title: Impact of experience with a retrograde-viewing device on adenoma detection rates and withdrawal times during colonoscopy: the Third Eye Retroscope study group.
abstract: BACKGROUND
  Colonoscopy has been adopted as the preferred method to screen for colorectal neoplasia in the United States. However, lesions can be missed because of numerous factors, including location on the proximal aspect of folds or flexures, where they may be difficult to detect with the forward-viewing colonoscope. The Third Eye Retroscope (TER) is a disposable device that is passed through the instrument channel of a standard colonoscope to provide a retrograde view that complements the forward view of the colonoscope during withdrawal.
  
  
  OBJECTIVE
  To evaluate whether experience with the TER affects polyp detection rates and procedure times in experienced endoscopists who had not previously used the equipment.
  
  
  METHODS
  This was an open-label, prospective, multicenter study at 9 U.S. sites, involving 298 patients presenting for colonoscopy, evaluating the use of the TER in combination with a standard colonoscope.
  
  
  METHODS
  After cecal intubation, the TER was inserted through the instrument channel of the colonoscope. During withdrawal, the forward and retrograde video images were observed simultaneously on a wide-screen monitor.
  
  
  METHODS
  Primary outcome measures were the number and size of adenomas and all polyps detected with the standard colonoscope and with the colonoscope combined with the TER. Secondary outcome measures were withdrawal phase time and total procedure time. Each endoscopist examined 20 subjects, divided into quartiles according to the order of their procedures, and results were compared among quartiles.
  
  
  RESULTS
  Overall, 182 polyps were detected with the colonoscope and 27 additional polyps with the TER, a 14.8% increase (P < .001). A total of 100 adenomas were detected with the colonoscope and 16 more with the TER, a 16.0% increase (P < .001). For procedures performed after each endoscopist had completed 15 procedures while using the TER, the mean additional detection rates with the TER were 17.0% for all polyps (P < .001) and 25.0% for adenomas (P < .001). For lesions 6 mm or larger, the overall additional detection rates with the TER for all polyps and for adenomas were 23.2% and 24.3%, respectively. For lesions 10 mm or larger, the overall additional detection rates with the TER for all polyps and for adenomas were 22.6% and 19.0%, respectively. The mean withdrawal times in the first and fourth quartiles were 10.6 and 9.2 minutes, respectively (P = .044).
  
  
  CONCLUSIONS
  There was no randomization or separate control group. The endoscopists judged whether each lesion could have been detected with the colonscope alone by using their standard technique.
  
  
  CONCLUSIONS
  Polyp detection rates improved significantly with the TER, especially after 15 procedures, when the mean additional detection rate for adenomas was 25.0%. Additional detection rates with the TER for medium-size and large adenomas were greater than for smaller lesions. These results suggest that, compared with a colonoscope alone, a retrograde-viewing device can increase detection rates for clinically significant adenomas without detriment to procedure time or procedure complications. (
  
  
  BACKGROUND
  NCT00969124.).
authors.affiliation: Baylor University Medical Center, Dallas, TX 75246, USA. DanielD@BaylorHealth.edu
authors.forename: Daniel C
authors.initials: DC
authors.lastname: DeMarco
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Odstrcil
authors.forename: Luis F
authors.initials: LF
authors.lastname: Lara
authors.forename: David
authors.initials: D
authors.lastname: Bass
authors.forename: Chase
authors.initials: C
authors.lastname: Herdman
authors.forename: Timothy
authors.initials: T
authors.lastname: Kinney
authors.forename: Kapil
authors.initials: K
authors.lastname: Gupta
authors.forename: Leon
authors.initials: L
authors.lastname: Wolf
authors.forename: Thomas
authors.initials: T
authors.lastname: Dewar
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Deas
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Mehta
authors.forename: M Badar
authors.initials: MB
authors.lastname: Anwer
authors.forename: Randall
authors.initials: R
authors.lastname: Pellish
authors.forename: J Kent
authors.initials: JK
authors.lastname: Hamilton
authors.forename: Daniel
authors.initials: D
authors.lastname: Polter
authors.forename: K Gautham
authors.initials: KG
authors.lastname: Reddy
authors.forename: Ira
authors.initials: I
authors.lastname: Hanan
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis; D020685:Colonoscopes; D003113:Colonoscopy; D004209:Disposable Equipment; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies