title: Preoperative colonoscopy for detection of synchronous neoplasms after insertion of self-expandable metal stents in occlusive colorectal cancer: comparison of covered and uncovered stents.
abstract: OBJECTIVE
  In patients with occlusive colorectal cancers, a complete preoperative evaluation of the colon proximal to the obstruction is often impossible. We aimed to evaluate the feasibility of preoperative colonoscopy after stent placement and to determine whether the success rate of colonoscopy differs between covered and uncovered stents.
  
  
  METHODS
  Seventy-three patients with malignant colorectal obstruction were enrolled prospectively. In patients with a resectable cancer, a preoperative colonoscopy was performed after insertion of a self-expandable metal stent (SEMS). The success rate of complete preoperative colonoscopy was compared between covered and uncovered stents.
  
  
  RESULTS
  Forty-five of 73 patients who underwent stent placement had a resectable cancer (61.6%). A complete preoperative colonoscopy was possible in 40 of 45 patients (88.9%). The success rate of complete preoperative colonoscopy was significantly lower in the covered-stent group when the obstructing mass lesion was located in the sigmoid colon (p=0.024). Synchronous cancer was detected in one patient (2.2%). Stent migration was observed in four patients with a covered stent.
  
  
  CONCLUSIONS
  A preoperative complete colonoscopy after SEMS placement was feasible and safe in most patients with malignant colorectal obstruction. Uncovered stents seem to have more advantages than covered stents in preoperative colonoscopy proximal to the obstruction.
authors.affiliation: Department of Gastroenterology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Sun Gyo
authors.initials: SG
authors.lastname: Lim
authors.forename: Kwang Jae
authors.initials: KJ
authors.lastname: Lee
authors.forename: Kwang Wook
authors.initials: KW
authors.lastname: Suh
authors.forename: Seung Yeop
authors.initials: SY
authors.lastname: Oh
authors.forename: Soon Sun
authors.initials: SS
authors.lastname: Kim
authors.forename: Jun Hwan
authors.initials: JH
authors.lastname: Yoo
authors.forename: Jeong Ook
authors.initials: JO
authors.lastname: Wi
keywords: Colonoscopy; Colorectal neoplasms; Neoplasms, multiple primary; Stents