Last updated: 02/17/2009

Manometry

This study is designed to measure the pressure changes produced by contraction of the muscular portions of the esophagus. An abnormality in the function of any one of the segments of the esophagus can cause difficulty in swallowing...

(dysphagia). A manometric examination is most useful in evaluating patients when an endoscopy yields normal results.

During manometry, the patient swallows a thin tube carrying a device that senses changes in pressures in the esophagus. Readings are taken at rest and during the process of swallowing. Medications are sometimes given during the study to aid in the diagnosis. The results are then transmitted to recording equipment. Manometry is most useful in identifying diseases that produce disturbances of motility or contractions of the esophagus. In 2003, a solution containing five drops of peppermint oil in 10 mL of water was found to improve the manometric features of diffuse esophageal spasm (DES). The peppermint oil solution eliminated simultaneous esophageal contractions in all patients in the study.

Esophageal pH monitoring

This procedure measures the esophagus' exposure to acid reflux from the stomach. The test is ideal for evaluating recurrent heartburn or gastroesophageal reflux disease (GERD). Excessive acid reflux may produce ulcers, or strictures resulting from healed ulcers, in addition to the symptom of heartburn.

Normally, acid from the stomach washes backward into the esophagus in small amounts for short periods of time. The lower esophageal sphincter usually prevents excessive reflux in patients without disease. Spontaneous contractions that increase esophageal emptying and production of saliva also act to prevent damage to the esophagus.

Researchers have shown that in the esophagus, the presence of acid is damaging only if it lasts over long periods of time. Therefore, esophageal pH monitoring has been designed to monitor the level of acidity over a 24-hour period, usually in the patient's home. In this way, patients are able to maintain their daily routine, document their symptoms, and correlate symptoms with specific activities. During this period, a thin tube with a pH monitor remains in the esophagus to record changes in acidity. After the study, a computer is used to compare the changes with symptoms reported by the patient.

In addition to esophageal pH monitoring, the doctor may perform a Bernstein test (also known as the acid perfusion test) and an acid clearing test. In the Bernstein test, a small quantity of hydrochloric acid (HCl) is directed into the patient's esophagus. If the patient feels pain from the acid, the test is positive for reflux esophagitis. If there is no discomfort, another explanation must be sought for the patient's symptoms. In the acid clearing test, HCl is also directed into the esophagus. This test, however, measures the patient's ability to quickly swallow the acid. If the patient has to swallow more than 10 times to move the acid down the esophagus, he or she has a problem with esophageal motility.

pH monitoring is usually performed before surgery to confirm the diagnosis and to judge the effects of drug therapy. In 2003, studies showed that integrated esophageal and gastric acidity provided better quantitative measures of esophageal dysfunction in GERD than conventional measurements of pH. This finding may suggest better ways to evaluate the effectiveness of different treatments for GERD.

X-ray tests

X-ray tests of esophageal function fall into two categories: (1) tests performed with barium and a fluoroscope; and (2) those performed with radioactive materials. Studies performed with fluoroscopy are especially useful in identifying structural abnormalities of the esophagus. Sometimes the patient is given a sandwich or marshmallow coated with barium in order to identify the site of an obstruction. Fluoroscopy can diagnose or provide important information about a number of disorders involving esophageal function, however, including cricopharyngeal achalasia (a swallowing disorder of the throat); decreased or reverse peristalsis; and hiatal hernia.

During fluoroscopy, the radiologist can observe the passage of material through the esophagus in real time, and also make video recordings. These observations are particularly useful when the swallowing symptoms appear to occur mostly in the upper region of the esophagus. The most common cause of difficulty swallowing is a previous stroke, although other diseases of the neuromuscular system (like myasthenia gravis) can produce similar symptoms.

Scans using low-dose radioactive materials are useful because they may demonstrate that food passes more slowly than usual through the esophagus. They can also measure the speed of the bolus' passage. These studies involve swallowing food coated with radioactive material, followed by a nuclear medicine scan. Scans are often used when other methods have failed to make a diagnosis, or if it is necessary to determine the degree of the abnormality.