Trial Information

Probe-based Confocal Laser Endomicroscopy in Colonoscopic Surveillance of Patients With Primary Slerosing Cholangitis Related Inflammatory Bowel Disease (PSC-IBD)

Chromoendoscopy by applying a dye (indigo-carmine) through the colonoscop is the new
standard for cancer surveillance in patients with IBD . It gives the opportunity to identify
suspected areas of dysplasia and to take targeted biopsies. The diagnostic accuracy improves
and the chances for detecting dysplastic areas increase. In recent years new endoscopic
techniques have been developed, including laser-based endomicroscopy. There is an increasing
need for structured evaluation of the efficiency of these techniques. Laser-based
endomicroscopy, taking in vivo confocal microscopy pictures during the colonoscopy
examination, is the most promising new method. This method is established in highly rated
centers for the early diagnosis of neoplasia in the bile ducts and the esophagus but its
role for detection early malignancies in the colon is not known and studying this issue is
of very high clinical value.

Specific questions: Does the use of laser-based endomicroscopy increase the chances for
early detection of dysplasia? What is the intraobserver variability? What is the learning
curve for interpretation of confocal microscopy pictures? Material and methods: A
laser-based endomicroscope (Cellvizio®, Mauna Kea Technologies) have been acquired and the
examination procedure has been established at the Unit for Gastroenterology and Hepatology,
Karolinska University Hospital Huddinge. Eighty patients with PSC and IBD included in annual
surveillance with colonoscopy with routine biopsy regime will be included in the study.
After informed consent, patients are investigated with laser-based endomicroscopy during
surveillance colonoscopy. Each colonic segment will be examined before and after staining
with indigo-carmin. After intra-venous fluorescein (FITC) injection, all macroscopically
abnormal lesions will be examined by endomicroscopy. Intravenous administration of FITC
makes it possible to obtain in vivo microscopic pictures with up to a 1000x magnification of
the colon mucosa. The Cellvizio® technique allows for evaluation of epithelial and
endothelial cell structures in areas with suspicious changes as well as for acquisition of
directed biopsies. Confocal pictures from all sites where biopsies have been taken are saved
for future blind re-evaluation. The biopsies are taken according to the routine standard
with minimum of 2 biopsies from each 10 cm in the colon. For the immunological and
microbiological (specific aim 2) parts of the study, additional 16 biopsies are gathered
from left, transverse, and right colon. All the laser-based endomicroscopy pictures and
sequences are saved for further evaluation and further application in arranging pedagogical
sessions for evaluation of the learning curve of the technique.