Dysphagia Knowledge Hub — 吞嚥困難知識庫

Zenker’s Diverticulum: Symptoms, Diagnosis, and Treatment

Zenker’s diverticulum — named after Friedrich von Zenker, who described it systematically in 1877 — is a pulsion diverticulum of the posterior hypopharynx at Killian’s dehiscence, a triangular zone of relative muscular weakness between the oblique fibres of the inferior pharyngeal constrictor and the horizontal fibres of the cricopharyngeus muscle. Though relatively uncommon in the general population, it is the most frequent pharyngeal diverticulum encountered clinically and disproportionately affects elderly males. Its classic presentation is striking and often allows clinical diagnosis before imaging.

Pathophysiology: Posterior Hypopharyngeal Pouching

The mechanism of Zenker’s diverticulum formation is understood as follows: during swallowing, the inferior pharyngeal constrictor generates high intraluminal pressure to propel the bolus through the pharynx. This pressure is normally dissipated by timely relaxation and opening of the cricopharyngeus (upper oesophageal sphincter, UOS). In patients who develop Zenker’s diverticulum, cricopharyngeal dysfunction — whether incomplete relaxation, abnormal compliance, or premature closure — creates a zone of elevated intraluminal pressure posteriorly. Repeated pressure cycling over years causes the posterior hypopharyngeal mucosa to herniate through Killian’s dehiscence, forming a progressively enlarging mucosa-lined pouch dorsal to the oesophagus.

The diverticulum initially points posteriorly but as it enlarges it typically deflects to the left side of the neck. Large diverticula can compress the posterior oesophageal wall, creating a functional obstruction independent of the cricopharyngeal dysfunction.

Classic Triad

The three cardinal symptoms of Zenker’s diverticulum are:

  1. Regurgitation of undigested food, sometimes hours after eating, without acid or bile: food and liquid accumulate in the pouch and regurgitate passively when the patient reclines or bends forward. Patients may describe “food coming back up” at night or waking with food residue on the pillow.

  2. Gurgling or borborygmic neck sounds (Boyce’s sign): the characteristic gurgling noise produced as swallowed material enters the pouch. Patients and relatives often notice this clearly.

  3. Cervical mass: a soft, compressible, intermittently reducible swelling at the left side of the neck, often in the supraclavicular region, which may produce a gurgling or fluid sound when compressed (Boyce-Allen sign).

Additional symptoms include progressive dysphagia for both solids and liquids, halitosis from fermenting retained food, weight loss, recurrent aspiration pneumonia, and hoarseness from laryngeal irritation by regurgitated material. Aspiration risk is significant, particularly in elderly patients with impaired cough reflex.

Diagnosis: Barium Swallow

The investigation of choice for suspected Zenker’s diverticulum is the barium swallow (modified barium swallow or fluoroscopic oesophagram). The diverticulum is characteristically visualised as a contrast-filled outpouching at the pharyngo-oesophageal junction, best seen in the lateral projection. Size is typically classified as small (<2 cm), medium (2–4 cm), or large (>4 cm), which guides surgical approach.

Upper endoscopy is generally not the first-line investigation as the endoscopist may inadvertently enter the diverticulum rather than the true oesophageal lumen, creating perforation risk. However, endoscopy is routinely performed in the pre-surgical workup to assess oesophageal mucosa and exclude concurrent pathology.

Computed tomography (CT) of the neck and chest may be obtained in atypical presentations, when malignancy is suspected, or for pre-operative anatomical planning. High-resolution manometry (HRM) may be used to characterise cricopharyngeal dysfunction objectively and assists in predicting surgical outcomes.

Surgical Treatment: Endoscopic vs. Open

Treatment of symptomatic Zenker’s diverticulum is surgical. Conservative management (dietary modification, head positioning) may reduce symptoms but does not halt diverticulum growth and carries ongoing aspiration risk.

Endoscopic Zenker’s Diverticulotomy (Dohlman procedure, flexible or rigid)

The endoscopic approach has become the preferred surgical option in most centres, including those in Hong Kong. A rigid or flexible endoscope is used to identify the common wall (septum or bar) between the diverticulum and the oesophagus. This septum, which contains the cricopharyngeus muscle, is divided by laser (CO2 or KTP), stapler, or electrocautery, creating a common cavity between the pouch and the oesophagus and functionally eliminating the functional obstruction. The diverticulum itself is not excised.

Published outcomes for endoscopic diverticulotomy show symptom relief in 80–95% of patients (Ishaq et al., 2016), with recurrence rates of 10–30% at five years and a very low procedure-related mortality (<0.5%). Advantages include no external incision, shorter hospital stay (typically one to two nights), faster return to oral feeding, and lower complication rates compared with open surgery.

Open Surgical Diverticulectomy

Open surgery via an external left cervical approach involves either diverticulectomy (pouch excision and cricopharyngeal myotomy) or diverticulopexy (suturing the inverted pouch to the prevertebral fascia). Open surgery is reserved for very large diverticula (>4 cm), recurrent cases after endoscopic failure, or patients with anatomical factors making endoscopic access unsafe. Complication rates are higher (10–15%), including recurrent laryngeal nerve injury, fistula, and mediastinitis.

Post-Surgical Swallowing Rehabilitation

Following endoscopic or open diverticulotomy, an SLT-led swallowing rehabilitation programme optimises recovery. Key components:

Epidemiology: Elderly Males

Zenker’s diverticulum has an estimated prevalence of approximately 0.01–0.11% in the general population (Watemberg et al., 1996), with incidence rising sharply after age 60. The male-to-female ratio is approximately 2:1 to 3:1. In HK’s ageing population, this translates to a meaningful caseload in ENT and upper GI services.

HK ENT Surgical Options

In Hong Kong, endoscopic Zenker’s diverticulotomy is performed in public hospital ENT and upper GI endoscopy units. Queen Mary Hospital (HKU), Prince of Wales Hospital (CUHK), and Princess Margaret Hospital have reported experience with both rigid (Weerda diverticuloscope with CO2 laser or stapler) and flexible endoscopic techniques. Private ENT surgeons with upper GI subspecialisation also perform the procedure. Patients presenting with suspected Zenker’s diverticulum should be referred to ENT for assessment; the SLT’s role includes initial evaluation, aspiration risk quantification, and post-surgical rehabilitation.

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