title: Conventional Posterior Approach without Far Lateral Approach for Ventral Foramen Magnum Meningiomas.
abstract: OBJECTIVE
  We present our experience of conventional posterior approach without fat lateral approach for ventral foramen magnum (FM) meningioma (FM meningioma) and tried to evaluate the approach is applicable to ventral FM meningioma.
  
  
  METHODS
  From January 1999 to March 2011, 11 patients with a ventral FM meningioma underwent a conventional posterior approach without further extension of lateral bony window. The tumor was removed through a working space between the dura and arachnoid membrane at the cervicomedullary junction with minimal retraction of medulla, spinal cord or cerebellum. Care should be taken not to violate arachnoid membrane.
  
  
  RESULTS
  Preoperatively, six patients were of Nurick grade 1, three were of grade 2, and two were of grade 3. Median follow-up period was 55 months (range, 20-163 months). The extent of resection was Simpson grade I in one case and Simpson grade II in remaining 10 cases. Clinical symptoms improved in eight patients and stable in three patients. There were no recurrences during the follow-up period. Postoperative morbidities included one pseudomeningocele and one transient dysphagia with dysarthria.
  
  
  CONCLUSIONS
  Ventral FM meningiomas can be removed gross totally using a posterior approach without fat lateral approach. The arachnoid membrane can then be exploited as an anatomical barrier. However, this approach should be taken with a thorough understanding of its anatomical limitation.
authors.affiliation: Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea. ; Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea. ; Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seil
authors.initials: S
authors.lastname: Sohn
authors.affiliation: Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea. ; Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea. ; Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Chun Kee
authors.initials: CK
authors.lastname: Chung
keywords: Foramen magnum; Meningioma; Surgery