title: Stereotactic anatomy of the posterior cranial fossa. A study of the transcerebellar approach to the brainstem.
abstract: The stereotactic transcerebellar (suboccipital) approach to the brainstem is one of the most accessible routes to reach targets located in the pons or in the medulla oblongata. Its use requires a perfect knowledge of the stereotactic anatomy of the posterior cranial fossa, and a standard reference system related to structures of the brainstem itself which can easily be visualized by Nuclear Magnetic Resonance. The present work consists in a three-dimensional variability study of the human posterior cranial fossa with its main contents, based on the investigation of 30 normal specimens (hemifossae). A new stereotactic reference system is proposed for the pons and the medulla, comprising three orthogonal** planes: the midsagittal plane, the IVth ventricular floor plane and the pontomedullary junction plane. A standard "safety access tunnel" was defined for the transcerebellar approach to the pons and, with some limitations, to the medulla. A complementary investigation, based upon angiographic studies, was carried out to define a safe "entry zone" to the posterior cranial fossa of the occipital bone beneath the transverse venous sinus.
authors.affiliation: Department of Anatomy, University Hospital of Santa Maria, Lisbon, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Gonçalves-Ferreira
mesh_terms: D000328:Adult; D001933:Brain Stem / Q000033:anatomy & histology* / Q000601:surgery; D002531:Cerebellum / Q000033:anatomy & histology* / Q000601:surgery; D002533:Cerebral Angiography; D014695:Cerebral Ventriculography; D003196:Computer Graphics; D003198:Computer Simulation; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000601:surgery; D003392:Cranial Sinuses / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D008959:Models, Neurological; D013238:Stereotaxic Techniques