Fig. 1.9 Petrosal approaches. (a) Right retrolabyrinthine
approach. The posterior fossa dura is opened posterior to
the semicircular canals in the retrolabyrinthine approach.
This exposes the cochlear, vestibular, facial, and lower
cranial nerves, lateral pons and medulla above the jugular
bulb, and elements of the posterior circulation. (b) Right
translabyrinthine approach. Resecting the labyrinth
exposes the internal auditory canal and widens the angle