HIATAL HERNIA:

Hiatus means a defect and esophageal hiatus means a hole in the diaphragm through which

the esophagus passes from the thorax into the abdomen. Hiatus hernia occurs when part of stomach protrudes into the thoracic cavity through/or along the side of the esophageal

hiatus of diaphragm.

Pathophysiology:

The phrenico-esophageal membrane normally surrounds the lower esophagus and fixes it to the

diaphragm, thereby preventing gastric herniation through the esophageal hiatus into the thorax.

When the phrenico-esophageal membrane is deficient/weak, an axial herniation may develop

in the thoracic cavity.

Types of Hiatal hernia:

• Type I: Sliding Hiatal Hernia: 95%

In sliding hiatal hernia the gastro-esophageal Junction moves up into the thorax. 

This type of hernia is more common 95% but usually of asymptomatic.

• Type II: Para esophageal/rolling 

In paraesophageal type of hiatus hernia all or part/ of the stomach herniates into the thorax immediately adjacent and to the left of an undisplaced gastro-esophageal junction. Since the gastro-esophageal junction remains intact; reflux of gastric contents into the esophagus is not common.

• Type III: Mixed Hernia:

Is a combination of type 1 and 2 and is characterized by herniation of the greater curvature of stomach and gastro-esophageal junction into the thorax.

• Type IV:

It is Hiatal hernia in which the abdominal contents other than or in addition to stomach herniates through the hiatus. Typically these hernias are large and contain spleen, colon in addition to stomach.

Clinical features:

Type I hernia is usually associated with heartburn and regurgitation. Type II,III and IV are

associated with dysphagia and postprandial fullness which can be explained by compression  adjacent esophagus by distended cardia. Respiratory symptoms are more frequent in type

II,III and IV hernia and consists of dyspnea (caused by compression on the lungs) and aspiration pneumonia. Ulceration of herniated stomach is common and leads to anemia.

Herniated stomach can undergo volvulus leading to bleeding, ischemic infarction, perforation and sepsis

Investigation:

•  1. X-Ray chest:

It may show an air fluid level in the posterior mediastinum (stomach)

• 2. Barium Swallow:

Barium swallow is the best method of diagnosis.

• 3. Endoscopy:

The endoscopic appearance may be confusing, especially in large hernia when it is easy to become disoriented but with advent of fiber-optic endoscopy, paraesophageal hernia is identified on retroversion of the scope by noting a separate orifice adjacent to gastro- esophageal junction.

Treatment:

• 1. Asymptomatic sliding (Type I) hernia requires no treatment.

• 2. Patients with sliding hernia associated with GERD should be treated by medical therapy on GERD guidelines.

• 3. Type II, III and IV hernia are associated with significantly higher complications including volvulus, infarction, bleeding and perforation so they should be repaired. Operative repair can be performed by thoracic or by abdominal approach.