title: Facial nerve preservation surgery for koos grade 3 and 4 vestibular schwannomas.
abstract: BACKGROUND
  Facial nerve preservation surgery for large vestibular schwannomas is a novel strategy for maintaining normal nerve function by allowing residual tumor adherent to this nerve or root-entry zone.
  
  
  OBJECTIVE
  To report, in a retrospective study, outcomes for large Koos grade 3 and 4 vestibular schwannomas.
  
  
  METHODS
  After surgical treatment for vestibular schwannomas in 52 patients (2004-2013), outcomes included extent of resection, postoperative hearing, and facial nerve function. Extent of resection defined as gross total, near total, or subtotal were 7 (39%), 3 (17%), and 8 (44%) in 18 patients after retrosigmoid approaches, respectively, and 10 (29.5%), 9 (26.5%), and 15 (44%) for 34 patients after translabyrinthine approaches, respectively.
  
  
  RESULTS
  Hearing was preserved in 1 (20%) of 5 gross total, 0 of 2 near-total, and 1 (33%) of 3 subtotal resections. Good long-term facial nerve function (House-Brackmann grades of I and II) was achieved in 16 of 17 gross total (94%), 11 of 12 near-total (92%), and 21 of 23 subtotal (91%) resections. Long-term tumor control was 100% for gross total, 92% for near-total, and 83% for subtotal resections. Postoperative radiation therapy was delivered to 9 subtotal resection patients and 1 near-total resection patient. Follow-up averaged 33 months.
  
  
  CONCLUSIONS
  Our findings support facial nerve preservation surgery in becoming the new standard for acoustic neuroma treatment. Maximizing resection and close postoperative radiographic follow-up enable early identification of tumors that will progress to radiosurgical treatment. This sequential approach can lead to combined optimal facial nerve function and effective tumor control rates.
authors.affiliation: Departments of *Neurosurgery and ‡Otolaryngology-Head and Neck Surgery, University of Cincinnati (UC) College of Medicine; §Brain Tumor Center at the UC Neuroscience Institute; ¶Mayfield Clinic, Cincinnati, Ohio; and ‖Department of Neurological Surgery, University of California San Francisco, San Francisco, California.
authors.forename: Amjad N
authors.initials: AN
authors.lastname: Anaizi
authors.forename: Eric A
authors.initials: EA
authors.lastname: Gantwerker
authors.forename: Myles L
authors.initials: ML
authors.lastname: Pensak
authors.forename: Philip V
authors.initials: PV
authors.lastname: Theodosopoulos
mesh_terms: D000328:Adult; D000368:Aged; D005154:Facial Nerve / Q000601:surgery*; D020220:Facial Nerve Injuries / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods; D008297:Male; D042282:Microdissection; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D012189:Retrospective Studies