title: Endoscope-assisted microsurgery of large vestibular schwannomas.
abstract: OBJECTIVE
  The application of endoscope-assisted microsurgery in the treatment of small or medium-sized vestibular schwannomas is of proven value. The goal of our study is to evaluate its usefulness in cases of large schwannomas.
  
  
  METHODS
  Eighteen patients were included in this prospective study. Their average tumor diameter was 3.9 cm. The retrosigmoid approach was used in all cases. The endoscope was applied during all stages of tumor removal.
  
  
  RESULTS
  The facial nerve was visualized endoscopically at early stages of surgery in 9 patients and the abducent nerve in 7 patients. The source of bleeding was identified in 1 case. Tumor remnants in the region of the fundus of the internal auditory canal after apparently total removal were identified in 2 cases. Exposed and unobliterated temporal bone air cells were not observed.
  
  
  CONCLUSIONS
  Even in cases of large schwannomas, the location of the facial nerve can be determined endoscopically early in the procedure. The application of endoscope-assisted microsurgery increases the rate of cranial nerve preservation and of total tumor removal. Although the application of the endoscope did not provide useful information in some cases, it is a safe procedure that did not lead to any complications and/or to considerable prolongation of the operative time. Its application is justified in all cases.
authors.affiliation: Department of Neurosurgery, University Hospital Alexandrovska, Sofia, Bulgaria. venelingerganov@hotmail.com
authors.forename: V M
authors.initials: VM
authors.lastname: Gerganov
authors.forename: K V
authors.initials: KV
authors.lastname: Romansky
authors.forename: V A
authors.initials: VA
authors.lastname: Bussarsky
authors.forename: L T
authors.initials: LT
authors.lastname: Noutchev
authors.forename: I N
authors.initials: IN
authors.lastname: Iliev
mesh_terms: D000328:Adult; D000368:Aged; D005154:Facial Nerve / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000295:instrumentation*; D008875:Middle Aged; D044582:Neuroendoscopes; D009464:Neuroma, Acoustic / Q000473:pathology* / Q000601:surgery*; D011446:Prospective Studies; D016896:Treatment Outcome; D000159:Vestibulocochlear Nerve / Q000473:pathology