Gastroesophageal reflux test for esophageal cancer

There are many reasons for gastroesophageal reflux in patients with esophageal cancer, such as mechanical defects of the cardia, poor propulsion of the esophageal body, gastric atony, pyloric dysfunction, delayed gastric emptying, and after esophageal cancer surgery. The reflux of gastric contents (especially gastric acid) into the esophagus causes the esophageal mucosa to contact with gastric contents for a long time, causing damage to the esophageal mucosa. Patients often have symptoms such as heartburn, vomiting, and pain behind the sternum. The following tests are helpful for the determination of gastroesophageal reflux.

① Esophageal acid perfusion test: The tester sits down and alternately perfuses normal saline and 0.1 mol/L hydrochloric acid into the middle of the esophagus at a rate of 6 ml per minute to measure the sensitivity of the esophagus to acid. When the acid is perfused, the patient experiences symptoms such as heartburn, chest pain, cough, and vomiting, and the symptoms disappear after the normal saline is perfused, which is a positive test. If no symptoms occur after 30 ml of acid is perfused, the test is negative.

②24h esophageal pH monitoring: Place the pH electrode above the high-pressure belt in the lower esophagus and continuously monitor the pH for 24 hours to observe the reflux of the subject under daily conditions. When the pH drops below 4, it is considered a reflux, and when the pH rises above 7, it is an alkaline reflux. By recording the patient's condition in various body positions and when eating, it is possible to diagnose whether the patient has reflux, the frequency of reflux, and the time it takes for the esophagus to clear the reflux.

③Lower esophageal sphincter manometry test The lower esophageal sphincter plays a role in ensuring the unidirectional transport of food in the physiological activities of the digestive tract, that is, the role of anti-gastroesophageal reflux. The function of the lower esophageal sphincter depends not only on its basic pressure at rest, but also on the influence of chest and abdominal pressure and its response to different physiological factors such as gastric expansion, swallowing, and changes in body position. Another factor that determines the function of the lower esophageal sphincter is its length in the abdomen. A catheter with a transducer can be inserted through the nostril to this site for measurement.