title: Effect of Medialization Thyroplasty on Glottic Airway Anatomy: Cadaver Model.
abstract: OBJECTIVE
  The purpose of this study was to investigate the change in airway dimensions after medialization thyroplasty (MT) using a cadaveric model. Helical computerized tomography (CT) was performed before and after placement of a silastic block in human larynges to investigate the effect on airway anatomy at the level of the glottis. Tissue density (TD) of the medialized vocal fold (VF) was documented to understand the effect on tissue displacement.
  
  
  METHODS
  This is a cadaveric study.
  
  
  METHODS
  Thirteen human cadaveric larynges underwent fine-cut CT scan before and after MT was performed using carved blocks in two sizes (small block and large block [LB]). Clientstream software was used to measure laryngeal dimensions: intraglottic volume (IGV), cross-sectional area (CSA), posterior-glottic diameter (PGD), VF density (in Hounsfield units [HUs]), and anterior-posterior diameter (APD). Eight sequential axial sections 0.625 mm cuts) at the level of the true VFs were analyzed.
  
  
  RESULTS
  There was a significant decrease between the three conditions for IGV (P < 0.0001) and CSA (P < 0.0001). TD of the VF was increased after MT as indicated by HU increase (P = 0.0003). APD was not significantly changed. PGD was significantly different between the no block to LB placement (P = 0.0012).
  
  
  CONCLUSIONS
  MT significantly changes the IGV and CSA at the level of the glottis. Density in the true VF was significantly increased. These findings have important implications for understanding volumetric effects of MT.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Ontario, Canada; Department of Otolaryngology-Head and Neck Surgery, St. Michael's Hospital, Toronto, Ontario, Canada. Electronic address: Tulika.sh@gmail.com.
authors.forename: Tulika
authors.initials: T
authors.lastname: Shinghal
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Ontario, Canada; Department of Otolaryngology-Head and Neck Surgery, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Anderson
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Trillium Health Partners, Mississauga, Ontario, Canada.
authors.forename: Janet
authors.initials: J
authors.lastname: Chung
authors.affiliation: Department of Anesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Hong
authors.affiliation: Department of Medical Imaging, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Aditya
authors.initials: A
authors.lastname: Bharatha
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004129:Dimethylpolysiloxanes; D005260:Female; D005931:Glottis / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D058753:Laryngoplasty / Q000295:instrumentation / Q000379:methods*; D007830:Larynx / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011857:Radiographic Image Interpretation, Computer-Assisted; D012984:Software; D036542:Tomography, Spiral Computed
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon
keywords: Airway compromise; Complication; Glottic volume; Medialization thyroplasty; Postthyroplasty intubation; Vocal fold paralysis