Mo1559 Evaluating the Optimal Time for Colonoscopy Withdrawal: a Prospective Randomized Comparison of 3 Minute Versus 6 Minute Withdrawal

Abstract

Mo1559 Evaluating the Optimal Time for Colonoscopy Withdrawal: a Prospective Randomized Comparison of 3 Minute Versus 6 Minute Withdrawal Sheila Kumar*, Rajan Kochar, Shai Friedland, Uri Ladabaum, Ann M. Chen, Subhas Banerjee Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Palo Alto, CA Introduction: A minimum withdrawal time for screening colonoscopy of 6 minutes has been proposed, based on an observational study, and has become the de-facto standard of care. The 6-minute withdrawal time remains controversial and has not been compared in a standardized fashion to alternative withdrawal times. Aims: To perform a prospective randomized study to compare Polyp Miss Rates, Adenoma Miss Rates and Adenoma Detection Rates in patients undergoing colonoscopy with a 3-minute versus a 6-minute withdrawal time. Methods: Consecutive patients undergoing colonoscopy at Stanford University and the Palo Alto Veterans Administration Hospital were enrolled. Patients were prospectively randomized to undergo colonoscopy with either a 3-minute or 6minute withdrawal time during the 1st pass. A second pass was then performed with a 6-minute withdrawal in both groups to determine Polyp Miss Rates and Adenoma Miss Rates. The Adenoma Detection Rate (#colonoscopies where at least 1 adenoma was detected on the first pass/total #colonoscopies) was also determined for both groups. Results: 107 patients (73 men, 24 women) have been enrolled. 52 underwent 3-minute withdrawal and 55 underwent 6-minute withdrawal. Indications and baseline characteristics for both groups were similar (Table 1). The Polyp Miss Rate was significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group (57% vs. 26%, p 0.0012). The Adenoma Miss Rate was also significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group, (57% vs. 33%, p 0.013) (Table 2). The Adenoma Detection Rates were similar in both groups (31% vs. 24%, p NS). Conclusion: The Polyp Miss Rate and Adenoma Miss Rate were significantly higher in the 3-minute withdrawal group compared to the 6minute withdrawal group, suggesting that a 3-minute withdrawal may be inadequate and that a 6-minute withdrawal may be more appropriate for colorectal cancer screening. No significant difference was noted in the Adenoma Detection Rate between the two groups, which may be due to inadequate sample size.