Esophageal Diagnostic Testing
Due to the complexity of esophageal disorders, a variety of tests are available to diagnose the exact nature and location of the condition. Some of the tests used include:
- Upper GI endoscopy is a test that lets the doctor see the inside of the esophagus, stomach and the first part of small intestine. The instrument used to do this is called an endoscope. It is a long, thin flexible tube with a light and miniature camera at its end. Before starting, the patient is given medication to make him or her relax. The endoscope is placed into the mouth and then guided by the doctor into the esophagus, stomach and small intestine. Video camera images are shown on a monitor in the procedure room. This allows the doctor to examine the inside of the esophagus, stomach and intestine. Biopsies can be obtained from abnormal tissues. Special instruments also can be passed through the endoscope to treat some disorders.
- Esophageal manometry is used to evaluate the function of the esophagus. The test is done with a thin, flexible tube that is about five-milimeters in diameter. Pressure sensors are positioned along the length of the tube. This allows the pressure inside the esophagus to be measured at several sites at the same time. The sensors on the tube measure the strength and coordination of esophageal contractions. This test is useful when patients have difficulty swallowing, but no abnormal growths or scars are found. When surgery is needed to treat an esophageal disease, manometry is often used to help the surgeon decide which operation to perform.
- 24-hour ambulatory intra-esophageal pH testing is used to determine if stomach acid is moving backwards (refluxing) up the esophagus. The test is done by placing a pH sensor(s) in the esophagus and leaving it in place for 24 hours. The pH in the esophagus is recorded continuously on a small computer about the size of a pager that the patient carries. Two types of sensors can be used for this test. The most common is on a thin wire that is placed into the esophagus through the nose. The wire is then attached to the computer. The other type of sensor is combined with a tiny radio transmitter. It is clipped to the inner lining of the esophagus and transmits the pH continuously to a small computer the patient carries. This test is particularly useful for identifying gastro-esophageal reflux, and checking whether a symptom is related to acid reflux into the esophagus.
- Endoscopic ultrasound is a very specialized test that allows the doctor to examine the wall of the esophagus and the organs around it. The instrument used is a long, thin, flexible tube that has a miniature ultrasound emitter and receiver at its end. Before the procedure begins, the patient is given medication to make him or her relax. The ultrasound endoscope is placed into the mouth and then guided by the doctor into the esophagus. The ultrasound emitter sends out very high frequency sound waves that bounce off tissues in and around the esophagus. Some of those sound waves return to the receiver and are used by a computer to create detailed images of the esophagus and surrounding tissue. Endoscopic ultrasound is most often used to evaluate abnormal growths in or around the esophagus.