A Zenker's diverticulum, also pharyngeal pouch, is a

diverticulum In medicine or biology, a diverticulum is an outpouching of a hollow (or a fluid-filled) structure in the body. Depending upon which layers of the structure are involved, diverticula are described as being either true or false. In medicine, t ...

of the

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

of the

human pharynx The pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its ...

, just above the

cricopharyngeal muscle The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve ( ...

(i.e. above the upper

sphincter A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the human bo ...

of the

esophagus The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), c ...

). It is a pseudo diverticulum or false diverticulum (only involving the mucosa and submucosa of the esophageal wall, not the adventitia), also known as a pulsion diverticulum. It was named in 1877 after

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

pathologist Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...

Friedrich Albert von Zenker Friedrich Albert von Zenker (13 March 1825 – 13 June 1898) was a German Pathology, pathologist and physician, celebrated for his discovery of trichinosis. He was born in Dresden, and was educated in Leipzig and Heidelberg. While in Leipzig, he ...

Signs and symptoms

When there is excessive pressure within the lower

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

, the weakest portion of the pharyngeal wall balloons out, forming a

which may reach several centimetres in diameter. While traction and pulsion mechanisms have long been deemed the main factors promoting development of a Zenker's diverticulum, current consensus considers occlusive mechanisms to be most important: uncoordinated swallowing, impaired relaxation and spasm of the cricopharyngeus muscle lead to an increase in pressure within the distal pharynx, so that its wall herniates through the point of least resistance (known as

Killian's triangle Killian's dehiscence (also known as Killian's triangle) is a triangular area in the wall of the pharynx between the cricopharyngeus (upper esophageal sphincter (UES)) and thyropharyngeus (Inferior pharyngeal constrictor muscle) which are the two p ...

, located superior to the cricopharyngeus muscle and inferior to the thyropharyngeus muscle. Thyropharyngeus and cricopharyngeus are the superior and inferior parts of inferior constrictor muscle of pharynx respectively). The result is an outpouching of the posterior pharyngeal wall, just above the esophagus. While it may be asymptomatic, Zenker diverticulum can present with the following symptoms: *

Dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

(difficulty swallowing), and sense of a lump in the throat * Food might get trapped in the outpouching, leading to: ** Regurgitation, reappearance of ingested food in the mouth **

Cough A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and Microorganism, microbes. As a protective reflex, coughing can be repetitive with the cough reflex fol ...

, due to food regurgitated into the airway **

Halitosis Bad breath, also known as halitosis, is a symptom in which a noticeably unpleasant breath odour is present. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder. Th ...

, smelly breath, as stagnant food is digested by microorganisms ** Infection It rarely, if ever, causes any pain.

Esophageal web Esophageal webs are thin membranes occurring anywhere along the esophagus. Presentation Its main symptoms are pain and difficulty in swallowing (dysphagia). Esophageal webs are thin membranes of normal esophageal tissue consisting of mucosa an ...

s are seen associated in 50% of patients with this condition. Rarer forms of cervical esophageal diverticula are the Killian's diverticulum and the Laimer's diverticulum. Killian's diverticulum is formed in the Killian-Jamiseon triangle (between the oblique and transverse fibers of the

cricopharyngeus muscle The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve ...

). Laimer's diverticulum is formed in Laimer's triangle (located inferior to the cricopharyngeus in the posterior midline above the confluence of the longitudinal layer of the superior esophageal circular muscle). Laimer's triangle is covered only by the circular layer of esophageal muscle.

Diagnosis

A combination of the simple

barium swallow An upper gastrointestinal series, also called a barium swallow, barium study, or barium meal, is a series of radiographs used to examine the gastrointestinal tract for abnormalities. A contrast medium, usually a radiocontrast agent such as bariu ...

and a thorough endoscopy will normally confirm the

Treatment

If small (ie, <2 cm) and asymptomatic, no treatment is necessary. Larger, symptomatic cases of Zenker's diverticulum have been traditionally treated by neck

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

to resect the

and incise the cricopharyngeus muscle. However, in recent times non-surgical endoscopic techniques have gained more importance (as they allow for much faster recovery), and the currently preferred treatment is endoscopic stapling (i.e. diverticulotomy with staples ). This may be performed through a diverticuloscope. Other methods include fibreoptic diverticular repair. Other non-surgical treatment modalities also exist, such as endoscopic laser, which recent evidence suggests is less effective than stapling.

Epidemiology

Zenker's diverticulum mainly affects older adults. It has an incidence of 2 per 100,000 per year in the UK, but there is significant geographical variation around the world.

References

External links

* {{Gastroenterology Esophagus disorders