A new endoscopic technique for the detection of possible malignant mucosal changes in patients with Crohn's disease.

Background:

The increased cancer risk in longstanding ulcerative colitis (UC) is well established. In comparison, the risk of colorectal cancer in Crohn’s disease (CD) is not as well studied and remains subject of discussion. Risk estimates in CD differ considerably and it remains unclear whether dysplasia or cancer arises only in segments with known CD.

In addition, once suspicious lesions are detected endoscopically in inflammatory bowel disease, it is difficult to differentiate lesions from DALMs (requiring proctocolectomy), and from sporadic ALMs (requiring endoscopical resection).

Recent studies have suggested that chromoendoscopy-guided confocal laser endomicroscopy (CCLE) is a more efficient surveillance strategy than standard endoscopy in patients with ulcerative colitis, but this has to our knowledge never been reported in Crohn’s surveillance.



Aims:

The aims of this study are to assess the prevalence of dysplasia and cancer in Crohn’s disease and to evaluate the accuracy of CCLE during colonoscopy surveillance in Crohn’s disease.



Methods:

In 4 IBD-referral centres, patients with longstanding Crohn’s colitis in remission undergoing surveillance colonoscopy will be asked to participate in the study. All patients will undergo colonoscopy using chromoendoscopy (CE) for both detection and differentiation and confocal laser endomicroscopy (CLE) for differentiation of suspicious lesions.

After examination with CCLE, targeted biopsies will be taken of each detected lesion and of mucosa adjacent to each detected lesion. Lastly, 4 quadrant random biopsies each 10cm of the colon will be taken.

What is the prevalence of dysplasia or carcinoma in patients with Crohn's disease that undergo surveillance endoscopy with chromoendoscopy-guided confocal laser endomicroscopy?

1. Start inclusion: 01-07-2010;

2. End inclusion: 01-07-2011.

Each part of the colon (cecum, ascending, transverse, descending, sigmoid colon and rectum) will be sprayed with 0.1% methylene blue solution on withdrawal of the endoscope. In case of detected lesions, intravenous fluorescein (10%) will be administered as contrast and these lesions and their adjacent ‘normal’ mucosa will be inspected by confocal laser endomicroscopy.