Pharyngeal pouch

Introduction

A pharyngoesophageal pouch, also known as Zenker’s diverticulum, is an outpouching of mucosa through the posterior pharyngeal wall, typically at Killian’s dehiscence—an area of weakness between the inferior constrictor and cricopharyngeus muscles. It is considered a pulsion diverticulum and is most often associated with impaired relaxation or discoordination of the cricopharyngeal muscle during swallowing. The pouch can accumulate food and secretions, leading to dysphagia and other complications.

Peak Incidence

• Most commonly affects men over the age of 70.

Pathophysiology

• Zenker’s diverticulum arises due to increased intrapharyngeal pressure against a functionally obstructed upper oesophageal sphincter.
• This results in the herniation of mucosa and submucosa through the posterior hypopharyngeal wall.
• It is a false diverticulum, as it does not involve all layers of the oesophageal wall.

Symptoms

• Dysphagia – Especially for solids, but may progress to liquids.
• Regurgitation – Often of undigested food, hours after eating.
• Halitosis – Due to food retention in the pouch.
• Chronic cough.
• Neck swelling – May be visible or palpable, especially after eating.
• Aspiration pneumonia – From food or fluid entering the airway.
• Weight loss – In advanced or long-standing cases.
• Retrosternal discomfort – Often vague and non-specific.

Signs

• Palpable neck mass – Typically left-sided and fluctuant in large diverticula.
• Gurgling sound on swallowing (Boyce’s sign).
• Signs of aspiration or malnutrition – Such as cachexia or recurrent chest infections.

Diagnosis

• Barium swallow with video fluoroscopy – First-line investigation.
  • Shows a contrast-filled pouch arising from the posterior hypopharynx.
• Endoscopy – Used selectively:
  • Helps evaluate for coexisting conditions (e.g. cancer, strictures).
  • Must be performed with caution to avoid perforation.
• Oesophageal manometry – May be used to assess underlying motility disorders or to distinguish from mid or distal oesophageal diverticula.

Complications

• Aspiration pneumonia – Due to regurgitated contents entering the lungs.
• Malnutrition – From chronic dysphagia and inadequate intake.
• Oesophageal perforation – Rare, but may occur during endoscopy or spontaneously.
• Increased risk of squamous cell carcinoma – Although rare, long-standing diverticula are associated with malignancy risk.

Management

Endoscopic Management (First-line for most patients)

• Cricopharyngeal myotomy – Division of the cricopharyngeal muscle to relieve the functional obstruction.
• Endoscopic diverticulotomy – Division of the common wall (septum) between the diverticulum and oesophagus using a stapler or laser.
• Suitable for small to medium-sized diverticula (2–5 cm).
• Minimally invasive with faster recovery and lower complication rates.

Open Surgical Management (for larger or complicated cases)

• Diverticulectomy – Surgical removal of the pouch.

• Diverticulopexy – Suspension of the diverticulum to prevent food trapping.

• Often combined with cricopharyngeal myotomy to reduce recurrence risk.

• Typically reserved for:

  • Large diverticula.
  • Failed endoscopic treatment.
  • Complications (e.g. perforation, malignancy suspicion).