Atlas of Gastrointestinal Endomicroscopy

The following sections are included:

• Contents

• Prologue

• List of Contributors

Confocal laser endomicroscopy (CLE) is a newly introduced endoscopic tool that makes it possible to carry out confocal microscopic examination of the mucosal layer during ongoing endoscopy. The development of CLE is based on the technology of confocal laser microscopy…

Confocal laser endomicroscopy (CLE) is the fusion of endoscopy and confocal microscopy. This technology, currently available, is either integrated into a flexible endoscope (CLE, such as Pentax EC-3870CILK/CIK) or a probe-based system that can be passed through the working channel of an endoscope (pCLE, such as Cellvizio). They have different depths of imaging, fields of view, and lateral resolutions (Table 2.1). We focus mainly on the confocal microscope integrated into the distal tip of a conventional upper endoscope, which enables simultaneous white-light endoscopy and confocal microscopy…

The following sections are included:

• Normal Esophageal Mucosa

• Endomicroscopic Imaging of Normal Esophageal Mucosa

• References

Gastroesophageal reflux disease (GERD) is defined as a condition which develops when the reflux of stomach contents causes trouble-some symptoms and/or complications according to the Montreal definition.¹ It contains esophageal and extraesophageal syndromes. The esophageal syndromes include the symptomatic syndromes, i.e. the typical reflux syndrome and the reflux chest pain syndrome; and the syndromes with esophageal injury, i.e. reflux esophagitis, reflux stricture, Barrett's esophagus (BE) and esophageal adenocarcinoma…

The following sections are included:

• Barrett's Esophagus

• Adenocarcinoma

• References

Although relatively infrequent in Western countries, esophageal squamous cell carcinoma (SCC) is still a major disease for a large proportion of the world's population, especially in China and Japan.^1,2 The prognosis for SCC is poor because it is usually diagnosed at an advanced stage. Early detection is still regarded as the best option for improving the prognosis of this disease, and endoscopy is one of the most widely used techniques for early diagnosis. However, early SCC is frequently multifocal and hard to detect by conventional endoscopy. Endoscopic appearances include flat lesions with color variation, focal red areas, nodules, or erosions (Fig. 6.1). It has been reported that iodine staining, magnifying endoscopy, and narrow band imaging can improve the early diagnosis of esophageal cancer by providing details of the esophageal surface (Figs. 6.2 and 6.3).^3–5 Both endocytoscopy and CLE have enabled examination of cellular changes during ongoing endoscopy; CLE allows observation of not only squamous epithelial cells but also the vascular networks of the mucosal layer.^6,7…

The following sections are included:

• Heterotopic Gastric Mucosa in the Esophagus

• Vascular Malformation of the Esophagus

• References

Under the microscope, the wall of the stomach is composed of four layers: mucosa, submucosa, muscularis propria, and serosa. The layer of mucosa can be subdivided into epithelium, lamina propria, and muscularis mucosa (Fig. 8.1)…

Chronic gastritis is defined as the inflammatory reaction of gastric mucosa, which is caused by various injury factors. The updated Sydney system provides three major categories: nonatrophic gastritis, atrophic gastritis, and special forms of gastritis. Histologically, five morphological variables (H. pylori density, activity, chronic inflammation, glandular atrophy, and intestinal metaplasia) must be classified, because of the relationship to their associated diseases.¹ To some extent, with 500–1000-time magnification by CLE, in vivo visualization of the five variables can be achieved…

Gastric cancer remains the second-leading cause of cancer-related deaths worldwide, which emphasizes the need for early diagnosis. In terms of geographic distribution, almost two-thirds of gastric cancer occurs in less developed regions. In China, although remarkable declines in gastric cancer mortality have been noticed during the last decade due to the dramatic improvements in the social economy and health service, the absolute number of gastric cancer cases is still a significant burden of the national health program.¹…

Gastric tumor is subdivided into two main categories: benign and malignant. Because CLE has a scanning depth of 0–250 μm, this section deals only with gastric epithelial tumors. Benign epithelial tumors are known as adenomas, and malignant epithelial tumors are composed of adenocarcinoma and other variants of carcinoma. So, mainly adenoma and adenocarcinoma are discussed…

The following sections are included:

• Histology

• Endomicroscopic Imaging of Small Gastrointestinal Mucosa

• References

Malignant neoplasms are rare in the small intestine compared with the colon. This section mainly aims to discuss the inflammatory disorders of the small intestine. The inflammatory disorders are considered to be acquired conditions related to various causes, and different pathological mechanisms may cause the same morphological appearance. Therefore, we can divide them into two main groups: nonspecific inflammation (e.g. duodenitis, pouchitis) and inflammation due to other causes (e.g. celiac disease, Whipple's disease, inflammatory bowel disease)…

The following sections are included:

• Histology

• Endomicroscopic Imaging of Normal Colonic Mucosa

• References

The endoscopic assessment of patients with ulcerative colitis (UC) is essential in the diagnosis, treatment decision, and prediction of prognosis. Currently the application of endomicroscopy in UC remains in two main areas: inflammation activity assessment and identification of colitis associated intraepithelial neoplasia (IN)…

To improve the prognosis of colorectal cancer, surveillance and treatment of early-stage colorectal cancer and precancerous lesions such as adenomas are cost-effective.¹ According to the adenoma–carcinoma sequence, the identification and removal of colorectal adenomas is effective in reducing the morbidity and mortality of colorectal cancer.² Because the most common macroscopic type of colorectal adenoma appears to be the polyp, the removal of all colorectal polyps found during colonoscopy is recommended. However, given that a considerable proportion of colorectal polyps are hyperplastic, with little or no potential for malignancy, the removal of all polyps could increase the risk of unnecessary complications and health care costs…

The meaningful approaches for CLE in the diagnosis of colorectal cancer (CRC) can be summarized into four purposes: detection of inapparent cancer, reduction of biopsies, in vivo histology grading, and molecular diagnosis. Since detection of inapparent cancer has been discussed in the previous sections ("UC" and "CP"), this section mainly discusses the other three purposes…

The development of the confocal laser endomicroscope, an imaging modality that enables in vivo microscopic imaging of the gastrointestinal tract, is an advance that is clearly poised to impact future endoscopic screening and diagnosis of diseases. The ultrahigh-resolution magnifying endomicroscope, with its superior optical capability to characterize mucosal and subsurface tissue at the microstructural level, has already demonstrated how it could significantly enhance the ability to detect, characterize, and diagnose many types of gastrointestinal lesions.¹ In effect, it has also heralded the advent of real-time virtual in vivo histopathologic diagnosis of diseases. With the confocal endomicroscope, tissue architecture, vasculature, and cellular and subcellular structures are endoscopically visualized in detail at high resolution. Studies thus far have shown that CLE detects preneoplastic and neoplastic developments in the esophagus, stomach, and colon with high degrees of accuracy. Under fluorescein-enhanced confocal imaging, intraepithelial neoplasias could be identified visually by their characteristic tubular, villous, or irregular architectures and low presence of goblet cells. Similarly, changes in inflammatory gastrointestinal disease such as ulcerative colitis, Crohn's disease and collagenous colitis could be defined by their respective confocal diagnostic characteristics…

The following sections are included:

• Index