P195. Endomicroscopy for assessing mucosal healing in patients with ulcerative colitis a pilot study
C. Gheorghe1, R. Iacob1, B. Cotruta1, I. Bancila1, G. Becheanu1, M. Dumbrava1, L. Gheorghe1
1Fundeni Clinical Institute, Gastroenterology and Hepatology Center, Bucharest, Romania
Background: In patients with ulcerative colitis (UC), mucosal healing represents the ultimate therapeutic goal, because inflammation is limited to the mucosa. However, the assessment of inflammatory activity by conventional colonoscopy is inaccurate in some cases, therefore histological assessment of UC is inseparable from colonoscopic investigation. Recently, confocal endomicroscopy (CLE) has emerged to allow in vivo histological assessment during ongoing endoscopy. Considering that histologic remission should be part of sustained deep remission, we have conducted a pilot study to investigate the ability of CLE to differentiate between normal mucosa and residual inflammation.
Methods: Rectal CLE has been performed using 5 ml 10% fluorescein iv and targeted biopsies have been analysed by the pathologist. Inflammation activity was investigated by CLE assessing crypt architecture, as well as interstitial and cryptal fluorescein leakage. The image processing was performed using ImageJ, a public domain Java software. All images have been captured using the same LASER power setting at the superficial and medium-depth level. Semiautomatic computer estimation of interstitial and cryptal fluorescein leakage (ICFL) has been performed on stacks of images, by evaluating mean luminosity of pixels corresponding to crypts and interstitium, on a scale ranging from 0255. ICFL in patients with UC in histological remission has been compared to patients with active ulcerative colitis and to patients with irritable bowel syndrome undergoing screening colonoscopy for colorectal cancer, using Student's T Test.
Results: 18 different stacks of images with a total of 184 CLE images have been analysed. Only minor cryptal abnormalities have been noted for patients with ulcerative colitis in remission, whereas for patients with active ulcerative colitis a wide range of cryptal alterations have been registered, from crypt distortion to crypt destruction and crypt abcess. ICFL mean luminosity was 94±21 for patients with ulcerative colitis in histologic remission, 106±12.6 for IBS controls (p = 0.24 NS) and 178.6±21.6 for patients with active UC (p = 0.0001).
Conclusions: CLE is a reliable tool for real-time assessment of deep mucosal remission during endoscopic examination. The semiautomatic quantification of interstitial and cryptal fluorescein leakage can be used to objectively diagnose in vivo deep mucosal remission.