title: Impact of removing mastoid process for advanced parotid cancer on facial nerve identification, preservation and reconstruction.
abstract: BACKGROUND
  Advanced parotid cancers more than 4 cm are firmly fixed around the main trunk of the facial nerve that can be hardly detected in narrow working space between mastoid process and parotid cancer. Even though facial nerve was preserved, facial nerve stretching during surgery has significantly serious effect on postoperative facial palsy.
  
  
  OBJECTIVE
  To evaluate usefulness of removing mastoid process in managing advanced parotid cancers to contribute identifying and preserving facial nerve.
  
  
  METHODS
  The study was performed on 18 advanced parotid cancers which was more than 4 cm and invaded around the facial nerve. Thirteen cases were fresh cases and 5 were recurrent cases.According to a modified Blair incision, the sternocleidomastoid muscle is detached from the mastoid process with electrocautery. When the mastoid process is removed, the main trunk of the facial nerve can be observed from stylomastoid foramen.This procedure was evaluated based on the duration of surgery, working space, and postoperative facial nerve function.
  
  
  RESULTS
  In eleven cases, facial nerves were sacrificed. Negative margins were achieved in 100% of the patients. The mean duration for removing of the mastoid process to identify facial nerves was 4.6 minutes. The mean size of the removed mastoid process was 2.1 cm in height and 2.3 cm in width, and 1.8 cm in depth. The extended mean working space was 16.0 cm3, and, as a result, the tumors could be resected without retraction.
  
  
  CONCLUSIONS
  Removing the mastoid process for advanced parotid tumors facilitates identification of the facial nerve and better preservation of the facial nerve function.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Juntendo University School of Medicine, 2-1-1,Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. jyokoya@juntendo.ac.jp.
authors.forename: Junkichi
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ooba
authors.forename: Mitsuhisa
authors.initials: M
authors.lastname: Fujimaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Anzai
authors.forename: Masataka
authors.initials: M
authors.lastname: Kojima
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005154:Facial Nerve / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008416:Mastoid / Q000601:surgery*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D010307:Parotid Neoplasms / Q000473:pathology / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods*; D013701:Temporal Bone / Q000601:surgery