Esophageal Symptoms and Selection of Diagnostic Tests

Heartburn

The most common esophageal symptom of GERD is heartburn, usually resulting from reflux of acidic gastric juice into the esophagus. Acid irritates the esophageal mucosa, stimulating nociceptors and causing heartburn. The relationship between acid exposure and heartburn is quite complex, as evidenced by the variable response to acid suppression therapy (especially in patients with NERD). Up to 60% of the Western population experience heartburn at least once every year, and 20% to 30% have weekly symptoms. Heartburn is usually described as retrosternal burning that ascends from the epigastrium toward the throat. The classic billboard advertisements for proton pump inhibitors (PPIs) that feature a patient with a grimace and a balled-up hand held to the chest are an apt representation of the sensation.

Many patients describe aggravation of their heartburn brought about by eating spicy or fatty meals, drinking citrus juices, or consuming chocolate, alcohol, or coffee. It is frequently associated with regurgitation, which is exacerbated by postural changes. Heartburn is usually relieved by antacids or antisecretory medications, and the availability of over-the-counter PPIs and oft-prescribed antisecretory medications have led to widespread use of these remedies. Not infrequently, physicians may find that their patient is completely dependent on these medications, and withdrawal of PPIs results in the rapid return of heartburn. It is therefore important to ask the patient about their use of these medications and what symptoms they experience when the medication is withheld. Nocturnal heartburn appears to be an especially serious symptom, as noted by a Gallup poll conducted by the American Gastroenterologic Society ( Box 5.1 ).

The most appropriate objective measurement of refluxed gastric acid as a cause of the patient's symptoms is a 24-hour pH test. This test has been well studied and documented by Johnson and DeMeester, and their composite score helps distinguish normal acid exposure from abnormal levels, as described in Table 5.1 .

Functional Heartburn

The term functional heartburn , which is a concept developed further over the past decade, refers to the manifestation of heartburn in a patient with no objective evidence that relates the symptom to abnormal esophageal exposure of refluxed gastric juice. Similarly, functional chest pain is presumed to be of esophageal origin but has a negative work-up on routine testing. Galmiche and colleagues have defined the criteria for the diagnosis of functional heartburn. Diagnosing this condition requires a negative impedance study to exclude patients experiencing symptoms with either weak-acid or alkaline reflux. A recent study of pH impedance testing showed that 30% of PPI-refractory patients experience functional heartburn. These patients may have altered visceral hypersensitivity, as their condition frequently overlaps with other functional abnormalities and various psychiatric disorders. In patients with functional heartburn, antireflux surgery outcomes are often poor, which drives home the importance of pH testing before antireflux surgery is considered. Treatment for functional heartburn usually includes antidepressants, which are thought to have a neuromodulatory role in hypersensitivity disorders. However, scant data prove their efficacy.

The functional heartburn category of patients again reaffirms the sometimes-vague presentation of esophageal pathologies, and certainly adds weight to the argument that GERD must be objectively diagnosed with pH or pH impedance testing before surgery is considered.

Regurgitation

Regurgitation is the effortless return of gastric juice or recently ingested food or liquid into the back of the throat or mouth, and it is often exacerbated by postural changes. This symptom is most frequently accompanied by heartburn, but it may occur in isolation in patients with adequate acid-suppression therapy (i.e., with PPIs). Regurgitation occurring at night is especially significant, as it may result in silent aspiration and lung damage. Delayed gastric emptying may exacerbate regurgitation.

Dysphagia

Dysphagia may be either oropharyngeal or esophageal in origin. Oropharyngeal dysphagia may result from mechanical, obstructive, functional, or neurologic causes. Esophageal dysphagia usually results from a mechanical obstruction, or from poor bolus transport (i.e., hypomotility or uncoordinated, spastic contractions). Patients can frequently identify the general area in which dysphagia is occurring, but this is not always reliable. The symptom of dysphagia is often referred to as an alarm symptom , as it is usually the primary presenting symptom of esophageal cancer. It is a common symptom, however, and can accompany GERD with or without stricture and a number of other benign disorders. Symptom duration and rapidity of symptom progression often offer clues regarding the pathology. Rapid progression of dysphagia that inhibits swallowing solids first and ultimately impedes swallowing of liquids over a period of weeks or months forebodes a malignant process, whereas a slow progression over years suggests an underlying motility disorder such as achalasia. Patients often initially compensate for solid-food dysphagia by avoiding dense solid foods (e.g., steak, chicken breast), chewing food very well, or eating only very soft food.

If dysphagia is accompanied by a prominent history of heartburn, the surgeon should consider peptic stricture, but patients with achalasia sometimes experience heartburn, and reflux disease is the culprit behind the development of most esophageal carcinomas. Generally speaking, dysphagia should prompt a structural investigation such as endoscopy or dedicated barium esophagram. The former is more invasive but allows for biopsy of any abnormalities, whereas the latter provides evidence of narrowing from stricture or malignancy and offers some information on the propulsive capability of the esophagus. Potential causes of esophageal dysphagia are listed in Box 5.2 .

The least invasive study in the work-up of patients with dysphagia is the barium esophagram. When done correctly, this test should identify spastic motor disorders, diverticula, achalasia, and strictures (benign or malignant). Barium studies performed with liquids and foods of various consistencies or with a large barium tablet, as described later, provide additional information. Endoscopy is both diagnostic and therapeutic, as it can facilitate biopsy and provide an opportunity to dilate a Schatzki ring or stricture. More subtle motility abnormalities often require manometry for diagnosis, and this test is necessary before surgery for a manometric disorder is considered.

Noncardiac Chest Pain

One of the more difficult GERD symptoms to diagnose and treat is noncardiac chest pain. It is frequently of esophageal origin, and although it may be on the spectrum of GERD or of a motility disorder, surgeons should approach this symptom with caution. A convergence of sensory neurons from both the heart and the esophagus exists on the dorsal horns of the spinal cord, so myocardial infarction is often suspected in patients with severe esophageal spastic syndromes. Unfortunately, the fear of missing a myocardial infarction results in significant expense in examining patients presenting with chest pain. It is thought that as many as 150,000 of the 500,000 coronary angiograms performed annually in the United States are performed for functional disorders. Manometry is generally required to confirm suspicion of a motor disorder, but it is not always diagnostic, as many of these motor disorders are episodic in nature. Twenty-four-hour manometry (often combined with 24-hour pH monitoring) has been useful in diagnosing these patients, but is not widely available and is rarely used in clinical practice. pH testing has been found to be predictive of a therapeutic response to omeprazole in patients with severe reflux and noncardiac chest pain.

Chronic Cough and Asthma

Reflux as a cause of chronic cough is a challenge to diagnose. Silent aspiration is presumed to inflame and irritate the airway. Alexander and colleagues observed an increased prevalence of GERD symptoms and increased esophageal exposure to acid in asthmatic patients. Schnatz and Castell also noted a high proportion (78%) of positive pH tests in patients with chronic cough or asthma. Increased esophageal exposure to gastric juice in these patients is probably both the cause and the effect: Severe coughing with wheezing increases intraabdominal pressure, driving gastric juice into the relatively negative-pressure environment of the chest, and esophageal acidification can result in a reflexive bronchospastic response ( Fig. 5.1 ). Furthermore, as discussed later, chronic aspiration contributes to ongoing cough and to progressive parenchymal fibrosis. Evidence of pharyngeal reflux on pH testing helps identify patients with respiratory symptoms who may benefit from an antireflux operation.