A hernia is defined as the protrusion of part or whole of an organ or tissue through the wall of the cavity that normally contains it.
A hiatus hernia describes the protrusion of an organ from the abdominal cavity into the thorax through the oesophageal hiatus. This usually refers to the stomach moving up into the thoracic cavity (although rarely, small bowel, colon or mesentery can also herniate through). Other types of diaphragmatic hernia also exist (congenital, traumatic) but will not be discussed here.
The prevalence of hiatus herniae in the general population is difficult to accurately state, simply because the majority of them are completely asymptomatic. However it is estimated that around a third of individuals over the age of 50 have a hiatus hernia.
In this article, we shall look at the classification, clinical features and management of a hiatus hernia.
Classification of Hiatus Herniae
Hiatus herniae can be classified into two subtypes:
- Sliding hiatus hernia (80%) – the gastro-oesophageal junction (GOJ), the abdominal part of the oesophagus, and frequently the cardia of the stomach move or ‘slides’ upwards through the diaphragmatic hiatus into the thorax.
- Rolling or Para-Oesophageal hernia (20%) – an upward movement of the gastric fundus occurs to lie along side a normally positioned GOJ, which creates a ‘bubble’ of stomach in the thorax. This is a true hernia with a peritoneal sac. The proportion of the stomach that herniates is variable and may increase with time, eventually may evolve to have almost the entire stomach sitting in the thorax.
A mixed type hiatus hernia can also occur, which has both a rolling and sliding component.
Age is the biggest risk factor for developing a hiatus hernia, due to a combination of age-related loss of diaphragmatic tone, increasing intrabdominal pressures (e.g. repetitive coughing), and an increased size of diaphragmatic hiatus.
Pregnancy, obesity, and ascites are also risk factors, due to increased intra-abdominal pressure and superior displacement of the viscera.
The vast majority of hiatus herniae are completely asymptomatic.
Patients can experience gastroesophageal reflux symptoms, such as burning epigastric pain which is made worse by lying flat. In patients with a hiatus hernia, these symptoms are often more severe and treatment-resistant. Other signs and symptoms that can occur include:
- Vomiting and weight loss
- This is rare but the most serious presentation. Occasionally, gastric outflow can become blocked (sometimes intermittently), resulting in early satiety, vomiting and nutritional failure. In this instance, the patient needs to be transferred to the nearest oesophago-gastric unit for surgery.
- Bleeding and anemia
- Oesophageal ulceration may occur, potentially leading to bleeding (presenting as melena or haematemesis).
- Hiccups and palpitations
- If the hiatus hernia is of sufficient size, it may cause irritation to either the diaphragm or the pericardial sac.
- Swallowing difficulties
- Gradual worsening dysphagia may be due to ulceration resulting in oesophageal stricture formation or incarceration of the hernia.
The clinical examination is typically normal. In patients with a sufficiently large hiatus hernia, bowel sounds may be auscultated within the chest.
The important differentials that must be thought of and excluded are:
- Cardiac chest pain
- Gastric or pancreatic cancer
- Particularly if there is evidence of gastric outlet obstruction, early satiety or weight loss.
- Remember the symptoms of pancreatic cancer especially are vague and non-specific and include vague upper abdominal pain and nausea. Weight loss and malaise are late symptoms and usually evidence of advanced disease
- Gastro-oesophageal reflux disease
Hiatus herniae can be diagnosed incidentally, either on a routine endoscopy, CT scan, or on CXR as an air fluid level behind the heart or stomach bubble in the chest.
Flexible oesophagogastroduodenoscopy (OGD) is the gold standard investigation, showing upward displacement of the Gastro-Oesophageal Junction (GOJ, also termed the ‘Z-line’).
If there are symptoms of gastric outflow obstruction or weight loss, an urgent CT thorax and abdomen is mandatory.
A contrast swallow may also be used to diagnose a hiatus hernia, although are less commonly used. This involves the patient swallowing a radiopaque liquid, showing the stomach outline within the thorax and assessing the motility of the lower oesophagus.
The first line pharmacological management for a symptomatic hiatus hernia is a Proton Pump Inhibitor (PPIs), such as omeprazole. PPIs must be taken in the morning before food, otherwise the drugs’ binding site becomes internalised and they are ineffective.
Any patient should be advised of lifestyle modification, including weight loss, alteration of diet (low fat, earlier meals, smaller portions), and potentially sleeping with increased numbers of pillows. Smoking cessation and reduction in alcohol intake should be advised – as both nicotine and alcohol are thought to inhibit lower oesophageal sphincter function.
Surgical management is indicated when:
- Remaining symptomatic, despite maximal medical therapy.
- Increased risk of strangulation/volvulus (rolling type or mixed type hernia, or containing other abdominal viscera).
- Nutritional failure (due to gastric outlet obstruction).
Any patients presenting with suspected cases of obstruction, strangulation or stomach volvulus should have their stomach decompressed via a NG tube prior to surgical intervention. There are two aspects of hiatus hernia surgery:
- Curoplasty – The hernia is reduced from the thorax into the abdomen and the hiatus reapproximated to the appropriate size. Any large defects usually require mesh to strengthen the repair.
- Fundoplication – The gastric fundus is wrapped around the lower oesophagus and stitched in place; this strengthens the LOS thus helping to prevent reflux and keep the GOJ in place below the diaphragm. The wrap may be full or partial (mainly depending on surgeon preference).
Hiatus hernias, especially the rolling type, are prone to incarceration and strangulation, like any other type of hernia.
A gastric volvulus can also occur whereby the stomach twists on itself by 180 degrees, leading to obstruction of the gastric passage and tissue necrosis, and requiring prompt surgical intervention. Clinically, this can present with Borchardt’s triad:
- Severe epigastric pain
- Retching without vomiting
- Inability to pass an NG tube
Complications of Surgery
The specific complications relating to hiatus hernia surgery may include:
- Recurrence of the hernia
- Abdominal bloating
- Due to an inability to belch, secondary to the improved anti-reflux mechanism of the procedure
- Dysphagia may occur if the fundoplication is too tight or if the cural repair is too narrow – this is relatively common early after surgery due to oedema. It settles to a variable degree in the majority of patients but in some may need revisional surgery.
- Fundal necrosis, if the blood supply via the left gastric artery and short gastric vessels has been disrupted.
- A surgical emergency, typically requiring major gastric resection
Despite these complications, the success rate of repair is excellent with some centres reporting that >90% of patients have a good long term outcome.