Hiatal Hernia

Excerpt

A hiatal hernia is a condition characterized by the abnormal protrusion of the upper part of the stomach or other abdominal organs through the diaphragm's esophageal hiatus. Study results suggest that 50% to 94% of patients with gastroesophageal reflux disease (GERD) have a sliding hiatal hernia (see Image. Hiatal Hernia on Fluoroscopy). The diaphragm is a voluntary or striated muscle that separates the thoracic and abdominal cavities and serves as the primary muscle of respiration; there are separate openings for the inferior vena cava, the esophagus, and the aorta, arranged from anterior to posterior. The esophageal diaphragmatic hiatus is clinically relevant in hiatal hernia, as it permits protrusion of the stomach into the thoracic cavity. Hiatal hernias can produce heartburn, regurgitation, dysphagia, chest pain, and shortness of breath. The condition occurs more frequently in adults than in children and, rarely, results in life-threatening complications, such as incarceration of herniated contents or bleeding from Cameron ulcers.

The region where the esophagus joins the stomach is known as the gastroesophageal junction (GEJ). The lower esophageal sphincter (LES) is a physiologic high-pressure zone located immediately distal to the GEJ that functions as a barrier to reflux. Normally, approximately 2 cm of the distal esophagus resides below the diaphragm. In a hiatal hernia, the stomach protrudes through the esophageal hiatus into the thoracic cavity, displacing the LES. Laxity of the LES permits gastric contents and acid to reflux into the esophagus, resulting in GERD. Small hiatal hernias are frequently asymptomatic and are generally managed with medical therapy. Larger paraesophageal hiatal hernias usually require surgical intervention (see Image. Massive Hiatal Hernia).

Hiatal hernias are classified into 4 types. The categories are described as follows:

1. Type I: Sliding hiatal hernia, representing more than 95% of cases. The gastric fundus or cardia protrudes into the mediastinum along with the GEJ (see Images. Type I Hiatal Hernia and Sliding Hiatal Hernia on Barium Study).

2. Type II: Paraesophageal hiatal hernia, where the fundus is displaced into the mediastinum while the GEJ remains below the esophageal hiatus. This type is the rarest of hiatal hernias.

3. Type III: Mixed paraesophageal and sliding hernia, with both the GEJ and a variable portion of the stomach extending into the mediastinum (see Image. Radiographic Appearance of a Mixed Paraesophageal Hernia).

4. Type IV: Herniation of the stomach along with an additional abdominal organ, such as the colon, small intestine, or spleen, into the thoracic cavity.

Type I is referred to as a "sliding hiatal hernia," whereas types II to IV are classified as paraesophageal hernias (PEHs). All hiatal hernias are typically repaired surgically using various procedures, frequently combined with fundoplication of the stomach.