Chromoendoscopy
Last reviewed: 23.04.2024
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Chromoendoscopy is used for the differential diagnosis of diseases that are difficult to distinguish by endoscopy. Most often this concerns benign and malignant diseases, especially early forms, as well as determining the true boundaries of tumor lesions and inflammatory-degenerative changes in the mucosa. As colorants, methylene blue, Congo red, indigo carmine, Lugol solution, Evans blue are used.
The effectiveness of vital dyes is based on such properties as contrasting, biological, chemical and fluorescent effects on tissues. Due to contrasting, the relief of the mucous membrane of the organs is enhanced when a dye is applied to it (methylene blue, indigo carmine, Evans blue). Biological exposure means the penetration of paint through the cell membrane into the cytoplasm and staining in vitro (methylene blue). The dye (Congo red, neutral red, Lugol's solution) can chemically react with the substance of epithelial cells and a secret having an appropriate pH level, on the basis of which it is possible to judge the functional state of the organs.
Apply direct and indirect methods of chromoscopy.
In direct chromoscopy methods, the dye is applied to the surface of organs directly during endoscopic examination through a catheter or an endoscope instrumental channel. Spray the dye can be aimed at or totally. In this case, diagnostic errors (false positive results) are possible due to the fact that not only the organ tissue is colored, but also a number of other structures (fibrin, mucus). To avoid these errors, careful preparation of the organ before application of the dye (mechanical cleaning, dissolution and removal of mucus, neutralization of the environment, etc.) helps.
Indirect methods of chromoscopy are based on the introduction of the dye into the lumen of the organ under examination before endoscopic examination: the patient can drink a solution of the dye or it is injected through the probe. Just as with the application of direct methods, preliminary preparation of the mucosa for staining is necessary to obtain more accurate results.