title: Intraoperative long range optical coherence tomography as a novel method of imaging the pediatric upper airway before and after adenotonsillectomy.
abstract: OBJECTIVE
  While upper airway obstruction is a common problem in the pediatric population, the first-line treatment, adenotonsillectomy, fails in up to 20% of patients. The decision to proceed to surgery is often made without quantitative anatomic guidance. We evaluated the use of a novel technique, long-range optical coherence tomography (LR-OCT), to image the upper airway of children under general anesthesia immediately before and after tonsillectomy and/or adenoidectomy. We investigated the feasibility of LR-OCT to identify both normal anatomy and sites of airway narrowing and to quantitatively compare airway lumen size in the oropharyngeal and nasopharyngeal regions pre- and post-operatively.
  
  
  METHODS
  46 children were imaged intraoperatively with a custom-designed LR-OCT system, both before and after adenotonsillectomy. These axial LR-OCT images were both rendered into 3D airway models for qualitative analysis and manually segmented for quantitative comparison of cross-sectional area.
  
  
  RESULTS
  LR-OCT images demonstrated normal anatomic structures (base of tongue, epiglottis) as well as regions of airway narrowing. Volumetric rendering of pre- and post-operative images clearly showed regions of airway collapse and post-surgical improvement in airway patency. Quantitative analysis of cross-sectional images showed an average change of 70.52mm(2) (standard deviation 47.87mm(2)) in the oropharynx after tonsillectomy and 105.58mm(2) (standard deviation 60.62mm(2)) in the nasopharynx after adenoidectomy.
  
  
  CONCLUSIONS
  LR-OCT is an emerging technology that rapidly generates 3D images of the pediatric upper airway in a feasible manner. This is the first step toward development of an office-based system to image awake pediatric subjects and thus better identify loci of airway obstruction prior to surgery.
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Frances B
authors.initials: FB
authors.lastname: Lazarow
authors.affiliation: Children's Hospital of Orange County, Orange, CA, USA; Department of Otolaryngology-Head and Neck Surgery, University of California-Irvine, Irvine, CA, USA.
authors.forename: Gurpreet S
authors.initials: GS
authors.lastname: Ahuja
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California-Irvine, Irvine, CA, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Chin Loy
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Erica
authors.initials: E
authors.lastname: Su
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Tony D
authors.initials: TD
authors.lastname: Nguyen
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Giriraj K
authors.initials: GK
authors.lastname: Sharma
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Wang
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jing
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA.
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Beckman Laser Institute, University of California-Irvine, Irvine, CA, USA; Department of Otolaryngology-Head and Neck Surgery, University of California-Irvine, Irvine, CA, USA. Electronic address: bjwong@uci.edu.
authors.forename: Brian J F
authors.initials: BJ
authors.lastname: Wong
mesh_terms: D000233:Adenoidectomy; D000293:Adolescent; D000402:Airway Obstruction / Q000175:diagnosis* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D011182:Postoperative Care; D011300:Preoperative Care; D041623:Tomography, Optical Coherence; D014068:Tonsillectomy
keywords: Adenoidectomy; Long range optical coherence tomography; Tonsillectomy