title: Analysis of tracheostoma morphology.
abstract: OBJECTIVE
  Existing fixation methods of automatic speaking valves (ASVs) suffer from shortcomings which partly are the result of insufficient conformity of the intratracheal fixation method's shape to the tracheostoma anatomy. However, quantitative data are lacking and will be helpful to analyse solutions for airtight fixation. This article provides such data.
  
  
  METHODS
  The tracheostoma morphology was measured in computerized tomography scans of 20 laryngectomized patients. Measured were transverse and sagittal diameters, transition angle between skin level and tracheostoma lumen and between the tracheostoma lumen to the trachea, TE valve placement and stoma depth.
  
  
  RESULTS
  The mean transverse and sagittal diameters of the stoma at the peristomal lip are 19.2 mm [standard deviation (SD 5.2 mm)] and 17.6 mm (SD 5.3 mm), respectively. The mean transition angles are 84.5° (SD 15.6°) at skin level and 153.6° (SD 11.7°) into the trachea. The mean distance between TE valve and peristomal lip is 13.5 mm (SD 7.0 mm). The mean stoma depth is 14.0 mm (SD 6.4 mm).
  
  
  CONCLUSIONS
  Due to the large variation, no 'average tracheostoma morphology', suitable for shaping a generic intratracheal fixation device, can be defined. Therefore, providing an airtight fixation in each patient would require a large range of different sizes, customization or a new approach.
authors.affiliation: a Department of Biomedical Engineering , University of Twente , Enschede , T he Netherlands.
authors.forename: Maartje
authors.initials: M
authors.lastname: Leemans
authors.affiliation: b Department of Head and Neck Oncology and Surgery , t he Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital , Amsterdam , T he Netherlands.
authors.forename: Maarten J A
authors.initials: MJA
authors.lastname: van Alphen
authors.affiliation: b Department of Head and Neck Oncology and Surgery , t he Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital , Amsterdam , T he Netherlands.
authors.forename: Michiel W M
authors.initials: MWM
authors.lastname: van den Brekel
authors.affiliation: a Department of Biomedical Engineering , University of Twente , Enschede , T he Netherlands.
authors.forename: Edsko E G
authors.initials: EEG
authors.lastname: Hekman
mesh_terms: D006801:Humans; D007825:Laryngectomy; D007831:Larynx, Artificial; D012189:Retrospective Studies; D014132:Trachea / Q000000981:diagnostic imaging; D014139:Tracheostomy / Q000706:statistics & numerical data*
keywords: Total laryngectomy; automatic speaking valve; customized fixation; heat-and-moisture exchange filter; intratracheal fixation; tracheostoma anatomy; tracheostoma geometry; tracheostoma morphology