Colonoscopy modifications don't improve detection of serrated adenoma

Last Updated: 2019-07-17

By David Douglas

NEW YORK (Reuters Health) - Distal attachments or electronic chromoendoscopy do not generally improve detection of serrated adenomas during colonoscopy, according to pooled data from 17 randomized trials.

As Dr. Prateek Sharma told Reuters Health by email, "Serrated lesions of the colon typically occur on the right side, are flat, have indistinct borders and can be missed during standard colonoscopy. These results suggest that despite using modifications to current colonoscopy including using distal attachments or electronic chromoendoscopy, these lesions continue to be missed."

As reported July 6 online in Gastrointestinal Endoscopy, Dr. Sharma of the University of Kansas Medical Center, Kansas City, and colleagues conducted a a review and meta-analysis of trials that compared any distal attachment or electronic chromoendoscopy to high-definition white-light colonoscopy, in a total of 13,631 patients.

Groups were similar in terms of age, gender and indication for colonoscopy. In the intervention group, 4059 patients underwent colonoscopy with a distal attachment and 2878 patients had colonoscopy with electronic chromoendoscopy.

The primary outcome was the serrated adenoma detection rate (SADR), defined as the number of patients with at least one serrated adenoma out of the total of patients in that group.

Overall, the use of distal attachments (risk ratio, 1.21) and electronic chromoendoscopy (RR, 1.29) did not provide a significant improvement in SADR. Only in subgroup analysis involving studies using narrow-band imaging (NBI) was a significant improvement seen in the rate of serrated adenoma detection (RR, 2.04). More randomized controlled trials evaluating NBI, say the investigators "are needed to explore the effect."

"Our meta-analysis," the investigators concede, "is limited in terms of number of studies included highlighting the need for continuous efforts in conducting studies targeting SADR" as the primary objective for future research.

And added Dr. Sharma, "This important area needs further testing by improvements in tools and techniques."

Commenting by email, Dr. Nikhil A. Kumta of the Icahn School of Medicine at Mount Sinai, New York City, told Reuters Health, "Sessile serrated lesions are pre-malignant, so identification and removal is key to prevention of colon cancer. Only 17 high quality studies met inclusion criteria for analysis. The authors found in subgroup analyses that only colonoscopy with narrow band imaging (NBI) improved sessile serrated adenoma detection rate; all other electronic enhanced imaging and distal cap attachments did not increase the serrated adenoma detection rate."

Dr. Kumta, who is Director of the Sinai Laboratory for Innovation and Developmental Endoscopy, added, "The findings illustrate that more work is needed to improve the identification of sessile serrated lesions given their malignant potential. Currently NBI is not routinely used in screening colonoscopies, and further studies need to be conducted prior to widespread utilization."

"One key developing area under research that may have a big impact in the future is the use of artificial intelligence," he said. "Deep learning has already been shown to improve overall polyp detection rate during colonoscopy, and its use will need to be specifically studied for sessile lesions."

SOURCE: http://bit.ly/2SiNE71

Gastrointest Endosc 2019.