title: Key factors for successful en bloc endoscopic submucosal dissection of early stage gastric cancer using an insulation-tipped diathermic knife.
abstract: OBJECTIVE
  En bloc endoscopic mucosal resection (EMR) is presently considered to be the treatment of choice for endoscopically resectable early stage gastric cancer (EGC). Although a new EMR technique using an insulation-tipped diathermic knife (endoscopic submucosal dissection using an IT knife: IT knife-ESD) is reportedly suitable for en bloc resection, a failure in en bloc resection (piecemeal resection) can occur. We retrospectively analyzed factors affecting the success rate of en bloc resection by IT knife-ESD.
  
  
  METHODS
  A total of 71 gastric lesions were treated by IT knife-ESD. En bloc/piecemeal resection rates were investigated. Twelve potential factors associated with clinicopathological characteristics or procedures were analyzed univariately and multivariately.
  
  
  RESULTS
  IT knife-ESD was successfully performed in all 71 lesions. En bloc resection was achieved in 63 lesions (91%), while eight lesions (9%) were removed as two or more fragments (piecemeal resection). The multivariate analysis identified only one independent factor affecting the success rate of en bloc resection: the second-half period of procedure application. The en bloc resection rate was not associated with the tumor location/site, tumor size, specimen size, and ulceration within the tumor.
  
  
  CONCLUSIONS
  Much experience with IT knife-ESD may resolve the tumor-related technical difficulties. It is true for this advanced procedure that endoscopist experience is highly likely to be a critical factor for treatment success. We consider that IT knife-ESD for EGC is feasible and safe when performed by experienced endoscopists.
authors.affiliation: Department of Surgery, Kyorin University School of Medicine, Tokyo, Japan. abenbtg@kyorin-u.ac.jp
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Abe
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Izumisato
authors.forename: Osamu
authors.initials: O
authors.lastname: Yanagida
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Masaki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Mori
authors.forename: Masanori
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Atomi
mesh_terms: D000236:Adenoma / Q000601:surgery*; D000368:Aged; D005260:Female; D005753:Gastric Mucosa / Q000601:surgery*; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000601:surgery*; D013525:Surgical Instruments