The Utility of Time Segmental Withdrawal During Screening Colonoscopy for Increasing Adenoma Detection Rate.

Screening colonoscopy is an essential diagnostic tool in the early detection of precancerous
colonic lesions, preventing the progression of these lesions to cancer. Population-based and
case control studies found a 50% reduction in colo-rectal cancer (CRC) incidence and up to a
one-third reduction in mortality from CRC after screening colonoscopy. The effectiveness of
colonoscopy in preventing colon cancer is dependent on the adenoma detection rate (ADR)
during the procedure. Studies have demonstrated that withdrawal times of 6 minutes or more
had higher rates of detection of any neoplasia. In 2006 joint task force of the American
College of Gastroenterology and American Society for Gastrointestinal Endoscopy changed the
recommendation to indicate that average withdrawal time should exceed 6 minutes in normal
colonoscopies in which no polypectomies or biopsies were performed. Based on this
recommendation, the 6-minute benchmark is the current standard of care. Longer mean
withdrawal times are associated with increasing adenoma detection, mainly of small or
right-sided adenomas and proximal serrated adenomas, presumably due to longer inspection of
the right colon. However, it also have been showed withdrawal time using 6 minutes as the
threshold is not a strong predictor of the likelihood of finding a polyp during colonoscopy
and should not be used as a quality indicator. New CRC diagnosis within 3 years of negative
screening colonoscopy can be as high as 6%. Right-sided lesions, flat polyps, and variability
in endoscopist quality measures are all potential reasons why interval cancers develop. A
recent observational study was published showing increase in ADR after implementation of a
protocol of careful inspection during a minimum of 8 minutes was established. The
investigators hypothesized that if colonoscopists would spend at least half of the time of
the withdrawal time in the right side of the colon (referred as segmented protocol), ADR can
increase mainly due to the detection of lesions in the right side, which could have been
missed otherwise. The investigators are conducting a single center randomized trial
investigating the utility of timed segmental withdrawal of at least 3 minutes each in both
right and left side of the colon respectively, compared to the regular 6 minutes total
withdrawal time regardless of where the time was spent in the colon.

Inclusion Criteria:

- Adult patients (18-80 years) who are undergoing colonoscopy for screening or
surveillance purposes.

Exclusion Criteria:

1. Patients with a prior history of colonic surgeries

2. Patient with Crohns colitis or ulcerative colitis

3. Patient with prior history of colon cancer

4. Patient with poor bowel preparation

5. Pregnant women