At present, the way of endoscopic diagnosis of tumors has changed from finding masses, routine biopsies and definite pathology to abnormal mucosal surface morphology, glandular duct morphology, microvascular morphology and even direct observation of cells. the progress of endoscopic technology has significantly promoted the discovery of early tumors, thus improving the cure rate and reducing mortality.
1. Total colonic electronic endoscope.
At present, almost all guidelines regard total colon electronic endoscopy as the preferred detection method, which can not only directly observe the pathological changes of colorectal mucosa, but also biopsy to evaluate the histology of the lesions, and it is also the main means of postoperative follow-up of colorectal cancer.
two。. Magnifying endoscope and staining endoscope.
Magnifying endoscopy combined with staining technique can clearly show the shape of crypt on the surface of intestinal mucosa, and the fine structure of large intestinal mucosa, such as the opening shape of glandular duct, can be observed. The commonly used staining pigment is indigo carmine, which is sprayed directly and the crypt is stained to show the shape and size, but the diseased tissue does not show color. Methylene blue staining remained directly in the lesion, revealing minor lesions. This technique can roughly determine the histological classification of the lesions, with a coincidence rate of 95%.
3. Narrowband image.
Narrow-band imaging (NBI) is a new endoscopic diagnostic technique with the development of endoscopic diagnosis of early cancer, which focuses on the observation of fine glandular tubule morphology (pitpattern) and microvascular morphology (capil-larypattern) on the mucosal surface. it is easy to operate and takes a short time to observe the mucosal microvascular structure clearly, which is helpful to the diagnosis, prognosis and treatment strategy selection of the disease. At present, it is considered that it can replace the staining technique to a large extent and improve the deficiency of pigment endoscope. Many studies have reported that targeted biopsy under NBI technique can significantly improve the early diagnosis rate of colon cancer. However, the image analysis under NBI technology is subjective. With the gradual improvement of endoscopic resolution, the accuracy of NBI diagnosis is expected to be further improved.
