In two cases of a high basilar (BA) tip aneurysm with a short intracranial internal carotid artery (ICA), a new orbitozygomatic temporopolar approach was carried out. This approach consisted of en block fronto-orbitozygomatic temporal craniotomy and temporopolar access to the aneurysm. The bifurcation of the elongated basilar artery was 20mm in height and the intracranial ICA were 20mm in length and 6mm from the interclinoid line between the anterior and posterior clinoid processes in Case 1, and 18mm and 5mm in Case 2, respectively. The frontotemporal branch of the facial nerve was carefully preserved by subperiosteal and subfascial separation. Bony structures of the lateral and superior orbital wall, the zygomatic arch, the lesser wing, and the temporal bone were removed. In order to access the aneurysm as inferiorly and obliquely as possible through the emptied anterior temporal fossa, the bridging veins from the temporal tip were totally or partially devided. Through the wide working space encircled by the less retracted ICA and the middle cerebral artery, the tentorial hiatus, the oculomotor nerve, the BA aneurysms could be seen easily, and could be successfully clipped by upward and oblique viewing from below. The postoperative clinical course was uneventful in both cases and no cosmetic problem occurred in either.
In this paper, his new operative procedure and its usefulness are presented and compared with other approaches for high BA aneurysms previously described.