title: The supratonsillar approach to the inferior cerebellar peduncle: anatomy, surgical technique, and clinical application to cavernous malformations.
abstract: OBJECTIVE
  To introduce the supratonsillar approach, an approach that traverses the tonsillobiventral fissure in a trajectory over the cerebellar tonsil to the inferior cerebellar peduncle, and to demonstrate the utility of this approach for resecting peduncular cavernous malformations.
  
  
  METHODS
  Anatomy of the cerebellar tonsil and surrounding fissures, arteries, and veins are reviewed using cadaveric brain specimens. The surgical approach uses the three-quarter prone position, a suboccipital craniotomy, and wide splitting of the tonsillobiventral fissure.
  
  
  RESULTS
  Of our experience with 171 patients with cavernous malformations, six patients had lesions in the inferior cerebellar peduncle that were resected using the supratonsillar approach. All cavernous malformations were removed completely and no patients experienced surgical complications or new deficits.
  
  
  CONCLUSIONS
  The supratonsillar approach differs from the transvermian and telovelar approaches to the fourth ventricle, with a more superolateral trajectory that leads instead to the inferior cerebellar peduncle. By splitting the tonsillobiventral fissure and mobilizing the tonsil inferomedially, the point of access to the lesion is deepened and transgression of normal cerebellar tissue is minimized. This elegant approach is ideally suited to the removal of cavernous malformations.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, San Francisco, California 94143-0112, USA. lawtonm@neurosurg.ucsf.edu
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
authors.forename: Alfredo
authors.initials: A
authors.lastname: Quiñones-Hinojosa
authors.forename: Peter
authors.initials: P
authors.lastname: Jun
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery*; D002531:Cerebellum / Q000473:pathology* / Q000601:surgery*; D005260:Female; D020786:Hemangioma, Cavernous, Central Nervous System / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D014066:Palatine Tonsil / Q000473:pathology* / Q000601:surgery; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'