Diagnostic Evaluation of Gastroesophageal Reflux Disease (GERD)
Individuals with occasional, mild symptoms of gastroesophageal reflux disease (GERD) may not require any specific evaluation and may be candidates for direct treatment. Patients with regular symptoms of GERD (weekly symptoms or symptoms on a consistent basis) or patients with heartburn associated with difficulty in swallowing, weight loss, anemia or bleeding need to be evaluated on a more aggressive basis.
In general, the following diagnostic techniques may be used for evaluating patients with symptoms of GERD:
- Upper gastrointestinal (GI) endoscopy
- Esophageal ambulatory 24-hour pH monitoring
- Esophageal manometry
- Radiological studies (x-rays)
- PillCam esophageal capsule endoscopy
Upper Gastrointestinal Endoscopy
Upper gastrointestinal (GI) endoscopy is the most reliable and accurate examination performed in the evaluation of esophagitis. This procedure is generally performed by a gastroenterologist and includes the placement of flexible scope into the patient's esophagus and stomach and examining the area under direct vision following the administration of sedation with intravenous agents. The physician may take biopsies and photographs during the test as well. The main role of upper GI endoscopy in the setting of GERD is to determine whether the patient has Barrett's esophagus. In addition, this procedure will exclude a fixed and narrowing known as a stricture as well as a tumor.
Barrett's esophagus is a change in the esophageal lining that reflects a potential risk for a type of cancer known as adenocarcinoma of the esophagus. About 8% of patients have adenocarcinoma at the time of initial diagnosis of Barrett's esophagus. Barrett's esophagus occurs more frequently in men than in women by a ratio of about 3:1. The average age of diagnosis is 55 and it is most often diagnosed in patients with severe GERD symptoms. Barrett's esophagus diagnosed by upper GI endoscopy with biopsy of the gastroesophageal junction. If Barrett's esophagus is found, the patient will need a yearly upper GI endoscopy with biopsy of the esophagus to ensure that the Barrett's is not turning into a cancerous state. If Barrett's is excluded then there is no reason to do repeated upper GI endoscopy unless symptoms, such as difficulty in swallowing or regurgitation, occurs.
Esophageal Ambulatory 24-hour pH Monitoring
Another test that is occasionally employed in the evaluation of patients with GERD is called esophageal ambulatory 24-hour pH monitoring. This consists of placing an acid-measuring nasal probe into the esophagus and measuring the acid (pH) in the esophagus for a period of 24 hours. During that time the patient is asked to conduct a normal lifestyle and make notations when symptoms occur. Because esophageal ambulatory 24-hour pH monitoring is an uncomfortable and expensive procedure, it is usually reserved for patients with severe GERD symptoms who are being considered for anti-reflux surgery.
More recently, a new system called the "Bravo pH meter" (Medtronic, Inc.) has become available as a possible alternative to conventional esophageal ambulatory 24-hour pH monitoring. This system involves attaching a wireless capsule to the wall of the distal esophagus during an upper GI endoscopy and monitoring the pH for 48-hours. Studies are currently ongoing to evaluate the risks and benefits of the Bravo pH system in the management of patients with GERD.
Esophageal manometry, which is a technique that measures the pressures in the lower esophageal sphincter (LES) and any abnormal muscle contractions in the main part of the esophagus, may also be used in the evaluation of the GERD patient. This is accomplished using a computer to record the esophageal pressures which is connected to a thin nasal catheter (tube) that is temporarily placed in the esophagus. Pressure changes in the esophagus are detected by the catheter when the esophagus contracts and are then transmitted to and recorded by the computer to detect if they are normal or abnormal. Esophageal manometry will usually be done when elective anti-reflux surgery is being contemplated for the GERD.
Radiological (x-ray) studies, such as a barium esophagram or an upper GI series, may also be used in evaluating patients with GERD primarily to rule-out other conditions that may be responsible for the patient's symptoms such as a tumor or peptic ulcer disease. This test is occassionally used to evaluate dysphagia (difficulty swallowing) in patients with GERD. Although the esophagram is not capable of assessing grades of esophageal damage occurring in the setting of GERD, it is useful in the assesment of strictures and may demonstrate reflux of barium from the stomach to the esophagus. The esophagram, which is performed by a radiologist, is also useful in the assessment of hiatal hernias.
PillCam Esophageal Capsule Endoscopy
This test is a modification of the capsule endoscopy technique that is used for the evaluation of the small intestine. The Esophageal PillCam employs a camera on both ends of the capsule and is, therefore, capable of both forward and backward viewing of the esophageal mucosa as the capsule traverses the esophagus. The PillCam capsule, which is about the size of a multi-vitamin tablet, can easily be swallowed by the patient. As the capsule traverses down the esophagus, it captures images of the inner lining of the esophagus. The capsule is capable of determining the presence of Barret's esophagus, grades of esophageal damage, and the presence of masses or strictures in the esophagus. The study does not require sedation and can usually be performed in the outpatient setting.