title: A water-jet videoendoscope may reduce operation time of endoscopic submucosal dissection for early gastric cancer.
abstract: BACKGROUND
  One of the problems with endoscopic submucosal dissection (ESD) for early gastric cancer is that it prolongs procedure time considerably.
  
  
  OBJECTIVE
  The purpose of this study was to investigate whether a videoendoscope with water-jet function shortened the time of ESD for early gastric cancer.
  
  
  METHODS
  A total of 82 early gastric cancers that were intramucosal, differentiated-type adenocarcinoma ≤2 cm, without ulcer or scar, in 75 consecutive patients were investigated. Three supervised resident endoscopists participated as operators. After stratification by the operator and tumor location, the lesions were randomly assigned to the water-jet videoendoscope or a conventional videoendoscope groups. An insulated tipped knife was used for the ESD procedure. Total operation time was evaluated as a primary endpoint.
  
  
  RESULTS
  The median (25-75th percentile) total operation time for the water-jet videoendoscope group was 51 (33-87) minutes, which was shorter than the 62 (43-88) minutes for the conventional videoendoscope, but it did not reach significance (P = 0.201). Multivariate analysis revealed that the water-jet videoendoscope (OR 3.0, P = 0.046), tumor size ≤14 mm (OR 3.2, P = 0.040) and antral tumor (OR 4.5, P = 0.046) were significantly associated with short (≤60 min) operation time.
  
  
  CONCLUSIONS
  The water-jet videoendoscope may reduce operation time of ESD for early gastric cancer, compared with conventional videoendoscope. A large-scale multicenter trial is warranted to clarify the efficacy of the water-jet videoendoscope for gastric ESD.
authors.affiliation: Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Noriya
authors.initials: N
authors.lastname: Uedo
authors.forename: Ryu
authors.initials: R
authors.lastname: Ishihara
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Eriko
authors.initials: E
authors.lastname: Masuda
authors.forename: Motohiko
authors.initials: M
authors.lastname: Kato
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Koji
authors.initials: K
authors.lastname: Higashino
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iishi
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Kurokawa
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tatsuta
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000368:Aged; D005260:Female; D005773:Gastroscopy / Q000009:adverse effects / Q000295:instrumentation*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013274:Stomach Neoplasms / Q000601:surgery*; D013997:Time Factors