Hiatus Hernia

The term hiatus hernia refers to the herniation of a part of the abdominal viscera through the oesophageal aperture of the diaphragm. The vast majority of hiatus hernias involve only the herniation of a part of the gastric cardia through the muscular hiatal aperture of the diaphragm, however rarely, hernias with a large defect can allow other organs to enter the thoracic cavity such as spleen and pancreas.

Incidence

The precise incidence of hiatus hernia is not known, as most studies have looked only at individuals who presented with symptoms of dyspepsia. Of patients undergoing investigation for dyspepsia in western populations approximately 15-25% are discovered to have a hiatus hernia.¹ Males and females appear to be equally affected. The incidence increases with age and obesity but varies from country to country being more common in western societies and rare in the Far East.

A hiatus hernia may be caused by one or more of 3 possible mechanisms:

• Widening of the diaphragmatic hiatus.
• Pulling up of the stomach due to oesophageal shortening.
• Pushing up of the stomach by increased intra-abdominal pressure.²

There are two types

• Sliding hiatus hernia - gastro-oesophageal junction slides up into the thoracic cavity (80% of cases).
• Rolling hiatus hernia - gastro-oesophageal junction remains in place but a part of the stomach herniates into the chest next to the oesophagus (20% of cases).

The association between hiatus hernia and oesophagitis has been recognised for over 70 years, however it is only much more recently that the precise relationship between the two has been understood. It is now believed that the hiatus hernia has major pathophysiological effects resulting in gastro-oesophageal reflux and contributing to mucosal injury, particularly in patients with severe gastro-oesophageal reflux (GORD or GERD).

Many individuals with a hiatus hernia will be totally asymptomatic, others may present with any of the following:

• Retrosternal burning sensation or "heartburn" especially on bending or lying
• Flatulence
• Gastro-oesophageal reflux
• Large hernias may cause difficulty in swallowing (rare)

• Barium studies remain the only accurate method of measuring the size of a hiatus hernia.
• Upper GI endoscopy, although commonly used for assessing symptoms of dyspepsia, is not useful for assessing a hiatus hernia due to difficulties with measurement.
• Oesophageal manometry is not sufficiently sensitive for diagnostic purposes especially with small hernias.

• Barrett's oesophagus - 96% of Barrett's oesophagus patients have a hiatus hernia.³
• Oesophageal adenocarcinoma - presence of a hiatus hernia is associated with a 6 fold increased risk, which increases to 8 fold if reflux is also present.⁴

Non-drug

• Patients with hiatus hernia should be advised to avoid any factors likely to increase intra-abdominal pressure e.g. tight clothing, corsets.
• Nocturnal symptoms may be helped by elevating the head of the bed to reduce postural reflux.
• Weight loss should be advised in obese patients and patients who smoke and /or drink alcohol should be encouraged to stop.

Drugs

• Symptomatic relief may be gained by the use of alginates +/- use of proton pump inhibitors, although patients with hiatus hernia may require larger doses for symptom control.

Surgical

• The presence of a hiatus hernia is a marker for severe GORD. Patients with a hiatus hernia tend to have more severe symptoms and a poorer response to treatment, but its presence per se does not alter management strategies.
• Indications for surgery in patients with severe GORD include:
  • Patients who are unable to comply with therapeutic regimes
  • Patients who require high doses of drugs
  • Patients who wish to avoid lifelong medical treatment.
• The surgical procedure most commonly used involves mobilising the oesophagus in the thorax, bringing it down to restore the intra-abdominal portion and repairing the deficit (modified Nissen procedure).
• Oesophageal lengthening combined with fundoplication may be performed during laparoscopic surgery.
• Several novel endoscopic techniques have been used in the treatment of GORD with some success, but the results do not separate out patients with hiatus hernia.

The majority of patients will gain symptomatic relief from medical or surgical intervention, although a few will continue to have symptoms.