title: Real-time tracking of vocal fold injections with optical coherence tomography.
abstract: OBJECTIVE
  Optical coherence tomography (OCT) is a promising new imaging modality that can help discern the layered microstructure of vocal folds. In the future, subepithelial injections of implants will improve vocal fold pliability where there is stiffness of phonatory mucosa. Using OCT both to delineate the depth of subepithelial injections real-time and to serially image the implant over time would be valuable, and has not been demonstrated previously.
  
  
  METHODS
  Ex vivo study using excised calf larynges and survival study using canines in vivo.
  
  
  METHODS
  An investigation was done employing real-time OCT imaging of subepithelial injection pulses into phonatory mucosa of four calf larynges ex vivo to track the presence of subepithelial implants in phonatory mucosa in a survival study using an in vivo canine model.
  
  
  RESULTS
  OCT readily identified polyethylene glycol (PEG)-based hydrogel in the subepithelial plane in both the ex vivo calf study and the in vivo canine study. Ex vivo calf images correlated with histological specimens obtained immediately postinjection. Images obtained in this study provide confirmation of the hydrogel injection depth in real time, and allow for the implant to be tracked during a canine survival study.
  
  
  CONCLUSIONS
  OCT can confirm subepithelial placement of hydrogel implant in the vocal fold with sufficient resolution to provide instantaneous feedback of an injection pulse. Survival studies in an in vivo canine model indicate that OCT can potentially be helpful in monitoring rheologically appropriate implants within the superficial lamina propria.
authors.affiliation: Department of Surgery, Harvard Medical School, Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. burns.james@mgh.harvard.edu
authors.forename: James A
authors.initials: JA
authors.lastname: Burns
authors.forename: Ki Hean
authors.initials: KH
authors.lastname: Kim
authors.forename: James B
authors.initials: JB
authors.lastname: Kobler
authors.forename: Johannes F
authors.initials: JF
authors.lastname: deBoer
authors.forename: Gerardo
authors.initials: G
authors.lastname: Lopez-Guerra
authors.forename: Steven M
authors.initials: SM
authors.lastname: Zeitels
mesh_terms: D000818:Animals; D002417:Cattle; D004285:Dogs; D007267:Injections / Q000379:methods*; D013997:Time Factors; D041623:Tomography, Optical Coherence; D014827:Vocal Cords