Colonoscopy with Withdrawal Times (WT) > 6 Minutes Detects More Polyps That Are Mostly Small and Hyperplastic (H) but Also a Few That Are Larger and Neoplastic (A)

Purpose: Colonoscopy (C) is now an accepted standard as a screening test for colon cancer (CA). A recent published article demonstrated greater effeciently at polyp detection with colonoscopy withdrawal times >6 min. We hypothesized that the majority of polyps found would be small and hyperplastic.TableMethods: 300 consecutive outpatient colonoscopies from Feb 2007 to May 2007 were evaluated and compared to 300 similiarly aged colonoscopies from Feb 2006 to May 2006. All were performed by a single fellowship trained gastroenterologist. Study exclusions were incomplete colonoscopy, colonoscopy associated with complications, previous colonoscopy in the past 2 yrs, poor prep and previous colon resection. All 2007 colonoscopies had withdrawal times > 6 min as defined as the time from cecal identification to withdrawal across the anus. No withdrawal information was available for 2006 data but was assumed to be less then 6 minutes by experience. All polyps were measured and removed in a standard fashion. Results: See table below. Conclusion: Colonoscopy with withdrawal times > 6 minutes leads to higher polyp detection rates, especially for small ( < 5 mm) hyperplastic polyps. However, 4 additional cancers and 3 adenomatous polyps > 10 mm were seen in the study group over the control group. Since 4 of the 5 cancers were large and obvious, one must suspect an effect of sampling error. Repeating the study with a higher # of study patients would be beneficial.