title: Miss rate of right-sided colon examination during colonoscopy defined by retroflexion: an observational study.
abstract: BACKGROUND
  Colonoscopy is less effective in the proximal compared with the distal colon.
  
  
  OBJECTIVE
  To describe the success rate, yield, and safety of retroflexion of the right side of the colon after a careful forward-viewing examination.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Tertiary-care hospital outpatient endoscopy center and associated ambulatory surgery center.
  
  
  METHODS
  A total of 1000 consecutive adults undergoing elective screening or surveillance colonoscopy, without previous bowel resection, inflammatory bowel disease, or polyposis syndromes.
  
  
  METHODS
  After cecal intubation, a careful examination of the cecum to the hepatic flexure was performed in the forward view with removal of all identified polyps. The colonoscope was then reinserted to the cecum and retroflexed, and examination was performed to the hepatic flexure in retroflexion.
  
  
  METHODS
  Success rate, per-polyp and per-patient miss rates, and adverse events rate of retroflexion.
  
  
  RESULTS
  Retroflexion was successful in 94.4% of patients. Looping in the insertion tube was the apparent cause of 89% of failed attempts. The forward view identified 634 proximal colon polyps and 497 adenomas, and retroflexion identified an additional 68 polyps and 54 adenomas, representing a per-adenoma miss rate of 9.8% and an intention-to-treat, per-patient adenoma miss rate of 4.4%. Older age, male sex, and polyps seen on the forward view predicted polyps seen on retroflexion. There were no adverse events.
  
  
  CONCLUSIONS
  Single-center, uncontrolled study with only 2 endoscopists.
  
  
  CONCLUSIONS
  Right-sided colon retroflexion is generally achievable and safe in our hands. The yield is comparable to that expected from a second examination in the forward view.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Hewett
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Rex
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D002430:Cecal Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis* / Q000601:surgery; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods*; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D057194:Intention to Treat Analysis; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies