Description
A hiatus hernia refers to the protrusion (or herniation) of the upper part of the stomach into the thorax through the diaphragmatic oesophageal hiatus. Hiatus hernia has two main types: sliding hernia (Type I) and paraesophageal hernia (Type II, III, and IV), each with distinct clinical and radiological characteristics.
Pathogenesis & Subtypes
Hiatus hernia occurs when the upper part of the stomach protrudes through the oesophageal hiatus due to weakening or enlargement of the diaphragmatic muscle tissue. The mechanism behind the hernia depends on the subtype:
- Sliding (Type I): Occurs when the gastroesophageal junction and part of the stomach slide upward into the thorax.
- Paraesophageal (Type II): The gastroesophageal junction remains in place, while part of the stomach moves up into the thorax.
- Mixed/Combined (Type III): A combination of Type I and Type II, with both the gastroesophageal junction and part of the stomach herniating into the thorax.
- Type IV: This type involves the herniation of the stomach and another organ (such as the colon, spleen, or small intestine) into the thorax.
Epidemiology, Risk Factors & Associations
- Hiatus hernia is commonly found in the elderly population, with prevalence rates rising from 10% at age 40 to 70% at age 70.
- Sliding hernias are the most common type, representing approximately 95% of cases.
- Factors such as obesity, advanced age, and smoking are associated with an increased risk of developing a hiatus hernia.
- It is seen more frequently in women than in men.
Clinical Features
The most common symptoms of a hiatus hernia are:
- Heartburn
- Regurgitation
- Dysphagia
- Chest pain
However, up to 50% of individuals with a hiatus hernia are asymptomatic.
Complications
Complications associated with a hiatus hernia can include:
- Gastroesophageal Reflux Disease (GORD): GORD is a common complication of a hiatus hernia, especially with the sliding type, due to the displacement of the gastroesophageal junction into the thorax disrupting the lower oesophageal sphincter’s function.
- Gastric Volvulus: This is an abnormal rotation of the stomach of more than 180 degrees, creating a closed-loop obstruction that can lead to strangulation and necrosis. It is more commonly associated with paraesophageal hernias, which allow for greater mobility of the stomach. There are two primary types of volvulus:
- Organoaxial Volvulus: Most common form of gastric volvulus (60% of cases). The stomach rotates around its long (organ) axis, which runs from the gastroesophageal junction to the pylorus. This rotation can lead to an “upside-down” stomach, with the greater curvature positioned superiorly.
- Mesenteroaxial Volvulus: This form of volvulus involves the rotation of the stomach around its short (mesenteric) axis, which is perpendicular to the organoaxial line. The stomach rotates anteriorly and superiorly, causing the antrum to be positioned above the gastroesophageal junction. This type of volvulus is less common but tends to be more acute and severe.
- Strangulation or Perforation: These are severe complications, more commonly associated with paraesophageal hernias. Strangulation can occur when the blood supply to the herniated portion of the stomach is cut off. Perforation, or a tear in the stomach wall, can result in the contents of the stomach leaking into the thoracic or abdominal cavity, which is a medical emergency.
Pathological Features
Histopathology, biochemistry, and genetics: Not usually relevant in hiatus hernia. The primary pathology lies in mechanical and anatomical changes rather than cellular or biochemical changes.
Radiological Features
General Features
The diagnosis of hiatus hernia is commonly made on a barium swallow study or a CT scan of the chest or abdomen.
FL
- In sliding hernias, there’s an upward displacement of the gastric rugal folds and gastroesophageal junction.
- In paraesophageal hernias, the gastric rugal folds and gastroesophageal junction are separately identified, with the stomach appearing alongside the esophagus.
MRI
- Useful in demonstrating the diaphragmatic defect and herniated stomach.
- Can better delineate soft tissues, helping to exclude other possible thoracic or abdominal pathologies.
CT
- Can help identify complications such as volvulus or strangulation.
- Can distinguish between types of hiatus hernia, based on the position of the gastroesophageal junction and the stomach.
Differential Diagnosis
Differential diagnoses can include conditions such as gastroesophageal reflux disease, peptic ulcer disease, angina pectoris, or other gastrointestinal or cardiac conditions that can cause similar symptoms.
Management
Treatment depends on the type and severity of the hernia and the associated symptoms. In many cases, lifestyle modifications and medications (e.g., antacids, proton pump inhibitors) are sufficient. Surgical intervention may be necessary for large or symptomatic hernias, or those associated with complications. Surgical options include:
- Laparoscopic Nissen Fundoplication: This is the most common surgical procedure for a hiatus hernia. It involves wrapping the fundus of the stomach around the lower end of the oesophagus and suturing it in place. This reinforces the closing function of the lower oesophageal sphincter. The procedure can be performed laparoscopically, resulting in less postoperative pain and a faster recovery.
- Toupet Fundoplication: This procedure is similar to a Nissen fundoplication but involves wrapping the fundus only partially (about 270 degrees) around the oesophagus. It is often used for patients with oesophageal motility disorders.
- Paraesophageal Hernia Repair: Paraesophageal hernias are generally repaired surgically due to the risk of complications such as strangulation. The stomach is relocated to its normal position, the hiatus is tightened to prevent re-herniation, and typically a fundoplication procedure is added to address reflux.
- Hiatal Hernia Mesh Repair: In some cases, especially with larger hernias or recurrent hernias, a mesh may be used to reinforce the hiatal closure. This can help reduce the risk of recurrence, but there may be an increased risk of complications such as erosion or migration of the mesh.
- Endoluminal Fundoplication: This is a newer, minimally invasive procedure that is performed endoscopically. It involves placing small clips or sutures in the oesophagus to create pleats, which helps reinforce the lower oesophageal sphincter. This procedure may be an option for patients with smaller hernias and mild to moderate reflux who have not responded well to medication.