A hernia is defined as the protrusion of a whole or part of an organ through the wall of the cavity that contains it into an abnormal position.
A hiatus hernia describes the protrusion of an organ from the abdominal cavity into the thorax through the oesophageal hiatus. This is typically the stomach herniating although rarely small bowel, colon, or mesentery can also herniate through*.
Hiatus hernia are extremely common, however the exact prevalence in the general population is difficult to accurately state, simply because the majority are completely asymptomatic. However it is estimated that around a third of individuals over the age of 50 have a hiatus hernia.
*Other types of diaphragmatic hernia also exist (congenital, traumatic) but will not be discussed in this article
Hiatus herniae can be classified into two subtypes (Fig. 2)*:
- 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 alongside 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 may 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 (a rare but serious presentation*), bleeding and / or anaemia (secondary to oesophageal ulceration), hiccups or palpitations (if the hiatus hernia is of sufficient size, it may cause irritation to either the diaphragm or the pericardial sac), or swallowing difficulties (either oesophageal stricture formation or rarely 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.
*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
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.
- Gastro-oesophageal reflux disease
*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
Oesophagogastroduodenoscopy (OGD) is the gold standard investigation (Fig. 3), showing upward displacement of the Gastro-Oesophageal Junction (GOJ, also termed the ‘Z-line’).
They can also be diagnosed incidentally, either on a CT or MRI scan*. A contrast swallow may also be used to diagnose a hiatus hernia, although are less commonly used
*If there are symptoms of gastric outflow obstruction or weight loss, whereby an upper GI malignancy may be suspected, an urgent CT thorax and abdomen is mandatory.
The first line pharmacological management for a symptomatic hiatus hernia is a Proton Pump Inhibitor (PPIs), such as omeprazole, acting to reduce gastric acid secretion and aiding in symptom control. PPIs must be taken in the morning before food, otherwise the drugs’ binding site becomes internalised and are ineffective.
Any patient should be advised of lifestyle modification, including weight loss, alteration of diet (low fat, earlier meals, smaller portions), and sleeping with the head of the bed raised.
Smoking cessation and reduction in alcohol intake should be advised, as both nicotine and alcohol are thought to inhibit lower oesophageal sphincter function, thereby worsening symptoms.
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:
- Cruroplasty – 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 (Fig. 4)
- Aims to strengthen the LOS thus helping to prevent reflux and keep the GOJ in place below the diaphragm – the wrap may be full or partial (usually dependent on surgeon preference)
Complications of Surgery
Despite complications, the success rate of repair is excellent with some centres reporting that >90% of patients have a good long term outcome. 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 crural 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
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 requires prompt surgical intervention.
Clinically, this can present with Borchardt’s triad:
- Severe epigastric pain
- Retching without vomiting
- Inability to pass an NG tube
- Hiatus hernia are divided into two subtypes, sliding (80%) and rolling (20%)
- If there are symptoms of gastric outflow obstruction or weight loss, whereby an upper GI malignancy may be suspected, an urgent CT thorax and abdomen is mandatory
- Gold standard diagnosis is via endoscopy
- Surgical intervention is warranted in cases where patients remain symptomatic despite maximal medical therapy, at increased risk of strangulation/volvulus, or evidence of nutritional failure (due to gastric outlet obstruction)