Bleeding from ruptured esophageal varices is the most aggressive complication in patients with cirrhotic portal hypertension, and about one-third of them will eventually bleed; on the other hand, two-thirds of patients with cirrhotic portal hypertension will never have a ruptured esophageal variceal bleed in their lifetime. Esophageal varices are asymptomatic except for bleeding, and if the one-third of patients who bleed can be identified and treated prophylactically as early as possible, medical expenses and the dangers associated with the treatment itself can be reduced. Therefore, it is extremely important to identify those at risk and develop a rational treatment plan for patients with cirrhotic portal hypertension. In the past, the morphologic features of esophageal varices were observed under gastroscopy and combined with other clinical indicators for comprehensive assessment, but the prediction accuracy did not exceed 40%. In recent years, the pressure measurement of esophageal varices has received increasing attention and is considered to be the most important factor in predicting rupture and bleeding of esophageal varices. Esophageal variceal venous manometry is performed endoscopically, and there are two techniques, i.e., intraventricular manometry and extraventricular manometry. The former is performed by puncturing the variceal vein with a fine needle to determine the pressure, which was firstly reported by Palmer in 1951, because puncture manometry is the recognized standard method of manometry, but there are its fatal weaknesses in scientific research and clinical application: the first one is that it cannot be repeated; the second one is that 1/3 of the patients have major bleeding caused by puncture; and the third one is that puncture is the most important factor in predicting bleeding from ruptured esophageal varices. Secondly, 1/3 of the patients suffered from hemorrhage due to puncture, and thirdly, puncture manometry may cause bacterial infection, so the method has been abandoned in developed countries. In 1982, Swiss scholar Mosimann invented a new technique of pressure measurement of esophageal varicose vein by using the principle of respiratory pressure measurement, the principle of which is that due to the thin wall of the varicose vein and the lack of external tissue support, the pressure of the compressed vein is equal to the intraventricular pressure. The method is to use a double-lumen catheter connected to the pressure probe, which is fixed to the gastroscope, and the catheter is connected to the electronic manometer and micro gas pump through the biopsy hole and forms a gas circuit. The probe has a small cavity covered by a very thin rubber membrane, and the miniature air pump continuously sends air from the input tube into the small cavity of the probe. It then enters the output tube and then the input tube to form a gas circuit, with zero pressure when the probe is not in contact with any substance. When the probe is in contact with the varicose vein under endoscopy, the rubber tube causes the airflow to be obstructed, and the pressure in the gas return rises until it equals the pressure of the membrane, the gas circuit is restored, and at this time, the pressure recorded by the electronic manometer is equal to the internal pressure in the esophageal varicose vein. After that, scholars from various countries devoted to the clinical application of this technology and continuously improved it, the improvement is mainly in two aspects, one is to change the input air in the gas circuit to nitrogen to prevent water vapor from solidifying, and on the other hand, the improvement is that the probe is getting smaller and smaller, and the diameter of the probe is only 2mm. In 1987, the Swiss scholar, Gertsch invented another non-invasive method of manometry by installing a gas bag with the diameter of 3.5cm into the gastric lens, and then the pressure was measured with a gas bag. The method is to install a 3.5cm diameter air bag under the gastric lens, a plastic catheter through the biopsy hole connected to the air bag, the other end of the catheter through the tee tube and a 50ml syringe and electronic manometer connected to the inspection of the gastroscope into the lower esophagus, with 50ml syringe gently injected with gas, the air bag gradually filled through the transparent wall of the bag can be seen through the esophageal varices. When the balloon comes into contact with the blood vessel wall, the balloon collapses and the value recorded by the electronic manometer is the internal pressure in the esophageal varices. The principle of this method of manometry is the same as that of cuff manometry. Both non-invasive methods of manometry have been tested in vitro, in animal and clinical trials, and in comparative studies with direct puncture manometry, confirming that there is a good correlation between balloon manometry and puncture manometry. For veins with large caliber, balloon manometry can completely replace venous puncture manometry, while for veins with small caliber, the accuracy of balloon manometry is poor. On the basis of foreign research results, we independently developed a transendoscopic noninvasive esophageal variceal vein applanation manometer and conducted a preliminary clinical application study to explore the feasibility and clinical significance of noninvasive esophageal variceal vein pressure measurement.