New Technique Provides Microscopic Images of Suspicious Polyps During Colonoscopy

News from Digestive Disease Week 2008

A tiny microscope, less than one-sixteenth of an inch, attached to the end of the instrument used for a colonoscopy can provide magnified pictures of cells and small blood vessels in suspicious lesions allowing doctors to make on-the-spot decisions about whether a polyp is benign or precancerous.

The technique — confocal endomicroscopy — can identify benign polyps 98 percent of the time, avoiding having to remove the lesion and wait for results of the biopsy.  Precancerous polyps can be viewed, identified, and treated immediately during the colonoscopy.

Mayo Clinic researchers, Dr. Michael Wallace and Dr. Anna Buchner, presented their findings at Digestive Disease Week in San Diego this May.

After studying differences in benign and precancerous colon polyps, they used the new system to classify 37 polyps in 25 patients.  The lesions were then removed and diagnosed by pathologists.  The confocal endomicroscopy system was 89 percent accurate in identifying whether polyps were precancerous or benign.  Even better, it accurately identified 98 percent of benign polyps.

In a news release from the Mayo  Clinic, Dr. Wallace said,

Today, half of all polyps surgically removed during colonoscopy procedures are benign, and so this virtual biopsy will save time and expense, and reduce complications that can occur.

Dr. Buchner is working toward 100 percent accuracy in classifying benign polyps that don’t need to be removed for a pathologist’s scrutiny.  She says,

That is what you want in a device like this. Removing a polyp that looks precancerous, but turns out to be benign, is okay, but you don’t want to leave polyps intact in the colon that are actually cancerous. This probe is almost perfectly reliable in that regard and with more experience I am sure we can improve accuracy to nearly 100 percent.

SOURCE: Buchner et al., High Resolution Confocal Endomicroscopy Probe System for in vivo Diagnosis of Colorectal Neoplasia (Late Breaking Abstract), Digestive Disease Week 2008.