Clinical Articles
Pivotal Studies Regarding Colonoscopy Miss Rates
This information is not intended to be comprehensive, but is designed instead to provide highlights of recent studies that are likely to be of interest to health plan and hospital technology decision makers.A number of related studies have been published in peer-reviewed journals. The following three studies are frequently cited in other articles as demonstrating that current colonoscopy technology is limited in its accuracy and sensitivity, resulting in unacceptable miss rates for colorectal cancers and pre-cancerous adenomas:
- The pivotal study by Dr. Douglas Rex, et al. at Indiana University
- “Tandem” study - two expert endoscopists did “back-to-back” colonoscopies on the same patient.
- Average of 24% of all adenomas were missed by the first endoscopist (range 17-48%).
- Reference: Rex, et al. Colonoscopic Miss Rates of Adenomas Determined by Back-to-Back Colonoscopies. Gastroenterology 1997;112:24-28.
Full Abstract: ncbi.nlm.nih.gov/
- The CT colonography study by Dr. Perry, et al. at Pickhardt at University of Wisconsin
- Compared CT colonography (“Virtual Colonoscopy”) to standard colonoscopy.
- Miss rate for colonoscopy was 12% for large polyps (>1 cm), but didn’t consider smaller polyps because CT can’t see them.
- 2/3 of the polyps that were missed by the colonoscope were located on the proximal aspect of folds (i.e., the side that’s hidden when looking from below).
- Reference: Pickhardt, et al. Location of Adenomas Missed by Optical Colonoscopy. Ann Intern Med 2004;141:352-9.
Full Abstract: ncbi.nlm.nih.gov/
- Review of cancer patients in the Dietary Polyp Prevention Trial by Dr. Ajay Pabby, et al. (large multi-center study)
- Of all the patients in the study who developed colorectal cancer, 23% had a “normal” colonoscopy within 30 months (2½ years) before their diagnosis.
- Conclusion: 23% patients with cancer had either a cancer or a pre-cancerous adenoma missed at their previous exam.
- Reference: Pabby, et al. Analysis of colorectal cancer occurrence during surveillance colonoscopy in the dietary Polyp Prevention Trial. Gastrointest Endosc 2005;61:385-91.
Full Abstract: ncbi.nlm.nih.gov/
Two recent studies have confirmed the significance of high miss rates in colonoscopy and generated additional interest in the issue among endoscopists and patients:
- A meta-analysis of six tandem colonoscopy studies was performed by Dr. Jeroen van Rijn, et al. at University of Amsterdam.
- The overall average miss rate for colonoscopy was 22%
- Reference: Van Rijn, et al. Polyp Miss Rate Determined by Tandem Colonoscopy: A Systematic Review. Am J Gastroenterol 2006;101:343–350.
Full Abstract: ncbi.nlm.nih.gov/
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A study to determine the effect of the time spent during colonoscopy was conducted by Dr. Robert Barclay, et al. at University of Illinois, Rockford.
- 12 endoscopists performed 2,053 screening colonoscopies.
- Endoscopists who spent an average of 6 minutes or more during the withdrawal phase of colonoscopy found 2.4 times as many adenomas as those who averaged less than 6 minutes.
- These results supported new guidelines recommending that endoscopists spend at least 6-10 minutes during withdrawal.
- This study also resulted in extensive media attention, and now many patients are asking their physicians about their miss rates and withdrawal times.
- Reference: Barclay, et al. Colonoscopic Withdrawal Times and Adenoma Detection during Screening Colonoscopy. N Engl J Med 2006;355:2533-41.
Full Abstract: content.nejm.org/
Clinical Resources for Third Eye® Retroscope®
The latest peer-reviewed research using Third Eye RetroscopeThe following studies suggest that the Third Eye Retroscope may benefit you and your patients. Avantis supported research has been presented at various U.S. and international gastroenterological society meetings. Click a reference to view the full abstract.
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A Prospective Efficacy Evaluation of the Third Eye Retroscope Auxiliary Endoscopy System
Jerome D. Waye, Russell I. Heigh, David E. Fleischer, Jonathan a. Leighton, Leslie B. Aldrich, Jiayi Li, Sanjay Ramrakhiani, Steven a. Edmundowicz, Dayna Early, Robert S. Bresalier, William R. Kessler, Douglas Rex
Gastrointestinal Endoscopy
April 2008 (Vol. 67, Issue 5, Pages AB101-AB102)
Full Text: giejournal.org/ (Note: You will be prompted to create a free user account to view the article) -
First Human Use Evaluation of the Third Eye Retroscope™ Auxiliary Imaging System
George Triadafilopoulos, Jiayi Li, David Watts, John Higgins, Jacques Van Dam
Gastrointestinal Endoscopy
April 2007 (Vol. 65, Issue 5, Page AB333)
Full Text: ncbi.nlm.nih.gov/ -
A novel retrograde-viewing auxiliary imaging device (Third Eye Retroscope) improves the detection of simulated polyps in anatomic models of the colon
George Triadafilopoulos, H. David Watts, Jack Higgins, Jacques Van Dam
Gastrointestinal Endoscopy
January 2007 (Vol. 65, Issue 1, Pages 139-144)
Full-Text PDF
A related study, not funded by Avantis Medical Systems, evaluates CT Colonography and retrograde viewing:
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Surface Visualisation At CT Colonography Simulated Optical Colonoscopy: Wide Angle Colonoscopy and Retrograde Viewing Auxiliary Imaging Devices
James E. East, Brian P. Saunders, Darren Boone, David Burling, Steve Halligan, Stuart A. Taylor
Gastrointestinal Endoscopy
April 2007 (Vol. 65, Issue 5, Page AB94)
Full Text: ncbi.nlm.nih.gov/
MKT 16044, Rev A