抄録
This paper describes a surgical approach to basilar tip aneurysm. Direct operation for such aneurysms has not been performed at the acute stage due to the restriction on surgical space.
To overcome the narrow surgical space, the lesser wing of the sphenoid bone was removed extradurally. The anterior clinoid process and roof of the optic canal were drilled off by the extradural approach. The dural ring of the internal carotid artery (ICA) in the cavernous sinus was partially opened. By removing the lesser wing of the sphenoid bone, mobilization of the ICA and of the optic nerve was increased. Extensive mobilization of the ICA provided a wide surgical space, which permitted clipping of the basilar tip aneurysm at the acute stage. During retraction of the ICA, the patency of this vessel was maintained and the cerebral blood flow in the ICA territory was preserved as the ICA and optic nerve were not fixed by the lesser wing of the sphenoid bone at the point of entry into the intracranial space.
In conclusion, the lesser wing approach affords better mobilization of the ICA and the optic nerve, and provides a good surgical view for operation on basilar tip aneurysm.