What is (GERD)?

(GERD) Gastro-esophageal reflux disease
Spontaneous gastro-esophageal reflux may occur as a normal event, but gastro-esophageal reflux disease (GERD) is defined as symptoms (heartburn) and/or tissue damage caused by retrograde flow of gastric contents into the esophagus.
Epidemiology
Symptoms of GERD have been reported in approximately 44% of a surveyed population, but the precise prevalence varies according to the definition of the disease. The incidence increases with age and peaks at the age of 55-64 years, with an approximately equal gender distribution.
Pathology
The normal anti-reflux mechanism involves both anatomical and physiological factors: the lower esophageal sphincter, angle of His, crura of the diaphragm, mucosal rosette, swallowed saliva (lubrication and neutralization of acid), antegrade esophageal peristalsis and normal gastric motility/emptying.
A mild degree of reflux is experienced in most normal individuals, but a major cause of significant GERD is inappropriate transient lower esophageal sphincter relaxations (not preceded by a primary propagated esophageal contraction initiated by swallowing). Other causes include hiatus hernia and delayed gastric emptying.
Although a greater proportion of patients with symptoms of GERD smoke and consume alcohol, clinical studies confirm that traditional risk factors of increasing age, male sex, smoking and alcohol consumption are not strongly associated with symptoms of GERD.
Scope of disease
The majority have mild disease without esophagitis (non-erosive reflux disease). Symptoms can arise with minimal gastric reflux due to increased sensitivity of the esophagus to acid. Moderate disease is associated with esophagitis, and severe chronic disease results in the development of Barrett's esophagus (defined as metaplastic columnar degeneration above the gastro-esophageal junction). This is a premalignant condition, with a 0.5% per patient-year risk of malignant change to adenocarcinoma.
Severe or prolonged reflux can lead to ulceration, bleeding or perforation. Healing occurs by fibrosis and may lead to stricture formation. Severe reflux may also produce a hoarse voice from laryngitis. If the refluxate is aspirated, pneumonia may develop.
Clinical features
Most patients complain of heartburn, characterized by retrosternal burning pain, precipitated by meals. It may be aggravated by posture (lying flat, stooping, bending forwards) and conditions that raise intra-abdominal pressure (sneezing and coughing). It is often relieved by antacids and may be associated with water brash, the excessive secretion of saliva preceding reflux.
Atypical symptoms include back pain, cardiac-type chest pain, chronic wheeze, nocturnal 'asthma' or recurrent chest infections (due to aspiration), sore throat, hoarse voice, halitosis or dental decay. Dysphagia may occur with esophageal strictures from chronic disease.
Initial investigations
In general, the history can lead to a confident diagnosis of GERD and initial treatment can commence for uncomplicated cases. Older patients, or those who experience weight loss, dysphagia or hematemesis will require further investigations.
Further investigations
Upper gastrointestinal endoscopy
esophagoscopy is appropriate for patients with symptoms suggestive of complications (weight loss, dysphagia, hematemesis), when the diagnosis is unclear, when symptoms cannot be adequately controlled on medical therapy, or for screening for Barrett's epithelium (in patients over50 with chronic symptoms).
esophageal abnormalities that can be diagnosed at endoscopy include hiatus hernia, esophagitis, Barrett's esophagus, strictures and tumours. The severity of reflux esophagitis can also be assessed at endoscopy, and biopsies can be taken. GERD cannot be excluded by a normal endoscopy.
24-hour pH measurement
Intra-esophageal pH measurement may be required to diagnose GERD if the initial endoscopy is normal or if symptoms do not respond to medical therapy. It is usually performed as an ambulatory test over a 24-hour period, facilitating the diagnosis of GERD by assessment of the duration, frequency and severity of reflux attacks in relation to the pH of the esophagus. It does not provide any information as to the etiology of GERD and may be normal (false negative) in patients with significant bile or volume reflux.
esophageal manometry
Esophageal manometry is a useful investigation to assess esophageal function when planning surgical intervention, especially if achalasia and other esophageal motility disorders are suspected. It is possible to determine the length and position of the lower esophageal sphincter and to measure the sphincter pressure. A short or weak lower esophageal sphincter is often a major contributing cause of reflux esophagitis.
Initial management
Lifestyle modification
Suggestions that may improve symptoms include weight loss for obese patients, stopping smoking, frequent small meals, avoiding foods that are known to precipitate symptoms, avoiding eating for several hours before bedtime, and raising the head of the bed. However, evidence for improvement associated with these measuresis scarce.
Medical management
There are three pharmacological approaches to controlling symptoms of GERD: neutralization of acid (antacids and alginates), reduction in acid production (H2-receptor blockers, proton pump inhibitors) and increasing gastrointestinal motility (metoclopramide).
Step-up therapy
Most agents for initial therapy are available without prescription, and pharmacists offer the first-line management of GERD in a step-up regimen (starting from the simplest, most cost-effective agent).
Antacids and alginates
Antacids, such as bicarbonate, act by reducing the acidity within the stomach and lower esophagus. Alginate preparations (such as Gaviscon) act by coating the top of the gastric contents to reduce the effect of acid on the esophageal mucosa. Both these agents are effective, but the effects are often short-lived and suitable only for patients with mild symptoms.
H2-receptor antagonists
H2-receptor antagonists (e.g. cimetidine, ranitidine) block the H2-receptors in gastric mucosa, leading to a marked reduction in gastric acid production. Initial symptomatic relief is experienced in approximately 60%.
Step-down therapy
Patients who seek medical attention may already be on a combination of antacids, alginates and H2-receptor antagonists. Current consensus favours step-down therapy (starting with the most effective agent), as it is associated with greater symptomatic relief and fewer treatment failures and physician consultations.
Proton pump inhibitors
The proton pump inhibitors (e.g. omeprazole, lansoprazole) act by blocking the proton pump within the gastric mucosa, almost completely abolishing gastric acid production. Initial symptomatic relief is experienced in approximately 83%.6 An initial 2-4-week course is recommended followed by maintenance therapy. Failure to respond to initial therapy is an indication for further investigations (endoscopy, pH studies) to confirm and assess the severity of the disease.
Prokinetic agents
Due to the superiority of proton pump inhibitors, the role of prokinetic agents (metoclopramide) is ill defined. Prokinetic agents are usually reserved for use in combination with proton pump inhibitor for step-up therapy, or in combination with an H2-receptor blocker for long-term maintenance step-down therapy.
Maintenance therapy
After 6 months of initial therapy 75% of patients experience symptom relapse. A trial of withdrawal of drug therapy may be initiated but the majority will require maintenance therapy either by step-down treatment (long-term H2-receptor blocker) or intermittent on-demand proton pump inhibitor therapy, a 2-4-week course each time symptoms recur.
Surgical management
Before considering anti-reflux surgery, upper gastrointestinal endoscopy, 24-hour pH studies and esophageal manometry are required for confirmatory diagnosis and documentation of the presence and severity of reflux.
Anti-reflux surgery provides effective long-term treatment of GERD with symptomatic control equivalent to medical therapy but lower rates of esophagitis.10 The indications for surgery are failure of medical treatmentor development of complications (ulceration, strictures, Barrett's esophagus or respiratory complications). Relative indications include volume reflux (i.e. excessive volume rather than acid content) and patient preference.
Anti-reflux surgery has a 90% initial success rate. Complications of surgery include dysphagia (usually short-lived)in about 10%, inability to belch, the so-called 'gas bloat syndrome' (20%) and excessive flatus.
Nissen fundoplication
The most common operation is the Nissen (360 degree) fundoplication, which can be performed via an abdominal incision (midline laparotomy) or laparoscopically. The hiatus of the diaphragm is repaired, the lower esophagus is mobilized, then the greater curvature of the stomach via division of the short gastric arteries. The fundus of the stomach is wrapped completely around the lower esophagus.
To reduce the risk of dysphagia, various partial fundoplications have been described, including the anterior partial (Watson), posterior partial (Toupet) and Lind (270 degree) subtotal fundoplications.
Collis-Nissen procedure
This uncommon procedure is reserved for situations where the gastro-esophageal junction cannot be reduced below the diaphragm. An abdominal approach is used and a linear stapler is used to 'lengthen' the esophagus by incorporating the cardia of the stomach prior to creating the wrap.
Management of benign strictures
A barium swallow is often performed to delineate the site and extent of the stricture, followed by endoscopy and biopsies to determine the etiology. The treatment of benign strictures consists of bougie dilatation, and several sessions may be required for resistant strictures. Further treatment options include resection or bypass of the stricture and long-term intubation of the esophagus.
Following esophageal dilatation, the patient is keptnil by mouth if symptoms such as chest or back pain or surgical emphysema develop. A chest film is performed to exclude a pneumomediastinum, which will suggest esophageal perforation.
Prognosis
GERD is a chronic relapsing condition. Long-term studies report 10-year recurrence rates (based on use of anti-reflux medications) in 62% of surgically treated and 92% of medically treated patients. If Barrett's esophagus develops, regular endoscopic surveillance for dysplasia is required.