Zenker's Diverticulum
Overview
Zenker's diverticulum (also known as pharyngeal pouch or hypopharyngeal diverticulum) is a pulsion diverticulum that herniates through Killian's dehiscence, an area of muscular weakness in the posterior pharyngeal wall between the oblique fibers of the inferior pharyngeal constrictor and the horizontal fibers of the cricopharyngeus muscle. It is the most common type of pharyngoesophageal diverticulum, accounting for approximately 70-80% of cases.[1]
Zenker's diverticulum predominantly affects elderly individuals (>70 years) with a male predominance (2:1 to 3:1). The incidence is approximately 2 per 100,000 per year in the Western world. The condition presents with progressive dysphagia, regurgitation of undigested food, halitosis, and aspiration. Without treatment, symptoms typically worsen over time due to progressive enlargement of the diverticulum.[2]
History
Friedrich Albert von Zenker (1825-1898), a German pathologist, provided the first comprehensive description of this condition in 1877, along with Hugo Wilhelm von Ziemssen. Zenker systematically described the clinical presentation, anatomical location, and pathological features of the pharyngeal pouch, establishing it as a distinct clinical entity.
Gustav Killian subsequently characterized the anatomical weakness (Killian's dehiscence) through which the diverticulum herniates in 1908. Surgical treatment evolved from external open approaches in the early 20th century to endoscopic techniques introduced in the 1960s and refined in subsequent decades.
Pathophysiology
Relevant Anatomy
Zenker's diverticulum occurs as a result of a herniation of the esophageal mucosa through Killian's triangle. Killian's triangle is bounded superiorly by the inferior pharyngeal constrictor muscle (specifically the thyropharyngeus muscle) and inferiorly by the cricopharyngeus muscle.
Related anatomical areas of weakness include:
- Killian-Jamieson space: Anterolateral, BELOW cricopharyngeus (site of Killian-Jamieson Diverticulum)
- Laimer's triangle: Posterior, BELOW cricopharyngeus (site of Laimer's Diverticulum)
Critical adjacent structures:
- Recurrent laryngeal nerve (in tracheoesophageal groove)
- Common carotid artery and internal jugular vein
- Inferior thyroid artery
- Thoracic duct (left side)
Disease Etiology
Zenker's diverticulum is a pulsion diverticulum resulting from:
- Cricopharyngeal dysfunction: Incomplete relaxation of the upper esophageal sphincter during swallowing, hypertonic sphincter tone, or incoordination between pharyngeal contraction and sphincter relaxation
- Increased intrapharyngeal pressure: Repeated swallowing against a partially closed or poorly relaxed sphincter over years
- Mucosal herniation: Progressive herniation of mucosa and submucosa through the weakest point (Killian's dehiscence)
Risk factors include:
- Advanced age (decreased tissue elasticity)
- Gastroesophageal reflux disease
- Fibrosis of cricopharyngeus muscle
Classification by size:
- Small: <2 cm
- Medium: 2-4 cm
- Large: >4 cm
Histology
Histological section of a Zenker's diverticulum will reveal only the luminal mucosal layer and submucosal tissues. The lack of a muscular layer makes this a pseudodiverticulum rather than a true diverticulum.
Diagnosis
Patient History
Classic presentation (symptoms progress over years):
Dysphagia:
- Progressive difficulty swallowing
- Initially solids, then liquids
- May have "two-stage" swallow (initial attempt fails, second succeeds)
Regurgitation:
- Undigested food, sometimes hours after eating
- Worse when lying down
- May occur spontaneously
Halitosis:
- Foul breath from decomposing food in diverticulum
- Often noticed by family members
Aspiration symptoms:
- Chronic cough, especially nocturnal
- Recurrent pneumonia
- Choking episodes
Other symptoms:
- Globus sensation (lump in throat)
- Borborygmi (gurgling sounds) in neck
- Weight loss (in severe cases)
- Hoarseness (rare, if recurrent laryngeal nerve compressed)
Physical Examination
Physical examination is often unremarkable but may show:
- Gurgling sounds: In neck during swallowing (pathognomonic when present)
- Palpable mass: Left side of neck (large diverticulum), may increase with swallowing
- Malnutrition signs: In severe cases
- Pulmonary findings: If aspiration pneumonia present
- Laryngoscopy: May show pooling of secretions, signs of aspiration
Laboratory Tests
- No specific diagnostic laboratory test
- Nutritional assessment (albumin, prealbumin) if significant weight loss
- CBC, inflammatory markers if infection suspected
Imaging
Fluoroscopy, such as a barium esophagram, is the preferred imaging modality to characterize Zenker's diverticula. Modified barium swallow studies may also be beneficial if the radiology technician widens the view to include the entire cervical esophagus.
Barium swallow findings:
- Posterior outpouching from pharyngoesophageal junction
- Located ABOVE cricopharyngeus level (distinguishes from Laimer's Diverticulum and Killian-Jamieson Diverticulum)
- Fills with barium during swallowing
- May show air-fluid level
- Lateral views most diagnostic
CT of neck:
- Confirms anatomy
- Evaluates relationship to surrounding structures
- Screens for other pathology
Esophagogastroduodenoscopy (EGD):
- May visualize diverticulum entrance
- Risk of perforation if scope inadvertently enters diverticulum
- Useful to rule out esophageal malignancy
Differential Diagnosis
Other diverticula of the pharyngeal and esophageal mucosa should be considered:
- Laimer's Diverticulum
- Killian-Jamieson Diverticulum
- Esophageal stricture
- Esophageal carcinoma
- Cricopharyngeal bar (achalasia)
- External compression (thyroid, lymph nodes)
- Globus pharyngeus (functional)
- Esophageal web
Management
Medical Management
There is no medical management that will significantly impact the development or worsening of a Zenker's diverticulum. Medical management would be limited to the treatment of sequelae of the diverticulum, such as aspiration pneumonia.
Conservative measures (may be appropriate for poor surgical candidates):
- Small frequent meals
- Thorough chewing
- Drinking fluids with meals
- Upright positioning during and after meals
- Manual compression of diverticulum during swallowing
- Treatment of GERD
Surgical Management
Surgery is the definitive treatment for symptomatic Zenker's diverticulum:
Open Surgical Approach (Transcervical Diverticulectomy)
Technique:
- Left cervical incision along anterior border of sternocleidomastoid
- Dissection to identify diverticulum
- Cricopharyngeal myotomy (essential component)
- Diverticulectomy with stapled or sutured closure OR diverticulopexy (suspension) for smaller pouches
Advantages: Complete excision, direct visualization, well-established technique
Disadvantages: Longer recovery, cervical incision, risk of recurrent laryngeal nerve injury, fistula risk
Endoscopic Approaches
Rigid endoscopic stapling (Dohlman procedure/staple-assisted):
- Diverticuloscope inserted to expose septum between diverticulum and esophagus
- Stapler divides septum, creating common cavity
- Includes cricopharyngeal myotomy
Flexible endoscopic septotomy:
- Performed with standard upper endoscope
- Uses various cutting devices (needle knife, argon plasma coagulation, etc.)
- May require multiple sessions
Endoscopic advantages: No external incision, shorter recovery, outpatient or short hospital stay, lower morbidity
Endoscopic disadvantages: May require multiple procedures, higher recurrence rate, not suitable for small diverticula (<2 cm), limited neck extension may preclude approach
Cricopharyngeal Myotomy
- Essential component of treatment regardless of approach
- Addresses underlying pathophysiology
- Performed with both open and endoscopic approaches
Outcomes
Complications
The main complication associated with a Zenker's Diverticulum is aspiration secondary to reflux of contents of the diverticulum. Patients will also often complain of halitosis.
Without treatment:
- Progressive dysphagia
- Aspiration pneumonia
- Malnutrition
- Perforation (rare, spontaneous)
- Squamous cell carcinoma in diverticulum (rare, 0.3-0.5%)
Surgical complications:
- Pharyngocutaneous fistula: 1-3% (open), <1% (endoscopic)
- Recurrent laryngeal nerve injury: 1-2% (open)
- Mediastinitis: Rare but serious
- Recurrence: 5-15% (varies by technique)
- Dental injury: Endoscopic approaches
- Esophageal perforation: Both approaches
Prognosis
Outcomes are excellent with appropriate treatment:
Open surgery:
- Symptomatic improvement: >90%
- Recurrence rate: 3-7%
- Mortality: <1%
Endoscopic approaches:
- Symptomatic improvement: 85-95%
- Recurrence rate: 10-15% (may need repeat procedure)
- Mortality: <0.5%
Factors affecting outcomes:
- Diverticulum size
- Surgical technique and experience
- Completeness of cricopharyngeal myotomy
- Patient comorbidities
Long-term considerations:
- Repeat imaging if symptoms recur
- Low threshold for repeat intervention
- Surveillance for malignancy not routinely recommended
References
- ↑ Aiolfi A, Scolari F, Saino G, et al. Systematic review and meta-analysis of Zenker's diverticulum management. J Gastrointest Surg. 2019;23(10):2095-2110.
- ↑ Ferreira LE, Simmons DT, Baron TH. Zenker's diverticula: pathophysiology, clinical presentation, and flexible endoscopic management. Dis Esophagus. 2008;21(1):1-8.