title: Risk factors for incomplete polyp resection during colonoscopic polypectomy.
abstract: OBJECTIVE
  Colonoscopic polypectomy is highly efficient in preventing colorectal cancer, but polyps may not always be completely removed. Improved knowledge of the risk factors for incomplete polyp resection after polypectomy may decrease the cancer risk and additional costs. The aim of this study was to investigate the conditions that can cause incomplete polyp resection (IPR) after colonoscopic polypectomy.
  
  
  METHODS
  A total of 12,970 polyps that were removed by colonoscopic polypectomy were investigated. Among them, we identified 228 cases with a positive resection mar-gin and 228 controls with a clear resection margin that were matched for age, gender, and polyp size. We investigated the location, morphology, and histological type of the polyps and evaluated the skills of the endoscopist and assisting nurse.
  
  
  RESULTS
  Multivariate analysis revealed that the polyps, which were located in the proximal part of the colon and rectum, were at significant risk of IPR. Histologically, an advanced polyp and an inexperienced assistant were also independent risk factors for IPR.
  
  
  CONCLUSIONS
  Polypectomy should be performed more carefully for polyps suspected to be cancerous and polyps located in the proximal part of the colon or rectum. A systematic training program for inexperienced assistants may be needed to decrease the risk of IPR.
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Sang Pyo
authors.initials: SP
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: In Kyung
authors.initials: IK
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Chan Sup
authors.initials: CS
authors.lastname: Shim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002983:Clinical Competence; D003106:Colon / Q000473:pathology / Q000601:surgery; D003111:Colonic Polyps / Q000473:pathology / Q000601:surgery*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure
keywords: Ad-enomatous polyps; Colonic polyps; Colonoscopic polypectomy; Interval colorectal cancer; Polypectomy