Innovations in surgical approach: lateral cranial base approaches.

The extradural anterior transpetrosal approach possesses several advantages. First, the majority of the dissection is extradural, providing protection to the overlying neural structures. Second, only limited retraction of the temporal lobe is necessary, protecting venous outflow via the vein of Labbe'. Third, transposition of cranial nerves or vascular structures in unnecessary. Fourth, it enjoys natural compatibility with other surgical approaches to enhance exposure of the posterior cavernous sinus and petroclival region. The disadvantages are mostly related to the unfamiliar anatomy. Most surgeons are not accustomed to visualizing petrous apical anatomy from the middle fossa orientation. Therefore, practice of this technique in the cadaver laboratory is a mandatory prerequisite to its performance in the operating room. The cochlea, carotid artery, labyrinth, and cranial nerves five through eight are all at risk during drilling and dissection. When performed properly, this technique provides a solid adjunct to treating complex lesions of the central cranial base.