title: A novel animal model for hyperdynamic airway collapse.
abstract: OBJECTIVE
  Tracheobronchomalacia (TBM) is increasingly recognized as a condition associated with significant pulmonary morbidity. However, treatment is invasive and complex, and because there is no appropriate animal model, novel diagnostic and treatment strategies are difficult to evaluate. We endeavored to develop a reliable airway model to simulate hyperdynamic airway collapse in humans.
  
  
  METHODS
  Seven 20-kg male sheep were enrolled in this study. Tracheomalacia was created by submucosal resection of > 50% of the circumference of 10 consecutive cervical tracheal cartilage rings through a midline cervical incision. A silicone stent was placed in the trachea to prevent airway collapse during recovery. Tracheal collapsibility was assessed at protocol-specific time points by bronchoscopy and multidetector CT imaging while temporarily removing the stent. Esophageal pressure and flow data were collected to assess flow limitation during spontaneous breathing.
  
  
  RESULTS
  All animals tolerated the surgical procedure well and were stented without complications. One sheep died at 2 weeks because of respiratory failure related to stent migration. In all sheep, near-total forced inspiratory airway collapse was observed up to 3 months postprocedure. Esophageal manometry demonstrated flow limitation associated with large negative pleural pressure swings during rapid spontaneous inhalation.
  
  
  CONCLUSIONS
  Hyperdynamic airway collapse can reliably be induced with this technique. It may serve as a model for evaluation of novel diagnostic and therapeutic strategies for TBM.
authors.affiliation: Caritas Christi Health Care, Boston, MA 02135, USA.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tsukada
authors.forename: Carl R
authors.initials: CR
authors.lastname: O'Donnell
authors.forename: Robert
authors.initials: R
authors.lastname: Garland
authors.forename: Felix
authors.initials: F
authors.lastname: Herth
authors.forename: Malcolm
authors.initials: M
authors.lastname: Decamp
authors.forename: Armin
authors.initials: A
authors.lastname: Ernst
mesh_terms: D000402:Airway Obstruction / Q000517:prevention & control*; D000818:Animals; D001999:Bronchoscopy / Q000379:methods; D004195:Disease Models, Animal; D008297:Male; D001261:Pulmonary Atelectasis / Q000209:etiology / Q000517:prevention & control*; D015656:Respiratory Mechanics / Q000502:physiology; D012756:Sheep; D015607:Stents; D014057:Tomography, X-Ray Computed; D055089:Tracheobronchomalacia / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D014139:Tracheostomy / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome