Esophageal diverticula

Esophageal diverticula are abnormal pouches that arise from the wall of the esophagus. They most commonly occur in middle-aged and older men and are classified based on localization, pathophysiology, and histological findings. The most common type of esophageal diverticula is Zenker diverticulum, which extends posteriorly in the hypopharynx directly proximal to the upper esophageal sphincter. Esophageal diverticula can be caused by either an underlying motility disorder that exerts high intraluminal pressures on a weak esophageal wall or from forces pulling on the outside of the esophagus. The clinical presentation varies with pouch size and localization, with the most common symptoms being dysphagia, regurgitation, retrosternal pain, and pulmonary symptoms secondary to aspiration. The diagnosis is confirmed by barium swallow, which also aids in determining the size of the diverticulum and potential malignancy. Surgical treatment is rarely required and only recommended in symptomatic patients (primarily those with Zenker diverticula).

• Rare diverticula compared to other gastrointestinal sites ^[1]
• Peak incidence: middle-aged and older male individuals ^[2]
• Zenker diverticulum is the most common type. ^[3]

Epidemiological data refers to the US, unless otherwise specified.

Esophageal diverticula are classified according to their localization, histology, and pathophysiology. ^[1]

Localization

• Upper esophageal diverticulum
  • Pharyngoesophageal diverticulum
  • Most common type: Zenker diverticulum at Killian triangle (a triangular weak point in the dorsal muscular wall of the hypopharynx, between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor muscle) ^[3]
• Middle esophageal diverticulum: diverticulum at the tracheal bifurcation
• Lower esophageal diverticulum: epiphrenic diverticulum

Zenker diverticulum arises from the hypopharynx, although it is classified as an esophageal diverticulum.

Histology

• True diverticula: All layers of the esophageal wall protrude.
• False diverticula: Increased intraluminal pressure causes only the mucosa and submucosa to bulge through weak points in the muscularis propria (e.g., Zenker diverticulum).

Pathophysiology

• Pulsion diverticula
• Traction diverticula
• See “Pathophysiology” below for more information.

• Inadequate relaxation of the esophageal sphincter (e.g., caused by achalasia or spastic motility) and increased intraluminal pressure → outpouching of the esophageal wall → pulsion diverticulum
  • Usually a false diverticulum ^[4]
  • Common sites
    • Upper esophageal sphincter (UES) → pharyngoesophageal pulsion diverticulum (e.g., Zenker diverticulum)
    • Lower esophageal sphincter (LES) → epiphrenic pulsion diverticulum ^[1]
• Inflammation of the mediastinum with scarring and retraction (e.g., secondary to tuberculosis or fungal infection) → traction diverticulum ^[4]
  • Usually true diverticulum
  • Common site: the middle esophagus

Clinical presentation depends on diverticulum size and localization. ^[1][4]

• Dysphagia (most common)
• Regurgitation of undigested food
• Halitosis
• Aspiration
• Coughing after food intake
• Retrosternal pressure sensation and pain
• Weight loss
• Neck mass

Elder MIKE has bad breath: Elderly, Male individuals, Inferior pharyngeal constrictor, Killian triangle, Esophageal dysmotility, halitosis.

• Barium swallow (best confirmatory test) with dynamic continuous fluoroscopy ^[3]
  • Visualization of diverticula via barium swallow or gastrografin (soluble in water)
    • Best detected using lateral projection
    • Zenker diverticulum: contrast-filled pouch protruding dorsally from the hypopharynx at the level of C5/C6
  • Allows for the detection of underlying motor abnormalities and diverticulum size ^[5]
  • A traction diverticulum presents as a pointed, triangular bulge arising from the esophageal wall; the base of the triangle is oriented towards the wall.
• Endoscopy ^[5]
  • Indication: to rule out malignancy in the pouch and exclude other causes of the patient's symptoms (e.g., tumor and reflux esophagitis)
  • Less sensitive, since diverticula with small openings may be missed
  • Risk of diverticulum perforation (since the course of the esophagus is often irregular) ^[1]

• Esophageal manometry ^[6]
  • Usually not required
  • Useful for identifying underlying motor abnormalities in patients with dysphagia
• Transcutaneous ultrasound ^[7]
  • Detection of Zenker diverticula
  • Differential diagnosis of Zenker diverticula from thyroid/neck masses

• Medical treatment ^[6]
  • PPIs: for gastroesophageal reflux symptoms
  • Injection of botulinum toxin: in symptomatic patients with esophageal motility disorders and contraindications for surgery
• Surgical treatment ^[3]
  • Indications
    • Symptomatic Zenker diverticula
    • In rare cases, symptomatic epiphrenic diverticula ^[8]
  • Endoscopy; (rigid or flexible, with the former requiring general anesthesia) with diverticulostomy and myotomy
  • Open surgery
    • Zenker diverticulum: cricopharyngeal myotomy
    • Epiphrenic diverticula: esophagomyotomy ^[8]

Diverticula of the middle and distal esophagus rarely require any treatment since most of them are asymptomatic. ^[1]

• Aspiration pneumonia ^[3]
• Perforation with mediastinitis and fistula formation (rare)
• Esophageal cancer ^[9]

We list the most important complications. The selection is not exhaustive.