transpetrosal approach is a useful route to reach a basilar artery aneurysm at the midclivus and that the internal auditory foramen is a reliable landmark for safe and accurate removal of the petrosal ridge.