The higher mortality rate of GI tumors is related to the late stage of patients when they get the diagnosis. In developed countries such as Europe, America and Japan, the proportion of early GI tumors diagnosed can reach 30% to 50%, while in China it has been hovering at 10% to 15%. In recent years, the development of gastrointestinal endoscopy technology has provided us with an effective weapon to diagnose and treat early cancers of the GI tract. In China, gastric cancer is the first cause of death from malignant tumors, accounting for 23.03% of deaths from malignant tumors, and about 160,000 people die from gastric cancer every year. In addition, the incidence of colorectal cancer is also increasing year by year. How to “kill” the tumor at the early stage is a question that every doctor is thinking about. The application of new technology of gastrointestinal endoscopy, such as staining technology and magnifying endoscopy, has given gastroenterologists more wings.
It can be said that the application of staining technology and magnification endoscopy has brought endoscopy into the “microscopic era”. Staining endoscopy is the use of special stains to highlight hidden lesions in the stomach to facilitate detection during examination. As an auxiliary examination method for gastrointestinal tumors, the detection rate of small lesions after staining is 2 to 3 times higher than the normal method. Staining can be divided into chemical staining and physical staining.
Chemical staining refers to the application of special dyes to stain the mucosa of the gastrointestinal tract to make the mucosal structure clearer, enhance the contrast between the lesion site and the surrounding area, and make the outline clearer. As an auxiliary examination method for gastrointestinal tumors, the detection rate of small lesions after staining is 2 to 3 times higher than the normal method.
Physical staining, NarrowBand Imaging (NBI), uses a filter to filter out the broadband spectrum of the red, blue and green light emitted by the endoscopic light source, leaving only the narrowband spectrum for the diagnosis of various diseases of the GI tract. The NBI system uses a narrow-band filter instead of the traditional broad-band filter, which limits the light to different wavelengths, and the depth of penetration of the narrow-band light into the mucosa of the gastrointestinal tract is different, the blue band (415nm) penetrates shallowly, the red band (605nm) can reach deep into the submucosa for displaying the submucosal vascular network, and the green band (540nm) can better display the blood vessels in the middle layer. Since the optical properties of blood in the mucosa absorb blue and green light more strongly, the use of light waves that are difficult to diffuse and can be absorbed by blood can increase the contrast and clarity of the mucosal epithelium and submucosal blood vessels. Therefore, NBI has the equivalent effect of mucosal staining and is called electronic staining endoscopy because it can be applied with a push-button switch without spraying stain.
Magnification endoscopy is the process of magnifying these “suspicious” lesions. The structure and principle of the magnifying endoscope are not fundamentally different from those of a normal endoscope, except that the objective lens is equipped with a magnifying lens of a different magnification between the objective lens and the light guide beam or between the objective lens and the miniature camera (CCD), while the pixels are more dense and the reference unit is a microscopic pattern of dots or lines of about 0.1 mm. The new magnifying endoscope is a zoom endoscope that can magnify 60 to 170 times, close to the magnification of a solid microscope, and can focus on the crypt, glandular duct opening morphology or submucosal vascular morphology, which is significantly better than ordinary endoscopy for the diagnosis of early mucosal lesions.
In one such case, a male patient, about 80 years old, came to our hospital for gastroscopy for a month because of discomfort and fullness in the upper and middle abdomen, and the results showed a 2.5 cm foci of erosion in the upper curvature of the gastric body, and the local disorganization of the glandular duct openings was revealed by magnification endoscopy, and the extent of the foci was more obvious by indigo carmine staining. On this basis, we diagnosed early gastric cancer as a possibility, and the pathological section later confirmed our suspicion. Because of his age, the patient and his family discussed and felt that minimally invasive endoscopic treatment should be performed, and the result was satisfactory after treatment. When he was discharged from the hospital, the old man kept expressing his emotion and telling how advanced the medical technology is nowadays.
The discovery of digestive tract tumor is inseparable from these advanced endoscopic devices and the keen observation of endoscopists, which are the nemesis of tumor.