title: CT-colonography after incomplete colonoscopy: what is the diagnostic yield?
abstract: BACKGROUND
  Computed tomography-colonography is a diagnostic modality that can be used when the colon is not completely intubated during colonoscopy. It may have the additional advantage that information on extracolonic lesions can be obtained.
  
  
  OBJECTIVE
  The aim of this study was to investigate the yield of CT-colonography of relevant intra- and extracolonic findings in patients after incomplete colonoscopy.
  
  
  METHODS
  This was an observational, retrospective study.
  
  
  METHODS
  Data were be obtained from standardized radiology and endoscopy reports and electronic medical records.
  
  
  METHODS
  In total, 136 consecutive CT-colonographies performed after incomplete colonoscopy were evaluated.
  
  
  METHODS
  All intra- and extracolonic findings on CT-colonography were recorded and interpreted for clinical relevance, and it was determined whether further diagnostic and/or therapeutic workup was indicated.
  
  
  RESULTS
  Major indications for colonoscopy included iron-deficiency anemia (25.7%), hematochezia (20.6%), change in bowel habits (18.4%), and colorectal cancer screening or surveillance (11.0%). Major reasons for incomplete colonoscopy were a fixed colon (34.6%) and strong angulation of the sigmoid colon (17.6%). Introduction of the colonoscope was limited to the left-sided colon in 53.7% of cases. Incomplete colonoscopy detected colorectal cancer in 12 (8.8%) patients and adenomatous polyps in 27 (19.9%) patients. CT-colonography after incomplete colonoscopy additionally revealed 19 polyps in 15 (11.0%) and a nonsynchronous colorectal cancer in 4 (2.9%) patients. CT-colonography also detected extracolonic findings with clinical consequences in 8 (5.9%) patients, including fistulizing diverticulitis (n = 3), gastric tumor (n = 2), liver abscess (n = 1), osteomyelitis (n = 1), and an infected embolus in both renal arteries (n = 1).
  
  
  CONCLUSIONS
  This study was limited by the lack of confirmation of intraluminal CT-colonography findings in a subset of patients.
  
  
  CONCLUSIONS
  Computed tomography-colonography can be of added value in patients with incomplete colonoscopy, because it revealed 27 relevant additional (both intra- and extracolonic) lesions in 19.1% of patients. In cases where CT-colonography detected colorectal cancer after incomplete colonoscopy, it can also be used for staging purposes.
authors.affiliation: Department of Gastroenterology and Hepatology, University Medical Center, Utrecht, The Netherlands. H.J.M.Pullens@umcutrecht.nl
authors.forename: Hendrikus J M
authors.initials: HJ
authors.lastname: Pullens
authors.forename: Maarten S
authors.initials: MS
authors.lastname: van Leeuwen
authors.forename: Robert J F
authors.initials: RJ
authors.lastname: Laheij
authors.forename: Frank P
authors.initials: FP
authors.lastname: Vleggaar
authors.forename: Peter D
authors.initials: PD
authors.lastname: Siersema
mesh_terms: D000368:Aged; D000740:Anemia / Q000209:etiology*; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies