Magnifying endoscopic observation with narrow band imaging for specialized intestinal metaplasia in barrett's esophagus with special reference to light blue crests

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Diagnostic yield of the light blue crest sign in gastric intestinal metaplasia: a meta-analysis

BACKGROUND

The diagnostic yield of light blue crest(LBC) sign, which was observed by narrow band imaging with magnification endoscopy(NBI-ME), in detecting gastric intestinal metaplasia(IM) has shown variable results.

OBJECTIVE

We aimed to assess the diagnostic value of LBC under NBI-ME for detecting gastric IM.

METHODS

We performed a literature search of the Medline/PubMed, Embase, Web of Science, Science Direct and the Cochrane Library Databases; and a meta-analysis of pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and SROC area under the curve, using fixed- and random-effects models, for the accuracy of LBC-based IM diagnosis.

RESULTS

We initially included 4 articles, but excluded 1 article to counter significant heterogeneity. When pooled, the remaining 3 articles, which included 247 patients with 721 lesions, showed the following patterns in IM diagnosis: sensitivity: 0.90 (95% confidence interval [CI] 0.86-0.92); specificity: 0.90 (95% CI 0.86-0.93), positive likelihood ratio: 8.98 (95% CI 6.42-12.58), negative likelihood ratio: 0.12 (95% CI 0.09-0.16), and SROC area under the curve: 0.9560.

LIMITATIONS

As the studies varied by their definitions for positive LBC, endoscopy types, biopsy protocols, race of patient cohort, and physicians' proficiency, some sample sizes were limited so that subgroup analyses could not be performed.

CONCLUSION

We concluded that observing LBC under NBI-ME is an accurate and precise means of diagnosing gastric IM.

Endoscopic diagnosis of dysplasia in Barrett's esophagus

Barrett's esophagus, or columnar metaplasia with gastric cardiac cells or intestinal cells, develops in the squamous epithelium of the esophageal mucosa in relation to gastroesophageal reflux. An increased risk of neoplasia justifies surveillance at regular intervals. Conventional guidelines recommend detection of areas with intestinal metaplasia or dysplasia by taking random four-quadrant biopsies at every 1 or 2 cm. Alternatively, image processing with narrow band imaging (NBI), is proposed to improve detection. This international and randomized study in persons with Barrett's esophagus compares conventional endoscopy in white light with random four-quadrant biopsies and NBI imaging with focused biopsies only. Randomization enrolled 123 patients with Barrett's esophagus who successively underwent exploration with the two methods. The study confirmed that NBI had the same efficacy as white light in the detection of intestinal metaplasia, with a higher proportion of dysplasia detected (30 vs 21%) and a lower number of biopsies per patient (3.6 vs 7.6).

Usefulness of endoscopic brushing and magnified endoscopy with narrow band imaging (ME-NBI) to detect intestinal phenotype in columnar-lined esophagus

BACKGROUND

Barrett's esophagus with specialized intestinal metaplasia (SIM), which is at high risk of progressing to esophageal adenocarcinoma, has been identified by obtaining biopsy specimens randomly. Magnified endoscopy with narrow band imaging (ME-NBI) is reported to be useful for detecting SIM or the intestinal phenotype. We aimed to evaluate the usefulness of endoscopic brushing followed by ME-NBI for the detection of the intestinal phenotype.

METHODS

Biopsy and brushing samples were taken following endoscopic observation by ME-NBI. Total RNA was extracted from the whole sample and microdissected samples, and quantitative reverse transcription-polymerase chain reaction (PCR) analysis of SHH, CDX2, and mucin mRNA expression was performed.

RESULTS

Fifty patients (32 men, 18 women, average age 67.3 years) with metaplastic columnar epithelium of the lower esophagus were studied. MUC2 (85 vs. 65 %) and CDX2 (95 vs. 75 %) were detected more frequently in the brushing samples than in the biopsy samples. MUC2 expression levels were significantly higher in the brushing samples than those in the biopsy samples. CDX2 and MUC2 expression levels in the brushing samples were significantly higher in the mucosa with tubular/villous pattern observed by ME-NBI than the levels in mucosae with other patterns.

CONCLUSIONS

Endoscopic brushing in mucosa of columnar epithelium with a tubular/villous pattern visualized by ME-NBI is useful to detect the intestinal phenotype.

Efficacy of acetic acid-spraying method in diagnosing extension of Barrett's cancer under the squamous epithelium

AIM

Endoscopic diagnosis of the lateral extension of Barrett's cancer under the squamous epithelium (BCUS) is sometimes difficult because the cancer is unobservable in the esophageal lumen. The aim of the present study was to clarify the endoscopic features of the extension of BCUS and verify the usefulness of the acetic acid-spraying method (AAS) for diagnosis.

METHODS

A total of 25 patients with Barrett's cancer who had undergone endoscopic resection were included in this study. Histological examination of patients' resected specimens was performed to identify the presence of BCUS. Then, the endoscopic images of the BCUS cases were reviewed to summarize the findings and to evaluate the feasibility of diagnosing the extent of BCUS with each imaging technique.

RESULTS

Of the 25 patients, 10 (40%) had BCUS. With white-light imaging, subtle reddish change was observed in the area of BCUS in 80% of the patients, and a flat elevated lesion was recognized in 30%. With narrow band imaging, slight brownish change was observed in the area of BCUS in 86% of the patients. Slight white changes were visualized in all cases with AAS. The extension of BCUS was correctly diagnosed by white-light imaging, narrow band imaging and AAS in 50%, 43% and 100% of the cases, respectively. Histology verified the opening of cancerous glands, which extended under the squamous epithelium, into the esophagus in the area showing slight white changes by AAS.

CONCLUSION

AAS can be useful for diagnosing the extension of BCUS.

Autofluorescence and narrow band imaging in Barrett's esophagus

This review discusses the application of 2 novel imaging techniques in Barrett's esophagus: autofluorescence imaging and narrow band imaging (NBI). Autofluorescence as well as NBI may help to direct endoscopic therapy for early neoplasia in Barrett's esophagus; their value in daily practice, however, seems to be limited and needs further evaluation.