title: Using pulmonary function data to assess outcomes in the endoscopic management of subglottic stenosis.
abstract: OBJECTIVE
  This study aimed to examine the authors' experience with endoscopic management of idiopathic subglottic stenosis (iSGS), and to identify pulmonary function test (PFT) values that can be used to quantify outcomes.
  
  
  METHODS
  Retrospective review.
  
  
  RESULTS
  Twenty-five patients with a new diagnosis of iSGS were seen between 2006 and 2012. Median age at surgery was 45.3 years (interquartile range [IQR], 38.5-67.0), and median body mass index was 28.7 kg/m(2) (IQR, 23.5-32.1). Forty-five procedures were performed. Median preoperative stenosis was 56.8% (Cotton-Myer grade 2). The typical stenosis began 15 mm below the true vocal folds and was 12 mm long. Median follow-up was 21.4 months (IQR, 5.1-43.1). For patients receiving multiple dilations, median time between procedures was 23.7 months. Four PFT parameters demonstrated significant improvement after intervention: (1) PEF (absolute change = 2.54 L/s), (2) PIF (absolute change = 1.57 L/s), (3) FEV1/PEF (absolute change = 0.44), and (4) FIF50% (absolute change = 1.71 L/s). PIF was the only parameter affected by using a larger balloon (P = .047).
  
  
  CONCLUSIONS
  PEF, PIF, FEV1/PEF, and FIF50% improved significantly after endoscopic incision and dilation of iSGS, and this could potentially be used as a metric by which to evaluate outcomes in the endoscopic management of subglottic stenosis.
authors.affiliation: Department of Otolaryngology, University of Kansas, Kansas City, Kansas, USA skraft3@kumc.edu.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Kraft
authors.affiliation: Department of Otolaryngology, University of Kansas, Kansas City, Kansas, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Sykes
authors.affiliation: Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Palmer
authors.affiliation: Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Schindler
mesh_terms: D057186:Comparative Effectiveness Research; D004106:Dilatation / Q000009:adverse effects / Q000379:methods; D004724:Endoscopy / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D012008:Recurrence; D012086:Reoperation / Q000379:methods / Q000706:statistics & numerical data; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D014132:Trachea / Q000473:pathology / Q000601:surgery; D014135:Tracheal Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D014140:Tracheotomy / Q000009:adverse effects / Q000379:methods; D014481:United States
keywords: endoscopic; idiopathic subglottic stenosis; pulmonary function test