Having patients lie on their left side while the right side of their colon is being examined can result in more polyps being found, thus increasing the effectiveness of colonoscopy for colorectal cancer (CRC) screening, according to a study in the September issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE).
CRC is one of the most common cancers in the US and other western countries. Studies have shown that deaths from CRC are reduced significantly by the detection and removal of polyps through colonoscopy. Numerous factors have been identified as important in the detection of polyps and adenomas (two types of lesions that have the potential to become cancerous if ignored), such as the length of time the colon is examined and how thoroughly the colon is prepared for the procedure. Patient position also has been identified as a factor; however, studies have been conflicting as to the effectiveness of this strategy.
The new GIE study, "Position change during colonoscope withdrawal increased polyp and adenoma detection in the right but not in the left side of the colon: results of a randomized controlled trial" looked at 130 patients aged 40 to 80 years who presented for a diagnostic colonoscopy at one hospital between March 2012 and February 2014.
During colonoscopy, the colon is examined upon insertion and withdrawal of the colonoscope. For patients in the study, each segment of the colon was examined twice during colonoscope withdrawal. Endoscopists examined the patients in either the supine position (on the back) followed by position change (to one side or another) or vice versa. The position change was to the patient's left side for looking at the right side of the colon, or to the patient's right side for looking at the left side of the colon.
The researchers concluded that examining the right side of the colon while the patient was on his or her left side increased polyp and adenoma detection compared with examination in the supine position. This position change helped to bring certain segments of the colon into a place within the abdomen that allowed for optimal viewing. It also was associated with improved distension (inflation) of the colon, allowing for better visualization. Polyp detection in the left side of the colon was similar whether the patient remained supine or changed position to lie on the right side.
Most of the additional polyps and adenomas detected after the position change were small and therefore not of immediate clinical significance; however, the authors pointed out that finding more lesions can change the recommendation for how soon the patient should return for his or her next colonoscopy, making the tool more effective for ongoing surveillance and prevention.