You are in: eMedicine Specialties > Radiology > GASTROINTESTINAL Zenker DiverticulumArticle Last Updated: Jan 24, 2003AUTHOR AND EDITOR INFORMATIONSection 1 of 9
  Author: Spencer Sincleair, MD, Assistant Professor, Department of Radiology, Texas A&M University Health Science Center; Consulting Staff, Department of Diagnostic Radiology, Scott and White Memorial Hospital Spencer Sincleair is a member of the following medical societies: Alpha Omega Alpha, American College of Radiology, American Medical Association, and Texas Medical Association Coauthor(s): Brenda Holbert, MD, Consulting Staff, Associate Professor of Diagnostic Radiology, Department of Radiology, Scott and White Memorial Hospital and Clinic Editors: Eric P Weinberg, MD, Associate Professor, Department of Radiology, University of Rochester Medical Center, Strong Memorial Hospital; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Abraham H Dachman, MD, FACR, Professor, Department of Radiology, The University of Chicago School of Medicine; Director of CT, Department of Radiology, The University of Chicago Hospitals; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Eugene C Lin, MD, Consulting Staff, Department of Radiology, Virginia Mason Medical Center Author and Editor Disclosure Synonyms and related keywords: posterior hypopharyngeal diverticulum 1, false diverticulum, inferior pharyngeal constrictor muscle, Killian dehiscence, gastroesophageal reflux, hiatal hernia, pseudo-Zenker diverticulum INTRODUCTIONSection 2 of 9
  BackgroundA diverticulum is an outpouching that protrudes from the wall of a viscus. As with the entire gastrointestinal (GI) tract, diverticula of the hypopharynx may be true or false depending on the number of layers of the viscus wall that are involved. True diverticula consist of all layers of the wall, whereas false diverticula generally lack the muscularis layer. A Zenker diverticulum is a false diverticulum consisting of mucosa and submucosa that arises from the posterior portion of the inferior pharyngeal constrictor muscle. PathophysiologyZenker diverticulum occurs at an area of potential weakness in the inferior pharyngeal constrictor muscle referred to as the Killian dehiscence. It is located between the obliquely oriented fibers of the thyropharyngeal muscle and the horizontally oriented fibers of the cricopharyngeal muscle. Manometric examinations of patients with Zenker diverticulum have produced conflicting results, with some studies showing increased upper esophageal sphincter (UES) pressure and abnormal relaxation and others finding normal relaxation and low UES pressure. To date, no mechanism of pathogenesis has been generally accepted, although most recent studies confirm increased intrabolus pressure in patients with Zenker diverticulum. Zenker diverticulum is associated with gastroesophageal reflux and hiatal hernia. Some studies have shown that as many as 94% of patients with pharyngeal pouches have concurrent hiatal hernias and gastroesophageal reflux. Increased UES pressure is also associated with gastroesophageal reflux, but whether the reflux, the increased UES pressure, or the Zenker diverticulum arises first in patients is controversial. Pathologic studies of cricopharyngeal and hypopharyngeal muscle tissue resected from patients with Zenker diverticulum have shown that as many as 95% demonstrate abnormal histologic changes. These include atrophy, necrosis, hypertrophy, inflammation, and fibrosis. This muscle tissue also has been shown to have decreased anticholinesterase levels compared with those in normal tissue. FrequencyUnited StatesFluoroscopic studies of the upper GI tract have shown that the prevalence of Zenker diverticulum is 0.01-0.1%. They are present in approximately 2% of patients with nonspecific dysphagia who are referred for fluoroscopy. Mortality/MorbidityWeight loss occurs in approximately one third of patients; however, this is generally modest in severity.
SexZenker diverticulum is slightly more common in men than in women. AgeZenker diverticulum is seen most commonly in the elderly. More than 50% of affected patients present in the seventh or eighth decade of life. AnatomyThe diverticulum arises posteriorly between the thyropharyngeal muscle and cricopharyngeal muscle, as noted above. Clinical DetailsThe most common presenting feature is upper esophageal dysphagia, which occurs in as many as 98% of patients. Other common symptoms include halitosis, regurgitation of undigested food, noisy swallowing, and aspiration. Hoarseness can be present when the diverticulum is large enough to compress the recurrent laryngeal nerve. Some patients also report excessive salivation and the sensation of a mass within the throat. Weight loss and recurrent pulmonary infections occur in approximately one third of patients. Although patients are advised to thoroughly chew their food before swallowing to reduce symptoms of dysphagia, surgical treatment is indicated for symptomatic Zenker diverticula, as the lesions almost invariably enlarge and become more symptomatic. Patients with minimal symptomatology who do not desire surgical therapy may be followed up on a routine outpatient basis by monitoring their symptoms. Weight loss, progression in dysphagia, aspiration, recurrent pulmonary infections, and bleeding should prompt a consideration of surgical therapy. Postoperative patients are monitored for potential complications of surgery, including pharyngocutaneous fistulas, mediastinitis, esophageal and hypopharyngeal strictures, hoarseness, and laryngeal paralysis. Preferred ExaminationFluoroscopic barium esophagography is the mainstay of diagnosis of Zenker diverticulum. Physical examination findings are rare, although some extremely large diverticula are occasionally palpable on examination. These are usually to the left of midline. Limitations of TechniquesZenker diverticulum may be found on endoscopy; however, fluoroscopy remains the diagnostic study of choice. Care must be taken in performing endoscopy in patients with known Zenker diverticulum, as passage of the endoscope into the diverticulum carries some risk of perforation. Endoscopy may be indicated if carcinoma is suggested on the basis of the radiographic findings. The main limitation of barium esophagography is patient cooperation. DIFFERENTIALSSection 3 of 9
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| Media file 1: Single spot radiograph from a barium esophagographic series demonstrates a moderate-sized Zenker diverticulum (arrow) that protrudes posteriorly from the hypopharynx. | |
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| Media file 2: A Zenker diverticulum (arrow) is noted incidentally on a thoracic CT scan. It is filled with gas and particulate matter. | |
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| Media file 3: Zenker diverticulum. Anatomy of the pharynx. | |
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Article Last Updated: Jan 24, 2003
