Research presented at the 2009 meeting of the American College of Gastroenterology in San Diego this week found that some colonoscopy technologies fare better than others at improving detection of adenomas.
Interim results of a multicenter study of detection rates for polyps and adenomas using a retrograde-viewing device for the colonoscope, Avantis Medical Systems' Third Eye Retroscope (TER), found that endoscopists missed more polyps with the colonoscope alone than when using the TER with the colonoscope. In a separate study, investigators found that the overall detection of both polyps and adenomas was improved with use of TER, especially after the endoscopist had completed 15 procedures.
The TER is a disposable device that is passed through the instrument channel of a standard colonoscope to provide a retrograde view that complements the forward view of the colonoscopy during withdrawal of the scope from the colon, allowing a rear view look at the far side of the numerous anatomical folds and bends in the colon.
Peter Siersema, MD, professor of gastroenterology of University Medical Center Utrecht in Utrecht, Netherlands, reported interim findings from a randomized, controlled and prospective study of the effectiveness of the TER for increasing the diagnostic yield of colonoscopy. This preliminary analysis of 126 patients who underwent same-day back-to-back colonoscopy and colonoscopy with TER found that the relative risk of missing a lesion with colonoscopy versus TER was 2.57 for all polyps.
"When endoscopists used the colonoscope alone, they missed 2.57 times more polyps then when the used the retrograde viewing device along with the colonoscope," Siersema said.
Daniel DeMarco, MD, medical director of endoscopy at Baylor University Medical Center in Dallas, presented interim data from a multi-center study involving 17 investigators at nine medical institutions in the United States looking at detection rates and withdrawal of the scope. The prospective study suggests that TER can lead to an enhancement of the detection rate of polyps and adenomas compared with standard colonoscopy. As endoscopists performed more procedures, their detection rates for both polyps and adenomas improved from earlier exams compared with later exams, and the withdrawal times for the later procedures were somewhat shorter than for the earlier procedures, according to DeMarco.
"Colonoscopy is the most accurate method for evaluating the colon, but some lesions can be missed, especially if they are on the proximal aspect of folds or flexures in the colon," explained DeMarco. "This study evaluates the learning curve for use of the TER, both in terms of efficacy of detection of lesions and time-efficiency."