title: Vertebral Artery Transposition Via an Extreme-Lateral Approach for Anterior Foramen Magnum Meningioma or Craniocervical Junction Tumors.
abstract: OBJECTIVE
  Vertebral artery (VA) transposition in the extreme-lateral transcondylar approach can minimize the manipulation of the low cranial nerves and the brain stem. The authors describe the surgical technique of VA transposition.
  
  
  METHODS
  From March 2000 to December 2014, 28 of 48 patients underwent VA transposition for anterior foramen magnum meningioma (16 patients) and craniocervical junction (CCJ) tumors (12 patients). Tumor was resected via an extreme-lateral approach with partial condylectomy to expose the anterior portion of the brain stem. For intradural tumors, the VA was mobilized caudomedially after circumferential dural incision around the VA at the level of the foramen magnum. For extradural tumors involving the CCJ, VA was transposed medially from the transverse foramen of C1 without any dural incision.
  
  
  RESULTS
  Gross total resection was achieved in 26 of 28 patients (92.9%) with VA transposition. Histologically, meningioma and schwannoma were most common. The origin of the tumors was foramen magnum (57.1%), C1 nerve root (17.9%), clivus (10.7%), jugular foramen (7.1%), posterior skull base (3.6%), and hypoglossal canal (3.6%). VA transposition was performed intradurally in 19 patients (67.9%) and extradurally in 9 patients (32.1%). Surgical morbidity was 17.9% including 4 patients with hypoglossal nerve palsy and 1 patient with quadriparesis. The mean follow-up duration after surgery was 4.2 years (range, 0.1-14.8 years).
  
  
  CONCLUSIONS
  VA transposition can provide a wide surgical window for anterior foramen magnum meningioma or tumors involving the CCJ with the least manipulation of the neuraxis.
authors.affiliation: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University Health System, Seoul, Korea.
authors.forename: Hun Ho
authors.initials: HH
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University Health System, Seoul, Korea.
authors.forename: Kyu-Sung
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University Health System, Seoul, Korea. Electronic address: yedamin@yuhs.ac.
authors.forename: Chang-Ki
authors.initials: CK
authors.lastname: Hong
mesh_terms: D000328:Adult; D000368:Aged; D001269:Atlanto-Occipital Joint / Q000601:surgery; D005260:Female; D005539:Foramen Magnum / Q000601:surgery*; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome; D014711:Vertebral Artery / Q000601:surgery*
keywords: Anterior foramen magnum meningioma; Craniocervical junction tumor; Extreme-lateral transcondylar approach; Transposition; Vertebral artery