title: Preoperative indicators of failure of en bloc resection or perforation in colorectal endoscopic submucosal dissection: implications for lesion stratification by technical difficulties during stepwise training.
abstract: OBJECTIVE
  The technical difficulties inherent in endoscopic submucosal dissection (ESD) for colorectal neoplasms may result in the failure of en bloc resection or perforation. The aim of this retrospective study was to assess the predictors of en bloc resection failure or perforation by using preoperatively available factors.
  
  
  METHODS
  Between September 2002 and March 2013, 716 colorectal ESDs in 673 consecutive patients were performed at a tertiary cancer center. Patient characteristics, tumor location, tumor type, colonoscopy-related factors, and endoscopist experience were assessed based on a prospectively recorded institutional ESD database. Logistic regression analysis was performed to identify predictors of failure of en bloc resection or perforations, with subgroup analyses of ESDs performed by endoscopists less experienced in colorectal ESD (<40 cases) and for colonic lesions only.
  
  
  RESULTS
  On multivariate analysis, independent predictors of failure of en bloc resection or perforations were the presence of fold convergence (odds ratio [OR] 4.4; 95% confidence interval [95% CI], 1.9-9.9), protruding type (OR 3.6; 95% CI, 1.8-7.1), poor endoscope operability (OR 3.5; 95% CI, 1.8-6.9), right-sided colonic lesions (OR 3.0; 95% CI, 1.5-6.3 vs rectal lesions), left-sided colonic lesions (OR 3.2; 95% CI, 1.7-6.3, vs rectal lesions), the presence of an underlying semilunar fold (OR 2.1; 95% CI, 1.3-3.6), and a less-experienced endoscopist (OR 2.1; 95% CI, 1.3-3.6). Among less-experienced endoscopists, colonic lesions were independent predictors (right-sided colonic lesions 8.1; 95% CI, 2.9-25.1; left-sided colonic lesions 8.1; 95% CI, 2.5-28.3 vs rectal lesions). For colonic lesions, the presence of fold convergence (OR 3.7; 95% CI, 1.6-8.6), poor endoscope operability (OR 3.6; 95% CI, 1.8-7.2), a less-experienced endoscopist (OR 3.0; 95% CI, 1.7-1.8), and the presence of an underlying semilunar fold (OR 2.7; 95% CI, 1.5-4.7) were identified predictors.
  
  
  CONCLUSIONS
  This study successfully identified predictors of en bloc resection failure or perforation. Understanding these indicators could help to accurately stratify lesions according to technical difficulty and to appropriately select endoscopists.
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Kenichiro
authors: K
authors: Imai
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Kinichi
authors: K
authors: Hotta
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Yuichiro
authors: Y
authors: Yamaguchi
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Naomi
authors: N
authors: Kakushima
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Masaki
authors: M
authors: Tanaka
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Kohei
authors: K
authors: Takizawa
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Noboru
authors: N
authors: Kawata
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Hiroyuki
authors: H
authors: Matsubayashi
authors: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Tadakazu
authors: T
authors: Shimoda
authors: Clinical Trial Coordination Office, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Keita
authors: K
authors: Mori
authors: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors: Hiroyuki
authors: H
authors: Ono
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence; D003106:Colon / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology / Q000601:surgery*; D004210:Dissection / Q000009:adverse effects* / Q000193:education; D016099:Endoscopy, Gastrointestinal / Q000009:adverse effects* / Q000193:education; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000601:surgery; D007416:Intestinal Perforation / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000473:pathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017211:Treatment Failure