title: Transillumination for needle localization in the larynx.
abstract: OBJECTIVE
  Transillumination through laryngeal soft tissue may be used to direct percutaneous transcricothyroid membrane subepithelial needle placement in the larynx.
  
  
  METHODS
  Cadaver simulation (canine and human).
  
  
  METHODS
  Lighted devices, including sialendoscopes and fiberoptic cables, were tested as transilluminating obturators in trocars and needles through multiple studies to identify appropriate illumination, monitoring, and equipment for successful localization of needle/trocar tips placed within laryngeal tissue.
  
  
  RESULTS
  Lighted 250-micron fiberoptic cables within 23-gauge needles were successfully placed percutaneously through the cricothyroid membrane and maneuvered submucosally into Reinke's space, the midlateral vocal fold, and through the thyroarytenoid gap with monitoring via flexible transnasal laryngoscopy. Technical adaptations in the course of study permitted successful simulation of clinical use in full cadaver study for accurate injection laryngoplasty, confirmed by laryngeal dissection following collagen injection.
  
  
  CONCLUSIONS
  Small caliber fiberoptic cables are useful as transilluminating obturators to accurately direct needle position within laryngeal tissue. Clinical application of this new technique is anticipated to improve the accuracy of percutaneous needle localization in the larynx, as well as to assist in directed instrumentation of the larynx from an external approach.
  
  
  METHODS
  N/A.
authors.affiliation: Department of Otolaryngology University of Iowa, Iowa City, Iowa.
authors.forename: Henry T
authors.initials: HT
authors.lastname: Hoffman
authors.affiliation: Division of Otolaryngology, Department of Surgery, University of Wisconsin, Madison.
authors.forename: Seth H
authors.initials: SH
authors.lastname: Dailey
authors.affiliation: Department of Otolaryngology Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Bock
authors.affiliation: Division of Otolaryngology, Department of Surgery, University of Wisconsin, Madison.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Thibeault
authors.affiliation: Division of Otolaryngology, Department of Surgery, University of Wisconsin, Madison.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: McCulloch
mesh_terms: D001905:Botulinum Toxins / Q000008:administration & dosage; D004576:Electromyography; D006801:Humans; D015552:Injections, Intralesional / Q000379:methods*; D058753:Laryngoplasty / Q000295:instrumentation / Q000379:methods*; D007830:Larynx; D009498:Neurotoxins / Q000008:administration & dosage; D014172:Transillumination
chemical_list: D009498:Neurotoxins; D001905:Botulinum Toxins
keywords: Transillumination; botulinum toxin; injection; laryngeal electromyography (EMG); laryngoplasty; larynx; minithyrotomy; vocal fold