title: Exposure of wide cerebellomedullary cisterns for vascular lesion surgeries in cerebellomedullary cisterns: opening of unilateral cerebellomedullary fissures combined with lateral foramen magnum approach.
abstract: OBJECTIVE
  To clarify microsurgical anatomic features of the cerebellomedullary fissure (CMF), the natural cleavage plane between the cerebellum and the medulla, and its relationship to the cerebellomedullary cistern (CMC) and to describe a surgical technique that uses the unilateral trans-CMF approach for CMC surgeries.
  
  
  METHODS
  In the anatomic study, 2 formalin-fixed cadaver heads were used. In the clinical study, 3 patients with vertebral artery-posterior inferior cerebellar artery aneurysms and 3 patients with glossopharyngeal neuralgia were surgically treated through the unilateral trans-CMF approach combined with the transcondylar fossa approach, which is a lateral foramen magnum approach.
  
  
  RESULTS
  The CMC was present at the lateral end of the CMF. The CMF was closed by arachnoidal adhesion, and the cerebellar hemisphere was superiorly attached to the cerebellar peduncle. After the unilateral CMF was completely opened, the cerebellar hemisphere was easily retracted rostrodorsally. Clinically, almost completely opening the unilateral CMF markedly enabled the retraction of the biventral lobule to obtain a wide surgical field safely for vascular CMC lesions. We present 2 representative cases.
  
  
  CONCLUSIONS
  Combined unilateral trans-CMF/lateral foramen magnum approaches provide a wide and close surgical field in the CMC, allowing easy and safe CMC surgery.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsushima
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Saga University, Saga, Japan. Electronic address: m996kawa@cc.saga-u.ac.jp.
authors.forename: Masatou
authors.initials: M
authors.lastname: Kawashima
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Department of Surgical Neurology, University of Florida, Gainesville, Florida, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Matsushima
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Miki
mesh_terms: D000368:Aged; D002102:Cadaver; D002531:Cerebellum / Q000033:anatomy & histology / Q000098:blood supply / Q000601:surgery; D002946:Cisterna Magna / Q000033:anatomy & histology / Q000601:surgery*; D005260:Female; D005539:Foramen Magnum / Q000033:anatomy & histology / Q000601:surgery*; D020435:Glossopharyngeal Nerve Diseases / Q000473:pathology / Q000601:surgery*; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology / Q000601:surgery*; D008526:Medulla Oblongata / Q000033:anatomy & histology / Q000098:blood supply / Q000601:surgery; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D014711:Vertebral Artery / Q000473:pathology / Q000601:surgery
keywords: Cerebellomedullary cistern; Glossopharyngeal neuralgia; Subtonsillar approach; Telovelar approach; Transcerebellomedullary fissure approach; Vertebral artery aneurysm