title: Underwater endoscopic mucosal resection for recurrences after previous piecemeal resection of colorectal polyps (with video).
abstract: BACKGROUND
  Conventional endoscopic treatment of a recurrent adenoma after piecemeal EMR (PEMR) of a colorectal laterally spreading tumor (LST) is technically difficult with low en bloc resection rates because of the inability to snare fibrotic residual.
  
  
  OBJECTIVE
  To assess the feasibility of salvage underwater EMR (UEMR) for the treatment of recurrent adenoma after PEMR of a colorectal LST.
  
  
  METHODS
  Retrospective, cross-sectional study.
  
  
  METHODS
  Single, tertiary-care referral center.
  
  
  METHODS
  Patients who have recurrent adenoma after PEMR of colorectal LST (≥2 cm).
  
  
  METHODS
  UEMR versus EMR.
  
  
  METHODS
  En bloc resection rate, endoscopic complete removal rate, recurrence rate on follow-up colonoscopy, adjunctive ablation rate with argon plasma coagulation (APC) during salvage procedure, and independent predictive factors for successful en bloc resection and endoscopic complete removal.
  
  
  RESULTS
  Eighty salvage procedures (36 UEMRs vs 44 EMRs) were analyzed. En bloc resection rate (47.2% vs 15.9%, P = .002) and endoscopic complete removal rate (88.9% vs 31.8%, P < .001) were higher in the UEMR group than in the EMR group. APC ablation of visible residual during salvage procedure was lower in UEMR group than EMR group (11.1% vs 65.9%, P < .001). Recurrence rate on follow-up colonoscopy was significantly lower in the UEMR group than the EMR group (10% vs 39.4%, P = .02). UEMR was an independent predictor of successful en bloc resection and endoscopic complete removal.
  
  
  CONCLUSIONS
  Retrospective, single-center study.
  
  
  CONCLUSIONS
  UEMR can be a useful and feasible technique as a salvage procedure for recurrent colorectal adenoma after PEMR.
authors.affiliation: Institute for Digestive Research, Soonchunhyang University College of Medicine, Seoul, South Korea.
authors.forename: Hyun Gun
authors.initials: HG
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Nirav
authors.initials: N
authors.lastname: Thosani
authors.affiliation: Department of Gastroenterology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Subhas
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Department of Gastroenterology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, Stanford University School of Medicine, Stanford, California, USA; VA Palo Alto Health Care System, Palo Alto, California, USA.
authors.forename: Shai
authors.initials: S
authors.lastname: Friedland
mesh_terms: D000236:Adenoma / Q000601:surgery; D018256:Adenomatous Polyps / Q000601:surgery*; D000368:Aged; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000601:surgery*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D018365:Neoplasm, Residual; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods; D014867:Water
chemical_list: D014867:Water