Hiatus hernia

Introduction

A hiatus hernia is a type of hernia in which abdominal organs (typically the stomach) slip through the diaphragm into the middle compartment of the chest. This may result in Gastro-oesophageal Reflux Disease (GERD) or Laryngo-Pharyngeal Reflux (LPR) with symptoms such as a taste of acid in the back of the mouth or heartburn. Other symptoms may include trouble swallowing and chest pains. Complications may include Iron deficiency anaemia, volvulus, or bowel obstruction.

The most common risk factors are obesity and older age. Other risk factors include major trauma, scoliosis, and certain types of surgery. There are two main types: a sliding hernia, in which the body of the stomach moves up, and a paraesophageal hernia, in which an abdominal organ moves beside the Oesophagus. The diagnosis may be confirmed with endoscopy or medical imaging. Endoscopy is typically only required when concerning symptoms are present, symptoms are resistant to treatment, or the person is over 50 years of age.

Epidemiology

Incidence of hiatal hernias increases with age; approximately 60% of individuals aged 50 or older have a hiatal hernia. Of these, 9% are symptomatic, depending on the competence of the lower oesophageal sphincter (LES). 95% of these are "sliding" hiatus hernias, in which the LES protrudes above the diaphragm along with the stomach, and only 5% are the "rolling" type (paraesophageal), in which the LES remains stationary, but the stomach protrudes above the diaphragm. Hiatus hernia are most common in North America and Western Europe and rare in rural African communities. Some have proposed that insufficient dietary fibre and the use of a high sitting position for defecation may increase the risk.

Symptoms and signs

Hiatal hernia has often been called the "great mimic" because its symptoms can resemble many disorders. Among them, a person with a hiatal hernia can experience dull pains in the chest, shortness of breath (caused by the hernia's effect on the diaphragm), heart palpitation (due to irritation of the vagus nerve), and swallowed food "balling up" and causing discomfort in the lower oesophagus until it passes on to the stomach. In addition, hiatal hernias often result in heartburn, but may also cause chest pain or pain with eating. In most cases however, a hiatal hernia does not cause any symptoms. The pain and discomfort is due to the reflux of gastric acid, air, or bile. While there are several causes of acid reflux, it occurs more frequently in the presence of hiatal hernia. In newborns, the presence of Bochdalek hernia can be recognised from symptoms such as difficulty breathing, fast respiration, and increased heart rate.

Risk factors

The following are risk factors that can result in a hiatal hernia. Increased pressure within the abdomen caused by:

• Heavy lifting or bending over
• Frequent or hard coughing
• Hard sneezing
• Violent vomiting
• Straining
• Stress

Diagnosis

The diagnosis of a hiatus hernia is typically made by an upper GI series, endoscopy or high-resolution manometry.

Classification

Schematic diagram of different types of hiatus hernia. Green is the oesophagus, red is the stomach, purple is the diaphragm, blue is the HIS angle. A is the normal anatomy, B is a pre-stage, C is a sliding hiatal hernia, and D is a paraesophageal (rolling) type.

Four types of esophageal hiatal hernia are identified.

Type I

A type I hernia is also known as a sliding hiatal hernia. There is a widening of the muscular hiatal tunnel and circumferential laxity of the phrenoesophageal membrane, allowing a portion of the gastric cardia to herniate upward into the posterior mediastinum. The clinical significance of type I hernias is in their association with reflux disease. Sliding hernias are the most common type and account for 95% of all hiatal hernias. (C)

Type II

A type II hernia results from a localized defect in the phrenoesophageal membrane while the gastroesophageal junction remains fixed to the pre-aortic fascia and the median arcuate ligament. The gastric fundus then serves as the leading point of herniation. Although type II hernias are associated with reflux disease, their primary clinical significance lies in the potential for mechanical complications. (D)

Type III

Type III hernias have elements of both types I and II hernias. With progressive enlargement of the hernia through the hiatus, the phreno-esophageal membrane stretches, displacing the gastro-esophageal junction above the diaphragm, thereby adding a sliding element to the type II hernia.

Type IV

Type IV hiatus hernia is associated with a large defect in the phreno-esophageal membrane, allowing other organs, such as colon, spleen, pancreas and small intestine to enter the hernia sac.

The end stage of type I and type II hernias occurs when the whole stomach migrates up into the chest by rotating 180° around its longitudinal axis, with the cardia and pylorus as fixed points. In this situation the abnormality is usually referred to as an intra-thoracic stomach.

Treatment

In the great majority of cases, sufferers experience no life-altering discomfort, and no treatment is required. If there is pain or discomfort, 3 or 4 sips of room temperature water will usually relieve the pain. Symptomatic patients should elevate the head of their beds and avoid lying down directly after meals. If the condition has been brought on by stress, stress reduction techniques may be prescribed, or if overweight, weight loss may be indicated. Antisecretory drugs like proton pump inhibitors and H2 receptor blockers can be used to reduce acid secretion. Medications that reduce the lower esophageal sphincter (LES) pressure should be avoided.

However, in some unusual instances, as when the hiatal hernia is unusually large, or is of the paraesophageal type, it may cause oesophageal stricture or severe discomfort. About 5% of hiatus hernias are para-oesophageal.

If symptoms from such a hernia are severe for example if chronic acid reflux threatens to severely injure the oesophagus or is causing Barrett's oesophagus, surgery is sometimes recommended. However, surgery has its own risks including death and disability, so that even for large or paraesophageal hernias, watchful waiting may on balance be safer and cause fewer problems than surgery. Complications from surgical procedures to correct a hiatus hernia may include gas bloat syndrome, dysphagia (trouble swallowing), dumping syndrome, excessive scarring, and rarely, achalasia. Surgical procedures sometimes fail over time, requiring a second surgery to make repairs.

One surgical procedure used is called Nissen fundoplication. In fundoplication, the gastric fundus (upper part) of the stomach is wrapped, or plicated, around the inferior part of the oesophagus, preventing herniation of the stomach through the hiatus in the diaphragm and the reflux of gastric acid. The procedure is now commonly performed laparoscopically. With proper patient selection, laparoscopic fundoplication recent studies have indicated relatively low complication rates, quick recovery, and relatively good long-term results.