Gastroesophageal Reflux Disease

Condition

Definition

Gastroesophageal reflux disease

A condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications

Reflux esophagitis

Symptoms of gastroesophageal reflux disease with endoscopic or histopathologic evidence of esophageal inflammation

Functional heartburn

According to Rome III diagnostic criteria, a burning retrosternal discomfort or pain + absence of evidence that gastroesophageal acid reflux is the cause of the symptoms + absence of histopathology-based esophageal motility disorders with criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

GERD can manifest in a wide array of symptoms. Typical symptoms include heartburn (retrosternal burning) and acid regurgitation (feeling of acidic gastric contents reaching the pharynx). Atypical symptoms such as epigastric fullness or pressure, epigastric pain, nausea, bloating, and belching may be indicative of GERD but may overlap with other conditions in the differential diagnosis such as peptic ulcer disease, achalasia, gastritis, dyspepsia, and gastroparesis (see Table 4.2). Lastly, there are a variety of extraesophageal symptoms that have been attributed to GERD including cough, wheezing, hoarseness, and sore throat; however, these are not specific to GERD. In general, symptoms tend to be more common after meals and while lying in the right lateral decubitus position.

Table 4.2

Differential diagnosis for GERD

• Peptic ulcer disease

• Non-ulcer dyspepsia

• Esophageal motor disorders

• Infectious esophagitis

• Pill esophagitis

• Eosinophilic esophagitis

• Cardiac disease

• Biliary tract disease

• Esophageal cancer

The socioeconomic burden of GERD is considerable. From a health economic standpoint, the high prevalence of GERD combined with the cost of acid-lowering medications results in high healthcare costs. Furthermore, it is associated with a dramatic impact on quality of life. Several studies have demonstrated that health-related quality of life in reflux disease patients is significantly impaired in comparison to the general population. A recent systematic review concluded that patients with persistent reflux symptoms despite PPI therapy have clinically relevant impairments in physical and mental well-being that are comparable to those of untreated patients with GERD.

Epidemiology

Epidemiologic estimates of the prevalence of GERD are based primarily on the typical symptoms of heartburn and regurgitation. This approach introduces certain limitations to the actual prevalence calculation because there are patients with endoscopic evidence of GERD (e.g., esophagitis or Barrett’s esophagus) who do not present with heartburn or regurgitation. Furthermore, there are patients with these symptoms who do not have GERD.

Symptoms suggestive of GERD are common and become even more common with advancing age. In 2005, a systematic review found the prevalence of GERD to be 10–20 %, defined by at least weekly heartburn and/or acid regurgitation in the Western world, while in Asia it was lower, at less than 5 %. The incidence in the Western world was approximately 5 per 1,000 person-years, which appears low relative to the prevalence but is consistent with the disease’s chronicity.

Without treatment, this prevalent disease can result in numerous esophageal complications including erosive esophagitis, peptic stricture, Barrett’s esophagus, and esophageal adenocarcinoma. Complications of GERD are thought to be more common in males, Caucasians, and persons of advancing age. Of those with classical GERD symptoms who undergo an endoscopy, approximately one-third have erosive esophagitis, 10 % have benign strictures, and up to 20 % have Barrett’s esophagus. Fortunately, only an extremely small number are found to have esophageal adenocarcinoma.

Pathophysiology

The principal event in the pathogenesis of GERD is movement of gastric contents from the stomach into the esophagus. Normally, there are several mechanical barriers and mechanisms in place to prevent this potential insult to the esophageal lining.

The key barrier to reflux is the lower esophageal sphincter (LES), a segment of tonically contracted smooth muscle at the distal esophagus. The LES relaxes with swallowing and also with gastric distension, allowing for venting of air. The LES may also relax at times not associated with swallowing; these relaxations are termed transient lower esophageal sphincter relaxations (tLESRs) and are of longer duration than swallow-related LES relaxation. In patients with GERD, tLESRs allow for venting of gastric liquid contents instead of air alone, resulting in acid reflux. An increased frequency of tLESRs is considered to be the major mechanism in most GERD patients, and this appears to be even more common in obese patients, although why this occurs is not completely understood.

Another mechanism that can render the gastroesophageal junction incompetent is a hypotensive lower esophageal sphincter. Although only a minority of patients with GERD have a grossly hypotensive LES, there are multiple factors that result in a reduction of LES pressure. These include gastric distension; certain foods such as fat, chocolate, caffeine, and alcohol; smoking; and a multitude of medications including calcium channel blockers, nitrates, and albuterol.

A third mechanism is the presence of a hiatal hernia. There are two primary ways a hiatal hernia may lead to GERD. The first relates to the loss of the crural diaphragm and the augmentation it normally provides the LES. The second occurs via a lowering of the threshold for eliciting tLESRs in response to gastric distension.

Other important mechanisms to consider that normally protect the esophageal mucosa from acid reflux include intrinsic mucosal factors (e.g., surface mucous and bicarbonate, stratified squamous epithelium, intercellular tight junctions, blood flow), esophageal peristalsis, and neutralization of the residual acid by bicarbonate-rich saliva. Any defect in these mechanisms including esophageal dysmotility or decreased salivary flow can lead to GERD.

With respect to extraesophageal symptoms, the mechanism likely involves direct aspiration with damage to the respiratory mucosa and/or a vagally mediated reflex triggered by pathologic acid reflux of the distal esophageal mucosa.

Diagnosis and Evaluation

A diagnosis of GERD is made using some combination of patient symptomatology, objective testing with endoscopy and/or ambulatory esophageal pH monitoring, and response to antisecretory therapy (see Table 4.3). The symptoms of heartburn and regurgitation are the most reliable for making a presumptive diagnosis based on history alone. It is neither necessary nor practical to perform a comprehensive evaluation in every patient with heartburn or regurgitation.

Table 4.3

Diagnostic testing for gastroesophageal reflux disease

Diagnostic test	Indication
• Proton pump inhibitor trial	Classic symptoms without alarm symptoms
• Esophageal pH monitoring	Refractory GERD symptoms, preoperative evaluation, GERD diagnosis in question
• Upper endoscopy	Noncardiac chest pain, alarm symptoms
• Barium radiographs	Evaluation of dysphagia, otherwise not a recommended test for GERD
• Esophageal manometry	Evaluation for a motility disorder prior to planned anti-reflux surgery, otherwise not a recommended test for GERD

When GERD is suspected in those with typical symptoms and no alarm signs (see below), empiric medical therapy with a PPI is the recommended next step. A response can help support the diagnosis, although this is not a diagnostic criterion. There are some patients, however, who warrant further evaluation. Indications to proceed with further testing include: (1) confirming the diagnosis of GERD in those refractory to medical therapy, (2) assessing for complications of GERD, (3) assessing for alternative diagnoses, and (4) as part of a preoperative evaluation.

Upper endoscopy can aid in the diagnosis especially if evidence of erosive esophagitis, peptic strictures, or Barrett’s esophagus is found. The majority of patients (approximately 70 %) with typical symptoms of GERD, however, will not have these findings. An upper endoscopy should always be considered in patients with alarm symptoms such as dysphagia, anemia, melena, or weight loss, in order to rule out complications from GERD such as a peptic stricture or an esophageal malignancy.

< div class='tao-gold-member'>

Only gold members can continue reading. Log In or Register to continue