The supratonsillar approach to the inferior cerebellar peduncle: anatomy, surgical technique, and clinical application to cavernous malformations.
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.
Lawton
Michael T
MT
Department of Neurological Surgery, University of California, San Francisco, San Francisco, California 94143-0112, USA. lawtonm@neurosurg.ucsf.edu
Quiñones-Hinojosa
Alfredo
A
Jun
Peter
P
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'