1.4.7 Hiatal hernia
If the oesophageal hiatus is expanded because of a congenital or acquired weakness of the surrounding tissue, a diaphragmatic hernia can occur at this site. In such a hiatal hernia there is partial or complete displacement of abdominal organs into the chest cavity. Depending on the size of the hernia, different types are identified.
The most common type is the axial sliding hernia, where the stomach is pushed somewhat upwards, resulting in the entrance to the stomach together with the cardia (the site where the oesophagus enters the stomach) being displaced into the chest cavity. Often, a sliding hernia causes none, or few, complaints. Hence it is commonly diagnosed only by chance. However, if the muscular closure mechanism between the oesophagus and stomach does not function properly because of displacement of the stomach, there can be reflux (backflow) of stomach acid into the oesophagus. This, in turn, gives rise to irritation of the oesophageal mucosa causing reflux disease withthe typical symptoms of heartburn, swallowing disorders and pain in the upper abdomen. If hiatal hernia causes such complaints, attempts are made first of all to treat this by means of conservative measures such as weight reduction, change of diet, change of lifestyle and drug-based treatment. If these prove unsuccessful, the hernia should definitely be treated surgically as soon as possible.
In the less common paraoesophageal hernia the first (proximal) portion of the stomach is displaced through the oesophageal hiatus and along the oesophagus into the chest cavity (the entrance to the stomach, the cardia, remains within the abdominal cavity, unlike in the case of the axial sliding hernia). In some cases with this type of hiatal hernia parts of other organs, such as intestinal loops or parts of the greater omentum are displaced into the chest cavity. To begin with, patients have generally no complaints, as only later do symptoms such as a feeling of fullness, or pressure occur in the chest, swallowing disorders or respiratory distress. Life-threatening complications can occur because of strangulation of the displaced organs. Therefore the paraoesophageal hernia must always be surgically treated as soon as possible.
In some cases mixed forms of sliding hernia and paraoesophageal hernia are seen. A rare, but severe form of paraoesophageal hernia is the upside-down stomach, also known as a thoracic stomach. In such a case two-thirds or more of the stomach (or even the entire stomach) are displaced into the chest cavity. This causes distortion of the stomach and displacement of the chest cavity organs, in particular of the lungs and heart. Patients thus often suffer from cardiovascular complaints, respiratory distress or chest pain. Just like other paraoesophageal hernias, an upside-down stomach must be operated on as quickly as possible to prevent dangerous complications.