What new endoscopic imaging modalities will become important in the diagnosis of IBD?

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.

Assessment of Crohn's disease activity by confocal laser endomicroscopy

BACKGROUND

Confocal laser endomicroscopy (CLE) allows microscopic imaging within the mucosal layer of the gut during ongoing endoscopy. Different studies have addressed the potential of CLE for in vivo diagnosis of ulcerative colitis and microscopic colitis. However, there are no data on the utility of CLE for in vivo diagnosis of Crohn's disease (CD). The aim was to assess the clinical utility of CLE in patients with CD and to determine whether disease activity can be graded using CLE.

METHODS

Consecutive patients with and without CD were enrolled. The colonic mucosa was examined by standard white-light endoscopy followed by CLE. The features seen on CLE were compared between CD patients and controls.

RESULTS

In all, 76 patients with CD were screened, of whom 54 patients were included in the present study. Eighteen patients without inflammatory bowel disease (IBD) served as controls. A significantly higher proportion of patients with active CD had increased colonic crypt tortuosity, enlarged crypt lumen, microerosions, augmented vascularization, and increased cellular infiltrates within the lamina propria. In quiescent CD, a significant increase in crypt and goblet cell number was detected compared with controls. Based on our findings, we propose a Crohn's Disease Endomicroscopic Activity Score (CDEAS) for assessing CD activity in vivo.

CONCLUSIONS

CLE has the potential to significantly improve diagnosis of CD compared with standard endoscopy. These findings should be evaluated in future prospective trials to assess the value of this newly developed CLE score for prediction of disease course and therapeutic responses.

Colorectal cancer surveillance in patients with inflammatory bowel disease: What is new?

Several studies assessing the incidence of colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients have found an increased risk globally estimated to be 2 to 5 times higher than for the general population of the same age group. The real magnitude of this risk, however, is still open to debate. Research is currently being carried out on several risk and protective factors for CRC that have recently been identified in IBD patients. A deeper understanding of these factors could help stratify patient risk and aid specialists in choosing which surveillance program is most efficient. There are several guidelines for choosing the correct surveillance program for IBD patients; many present common characteristics with various distinctions. Current recommendations are far from perfect and have important limitations such as the fact that their efficiency has not been demonstrated through randomized controlled trials, the limited number of biopsies performed in daily endoscopic practice, and the difficulty in establishing the correct time to begin a given surveillance program and maintain a schedule of surveillance. That being said, new endoscopic technologies should help by replacing random biopsy protocols with targeted biopsies in IBD patients, thereby improving the efficiency of surveillance programs. However, further studies are needed to evaluate the cost-effectiveness of introducing these techniques into daily endoscopic practice.

Optical spectroscopy combined with high-resolution magnetic resonance imaging for digestive wall assessment: endoluminal bimodal probe conception and characterization in vitro, on organic sample and in vivo on a rabbit

Colorectal cancer is a major health issue worldwide. Conventional white light endoscopy (WLE) coupled to histology is considered as the gold standard today and is the most widespread technique used for colorectal cancer diagnosis. However, during the early stages, colorectal cancer is very often characterized by flat adenomas which develop just underneath the mucosal surface. The use of WLE, which is heavily based on the detection of morphological changes, becomes quite delicate due to subtle or quasi-invisible morphological changes of the colonic lining. Several techniques are currently being investigated in the scope of providing new tools that would allow such a diagnostic or assist actual techniques in so doing. We hereby present a novel technique where high spatial resolution MRI is combined with autofluorescence and reflectance spectroscopy in a bimodal endoluminal probe to extract morphological data and biochemical information, respectively. The design and conception of the endoluminal probe are detailed and the promising preliminary results obtained in vitro (home-built phantom containing eosin and rhodamine B), on an organic sample (the kiwi fruit) and in vivo on a rabbit are presented and discussed.