Hiatal, or diaphragmatic, hernia is a protrusion of the esophagus and upper part of the stomach from the abdominal cavity up into the thoracic cavity. Esophagus is a tube organ that connects the oral cavity with the stomach; it descends in the thoracic cavity down to the diaphragm and passes through a hole which is called esophageal hiatus. The average length of adult esophagus is about 25 cm, only 2-3 cm of its length are located below the diaphragm. The end of the esophagus that is connected to the entrance of the stomach is called cardia. In hiatal hernia, the esophageal hiatus broadens and cardia with a bigger or smaller part of the stomach passes through it into the thoracic cavity.
Classification of Hiatal Hernia
Exact cause for hiatal hernia is not known; it can develop due to congenital abnormality as well as after injuries. Each hernia, including hiatal hernia, consists of three components - hernial gate (opening through which the organ or its part gets into the abnormal location), hernial sac (the wrapping that covers penetrated organ, in case of hiatal hernia it is peritoneum wall) and hernial content (penetrated organ, in hiatal hernia cardia and part of stomach). Hiatal hernia can be divided into three types – sliding, paraesophageal and combined hiatal hernia.
Sliding Hiatal Hernia
Sliding hiatal hernia is so-called false hernia, since no hernial sac in created. It is usually caused by shortening of the esophagus; consequently, cardia and upper part of the stomach dislocates trough the esophageal hiatus. Determining in this type of hernia is the fact that also gastroesophageal junction is moved into the thorax, together with cardia and upper part of the stomach. At diagnosis of hiatal hernia, it is essential to evaluate so-called HIS-angle. HIS-angle is the angle of the gastroesophageal junction; it is formed by wall of the esophagus and cardia. Normally, this angle is acute. There also is a large mucosal fold at its vertex. Its function in healthy individuals probably is prevention against gastroesophageal reflux (leaking of the gastric acid into the esophagus). In case the gastric acid etches the esophageal wall frequently and for a long period, inflammation process begins in the mucosa of the esophagus. In sliding hiatal hernia, this angle is very difficult to differentiate which probably is also the reason, why sliding hiatal hernia is often connected with gastroesophageal reflux.
Paraesophageal Hiatal Hernia
Paraesophageal hiatal hernia occurs rarely. The hernial sac in this hernia is created and thus it is a true hernia; HIS-angle remains acute. In this type of hiatal hernia, the gastroesophageal junction stays below the diaphragm; only part of the stomach gets into the thoracic cavity. Sometimes, strangulation in the narrow space can develop, resulting in accumulation of blood and possible bleeding. Ulcers may arise on the mucosa, or the organ may be perforated.
Combined Hiatal Hernia
Combined hiatal hernia combines features of both previous types and occurs most frequently.
Causes of Hiatal Hernia
The main cause of hiatal hernia is the insufficiency of the connective tissue between the esophagus and diaphragm. To the risk factors obesity and higher age are assigned. In most patients, the hernia is asymptomatic. Symptoms usually occur only in case of complications. Due to obtuse HIS-angle, gastroesophageal reflux is often present. In this condition, the gastric acid gets into the esophagus causing the typical symptoms. It usually is heartburn and typical chest pain; however, the chest pain is rather caused by oppression of thoracic organs in the surroundings of the hernial sac.
Diagnosis of Hiatal Hernia
Diagnostics of hiatal hernia is based on careful history and clinical symptoms, imaging methods are also useful. For the diagnosis of hiatal hernia contrast X-ray is used. During the examination, the patient drinks contrast substance that is absorbed differently by different organs. When displayed by X-ray, structural abnormalities are made visible. Another method of choice is endoscopy. During this examination an endoscope is introduced by the patient's mouth. Endoscope is a flexible tube device with camera and source of light at the end. Mucosa changes and structural abnormalities of the upper gastrointestinal tract can be visualized.
Treatment of Hiatal Hernia
Satisfactory treatment for uncomplicated sliding hiatal hernia usually is only management of gastroesophageal reflux by drugs known as proton pump inhibitors, antacids, H2 receptor antagonists, and more. Their main effect is reduction of the acidity of gastric juices. Paraesophageal hiatal hernia and combined type of hiatal hernia have higher risk of complications; therefore the therapy must be more radical – surgical in most cases. Used surgical techniques include return of the stomach to the right place, removal of hernial sac, closure of hernial gate and attachment of the stomach to the diaphragm.
Complications of Hiatal Hernia
Hiatal hernia is not a life-threatening disease, the treatment is necessary for the risk of complications, however. One of the complications is esophageal reflux, already mentioned above. It causes unpleasant symptoms such as heartburn and return of stomach contents into the mouth. Final consequence of this condition may be various different diseases and even the tumor of the esophagus.