Zenker diverticulum

Zenker diverticulum, also known as a pharyngeal pouch, is a posterior outpouching of the hypopharynx, just proximal to the upper esophageal sphincter through a weakness in the muscle layer called the Killian dehiscence.

Epidemiology

More than 50% of the affected patients present in 60-80 years of life. It is rarely found in individuals less than 40 years of age ⁵. 

Clinical presentation

The entrapment of liquid and/or food within the diverticulum may result in:

• globus sensation
• dysphagia
• halitosis
• regurgitation
• chronic cough
• infection
• aspiration pneumonia 
• foreign body sensation 
• weight loss ⁴

Pathology

A Zenker diverticulum is a pulsion-pseudodiverticulum and results from herniation of mucosa and submucosa through the Killian triangle (or Killian dehiscence), a focal weakness in the hypopharynx at the normal cleavage plane between the fibers of the two parts of the inferior pharyngeal constrictor muscle - the cricopharyngeus and thyropharyngeus. 

This phenomenon may lead to the creation of a sac with a narrow neck that can trap liquid and food. The distended sac may compress the cervical esophagus.

Radiographic features

Fluoroscopy 

Ideally, a barium swallow examination is performed, which may show:

• a diverticulum arising from the midline of the posterior wall of the distal pharynx near the pharyngoesophageal junction
  • the outpouching may be transient, and some refer to the transient variety as a "pharyngeal pouch"
• the pouch is best identified during swallowing and is best seen on the lateral view, on which the diverticulum is typically noted at the C5-6 level

Since ~90% of patients with a Zenker diverticulum have a hiatal hernia and gastro-esophageal reflux, the distal esophagus should also be evaluated.

Treatment and prognosis

In addition to the clinical symptoms mentioned above, patients with a Zenker diverticulum are at increased risk for aspiration.

A Zenker diverticulum may be surgically treated with an endoscopic, surgical diverticulectomy, or diverticulopexy.

History and etymology

It is named after Friedrich Albert von Zenker (1825-1898), a German pathologist who held a position as teacher and researcher for more than 30 years at the University of Erlangen.

See also

• Killian-Jamieson diverticulum
• esophageal diverticula
• Tornwaldt cyst