title: In vitro model for testing novel implants for equine laryngoplasty.
abstract: OBJECTIVE
  To develop an in vitro laryngeal model to mimic airflow and pressures experienced by horses at maximal exercise with which to test laryngoplasty techniques.
  
  
  METHODS
  Randomized complete block.
  
  
  METHODS
  Cadaveric equine larynges (n=10).
  
  
  METHODS
  Equine larynges were collected at necropsy and a bilateral prosthetic laryngoplasty suture was placed with #5 Fiberwire suture to achieve bilateral maximal arytenoid abduction. Each larynx was positioned in a flow chamber and subjected to static flow and dynamic flow cycling at 2 Hz. Tracheal pressure and flow, and pressure within the flow chamber were recorded at a sampling frequency of 500 Hz. Data obtained were compared with the published physiologic values for horses exercising at maximal exercise.
  
  
  RESULTS
  Under static flow conditions, the testing system produced inspiratory tracheal pressures (mean+/-SEM) of -33.0+/-0.98 mm Hg at a flow of 54.48+/-1.8 L/s. Pressure in the flow chamber was -8.1+/-2.2 mm Hg producing a translaryngeal impedance of 0.56+/-0.15 mm Hg/L/s. Under dynamic conditions, cycling flow and pressure were reproduced at a frequency of 2 Hz, the peak inspiratory (mean+/-SEM) pharyngeal and tracheal pressures across all larynges were -8.85+/-2.5 and -35.54+/-1.6 mm Hg, respectively. Peak inspiratory flow was 51.65+/-2.3 L/s and impedance was 0.57+/-0.06 mm Hg/L/s.
  
  
  CONCLUSIONS
  The model produced inspiratory pressures similar to those in horses at maximal exercise when airflows experienced at exercise were used.
  
  
  CONCLUSIONS
  This model will allow testing of multiple novel techniques and may facilitate development of improved techniques for prosthetic laryngoplasty.
authors.affiliation: Department of Clinical Sciences, and Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. jc485@cornell.edu
authors.forename: Jon
authors.initials: J
authors.lastname: Cheetham
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Witte
authors.forename: Leo V
authors.initials: LV
authors.lastname: Soderholm
authors.forename: John W
authors.initials: JW
authors.lastname: Hermanson
authors.forename: Norm G
authors.initials: NG
authors.lastname: Ducharme
mesh_terms: D000818:Animals; D002102:Cadaver; D006429:Hemiplegia / Q000601:surgery / Q000662:veterinary; D006734:Horse Diseases / Q000473:pathology / Q000601:surgery*; D006736:Horses; D066298:In Vitro Techniques; D007825:Laryngectomy / Q000379:methods / Q000662:veterinary; D007830:Larynx / Q000601:surgery*; D010805:Physical Conditioning, Animal; D011897:Random Allocation; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000601:surgery / Q000662:veterinary*; D014827:Vocal Cords / Q000601:surgery