A Comparison of Two Colonoscopic Withdrawal Techniques

A Comparison of Two Colonoscopic Withdrawal Techniques on Colonic Polyp Detection: an Open, Randomised, Cross Over Trial

This study will compare two strategies for colonoscope withdrawal, using polyp detection as the primary outcome measure, to determine the optimal withdrawal strategy. Null Hypothesis: On withdrawal of the colonoscope, examining patients with dynamic position change does not yield more polyps than the supine position. Alternative Hypothesis: On withdrawal of the colonoscope, examining the patients with dynamic position change improves polyp detection compared to the supine position.

The identification and removal of polyps has been shown to prevent bowel cancer. Although colonoscopy is the best technique to identify polyps, polyps can be missed even in expert hands. Inspection of the bowel occurs predominantly during colonoscope withdrawal. Tailoring a patients position according to the segment of bowel being examined (dynamic position change) is a technique that has been shown to improve visualisation of the bowel wall and polyp detection. However, changing patient position during colonoscope withdrawal has not been widely accepted in clinical practice. This may be because of a lack of awareness of the literature, a perception that the benefit is negligible and the inconvenience of changing a patients position in addition to the small number of publications demonstrating this to be beneficial. We plan to compare the detection of polyps when colonoscope withdrawal is done with dynamic position change (a planned series of position changes to optimise mucosal visualisation) and the supine position (laid on back). These strategies will be compared by performing a double colonoscope withdrawal; The first withdrawal will be performed either supine or in the dynamic position. This will be followed by a second insertion and withdrawal in the alternative position. The order in which these strategies are performed will be randomised i.e. supine then dynamic or dynamic then supine.

This study will be performed as a cross over study, comparing withdrawal in the supine position versus withdrawal with dynamic position change. Withdrawal in supine position followed by withdrawal with dynamic position change

This study will be performed as a cross over study, comparing withdrawal in the supine position versus withdrawal with dynamic position change.

The initial withdrawal in each of 4 segments of the colon: 1)Caecum, Ascending colon and Hepatic flexure 2) Transverse colon 3) Splenic flexure and descending colon 4) Sigmoid colon, will be performed in two different positions. The intervention in this arm will be withdrawal in the supine position and then with dynamic position change.

The initial withdrawal in each of 4 segments of the colon: 1)Caecum, Ascending colon and Hepatic flexure 2) Transverse colon 3) Splenic flexure and descending colon 4) Sigmoid colon, will be performed in two different positions. The intervention in this arm will be withdrawal with dynamic position change first followed by the supine position.

The primary outcome for this study is the presence or absence of polyps, detected during colonoscope withdrawal in either the supine position or with dynamic position change.

Patients will be included for the duration of their colonoscopy. This would typically be 30-45 minutes.

Patients will be included for the duration of their colonoscopy. This would typically be 30-45 minutes.

Compare the luminal distension of bowel segments in the supine position and with dynamic position change

Patients will be included for the duration of their colonoscopy. This would typically be 30-45 minutes.

Inclusion Criteria: Having a diagnostic colonoscopy Age >40 and <80 Exclusion Criteria: Inflammatory bowel disease Known polyposis syndrome Poor mobility which would limit a patients ability to turn

Ball AJ, Johal SS, Riley SA. Position change during colonoscope withdrawal increases polyp and adenoma detection in the right but not in the left side of the colon: results of a randomized controlled trial. Gastrointest Endosc. 2015 Sep;82(3):488-94. doi: 10.1016/j.gie.2015.01.035. Epub 2015 Apr 22.