Fig. 1.7 Retrosigmoid and far-lateral approaches. (a)
Posterior view of the right retrosigmoid approach. The
retrosigmoid approach provides exposure extending from
the tentorium to the foramen magnum, as well as the cer-
ebellopontine angle. Structures identified include cranial
nerves 4–12, flocculus, and internal auditory meatus. The
superior petrosal bridging vein (Dandy’s vein) is seen
draining into the superior petrosal sinus. (b) The supramea-
tal tubercle, which lies superior and anterior to the inter-
nal auditory canal, can be drilled to access the proximal