In this study, methylene blue (MB) was used as vital nerve staining agent. During gastroenteroscopy, mucosal nerve staining was achieved by endoscopic submucosal injection of MB solution. To observe the staining of nerve fibers, neurons and glial cells in mucosa and submucosa, as well as the morphological changes, density differences and function of mucosal nerve tissues in different gastrointestinal lesions, in order to explore the role of endoscopic vital nerve staining in the diagnosis of gastrointestinal lesions.

This study is a prospective experimental study. The baseline data of the patients were recorded objectively: sex, age, vital signs, body weight, some laboratory examination results (blood routine, liver function, blood coagulation function and electrolytes, etc.) and related medical history (comorbidities, treatment history and life history). Mucosal nerve staining was achieved by endoscopic submucosal injection of methylene blue (MB) solution. The following features were identified and then compared between normal, adenoma and neoplastic mucosa on magnifying endoscopy images in vivo: nerve morphology (straight or irregular), nerve diameter, branching patterns and nerve density. Immunohistochemistry was used to further confirm the presence and to study the morphology of neural structures (PGP9.5 and GFAP staining) and neural attribute (VIP, nNOS, TH, ChAT and SOM staining) on tumor, adenoma and normal mucosal sections.The aim of this study was to explore the role of MB based topical submucosal chromoendoscopy in the identification of neural architecture and special morphology in normal gastrointestinal mucosa, adenomas and malignant lesions during routine endoscopy.

Inclusion Criteria:

1. Diagnosis or suspected diagnosis of one of the following common gastrointestinal diseases: chronic non-atrophic gastritis, chronic atrophic gastritis, gastric polyps, gastric early cancer, advanced gastric cancer; colonic polyps, colonic Melanosis, early colon cancer, advanced colon cancer
2. Written informed consent

Exclusion Criteria:

1. Those who are allergic to nerve dye components (such as methylene blue, etc.)
2. Complicated with cardiovascular and cerebrovascular diseases, or severely impaired liver, kidney and hematopoietic system.
3. Psychopath
4. There are hemorrhagic diseases
5. Platelet count < 50 × 10 ^ 9 / L
6. Those who are allergic to body mass are
7. Unable to tolerate or cooperate with endoscopy
8. Patients with serious complications, such as severe infection, gastrointestinal bleeding, obstruction and perforation, etc.
9. Pregnant or lactating women