title: Hearing and facial function after surgical removal of cholesteatomas involving petrous bone.
abstract: OBJECTIVE
  The purpose of this study was to inspect the clinical characteristics, surgical approaches, functional preservation, and complications of petrous bone cholesteatoma and to propose appropriate surgical approaches based on long-term follow-up cases and previous reports in the literature.
  
  
  METHODS
  The medical records of 31 patients who underwent surgery for petrous bone cholesteatoma between 1990 and 2011 at two tertiary referral hospitals were retrospectively analyzed with regard to the classification, type of surgical approach, preservation of facial and auditory function, and recurrence.
  
  
  RESULTS
  Of 31 cases, 16 were supralabyrinthine (class I), 1 was infralabyrinthine-apical (class III), 13 were massive (class IV), and 1 was apical (class V). Facial nerve palsy was found in 35.5% of the cases (11 cases). Hearing was preserved in 11 of 22 patients who had better than a 50-dB hearing level of bone conduction pure tone average preoperatively. Preoperative hearing was preserved in only four of the patients in class I (supralabyrinthine). Facial function was preserved or improved in 29 patients (93.5%).
  
  
  CONCLUSIONS
  Complete removal of cholesteatoma of petrous bone can be achieved by choosing the appropriate approach based on location and extent. Facial function was preserved postoperatively in most reviewed cases. Auditory function could not be preserved postoperatively in some cases, but preserving residual hearing levels can be accomplished mostly in supralabyrinthine cholesteatomas with the appropriate surgical approach.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Min Joo
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yun Suk
authors.initials: YS
authors.lastname: An
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Jang
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yang-Sun
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jong Woo
authors.initials: JW
authors.lastname: Chung
keywords: Cholesteatoma; Classification; Facial nerve; Hearing; Petrous bone