Gastro-esophageal reflux disease

Gastro-oesophageal reflux disease (GORD) is a spectrum of disease that occurs when gastric acid refluxes from the stomach into the lower end of the oesophagus across the lower oesophageal sphincter (LOS).

Clinical presentation

Common clinical features in adults include epigastric and retrosternal burning sensations (heartburn or pyrosis), regurgitation leaving an acidic taste in the mouth, waterbrash (increased salivation), enamel erosions, and a chronic dry cough ¹. Symptoms are particularly pronounced during the night ¹.

In paediatrics, the presentation is often non-specific, with vomiting, upper and lower respiratory symptoms, irritability, aversion to food, and failure to thrive ². A minority of paediatric patients with GORD (<1%) will additionally have spasmodic torticollis and dystonia, a constellation of symptoms known as Sandifer syndrome³.

Pathology

Minor reflux disease

In most patients with reflux disease, reflux is initiated by transient collapses of LOS pressure. This results in the lower end of the oesophagus being bathed in gastric acid for longer than normal. Patients may be symptomatic without developing endoscopic appearances of oesophagitis (40% of cases). These patients will also have no detectable abnormality on a barium swallow.

Loss of appropriate LOS function gives rise to symptoms of reflux and globus symptoms, e.g. sensation of a lump at the back of the throat. It is affected by anatomical and physiological abnormalities:

• prolonged fundal distension
• sphincter shortening
• repetitive transient LOS pressure collapse

Hiatus hernia

In normal patients, the intra-abdominal oesophagus improves LOS function. However, in patients with hiatus hernia, the amount of intra-abdominal oesophagus is reduced and increases in intra-abdominal pressure are more likely to overcome the LOS pressure and cause reflux.

Advanced reflux disease

In patients with a permanently low LOS pressure, symptoms are generally more severe and there is evidence of disease in endoscopic or barium studies. Abnormalities that are radiologically detectable include:

• free reflux
• impaired primary peristalsis and poor clearance
• abnormal oesophageal contractions
• oesophagitis with scarring
• strictures, Barrett oesophagus and aspiration
• sacculations and intramural pseudodiverticula

Theoretical response to acid

Traditional theories hold that GORD invokes a linear response of severity dependant on exposure to acid. Mild oesophagitis progresses severe ulcerated oesophagitis. This then progresses to Barrett oesophagus and then, in a proportion of patients, dysplasia and eventually cancer develop.

Modern theory suggests that there is no such linear response to acid exposure in the lower osesophagus. Instead, the oesophagus, under the stimulus of excess acid exposure, undergoes change in one of three ways:

1. columnal lined oesophagus (metaplastic): short-segment; long-segment; cancer
2. reflux oesophagitis (inflammatory): low grade; high grade; peptic stricture
3. endoscopically negative GORD: little visible response but have significant symptoms

Treatment and prognosis

Options include:

• medical treatment in minor cases.
• surgery for advanced and resistant cases; fundoplication is the operation of choice, it can be done endoscopically or open surgery; a fold from the gastric fundus is wrapped around the lower esophageal junction to enforces the action of the sphincter