title: The influence of clips on scars after EMR: clip artifact.
abstract: OBJECTIVE
  Laterally spreading lesions ≥20 mm are conventionally removed by EMR. Endoscopic clips are increasingly used to mitigate the risk of delayed bleeding. Clips may alter the endoscopic appearance of the scar after EMR, interfering with the assessment of adenoma recurrence. We aimed to evaluate this.
  
  
  METHODS
  Prospective, single-center data from the Australian Colonic Endoscopic resection study (January 2011-May 2015) were analyzed. Patients undergoing EMR of laterally spreading lesions with endoscopic clips used at the EMR defect were eligible. Data included patient and lesion characteristics and procedural, clinical, and histologic outcomes.
  
  
  RESULTS
  Clips were used in 111 of 885 lesions (12.5%). A total of 62 of 111 clipped lesions had standardized, high-definition, white light, and narrow-band images of the scars after EMR at first surveillance colonoscopy, and the patients were enrolled. Analysis of the images showed 4 situations: a bland scar (N = 27), residual adenoma (N = 6), mucosal elevation with normal pit pattern (N = 14), or granulation tissue related to the presence of residual clips (N = 15). The latter 2 entities were termed post-EMR scar clip artifact (ESCA). Overall, 29 of 62 previously clipped EMR sites (46.8%) had ESCA at a median follow-up of 5.2 months. Twenty scars had residual clips, and 15 of 20 (75.0%) showed ESCA (P = .002). Lesions clipped for prophylaxis of bleeding were more likely to show ESCA than those clipped for deep mural injury or intraprocedural bleeding (65.5% vs 41.7%; P = .006). ESCA was associated with female sex (P = .010) and greater age (P = .011).
  
  
  CONCLUSIONS
  ESCA is characterized by a nodular elevation of the mucosa with a normal pit pattern and can occur with or without residual clips. Prophylactic clip closure and the presence of residual clips are associated with ESCA. (
  
  
  BACKGROUND
  NCT01368289.).
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Pellisé
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia.
authors.forename: Lobke
authors.initials: L
authors.lastname: Desomer
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia; Westmead Clinical School, University of Sydney, New South Wales, Australia.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Burgess
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Williams
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Sonson
authors.affiliation: Department of Pathology, Westmead Hospital, New South Wales, Australia.
authors.forename: Duncan
authors.initials: D
authors.lastname: McLeod
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, New South Wales, Australia; Westmead Clinical School, University of Sydney, New South Wales, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bourke
mesh_terms: D000236:Adenoma / Q000601:surgery*; D000368:Aged; D016477:Artifacts; D002921:Cicatrix / Q000000981:diagnostic imaging*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000601:surgery*; D000069916:Endoscopic Mucosal Resection; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging; D019106:Postoperative Hemorrhage / Q000517:prevention & control*; D011446:Prospective Studies; D013525:Surgical Instruments