Esophageal Diverticula

An esophageal diverticulum is a relatively rare disorder of the esophagus. It is an outpouching of the esophageal mucosa and is usually asymptomatic. Patients typically present when they have symptoms of regurgitation or dysphagia.

There are different ways to categorize esophageal diverticulum. Esophageal diverticula can be divided into true and false diverticula. True diverticula are outpouchings that include all layers of the esophageal wall while false diverticula only include the mucosa or submucosa.

An esophageal diverticulum can also be characterized by how it is formed: pulsion or traction. Pulsion diverticula are created when there is increased intraluminal pressure causing herniation of the esophageal wall in an area of weakness and usually occur in the setting of dysmotility of the esophagus. Traction diverticula occur when there is an external force on the esophageal wall such as mediastinal inflammation that adheres and pulls on the esophageal wall creating a defect or diverticulum.

An esophageal diverticulum can also be categorized based on location as pharyngeal (Zenker) diverticula, mid-esophageal diverticula, and epiphrenic diverticula. Pharyngeal diverticula are considered false diverticula. They usually occur in the hypopharynx where there is a weakness in the area known as Killian's triangle. Killian's triangle is an area bound by the cricopharyngeus muscles and inferior pharyngeal constrictor muscles. These are usually formed by pulsion. A mid-esophageal diverticulum is usually true diverticulum and normally caused by traction from mediastinal inflammation. Epiphrenic diverticula are usually false diverticula located in the distal 10 cm of the esophagus. Similar to pharyngeal diverticula, they are also usually caused by pulsion from motility disorders that cause an increase in lower esophageal sphincter pressure such as achalasia.

An esophageal diverticulum can occur in individuals of all ages but overall are most common in adults. Zenker diverticulum is most common in the elderly.