The Extended Retrosigmoid Approach

The extended retrosigmoid craniotomy is an approach designed to gain maximal access to the cerebellopontine angle and petroclival region. The approach is characterized by the extension of the well-known retrosigmoid craniotomy by skeletonization of the sigmoid and transverse sinus and the option of a mastoidectomy. It can be employed for extraaxial lesions in the cerebellopontine angle and intraaxial lesions arising along the petrosal surface of the cerebellum, cerebellar peduncles, or brainstem.