title: Ultrathin endoscope flexibility can predict discomfort associated with unsedated transnasal esophagogastroduodenoscopy.
abstract: OBJECTIVE
  To evaluate the effects of choice of insertion route and ultrathin endoscope types.
  
  
  METHODS
  This prospective study (January-June 2012) included 882 consecutive patients who underwent annual health checkups. Transnasal esophagogastroduodenoscopy (EGD) was performed in 503 patients and transoral EGD in 235 patients using six types of ultrathin endoscopes. Patients were given a choice of insertion route, either transoral or transnasal, prior to EGD examination. For transoral insertion, the endoscope was equipped with a thin-type mouthpiece and tongue depressor. Conscious sedation was not used for any patient. EGD-associated discomfort was assessed using a visual analog scale (VAS; no discomfort 0- maximum discomfort 10).
  
  
  RESULTS
  Rates of preference for transnasal insertion were significantly higher in male (male/female 299/204 vs 118/117) and younger patients (56.8 ± 11.2 years vs 61.3 ± 13.0 years), although no significant difference was found in VAS scores between transoral and transnasal insertion (3.9 ± 2.3 vs 4.1 ± 2.5). Multivariate analysis revealed that gender, age, operator, and endoscope were independent significant predictors of VAS for transnasal insertion, although gender, age, and endoscope were those for transoral insertion. Further analysis revealed only the endoscopic flexibility index (EFI) as an independent significant predictor of VAS for transnasal insertion. Both EFI and tip diameter were independent significant predictors of VAS for transoral insertion.
  
  
  CONCLUSIONS
  Flexibility of ultrathin endoscopes can be a predictor of EGD-associated discomfort, especially in transnasal insertion.
authors.affiliation: Satoshi Ono, Tomoko Nakao, Kazushi Suzuki, Yumiko Ohike, Tsutomu Yamazaki, Center for Epidemiology and Preventive Medicine, Graduate School of Medicine, the University of Tokyo, Tokyo 113-8655, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ono
authors.forename: Keiko
authors.initials: K
authors.lastname: Niimi
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Fujishiro
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakao
authors.forename: Kazushi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ohike
authors.forename: Shinya
authors.initials: S
authors.lastname: Kodashima
authors.forename: Nobutake
authors.initials: N
authors.lastname: Yamamichi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
keywords: Discomfort; Esophagogastroduodenoscopy; Surveillance; Ultrathin endoscope; Visual analog scale