title: Radiographic and endoscopic measurements of esophageal length in pediatric patients.
abstract: OBJECTIVE
  Knowledge of the length between the upper esophageal sphincter (UES) and the lower esophageal sphincter (LES) in pediatric patients is essential for intraluminal impedance and dual pH probe recordings.
  
  
  METHODS
  We measured the vertical distance between the true vocal cords (TVCs) and the LES in chest x-rays (CXRs) of 118 children (ages, 6 weeks to 13 years) and measured the vertical distance between the UES and the LES during endoscopy in 31 patients (ages, 14 months to 17 years) and correlated the measurements to height, weight, and age.
  
  
  RESULTS
  Esophageal length correlated best with patient height (R = 0.96 by CXR, R = 0.88 by endoscopy) and less well with weight (R = 0.87, R = 0.67) and age (R = 0.94, R = 0.86). Linear regression analyses using radiographic measurements revealed that esophageal length (TVC to LES) can be estimated from a patient's height by the following equation: 1.048 + 0.167 x height (in centimeters). With the upper pH probe placed in the hypopharynx at the TVC level and the inferior probe placed in the esophagus 3 to 6 cm above the LES, the patients were divided into 6 groups corresponding to the currently available number of sizes of dual pH-impedance probes. With the patients' heights between 71.5 and 161.3 cm, 64.7% to 100% of patients were within 1 cm of the desired location with preselected probes. Confirmation of placement was performed with CXR.
  
  
  CONCLUSIONS
  A pediatric patient's height can be used to estimate the esophageal length (TVC to LES) and facilitate the selection of dual pH-impedance probes. Our method decreases the risk of morbidity while increasing the accuracy of the study of extraesophageal reflux disease.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery University of Iowa, 200 Hawkins Dr, Iowa City, IA 52242, USA.
authors.forename: Grace S
authors.initials: GS
authors.lastname: Yang
authors.forename: Warren P
authors.initials: WP
authors.lastname: Bishop
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Smith
authors.forename: Steven L
authors.initials: SL
authors.lastname: Goudy
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sato
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Bauman
mesh_terms: D000293:Adolescent; D000375:Aging; D000886:Anthropometry; D001827:Body Height; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D017097:Electric Impedance; D016145:Endoscopy, Digestive System; D049630:Esophageal Sphincter, Lower / Q000000981:diagnostic imaging / Q000473:pathology; D004947:Esophagus / Q000000981:diagnostic imaging* / Q000473:pathology*; D005764:Gastroesophageal Reflux / Q000175:diagnosis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D016014:Linear Models; D010036:Otolaryngology / Q000379:methods; D013902:Radiography, Thoracic; D014827:Vocal Cords / Q000000981:diagnostic imaging / Q000473:pathology