Light up the "no-man's land" on the brain stem.

The ventral surface of the brain stem is anatomically surrounded by the clivus anteriorly, brain stem posteriorly and by the petrous pyramid and cranial nerves from IIIrd to XIIth laterally in the deep posterior cranial fossa. Neurosurgical extra-axial pathologies arising from the area are aneurysms on the vertebro-basilar artery, benign tumors such as clival meningiomas, chordomas, chondromas, trigeminal neurinomas and prepontine epidermoid tumors. Surgical access to the area had been difficult for long years since the neurosurgery was established, because located deeply in such a surgical blindness, so-called "no-man's land". However, recent technical development of "skull base surgery" is opening new doors to light up the surgical darkness of the "no-man's land". This paper reviews the history, development, technique and future prospect of the skull base surgery to open the "no-man's land".