title: [Microsurgical approach to the ambient cistern].
abstract: OBJECTIVE
  To describe a step-by-step approach to the ambient cistern by the suboccipital retrosigmoid supracerebellar infratentorial (RSI) approach.
  
  
  METHODS
  The RSI approach is performed in the same manner as the suboccipital retrosigmoid approach, usually used to access the pathology of the cerebellopontine angle, with the following modifications: (1) we always use the semi-sitting position, (2) the craniotomy-craniectomy must expose the transverse sinus and extend 5 cm medially to the inion, (3) when performing the dural opening it is necessary to mobilize the dura with the transverse sinus upwards, (4) under magnification with surgical microscope the cerebellomedullary cistern should be opened in order to drain cerebrospinal fluid for relaxing the cerebellum, and (5) arachnoidal adherences and bridging veins must be coagulated and cut if necessary. These maneuvers create a wide corridor to the ambient cistern.
  
  
  CONCLUSIONS
  This approach allows a safe access to the ambient cistern, especially to the infratentorial portion.
authors.affiliation: Servicio de Neurocirugía, Hospital Italiano de Buenos Aires, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Pablo
authors.initials: P
authors.lastname: Ajler
authors.affiliation: Servicio de Neurocirugía, Hospital Italiano de Buenos Aires, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Michael Cruz
authors.initials: MC
authors.lastname: Bravo
authors.affiliation: Servicio de Neurocirugía, Hospital Italiano de Buenos Aires, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Lucas
authors.initials: L
authors.lastname: Garategui
authors.affiliation: Servicio de Neurocirugía, Hospital Italiano de Buenos Aires, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Goldschmidt
authors.affiliation: Centro Avançado de Neurologia e Neurocirurgia (CEANNE), Graduate Course in surgery, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Isolan
authors.affiliation: Servicio de Neurocirugía, Hospital Padilla, Tucumán, Argentina.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Campero