This can occur with violent vomiting producing severe chest pain and collapse. It may follow alcohol ingestion and a chest X-ray shows a hydropneumothorax.
In a sliding hiatus hernia, the gastro-oesophageal junction ‘slides’ through the hiatus so that it lies above the diaphragm. This type of hernia occurs in approximately 30% of people of 50 years of age and by itself is of no diagnostic significance. It does not produce symptoms on its own; symptoms occur because of the presence of associated reflux.
A para-oesophageal or rolling hernia is when a small part of the stomach rolls up through the hernia alongside the oesophagus. The sphincter stays below the diaphragm and remains competent. Occasionally a rolling para-oesophageal hernia will produce pain and require surgical treatment.
Gastro-oesophageal reflux occurs as a normal event, and the clinical features of GORD only occur when the antireflux mechanisms fail sufficiently to allow gastric contents to make prolonged contact with the lower oesophageal mucosa.
ANTI REFLUX MECHANISMS. The most important is the LOS which is formed by the distal 4 em of oesophageal smooth muscle. It rapidly regains its normal tone after relaxation to allow a bolus to enter the stomach and thereby prevent reflux. It is capable of increasing tone in response to rises in intra-abdominal and intra gastric pressure.
Other antireflux measures involve the intra-abdominal segment of the oesophagus which acts as a flap valve and the mucosal rosette formed by folds of the gastric mucosa also help to occlude the gastro-oesophageal junctional lumen.
The oesophagus is normally rapidly cleared of any reflux contents by secondary peristalsis.
PATHOGENESIS OF GORD
The following mechanisms have been implicated:
• The resting LOS tone is low and LOS tone fails to increase, as occurs in normal patients, when lying flat.
• LOS tone fails to increase when intra-abdominal pressure increases.
• Oesophageal mucosal resistance to acid is reduced.
• There is relatively poor oesophageal peristalsis which leads to poor clearance of gastric contents.
• Delayed gastric emptying occurs and this may increase the chance of reflux.
• Prolonged episodes of gastro-oesophageal reflux occur at night and postprandially. Factors associated with increased gastro-oesophageal.
Allor some of these features playa role in the individual patient and can occur whether or not a hiatus hernia is present. GORD can undoubtedly occur without a hiatus hernia.
Heartburn is the major feature of GORD. Pain is mainly due to direct stimulation of the hypersensitive oesophageal mucosa, but is also partly due to spasm of the distal oesophageal muscle. The burning is aggravated by bending, stooping or lying down and may be relieved by antacids. The patient may complain of pain on drinking hot liquids or alcohol. The correlation between heartburn and minor degrees of oesophagi tis is poor. Some patients have mild oesophagi tis, but severe heartburn; others have severe oesophagi tis without symptoms and present with a haematemesis or an iron deficiency anaemia from chronic blood loss. Regurgitation of food and acid into the mouth can occur, particularly when the patient is bending or lying flat. Aspiration into the lungs, producing pneumonia, is unusual without an accompanying stricture, but cough and nocturnal asthma from regurgitation and aspiration can occur. The differential diagnosis from angina can be difficult; 20% of cases admitted to a coronary care unit have GORD (Information box 4.1).
BARIUM SWALLOWis still the most widely used investigation. A hiatus hernia by itself is of no diagnostic significance and free reflux of barium must be demonstrated. Reflux can also be demonstrated with radio labelled technetium.
24 HOUR INTRALUMINAL pH MONITORING .
The number of reflux episodes (below pH 4) occurring over 24 hours is noted (Fig. 4.7). This is now considered the most accurate test available, there being a reasonable correlation between frequency of reflux and symptoms.
OESOPHAGOSCOPY is used to show the presence of oesophagi tis with a red friable mucosa and, in more severe cases, linear ulceration. The mucosa can be normal in GORD.
BERNSTEIN TEST may be helpful in investigating retrosternal chest pain to differentiate oesophageal pain from angina.
Many patients (approximately 50%) can be treated successfully with simple antacids, loss of weight, and raising the head of the bed at night. Precipitating factors should be avoided with a reduction in alcohol consumption and cessation of smoking. These measures are simple to say, difficult to carry out, but are useful in mild cases. The chief antacids are magnesium trisilicate and aluminium hydroxide; the former often causes diarrhoea whilst the latter causes constipation. Many antacids contain sodium which may exacerbate fluid retention; aluminiumhydroxide has less sodium than magnesium trisilicate.
ALGINATE-CONTAINING ANTACIDS (10 ml three times daily) are the most frequently prescribed agents for GORD. They form a gel or ‘foam raft’ with gastric contents and thereby prevent reflux.
H2-RECEPTOR ANTAGONISTS are frequently used , to be taken at 6 p.m., doubling the normal dosages if necessary.
PROTON PUMP INHIBITORS, such as omeprazole, a substituted benzimidazole which inhibits the H+, K+ proton pump. This produces almost complete reduction of gastric acidity, is extremely effective, and is the drug of choice for all but mild cases. Patients with severe symptoms need prolonged treatment, often for years.
METOCLOPRAMIDE, a dopamine antagonist, is occasionally helpful as it enhances peristalsis and speeds gastric emptying.
CISAPRIDE, a prokinetic agent devoid of dopaminergic activity, increases oesophageal peristalsis, increases LOS pressure and is of value, particularly for maintenance therapy.
Surgery should never be performed for a hiatus hernia alone. The properly selected case with severe reflux and oesophagi tis responds well to surgery. Repair of the hernia and some sort of additional antireflux surgery, e.g. Nissen fundoplication, is required. Surgery can now be performed laparoscopically.
The major complication of reflux is peptic stricture, which usually occurs in patients over the age of 60. The symptoms are those of intermittent dysphagia over a long period. Treatment is by dilatation of the stricture and management of the reflux usually medical, with orneprarole, but very occasionally surgery is required. There is no increased incidence of carcinoma in hiatus hernia per se. However, long-standing acid reflux causes colurnnization of the oesophageal mucosa (Barrett’s oesophagus) vhich is premalignant, but can be reversed with antireflux therapy.