Diagnosis of Barrett's esophagus

Until now, timely diagnosis of Barrett's esophagus has presented significant difficulties.

In some cases, when examining patients with Barrett's esophagus, esophageal manometry is performed, which allows detecting a decrease in pressure in the lower esophageal sphincter. The capabilities of endoscopic ultrasound scanning of the esophagus in diagnosing Barrett's esophagus are not yet clear.

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Endoscopic diagnosis of Barrett's esophagus

Among the objective methods of diagnosing Barrett's esophagus, esophagoscopy with targeted esophagobiopsy of the mucous membrane currently occupies a significant place. According to endoscopic studies, the color of the mucous membrane of the esophagus largely depends on the intensity of its illumination, however, the unchanged mucous membrane of the esophagus is often pale with a slight pink tint; folds of medium size, straighten out well when the esophagus is filled with air.

As our observations have shown, Barrett's esophagus is most likely to be detected based on visual examination through an endofibroscope in the following cases:

• in the presence of a more or less reddish or bright pink in coloration of the mucous membrane of the terminal section of the esophagus, of varying length, in the proximal direction 2-4 cm from the cardia rosette in the form of a continuous, more or less circularly located section of the mucous membrane or in the form of reddish "tongues" of varying length, similar in coloration, localized proximal to the cardia rosette and further in the proximal direction, gradually decreasing in transverse dimensions, between which and proximally a pale, unchanged mucous membrane of the esophagus with a glossy surface is visible in coloration;
• in the presence of an ulcer of the esophagus, surrounded by a rim of reddish or pink mucous membrane, the width of which may vary against the background of a pale, glossy surface of the mucous membrane of the esophagus;
• as the condition changes, the epithelium becomes increasingly pinkish-red (later red), and a “velvety” and loose mucous membrane appears.

In such cases, the boundary between mucous membranes of different structures is easily distinguishable (especially in the absence of pronounced inflammatory changes). A combination of the above symptoms is possible.

It is customary to distinguish between long and short segments of the "tongues" of the metaplastic epithelium of the terminal section of the esophagus, respectively, in the proximal direction from the cardia rosette more than 3 cm and less. In patients with long red "tongues" of the esophageal mucosa, according to pH-metry data, hypersecretion of acid secreted by the stomach is more often detected, and in patients with short "tongues" - reduced or normal acid formation in the stomach.

In general, the above-described signs should be treated with some caution. We have repeatedly observed that with successful treatment of patients, these "tongues" in some patients disappeared quite quickly (often in 3-4 weeks); in such cases, histological examination of biopsy material also did not show any data in favor of Barrett's esophagus. Therefore, only long-term observation of patients during the treatment and multiple targeted esophagobiopsies will allow us to establish or exclude the presence of such a condition as Barrett's esophagus.

The boundary between the simple columnar epithelium of the stomach and the stratified squamous epithelium of the esophagus, the so-called Z-line, is somewhat "shifted" in the proximal direction in some patients. Therefore, detection of gastric epithelium in the terminal section of the esophagus in such patients less than 2 cm proximal to the Z-line is not yet an indicator of the presence of Barrett's esophagus. The opinion of some researchers on the advisability of circular multiple targeted esophagobiopsies of the mucous membrane in case of suspected Barrett's esophagus (at least 4 fragments at a distance of about 2 cm from each other) 2-4 cm proximal to the upper border of the gastric folds, which are usually clearly visible through an endofibroscope, is quite justified. Only detection of goblet cells in the metaplastic columnar epithelium localized in the distal section of the esophagus can serve as a convincing criterion for the presence of Barrett's esophagus.

The endoscopic picture of the esophageal mucosa in reflux esophagitis in patients with GERD is quite variable. This is largely due to the condition of patients during endoscopy and the endoscopist's ability to describe the detected changes in the esophageal mucosa, the presence of many GERD classifications, individual stages of which often differ significantly from each other. The endoscopic picture of the esophageal mucosa condition depends, according to our observations, on the intensity and prevalence of diffuse inflammatory changes, the presence of erosions, ulcers and/or strictures of the esophagus, their severity (including in the same patient during the period of improvement and/or deterioration of his condition), as well as on the illumination of the mucosa during the endoscopic examination of patients. In some cases, endoscopic signs of esophagitis may include swelling of the esophageal mucosa with foci of hyperemia (including in the form of red spots of various sizes and lengths); with more severe esophagitis, against the background of a superficial whitish coating (necrosis), hyperemic stripes of uneven width and directed longitudinally are visible; with moderate esophagitis, uneven-sized white strands (stripes) may be visible, among which more significant damage to the esophageal mucosa is clearly visible; with severe esophagitis, grayish-white necrosis of the mucosa with or without narrowing of the esophageal lumen. In more severe cases, the esophageal mucosa may be covered with a “spot-like” necrotic pseudomembrane that is easily removed, under which a bleeding surface is exposed. Such changes in the esophageal mucosa are very similar to the pathological changes that occur in ulcerative colitis.

The extent of metaplasia in Barrett's esophagus is directly proportional to the time that the esophageal pH is less than 4. However, it is unclear whether prior acid-inhibiting therapy affects the extent of previously diagnosed Barrett's esophagus.

Based on the results of a study of the computer database of the Department of War Veterans and prospectively selected patients with Barrett's esophagus, previously treated with acid-inhibiting drugs before the detection of Barrett's esophagus, and patients who did not receive such therapy, according to endoscopic data of comparison of the length of Barrett's esophagus, it was established that its average length at the time of primary diagnosis was 4.4 cm. Among these patients, 139 (41%) were previously treated with H2-receptor antagonists or proton pump inhibitors (41 patients were treated with both drugs), and 201 patients (59%) did not take either of these drugs before the detection of Barrett's esophagus. The mean length of Barrett's esophagus was significantly shorter in patients previously treated with proton pump inhibitors (3.4 cm) or proton pump inhibitors in combination with histamine H2-receptor antagonists (3.1 cm) compared with those patients who did not receive either of the above drug therapies (4.8 cm). Based on the study, the authors suggest that the use of acid-inhibiting therapy is associated with the previous possible length of newly diagnosed Barrett's esophagus in GERD. This fact does not depend on the year of diagnosis (1981-2000) or demographic parameters of patients (age, gender, ethnicity, presence of intestinal metaplasia). However, to confirm the obtained data, the authors of this report consider it necessary to conduct further studies.

During esophagoscopy, certain difficulties arise in performing a targeted esophagobiopsy (increased peristalsis of the esophagus, pronounced gastroesophageal reflux, small sizes of biopsy forceps spoons, which allow obtaining only a small amount of material for histological examination, restless behavior of the patient).

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Differential diagnosis of Barrett's esophagus

When conducting differential diagnostics of the unchanged mucous membrane of the esophagus with the mucous membrane considered as characteristic of Barrett's esophagus, it is necessary to take into account that even in normal conditions the mucous membrane of the stomach in some patients is somewhat displaced to the distal part of the esophagus, therefore the detection in such patients of epithelium similar in color to gastric epithelium is not yet an indicator indicating the presence of Barrett's esophagus (in such cases, to clarify the diagnosis, it is advisable to conduct multiple targeted biopsies with subsequent histological examination of the obtained fragments of the mucous membrane).

A frequently encountered unevenness ("spot-likeness") of the location of areas of metaplasia and dysplasia on the mucous membrane of the esophagus has been noted, as a result of which in some cases biopsy is not performed on these areas. When small fragments of the mucous membrane are obtained during biopsy, difficulties in their interpretation often arise.

When evaluating biopsy material, as observations have shown, it is necessary to differentiate neoplastic transformation from reactive and regenerative changes in the mucous membrane. It is proposed in doubtful cases to distinguish such dysplasia as "indefinite" in contrast to high- and low-level dysplasia and, of course, to take such patients under dynamic observation.

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