News Release

Flaws in colonoscopies may increase risk of colon cancer

Studies examine age, location and training as quality factors

Peer-Reviewed Publication

American Gastroenterological Association

WASHINGTON, D.C. (May 23, 2007) -- Colonoscopies are considered the gold standard for detecting colon cancer, the second leading cause of cancer deaths in the United States. Research presented today at Digestive Disease Week® 2007 (DDW®) discusses contributing factors that could prevent patients from getting optimal results from their colonoscopy, including age of the patient, location of the screening and proper technician training. DDW is the largest international gathering of physicians and researchers in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

Adequate Level of Training for Technical Competence in Colonoscopy: A Prospective Multicenter Evaluation of the Learning Curve (Abstract # 659) For a physician to be considered "competent" at diagnostic colonoscopies, training programs recommend that trainees complete between 100 and 200 procedures. This study conducted by researchers from the Soonchunhyang University College of Medicine in Korea argues that there are other markers of competency, most notably cecal intubation (the process of inserting of a tube into the first portion of the large bowel), which has been known to cause complications if it takes too long.

Investigators evaluated the procedures of 24 first-year fellows in 15 tertiary care academic centers – a total of 4,351 colonoscopies. Procedures were excluded if they were related to the following: emergency colonoscopies, colonic obstructions, previous histories of colonic operations, therapeutic procedures, monitoring for inflammatory bowel disease (IBD) and age (no one older than 80 or younger than 18). The success rate was measured by the completion rate (greater than 90%) and the cecal intubation time (less than 20 minutes).

After examining the completion rate and the cecal intubation time, the team concluded that competence in efficient colonoscopy generally requires more than 150 cases. Overall, 83.5 percent of the colonoscopies were successful and the average cecal intubation time was 9.23 minutes. The success rate was significantly improved and reached the competency standard after 150 procedures (71.5, 82.6, 91.3, 94.4, 98.4 and 98.7%, respectively, for every 50 procedures). After 150, procedures cecal intubation time decreased from 14.2 to nine minutes.

"We feel this study was extremely valuable in further assessing the level of technical competency that will minimize patient complications when undergoing colonoscopy," said Suck-Ho Lee of the Soonchunhyang University College of Medicine, and lead author of the study. "We hope that institutions will be cognizant of these statistics as they train new technicians in order to obtain the best results for our patients with the least risk possible."

Dr. Lee will present this study on Tuesday, May 22, at 10:30 a.m. in Room 143.

Incomplete Colonic Examination in the Elderly: A Consequence of Inadequate Preparation (Abstract #W1275) The use of endoscopy has rapidly increased in the elderly over the past few years as research has verified its safety and efficacy. Colonoscopies have also proven to be safe for the elderly, but are often more technically challenging than endoscopies due to inadequate preparation and the safe administration of sedatives. This study, conducted by researchers from the Imperial College Faculty of Medicine in London, sought to determine the effectiveness of colonoscopy for complete examination of the colon in patients over the age of 75.

All colonoscopies were performed in a teaching hospital throughout a one-year period and were analyzed for rates of complete examination, as defined by cecal intubation and the ability to obtain a full image of the area at the beginning of the colon near the small intestines. Overall, 1,981 colonoscopies were performed, and only 11.8 percent of patients under the age of 75 had incomplete examinations. However, that number increased to 20.7 percent in those over the age of 75. The leading reason for unsuccessful examinations was poor preparation (42.5%). Contrary to popular belief, just 0.7 percent of the colonoscopies were stopped due to discomfort in patients over 75, as opposed to 2.6 percent in those under 75.

"Colonoscopy in a population over 75 years of age is less successful in imaging the colon, mainly due to problems with bowel preparation. However, contrary to popular belief, aborted examinations due to discomfort in the elderly are rare," said Kinesh Patel, MBBS, of Imperial College Faculty of Medicine, and lead author of the study. "Strategies to improve bowel preparation will help increase the effectiveness of colonoscopy in this population. Additionally, further studies on bowel preparation are urgently required to optimize the safety and efficacy of colonoscopy in a vulnerable patient group."

Dr. Patel will present this study on Wednesday, May 23, at 8:00 a.m. in Hall E.

Process Quality Indicators in a Series of 145,401 Outpatient Colonoscopies (Abstract #W1238) As more and more people rely on colonoscopies for the prevention and early detection of colon cancer, it is crucial that researchers assess the process quality of colonoscopies and identify factors associated with poor quality, specifically in outpatient colonoscopies. Investigators from the University of Munich in Germany analyzed a database containing details of 145,401 colonoscopies performed by the Compulsory Health Insurance Physicians in Bavaria, Germany from January through September of 2006 for these quality indicators.

Of the patients examined, 110,648 had a clean enough bowel to perform the colonoscopies and only 3,976 examinations were considered incomplete. Most of the examinations (n=134,655) were taken with a sedative. Incomplete exams were largely due to adhesions (scar tissues that attach to the surfaces of organs, n=512), impassable stenosis (narrowing of the gut, n=506), long and curved colon (n=284), and additional complications (n=50). While male and sedated patients were more likely to have a complete colonoscopy, older patients were less likely to complete the procedure.

"For the first time, we report findings for a large range of process quality indicators for outpatient colonoscopies," said Berndt Birkner, M.D., a gastroenterologist from the Munich study team. "They may serve as a benchmark for comparisons with other programs. Sedation and thorough bowel cleansing are modifiable factors conducive to the completeness of colonoscopies and can play a critical role in the ultimate outcome for these patients."

Dr. Birkner will present this study on Wednesday, May 23, at 8:00 a.m. in Hall E.

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Digestive Disease Week® (DDW®) is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases (AASLD), the American Gastroenterological Association (AGA) Institute, the American Society for Gastrointestinal Endoscopy (ASGE) and the Society for Surgery of the Alimentary Tract (SSAT), DDW takes place May 19-24, 2007 in Washington, D.C. The meeting showcases more than 5,000 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology.


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