Right-Sided Colon Retroflexion Lowers Adenoma Miss Rate

A new study suggests that right-sided colon retroflexion during colonoscopy is safe and may lower the miss rate for adenomas.

Researchers at the Indiana University School of Medicine (Indianapolis, USA) conducted a prospective observational study involving a total of 1,000 consecutive adults undergoing elective screening or surveillance colonoscopy, without previous bowel resection, inflammatory bowel disease, or polyposis syndromes. After cecal intubation, a careful examination of the cecum to the hepatic flexure was performed in the forward view with removal of all identified polyps. The colonoscope was then reinserted to the cecum, and examination was performed to the hepatic flexure in retroflexion. The main outcome measurements ware success rate, per-polyp and per-patient miss rates, and adverse events rate of retroflexion.

The results showed that retroflexion was successful in 94.4% of patients. Looping in the insertion tube was the apparent cause of 89% of failed attempts. The forward view identified 634 proximal colon polyps and 497 adenomas, and retroflexion identified an additional 68 polyps and 54 adenomas, representing a per-adenoma miss rate of 9.8%, and an intention-to-treat, per-patient adenoma miss rate of 4.4%. Older age, male sex, and polyps seen on the forward view predicted polyps seen on retroflexion. There were no adverse events. The study was published in the August 2011 issue of Gastrointestinal Endoscopy.

“Retroflexion is commonly used during colonoscopy to improve detection of neoplasia in the distal rectum and to achieve polypectomy of lesions that are difficult to access because of their location on the proximal sides of folds and flexures,” concluded study coauthors David Hewett, MBBS, MSc, PhD, and Douglas Rex, MD , of the division of gastroenterology. “Right-sided colon retroflexion is generally achievable and safe in our hands. The yield is comparable to that expected from a second examination in the forward view.”

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Indiana University School of Medicine