title: Real-time subglottic stenosis imaging using optical coherence tomography in the rabbit.
abstract: OBJECTIVE
  Subglottic stenosis (SGS) is a severe, acquired, potentially life-threatening disease that can be caused by endotracheal tube intubation. Newborns and neonates are particularly susceptible to SGS owing to the small caliber of their airway.
  
  
  OBJECTIVE
  To demonstrate optical coherence tomography (OCT) capabilities in detecting injury and scar formation using a rabbit model. Optical coherence tomography may provide a noninvasive, bedside or intensive care unit modality for the identification of early airway trauma with the intention of preventing progression to SGS and can image the upper airway through an existing endotracheal tube coupled with a small fiber-optic probe.
  
  
  METHODS
  Rabbits underwent suspension laryngoscopy with induction of of SGS via epithelial injury. This model was used to test and develop our advanced, high-speed, high-resolution OCT imaging system using a 3-dimensional microelectromechanical systems-based scanning device integrated with a fiber-optic probe to acquire high-resolution anatomic images of the subglottic epithelium and lamina propria.
  
  
  METHODS
  All experiments were performed at the Beckman Laser Institute animal operating room. INTERVENTION OR EXPOSURE: Optical coherence tomography and endoscopy was performed with suspension laryngoscopy at 6 different time intervals and compared with conventional digital endoscopic images and histologic sections. Fifteen rabbits were killed at 3, 7, 14, 21, and 42 days after the induction of SGS. The laryngotracheal complexes were serially sectioned for histologic analysis.
  
  
  METHODS
  Histologic sections, endoscopic images, and OCT images were compared with one another to determine if OCT could accurately delineate the degree of SGS achieved.
  
  
  RESULTS
  The rabbit model was able to reliably and reproducibly achieve grade I SGS. The real-time OCT imaging system was able to (1) identify multiple structures in the airway; (2) delineate different tissue planes, such as the epithelium, basement membrane, lamina propria, and cartilage; and (3) detect changes in each tissue plane produced by trauma. Optical coherence tomography was also able demonstrate a clear picture of airway injury that correlated with the endoscopic and histologic images. With subjective review, 3 patients had high correlation between OCT and histologic images, 10 demonstrated some correlation with histologic images, and 2 showed little to no correlation with histologic images.
  
  
  CONCLUSIONS
  Optical coherence tomography, coupled with a fiber-optic probe, identifies subglottic scarring and can detect tissue changes in the rabbit airway to a depth of 1 mm. This technology brings us 1 step closer to minimally invasive subglottic airway monitoring in the intubated neonate, with the ultimate goal of preventing SGS and better managing the airway.
authors.affiliation: Beckman Laser Institute, University of California Irvine, Irvine, CA 92617, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Lin
authors.forename: Amy Y
authors.initials: AY
authors.lastname: Yau
authors.forename: Jonathon
authors.initials: J
authors.lastname: Boyd
authors.forename: Ashley
authors.initials: A
authors.lastname: Hamamoto
authors.forename: Erica
authors.initials: E
authors.lastname: Su
authors.forename: Lauren
authors.initials: L
authors.lastname: Tracy
authors.forename: Lauren
authors.initials: L
authors.lastname: Tracey
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Heidari
authors.forename: Alex H
authors.initials: AH
authors.lastname: Wang
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Ahuja
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Chen
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Wong
mesh_terms: D000818:Animals; D002921:Cicatrix / Q000473:pathology; D004195:Disease Models, Animal; D005336:Fiber Optic Technology; D007090:Image Interpretation, Computer-Assisted; D007442:Intubation, Intratracheal / Q000009:adverse effects* / Q000379:methods; D007828:Laryngoscopy / Q000379:methods; D007829:Laryngostenosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D011817:Rabbits; D011859:Radiography; D011897:Random Allocation; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*