title: Topical submucosal chromoendoscopy defines the level of resection in colonic EMR and may improve procedural safety (with video).
abstract: BACKGROUND
  Blue dyes such as indigo carmine have become a frequent component of the submucosal injectate for EMR. Confirmation of the correct resection plane and assessment of the resection defect are facilitated by the selective staining of the submucosal layer. Nonstained areas are more difficult to evaluate and may contain inadvertent muscularis propria (MP) injury. The use of topical submucosal chromoendoscopy (TSC) may allow rapid and accurate assessment of these unstained areas and visual recognition of MP injury.
  
  
  OBJECTIVE
  To evaluate the utility of a novel technique in the assessment of nonstained areas within the post-EMR defect.
  
  
  METHODS
  Single-center prospective cohort study.
  
  
  METHODS
  Academic, tertiary care referral center.
  
  
  METHODS
  A total of 143 patients undergoing wide-field colonic EMR for sessile lesions 20 mm or larger.
  
  
  METHODS
  A standard inject-and-resect EMR technique was applied with indigo carmine blue dye in the injectate. Defects with areas of nonstaining were recorded and examined, and then irrigated with the submucosal injectate by using the blunt tip of the injection catheter.
  
  
  METHODS
  Detection of additional cases of MP injury by using TSC.
  
  
  RESULTS
  A total of 147 EMRs were performed. Focal areas of defect nonstaining were seen in 25 of cases (17%), with no MP injury identified on initial examination. After TSC, 2 additional cases of MP injury were identified, and these were successfully managed endoscopically. Intraprocedural recognition of deep resection increased from 4 cases (2.8%) to 6 cases (4.1%), thereby avoiding potential delayed perforation in 2 patients.
  
  
  CONCLUSIONS
  Single-center, nonrandomized study.
  
  
  CONCLUSIONS
  TSC is simple and effective and rapidly confirms the plane of resection and may improve detection of intraprocedural perforation.
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia.
authors.forename: Bronte A
authors.initials: BA
authors.lastname: Holt
authors.forename: Vanoo
authors.initials: V
authors.lastname: Jayasekeran
authors.forename: Rebecca
authors.initials: R
authors.lastname: Sonson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bourke
mesh_terms: D015331:Cohort Studies; D003106:Colon / Q000293:injuries*; D003108:Colonic Diseases / Q000175:diagnosis*; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy / Q000379:methods*; D004396:Coloring Agents; D006801:Humans; D007203:Indigo Carmine; D007413:Intestinal Mucosa / Q000473:pathology* / Q000601:surgery; D011446:Prospective Studies
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine