Is virtual chromoendoscopy useful in the evaluation of subtle ulcerative small-bowel lesions detected by video capsule endoscopy?

Virtual Chromoendoscopy in Capsule Endoscopy: A Narrative Review

The usefulness of virtual chromoendoscopy (VC) in capsule endoscopy (CE) isa controversial issue, with conflicting studies regarding its efficacy. FICE and a blue filter were embedded in the PillCamTM software, with the aim to assist readers in identifying the source of obscure gastrointestinal (GI) bleeding (OGIB), coeliac disease mucosal changes and other small and large bowel lesions, including polyps and tumors. This review aims to summarize the existing evidence on the value of VC in the visualization and identification of different types of pathology. Overall, VC in CE with FICE 1 and 2 can be a useful adjunctive tool and may increase the visibility of pigmented lesions, such as angiectasias and ulcers. However, it does not appear to improve the detection of polyps or tumors. On the other hand, the role of FICE 3 and the blue filter appears to be limited. FICE may also be helpful in differentiating hyperplastic and adenomatous colonic polyps during colon capsule endoscopy, although more evidence is needed.

Evaluation of the Usefulness of Virtual Chromoendoscopy with Different Color Modes in the MiroCam® System for Characterization of Small Bowel Lesions

Background

Virtual chromoendoscopy (VC) in small bowel capsule endoscopy can improve the visualization and characterization of different small bowel lesions (SBLs). There are few studies of its usefulness in the Given® system, and there is no evidence yet of its utility in the MiroCam® system.

Aim

The aim of this study was to evaluate whether VC can improve the characterization of SBLs with the MiroCam® system.

Methods

Twenty-two patients were selected, in which 100 elementary lesions were identified, including erosions (n = 45), ulcers (n = 17), and angioectasias (n = 38). For each lesion identified, images were captured without chromoendoscopy (normal image [NI]) and with chromoendoscopy modes 1 (color mode [CM] 1), 2 (CM2), and 3 (CM3). A score from 1 to 4 was assigned to each image, in which a better evaluation of the characteristics and limits of the lesion was classified in ascending order, where 1 is the worst and 4 the best evaluation. The scores of the various modes were compared with Kendall's tau-c coefficient.

Results

The average scores attributed to the photographs in NI, CM1, CM2, and CM3 were 3.83, 2.89, 1.85, and 1.43, respectively (tau-c = -0.75, p < 0.001). Evaluating the elementary lesions independently, the average scores for modes NI, CM1, CM2, and CM3 were 3.83, 2.92, 1.86, and 1.38 (tau-c = -0.77, p < 0.001) for erosions, respectively; 3.87, 2.96, 1.76, and 1.40 (tau-c = -0.80, p < 0.001) for ulcers, respectively; and 3.81, 2.82, 1.87, and 1.50 (tau-c = -0.71, p < 0.001) for angioectasias, respectively.

Conclusions

VC using the CMs available in the MiroCam® system has not proven useful for a better assessment of any of the SBLs.

Role of new endoscopic techniques in inflammatory bowel disease management: Has the change come?

Despite significant therapeutic progress in recent years, inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, remains a challenge regarding its pathogenesis and long-term complications. New concepts have emerged in the management of this disease, such as the “treat-to-target” concept, in which mucosal healing plays a key role in the evolution of IBD, the risk of recurrence and the need for surgery. Endoscopy is essential for the assessment of mucosal inflammation and plays a pivotal role in the analysis of mucosal healing in patients with IBD. Endoscopy is also essential in the detection of dysplasia and in the identification of the risk of colon cancer. The current surveillance strategy for dysplasia in IBD patients indicates white-light endoscopy with non-targeted biopsies. The new chromoendoscopy techniques provide substantial benefits for both clinicians and patients. Narrow-band imaging (NBI) has similar rates of dysplastic lesion detection as white-light endoscopy, and it seems that NBI identifies more adenoma-like lesions. Because it is used instinctively by many endoscopists, the combination of these two techniques might improve the rate of dysplasia detection. Flexible spectral imaging color enhancement can help differentiate dysplastic and non-dysplastic lesions and can also predict the risk of recurrence, which allows us to modulate the treatment to gain better control of the disease. The combination of non-invasive serum and stool biomarkers with endoscopy will improve the monitoring and limit the evolution of IBD because it enables the use of a personalized approach to each patient based on that patient’s history and risk factors.

Capsule endoscopy of the small bowel

Capsule endoscopy (CE) is a first line small bowel investigative modality which provides more sensitive mucosal imaging than comparators. It is a non-invasive, non-irradiating tool well tolerated by patients. The risk of retention of the capsule can be minimised by ensuring luminal patency using the Agile patency device. Research continues into how to minimise missed pathology and variability in the identification of pathology or interpretation of images. The consensus is that bowel preparation using laxatives improves visibility and diagnostic yield. Research includes the development of image recognition software, both to eliminate sequentially identical images to improve viewing speed and to select or enhance images likely to represent pathology. However, careful reading by experienced capsule endoscopists remains the benchmark. This should be performed at a speed comfortable to the viewer, probably at a maximum of 15 frames per second. Some prior experience of endoscopy appears to be helpful for novice capsule endoscopists and formal training on a hands-on training course seems to improve pathology recognition, for novices and for those with CE experience.

Usefulness of virtual chromoendoscopy in the evaluation of subtle small bowel ulcerative lesions by endoscopists with no experience in videocapsule

BACKGROUND AND STUDY AIMS

In videocapsule endoscopy examination (VCE), subtle variations in mucosal hue or pattern such as those seen in ulcerations can be difficult to detect, depending on the experience of the reader. Our aim was to test whether virtual chromoendoscopy (VC) techniques, designed to enhance the contrast between the lesion and the normal mucosa, could improve the characterization of ulcerative mucosal lesions.

PATIENTS AND METHODS

Fifteen trainees or young gastroenterologists with no experience in VCE were randomly assigned to evaluate 250 true ulcerative and 100 false ulcerative, difficult-to-interpret small bowel lesions, initially as white light images (WLI) and then, in a second round, with the addition of one VC setting or again as WLI, labeling them as real lesions or artifacts.

RESULTS

On the overall image evaluation, an improvement in lesion characterization was observed by adding any chromoendoscopy setting, especially Blue mode and FICE 1, with increases in accuracy of 13 % [95 %CI 0.8, 25.3] and 7.1 % [95 %CI - 17.0, 31.3], respectively. However, when only false ulcerative images were considered, with the same presets (Blue mode and FICE 1), there was a loss in accuracy of 10.7 % [95 %CI - 10.9, 32.3] and 7.3 % [95 %CI - 1.3, 16.0], respectively. The interobserver agreement was poor for both readings.

CONCLUSIONS

VC helps beginner VCE readers correctly categorize difficult-to-interpret small bowel mucosal ulcerative lesions. However, false lesions tend to be misinterpreted as true ulcerative with the same presets. Therefore care is advised in using VC especially under poor bowel preparation.