Abstract
For giant or large aneurysms on and around the basilar artery bifurcation, the (Cranio) orbito-zygomatic osteotomy is quite helpful for approach in multiple directions. Preservation of the bridging vein coming off the temporal lobe tip is preferable; for this purpose as well as for ample working space, the author often cuts the basal polar portion of the temporal lobe.
For usual sized aneurysms around the high placed basilar bifurcation, the arch of the zygomatic bone is removed, but orbitotomy is not needed except for the lateral rim. If the lateral superior portion of the orbit disturbs the trajectory to the basilar tip, the cavernous carotid or the anterior communicating artery aneurysm, this portion of the orbital bone is removed at those stages of the operation. Removal of the supraorbital bar, including the nasal bone, is also helpful for approaching the anterior communicating artery aneurysm interhemispherically.
Preservation of the olfactory nerves and the frontal sagittal bridging veins are constantly achieved through the basal interfalcine approach. The craniotomy for the basal interfalcine approach involves the frontal sinus. The outer table is incorporated to the craniotomy, but the inner table is discarded, the mucous membranes are removed, and the fronto-nasal duct is closed.
