Orbitozygomatic temporopolar approach for a high basilar tip aneurysm associated with a short intracranial internal carotid artery: a new surgical approach.

For two cases of a high basilar tip aneurysm accompanied by a short intracranial internal carotid artery, the orbitozygomatic temporopolar approach consisting of an en bloc fronto-orbitozygomatic temporal craniotomy and temporopolar approach was carried out. On angiograms, the height of the bifurcation of an elongated basilar artery and the length of the intracranial internal carotid artery from the interclinoid line between the anterior and posterior clinoid process were 20 mm and 6 mm in Case 1, and 18 mm and 5 mm in Case 2, respectively. The skin flap was separated subfascially to preserve the frontotemporal branch of the facial nerve. The fronto-orbitozygomatic temporal bone flap was made, and a part of the basal bony structures of the orbital roof, the sphenoid ridge, and the temporal bone were removed. The basilar tip aneurysm could be seen and clipped easily by upward and oblique viewing from below through the wide operative space consisting of the less retracted internal carotid and middle cerebral arteries, the oculomotor nerve, the tentorial hiatus, and the emptied anterior temporal fossa obtained by partial division of the temporal bridging veins. The operative procedure is presented in detail and compared with other surgical approaches that have been described previously.