title: A learning curve for endoscopic submucosal dissection of gastric epithelial neoplasms.
abstract: OBJECTIVE
  Endoscopic submucosal dissection (ESD) has become a widely accepted method for treating gastrointestinal neoplasms. The objective of our study was to assess the learning curve for ESD of gastric epithelial neoplasms.
  
  
  METHODS
  Clinicopathological data were retrospectively collected from 383 ESD procedures for gastric epithelial neoplasms that were performed over a 5-year period. Thirteen endoscopists were involved as operators during this period. In study 1, the performance of the two principal operators was assessed every 25 patients. In study 2, the performance of all 13 operators was assessed according to their experience.
  
  
  RESULTS
  In study 1, the caseloads of the two principal operators were 188 and 118 ESD procedures. There were no significant differences found between successive groups of 25 patients with regard to en-bloc resection rate and bleeding and perforation complication rates. The size of the lesions and the resected specimen diameter increased significantly as the number of treated cases increased, whereas the average procedure time decreased significantly. In study 2, the operators' caseloads ranged from 1 to 188 cases, with 11/13 operators having experience of fewer than 30 cases. There was no significant difference in treatment efficacy and complication rates between the operators throughout the study period. The lesions were mainly located in the lower part of the stomach in the procedures performed by the 11 less experienced endoscopists. The procedure times shortened as experience in the method increased.
  
  
  CONCLUSIONS
  Constant rates of both treatment efficacy and complications were achieved over a 5-year period of experience with ESD. A decrease in procedure time was found to be a marker of proficiency in this technique.
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kakushima
authors.forename: M
authors.initials: M
authors.lastname: Fujishiro
authors.forename: S
authors.initials: S
authors.lastname: Kodashima
authors.forename: Y
authors.initials: Y
authors.lastname: Muraki
authors.forename: A
authors.initials: A
authors.lastname: Tateishi
authors.forename: M
authors.initials: M
authors.lastname: Omata
mesh_terms: D002983:Clinical Competence; D016001:Confidence Intervals; D016099:Endoscopy, Gastrointestinal / Q000379:methods / Q000592:standards*; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D006801:Humans; D009375:Neoplasms, Glandular and Epithelial / Q000473:pathology / Q000601:surgery*; D013274:Stomach Neoplasms / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome