1. Dynamic patient position changes during colonoscope withdrawal increase adenoma detection : a randomized, crossover trial James E. East, MRCP, MD, Paul Bassett, MSc, Naila Arebi, PhD, MRCP, Siwan Thomas-Gibson, MD, MRCP, Thomas Guenther, MD, PhD, Brian P. Saunders, MD, FRCP Gastrointest Endosc 2011;73:456-63 2011.3.21 Hyun Hee Jae

2. Introduction  Lower adenoma miss rates  Good colonoscopic withdrawal technique  Longer withdrawal times  Taking >6minutes  Use of antispasmodics  Optimal equipment  Patients of operators with a low (<20%) adenoma detection rate  Increased risk of interval cancer => Comprehensive adenoma detection may be important

3.  Position changes during the withdrawal  Adequate distension of the colon & Movement of excess fluid away  Gas to rise : fill the air  Fluid to fall away to dependant areas  Hepatic flexure  RUQ -> left lateral position  Transverse colon  Relatively anteriorly in the abdomen -> supine position  Splenic flexure & descending colon  LUQ -> right lateral position

4.  Position changes during the withdrawal  Recommend in some standard texts  Rare in routine clinical practice  Previous study  Dynamic position change during colonoscope withdrawal on luminal distension  The clinically important outcome measure of polyp and adenoma detection were not measured

5. Methods  Patients  Aged 50 to 80 years  Intact colons  Routine colonoscopy  Between November 2005 and August 2007  Colonoscopy  By single experienced operator  Examined in 3 segments  Cecum, ascending colon, hepatic flexure  Transverse colon  Splenic flexure, descending colon

7. Methods  Examination either entirely in the left lateral position followed by position changes or vice versa  Polyp size in mm, polyp shape, colon area  Distension score (1 to 5)  1: total collase  5: widely distended

8. Methods  Primary outcome measure  Proportion of patients with >1 adenoma detected in the segments  Secondary outcome measures  Number of patients with >1 polyp or adenoma detected in each colon segment  Median adenoma and polyp size detected  Number of patients who had a polyp or adenoma detected related to the distension

11. Table 2. Patients with > 1 adenoma detected by colon segment

12. Table 3. Patients with > 1 polyp detected by colon segment

13. Table 4. Comparison of adenoma and polyp detection related to distension score

14. Conclusion  Dynamic position changes during colonoscope withdrawal significantly improved polyp and adenoma detection