title: Short turn radius colonoscope in an anatomical model: retroflexed withdrawal and detection of hidden polyps.
abstract: OBJECTIVE
  To evaluate the new RetroView™ colonoscope and compare its ability to detect simulated polyps "hidden" behind colonic folds with that of a conventional colonoscope, utilizing anatomic colon models.
  
  
  METHODS
  Three anatomic colon models were prepared, with twelve simulated polyps "hidden" behind haustral folds and five placed in easily viewed locations in each model. Five blinded endoscopists examined two colon models in random order with the conventional or RetroView™ colonoscope, utilizing standard withdrawal technique. The third colon model was then examined with the RetroView™ colonoscope withdrawn initially in retroflexion and then in standard withdrawal. Polyp detection rates during standard and retroflexed withdrawal of the conventional and RetroView™ colonoscopes were determined. Polyp detection rates for combined standard and retroflexed withdrawal (combination withdrawal) with the RetroView™ colonoscope were also determined.
  
  
  RESULTS
  For hidden polyps, retroflexed withdrawal using the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (85% vs 12%, P = 0.0001). For hidden polyps, combination withdrawal with the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (93% vs 12%, P ≤ 0.0001). The RetroView™ colonoscope in "combination withdrawal" was superior to other methods in detecting all (hidden + easily visible) polyps, with successful detection of 80 of 85 polyps (94%) compared to 28 (32%) polyps detected by the conventional colonoscope in standard withdrawal (P < 0.0001) and 67 (79%) polyps detected by the RetroView™ colonoscope in retroflexed withdrawal alone (P < 0.01). Continuous withdrawal of the colonoscope through the colon model while retroflexed was achieved by all endoscopists. In a post-test survey, four out of five colonoscopists reported that manipulation of the colonoscope was easy or very easy.
  
  
  CONCLUSIONS
  In simulated testing, the RetroView™ colonoscope increased detection of hidden polyps. Combining standard withdrawal with retroflexed withdrawal may become the new paradigm for "complete screening colonoscopy".
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: McGill
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Shivangi
authors.initials: S
authors.lastname: Kothari
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Shai
authors.initials: S
authors.lastname: Friedland
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Ann
authors.initials: A
authors.lastname: Chen
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Walter G
authors.initials: WG
authors.lastname: Park
authors.affiliation: Sarah K McGill, Shivangi Kothari, Shai Friedland, Ann Chen, Walter G Park, Subhas Banerjee, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, United States.
authors.forename: Subhas
authors.initials: S
authors.lastname: Banerjee
mesh_terms: D001291:Attitude of Health Personnel; D003106:Colon / Q000473:pathology*; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D020685:Colonoscopes; D003113:Colonoscopy / Q000295:instrumentation* / Q000379:methods; D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D008953:Models, Anatomic; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires
keywords: Adenoma detection; Colon cancer; Colonoscope retroflexion; Colonoscopy; Polyp detection