Gastroesophageal Reflux Disease

Paul Cohen MD

Gastroesophageal reflux disease (GERD) is such a common problem that it affects more than 1 out of 10 people on a daily basis. The presence or absence of a hiatal hernia often helps determine the severity of GERD and the ease or difficulty with which it can be treated. Several treatment options are available, but in addition to medications, use of self-care techniques is paramount.

ANATOMY, PHYSIOLOGY, AND PATHOLOGY

GERD occurs for various reasons, ranging from dietary factors to disruption of the antireflux barrier, allowing gastric content to reflux into the esophagus. In addition to these reasons, the lower esophageal sphincter (LES) normally relaxes approximately four times per hour (Mittal & McCallum, 1987; Holloway et al, 1995), and gastric juices may reflux during these times.

The antireflux barrier is composed of the crura diaphragm, the phrenoesophageal ligament, the acute angle of His, and the LES. These components physically block the reflux of gastric juices into the esophagus. The crura diaphragm wraps around the esophagus and helps create this barrier. The acute angle of His is the angle created when the esophagus passes through the diaphragm and empties into the stomach.

The LES is perhaps the most important component of this antireflux barrier. The intrinsic pressure of the LES keeps it closed until swallowing occurs. Once a bolus of food is swallowed, the LES receives a signal to relax and allows the bolus to pass into the stomach. The normal relaxation of the LES is believed to occur as part of digestion, perhaps to allow accumulating gases to escape. This relaxation is believed to play a major role in the etiology of reflux disease. Seasoned foods, cigarette smoking, alcohol ingestion, and caffeine are all well-known causes of LES relaxation with resultant reflux. Progesterone has also been found to decrease the LES pressure (Baron & Richter, 1992).

Hiatal Hernias

A hiatal hernia disrupts the antireflux barrier. Although the LES still functions normally, by allowing the LES to be displaced upward and separated from the other components of the antireflux barrier, the barrier is not as effective. The sliding hiatal hernia is the most common form of hiatal hernia. This type of hiatal hernia slides back and forth through the diaphragmatic hiatus. Because of this sliding back and forth, hiatal hernias, especially when small, may seem to appear and disappear on various diagnostic studies.

Paraesophageal hiatal hernias are more dangerous and far less common than sliding hiatal hernias. With paraesophageal hernias, GERD is not a complication, because the LES is not displaced. Rather, a distal portion of the stomach actually migrates upward and becomes trapped between the diaphragm and the esophagus. This can lead to ischemic changes and eventually necrosis of the stomach, with catastrophic consequences.

Histologic Changes

Histologic changes can be found in GERD, especially in patients with chronic GERD. The repetitive insult of the gastric juices causes metaplastic changes in the esophagus. Barrett’s esophagus represents the replacement of the squamous epithelia of the esophagus with columnar epithelia normally found in the stomach or small bowel. Barrett’s esophagus is a premalignant condition that occurs in 10% to 20% of patients with GERD (Spechler & Goyal, 1985; Reid et al, 1988). The incidence of adenocarcinoma in the presence of Barrett’s esophagus varies, but studies suggest an initial prevalence of approximately 8% (Cameron et al, 1985).

Knowing the type of metaplastic change helps to determine the risk of developing adenocarcinoma. Intestinal metaplasia has a much greater malignant potential than gastric metaplasia (Chalasani et al, 1987). These adenocarcinomas often begin as flat lesions that can be missed on diagnostic studies. Therefore, any suspicious lesion should be biopsied at endoscopy and evaluated for dysplastic changes or a malignant focus.

EPIDEMIOLOGY

The incidence and prevalence of reflux disease are based more on estimates than actual data because there is no accepted gold standard for recognizing or excluding GERD (Wienbeck & Barnert, 1989). However, a study done by questionnaire (Isolauri & Laippala, 1995) found that 10.3% of the participants experienced gastroesophageal reflux on a daily basis. The group with the highest incidence of daily heartburn is pregnant women (48% to 79% in European studies; Bainbridge, 1983; Baron & Richter, 1992).

DIAGNOSTIC CRITERIA

A diagnosis of GERD is often made by history alone. A definitive diagnosis, however, can be made by endoscopy or, with more advanced inflammation, a barium swallow, or by pH probe monitoring.

HISTORY AND PHYSICAL EXAMINATION

Patients with GERD often have some degree of symptomatology, but the degree of symptoms and the objective findings on diagnostic studies do not always correlate. All too often, patients
with GERD are evaluated via a barium swallow that is interpreted as normal, and patients are told nothing was found—therefore, nothing is wrong. In reality, they may have only mild inflammation, which is not detected by barium studies but nevertheless causes a great deal of discomfort.

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