A hiatal hernia is a protrusion of the abdominal contents into the thorax through an enlarged esophageal hiatus caused by a weakness or opening in the diaphragm. The upper part of the stomach usually protrudes upwards but it can also be the small intestine, transverse colon or omentum. The two types of hiatal hernias are Sliding and Paraesophageal. In sliding hernias the gastro-oesophageal junction slides up into the thorax and this is the more common out of the two types, finding it to be more than 80% of the cases. Paraesophageal hernias are where the gastro-oesophageal junction stays in place however the top part of the stomach protrudes up next to the oesophagus into the thorax. Paraesophageal hiatus hernias comprise for almost 20% of the cases. Hiatal hernias are results in gastro-oesophageal reflux disease and contribute to cell changes and further complications.
Hiatal hernia classification
Hiatal hernia can be classified into four different types:
Type I – The most common type is the sliding hiatal hernia that occurs when the gastro-oesophageal junction or cardia protrudes into the hiatus of the diaphragm. The acute angle between the esophagus and stomach disappears. Increased abdominal pressure plays a significant role in its aetiology. Other factors include relaxed muscles of the lower part of the esophagus and any pathology associated with phrenico-esophageal ligament. The phrenoesophageal ligament may have an absent inferior attachment or can becomes disrupted due to age effect and the muscular hiatal tunnel widens which results in type 1 hiatal hernias. The stomach stays in a longitudinal plane with the fundus below the gastro-oesophageal junction as normal. This type is most commonly associated with gastro-oesophageal reflux disease due to an insufficiency of the lower esophageal sphincter.
Type II – Pure para-oesophageal junction hernia also known as rolling hernia occurs with the gastro-oesophageal junction staying in its normal anatomical position, however, the fundus of the stomach protrudes up through the diaphragm next to the oesophagus. It usually occurs in individuals above 40 years of age. Factors contribute in the aetiology of this hernia are history of previous gastroesophageal surgery, thoracoabdominal trauma, skeletal deformity and congenital malformations. There can be localised defect in the phrenoesophageal membrane however the gastro-oesophageal junction is fixed to the preaortic fascia and the median arcuate ligament and so the fundus of the stomach protrudes upwards. This type is also associated with reflux disease.
Type III – Both the gastro-oesophageal junction and fundus protrude through the hiatus with the fundus lying superior to the gastro-oesophageal junction. This is a combination type of I and II also known as mixed type. The gastro-oesophageal junction is displaced above the diaphragm and therefore the hernia slides upwards in this type.
Type IV – A giant hiatal hernia, this is a classification if there is more than one third or one half of the stomach or any other abdominal organ or structure herniate through the diaphragm, for example, small intestine, transverse colon, omentum, liver or even spleen. This type is due to a large defect in the phrenoesophageal membrane causing it to stretch a lot more and leads to organs herniating upwards. Gastroesophageal reflux is common in this type, and iron deficiency anaemia is another important symptom.
Signs and Symptoms
In most cases hiatal hernias can remain asymptomatic or for some can present with signs and symptoms such as:
- Gastro-oesophageal reflux
- Abdominal epigastric pain
- Non bilious vomiting
- Chest pain
- Shortness of breath
- Rarely dysphagia
- Bowel sounds present in chest
Some symptoms can be mistaken for other diseases and therefore need to be investigated thoroughly to rule out any possible medical emergencies.
Increased intra-abdominal pressure can lead to hiatal hernias. Certain risk factors can lead to this for example:
- Heavy lifting
- Straining during bowel movements
- Previous gastro-oesophageal surgical procedure
- History of hernias
- Collagen disorder
Investigations to help diagnose hiatal hernias are chest x-rays which shows retrocardiac opacity with air fluid level or can be normal.
In addition Barium swallow studies can be used and this test is the only accurate method of measuring the size of a hiatus hernia. This test can show the stomach to be partially or completely intrathoracic.
Hiatus hernia can be diagnosed by endoscopy. It is used to view the stomach and oesophagus and will be able to gain visibility of the hernia protruding into the diaphragm. It will also to show signs of strangulation or obstruction, or inflammation of the oesophagus.
An abdominal CT scan or abdominal MRI are imaging scan options that are carried out in some cases if there are concerns of other diseases.
Oesophageal manometry has been used for additional help in the diagnosis of hiatus hernia by testing for an abnormal pH level or showing a double hump configuration however it is mostly used for the diagnosis of oesophageal motility disorders.
Avoiding risk factors and preventing increased intra-abdominal pressure is advised. Lying elevated at nighttime can prevent nocturnal symptoms. Lifestyle advice for patients with obesity-related hiatal hernias, weight loss is advised and avoiding large meals, nicotine, caffeine and alcohol.
Medications such as proton pump inhibitors such as Omeprazole or H2 receptor antagonists such as Ranitidine are advised for symptomatic relief of reflux.
Surgical procedure called a Nissen Fundoplication is used for sliding hernia repair. This can be done laparoscopically by the fundus of the stomach being placed around the inferior part of the oesophagus. This prevents the stomach from herniating into the diaphragm and stops reflux symptoms and disease.
Para-oesophageal hiatus hernia repair is also done through minimally invasive laparoscopic technique. If there are signs of volvulus, haemorrhage or obstruction urgent surgical treatment is required.
Hiatal hernias can lead to gastric volvulus this is rare but life threatening. It means that the stomach rotates on its mesentery and can lead to bowel obstruction and necrosis. Type II and III are more commonly associated with gastric volvulus. Patients present with epigastric abdominal pain, hematemesis, retching, and inability to pass a nasogastric tube and need to be surgically treated.
Recurrence of hernia can usually occur after the breakdown of a hiatal hernia repair due to damage to sutures and increased intra-abdominal pressure. A mesh repair is advised to treat in cases of recurrence.
Barrett’s oesophagus is associated with chronic gastro-oesophageal reflux disease and is most commonly seen with sliding hernias.
Gastrointestinal bleeding may occur as a result of gastro-oesophageal reflux disease leading to oesophagitis.
Dysphagia following Nissen fundoplication is due to the fundoplication being too tightly wrapped around the oesophagus leading to narrowing and patients unable to swallow solids.