Gastric endoscopy technique

When examining the stomach with a fiber endoscope with end optics, after straightening the stomach with air, the greater curvature usually comes into view, which is determined by the characteristic appearance of the folds. In this case, the fiber endoscope should be advanced in the direction corresponding to the direction of the longitudinal folds of the stomach. With this orientation, the lesser curvature will be determined at 12 o'clock, the greater curvature at 6 o'clock, the anterior and posterior walls at 9 and 3 o'clock, respectively. By successively examining the sections of the stomach and moving the device forward, the greater curvature is reached, after which, by increasing the angle of bending of the distal end upward, the lesser curvature and the angle of the stomach are examined first at a distance, and then close up. By advancing the endoscope along the greater curvature, it is brought to the antral section, and then to the pylorus. Examination of the cardia and fornix is possible only with a sharp bending of the distal end of the endoscope, which is performed after examining the body of the stomach and the antral section. In this case, it is also possible to examine the lesser curvature well. The pyloric section of the stomach is a smooth-walled cylinder, at the end of which the pyloric canal is easily found.

Examination of the cardiac part of the stomach with a fiber endoscope with end optics is not always informative. In such cases, an endoscope with lateral optics is used. In this case, the stomach is examined in a certain sequence after a clear orientation of the position of the distal end of the endoscope. Usually, the angle and the body of the stomach serve as a reference point, by which the axis of the stomach is determined and the device is set in a position in which the arc of the lesser curvature in the field of view occupies a horizontal and symmetrical position. This allows avoiding excessive pressing of the curved knee of the endoscope into the greater curvature and the occurrence of pain.

First, the lesser curvature, subcardial zone and adjacent anterior and posterior walls of the body of the stomach, as well as the greater curvature, are examined by rotating the device around the axis. By bending the distal end upward and backward, the fundus and cardiac region are examined. The color of the folds of the mucous membrane of the lesser curvature is pale pink; towards the posterior wall it becomes dark pink. The angle of the stomach is represented by a transverse, widely overhanging fold of a bright pink color. The mucous membrane of the cardiac zone is a soft pink color, with low longitudinal folds with poorly developed folding; small blood vessels are visible through the mucous membrane. The mucous membrane of the proximal region and fundus of the stomach is pink-yellow, bumpy, the size of the folds in the fundus area increases significantly.

The next stage of gastroscopy is examination of the body of the stomach. The endoscope is oriented at 12 o'clock and bent toward the greater curvature (the greater curvature of the stomach is easily determined by the mucous "lake" and folds running parallel to the outlet), as a result of which the entire body of the stomach is in the field of view. After a panoramic view, the mucous membrane is examined from a close distance. The angle of the stomach and both its surfaces are examined especially carefully. As the endoscope is advanced forward, the antral section of the stomach and the pyloric canal, which have a rounded shape, appear due to the semicircular fold formed by the angle. The pyloric opening serves as a landmark. By advancing the endoscope forward and bending it in different directions, the antral section and the pylorus are examined in a circle. In the area of the greater curvature, the folds are predominantly longitudinal, in other places - longitudinal and transverse.

The stomach cavity initially has a slit-like shape with pronounced longitudinal folds of the mucous membrane. On the greater curvature, the folds are sharply expressed and look like long, parallel and closely adjacent ridges. The mucous membrane of the antral section is smooth, shiny, the folds are delicate, barely expressed and have an irregular shape. Even with moderate air insufflation, the antral section acquires a conical shape, the folds are completely straightened. The pylorus constantly changes its appearance, sometimes it is a pinpoint opening, and then the pylorus area resembles a rosette. This appearance is given to it by short thickened folds converging towards the opening. At the moment of passage of the peristaltic wave, the pylorus straightens, the surface of the mucous membrane is smoothed out, and the entire pyloric canal can be examined, which is a cylinder up to 5 mm long. The mucous membrane in the canal area is smooth, shiny, sometimes gathers into wide longitudinal folds. Here you can also find roller-shaped circular folds, which, when the pyloric orifice opens, form a roller-shaped thickening around it. Through the gaping pyloric canal, which is more often observed in the atonic state of the stomach, you can see the bulb of the duodenum. When the pylorus closes under the influence of the peristaltic wave, radially diverging tortuous folds frame its pinpoint opening, resembling a star.

The degree of folding decreases as air is injected. As air is introduced, the folds of the anterior wall and the lesser curvature almost completely straighten out. The folds of the greater curvature and the posterior wall of the stomach are more stable, although they also flatten significantly when inflated with air. In order to better assess the functional and organic changes, the stomach should be examined at various stages of its expansion with air.