CHICAGO — Confocal scanning laser endomicroscopy combined with chromoendoscopy identifies more precancerous lesions in patients with ulcerative colitis than does standard colonoscopy, investigators reported at the annual Digestive Disease Week.
This new method can accurately detect both intraepithelial neoplasms and colitis-associated colorectal carcinomas, according to the study's principal investigator, Ralf Kiesslich, M.D., of Johannes Gutenberg University, Mainz, Germany. Called confocal endomicroscopy, the method involves insertion of a confocal microscope into a traditional endoscope.
The study enrolled 153 patients with long-term ulcerative colitis in remission. Of those, 80 were randomized to undergo panchromoendoscopy with injection of 0.1% methylene blue dye for enhanced viewing of the colonic mucosal surface. All circumscribed lesions in the colonic mucosa that chromoendoscopy detected were then evaluated with confocal endomicroscopy for cellular and vascular changes. Targeted biopsies were performed of all circumscribed lesions.
The other 73 patients underwent standard colonoscopy. In this group, targeted biopsy specimens of visible mucosal changes were obtained in addition to biopsy specimens every 10 cm between the anus and cecum.
Confocal endomicroscopy helped detect 19 intraepithelial neoplasms, but colonoscopy found only 4, a statistically significant difference. The new technique identified lesions with an accuracy of nearly 98%. This high accuracy is the result of a combination of chromoendoscopy, which unmasks circumscribed lesions, and endomicroscopy, which allows in vivo diagnosis, Dr. Kiesslich said in an interview.
Confocal endomicroscopy also reduced the number of biopsies to 21, compared with 42 in the conventional endoscopy group.
With this new system, biopsies can be limited to relevant lesions—those with visible mucosal changes—thus allowing for “smart” biopsies, Dr. Kiesslich said in a statement. Confocal endomicroscopy may, therefore, improve the management of ulcerative colitis and lead to early detection of precancerous and cancerous lesions of the colon.
Paul Silva, director of regulatory affairs for Pentax Precision Instrument Corp., the device maker, said, “In North America, Pentax is sponsoring a clinical multisite trial of the device to collect data for [FDA] clearance as a biopsy-targeting system.”
Pentax's European division provided research support for this study.