Does chromoendoscopy improve the colonoscopic adenoma detection rate?

It is not clear whether chromoendoscopy with indigo carmine improves the rate of detection of colorectal polyps compared to: detection via standard colonoscopy. The aim of our study was to determine whether chromoendoscopy with indigo carmine significantly improves the detection of adenomas in the distal colon and rectum.

Using back-to-back sigmoidoscopies in each study patient, we prospectively evaluated whether chromoendoscopy with indigo carmine picked up more adenomatous polyps than standard colonoscopy. In all patients, standard high-resolution complete colonoscopy without indigo carmine was performed at the first examination. The second examination was restricted to colonoscopy distal to the splenic flexure of the colon. For the second examination, patients were randomized to chromoendoscopy with indigo carmine or colonoscopy without indigo carmine application. The second examination's detection rate was compared between the two groups.

In the 60 patients in the chromoendoscopy with indigo carmine group, 38 adenomas were found in the first examination and 14 adenomas in the second examination. In the 70 patients in the standard colonoscopy group, 66 adenomas were found in the first examination and 32 adenomas in the second examination. The detection rates in the two groups were 26.9% and 32.7%, re spectively, which were not significantly different (p = 0.47).

Chromoendoscopy did not detect more adenomatous polyps in comparison to standard colonoscopy.