title: Effect of Previous Gastrectomy on the Performance of Postoperative Colonoscopy.
abstract: OBJECTIVE
  The purpose of this study was to determine the effect of a prior gastrectomy on the difficulty of subsequent colonoscopy, and to identify the surgical factors related to difficult colonoscopies.
  
  
  METHODS
  Patients with a prior gastrectomy who had undergone a colonoscopy between 2011 and 2014 (n=482) were matched (1:6) to patients with no history of gastrectomy (n=2,892). Cecal insertion time, intubation failure, and bowel clearance score were compared between the gastrectomy and control groups, as was a newly generated comprehensive parameter for a difficult/incomplete colonoscopy (cecal intubation failure, cecal insertion time >12.9 minutes, or very poor bowel preparation scale). Surgical factors including surgical approach, extent of gastrectomy, extent of lymph node dissection, and reconstruction type, were analyzed to identify risk factors for colonoscopy performance.
  
  
  RESULTS
  A history of gastrectomy was associated with prolonged cecal insertion time (8.7±6.4 vs. 9.7±6.5 minutes; P=0.002), an increased intubation failure rate (0.1% vs. 1.9%; P<0.001), and a poor bowel preparation rate (24.7 vs. 29.0; P=0.047). Age and total gastrectomy (vs. partial gastrectomy) were found to be independent risk factors for increased insertion time, which slowly increased throughout the postoperative duration (0.35 min/yr). Total gastrectomy was the only independent risk factor for the comprehensive parameter of difficult/incomplete colonoscopy.
  
  
  CONCLUSIONS
  History of gastrectomy is related to difficult/incomplete colonoscopy performance, especially in cases of total gastrectomy. In any case, it may be that a pre-operative colonoscopy is desirable in selected patients scheduled for gastrectomy; however, it should be performed by an expert endoscopist each time.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sunghwan
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae Han
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Kong
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yun-Suhk
authors.initials: YS
authors.lastname: Suh
authors.affiliation: Department of Internal Medicine, Liver Research Institute, Seoul, Korea.
authors.forename: Jong Pil
authors.initials: JP
authors.lastname: Im
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Liver Research Institute, Seoul, Korea.
authors.forename: Sang Gyun
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Internal Medicine, Liver Research Institute, Seoul, Korea.
authors.forename: Joo Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
keywords: Colonoscopy; Gastrectomy; Postoperative period; Risk factors; Time