Abstract
Midline and paramedian suboccipital exposures are used for resection of midline tumors of the posterior fossa, removal of vascular malformations, and treatment of aneurysms and congenital anomalies. Whenever a lesion in the cerebellopontine angle appears to be too large for a routine retromastoid approach (see chapter 25), a paramedian exposure should be employed. In general, these procedures give wide exposure to one or both cerebellar hemispheres, the cerebellar vermis, one or both lateral sinuses and their confluence, the foramen magnum, and one or both mastoid processes. Formerly, midline and paramedian suboccipital craniectomies were carried out in the sitting position; at present they are most frequently performed in a lateral decubitus or prone position (see Chapter 25).