hiatal hernia : Epidemiology

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.2 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.

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. A hiatus hernia may be caused by one or more of 3 possible mechanisms i) widening of the diaphragmatic hiatus. ii) pulling up of the stomach due to oesophageal shortening. iii) pushing up of the stomach by increased intra-abdominal pressure.1 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)

Presentation 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
Flatulance
Gastro-oesophageal reflux
Large hernias may cause difficulty in swallowing (rare)

Investigations 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, it 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

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