title: Relationship Between Muscle Dissection Method and Postoperative Muscle Atrophy in the Lateral Suboccipital Approach to Vestibular Schwannoma Surgery.
abstract: BACKGROUND
  Various techniques are available for occipital skull exposure with muscle dissection, as well as different types of skin incisions in the lateral suboccipital approach to vestibular schwannoma (VS) surgery. The skin incisions are generally classified as S-shaped, J-shaped, or C-shaped. In each method, the technique used for muscle dissection differs in terms of cut, single layer, and multiple layers. This study was performed to identify the relationships among muscle dissection method, skin incision type, and muscle atrophy in the lateral suboccipital approach to surgery for VS.
  
  
  METHODS
  Between 2002 and 2011, we performed surgical resection in 53 patients with VS at Shinshu University Hospital. Of these 53 patients, 35 with radiographic annual follow-up for >3 years after surgery were evaluated retrospectively. These patients included 14 who underwent an S-shaped incision, 6 with a J-shaped incision, and 15 with a C-shaped incision. Bilateral areas of the skin and occipital muscles were measured, and rates of atrophy were calculated and compared among the 3 methods.
  
  
  RESULTS
  Postoperative muscle atrophy was significantly advanced in the second postoperative year, but did not tend to develop further after the third year. The postoperative muscle atrophy ratio was significantly lower in the C-shaped incision group (mean ± SD, 4.0% ± 6.9%) compared with the S-shaped (17.1% ± 9.8%) and J-shaped (17.6% ± 10.0%) incision groups within 2 years after surgery (P < 0.05).
  
  
  CONCLUSIONS
  The C-shaped skin incision with multilayer muscle dissection was associated with significantly reduced postoperative muscle atrophy compared with the other methods.
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ogiwara
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan. Electronic address: tegotou@shinshu-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Goto
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Aoyama
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan; Department of Neurosurgery, Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
authors.forename: Alhusain
authors.initials: A
authors.lastname: Nagm
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan; Department of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hongo
mesh_terms: D000328:Adult; D000368:Aged; D004210:Dissection / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000601:surgery*; D009133:Muscular Atrophy / Q000453:epidemiology* / Q000517:prevention & control; D009464:Neuroma, Acoustic / Q000453:epidemiology* / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data; D009778:Occipital Lobe / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Lateral suboccipital approach; Muscle atrophy; Muscle dissection; Vestibular schwannoma