Oesophageal diverticulum

General

• Most diverticula are the result of a primary motor disturbance, or abnormality of the UOS/LOS
• Pulsion diverticula - false diverticula that occur because of elevated intraluminal pressures, generated from abnormal motility disorders
  • Zenker
  • Epiphrenic
• Traction diverticula - external inflammatory mediastinal lymph nodes adhering to the oesophagus as they heal and contract, distorting it
  • More common in the mid-oesophageal region around the carinal nodes

Zenker diverticulum

• Anatomy
  • False diverticulum (mucosa and submucosa)
  • Forms between oblique fibres of thyropharyngeus and horizontal fibres of cricopharyngeus (Killian triangle)
  • As the diverticulum enlarges, it projects down the left side of the oesophagus into the superior mediastinum, along the paravertebral space
• Pathophysiology
  • Probably related to loss of muscle tone and tissue elasticity with age
  • ?secondary to impaired relaxation or fibrosis of the cricopharyngeus component of upper oesophageal sphincter - sometimes referred to as cricopharyngeal achalasia
  • Most often seen in 60-80 year olds, and mostly men
  • Most common oesophageal diverticulum
• Clinical
  • Asymptomatic until it begins to enlarge
  • Dysphagia - most common
  • Throat discomfort
  • Nagging cough
  • Excessive salivation
  • Regurgitation of foul-smelling material
  • Halitosis, voice change, retrosternal pain
  • Respiratory infections
  • Can lead to weight loss, malnutrition
  • Boyce's sign - cervical borborygmus in setting of palpable neck mass and emaciation
  • Can present with bleeding ulcer in diverticulum
  • Can harbour malignancy
• Diagnosis
  • Barium swallow - need a lateral view
    • 'Cricopharyngeal bar' - the diverticulum can be seen filled with contrast, resting posteriorly against the oesophagus
  • Gastroscopy and manometry are unnecessary to diagnose

• Surgical approaches
  • Open options
    • Myotomy + diverticulectomy (patients with good tissue and sac >5cm)
      • Expose cervical oesophagus
        • Shoulder balloon, head ring, turn head to right
        • Anterior SCM incision from thyroid notch to sternum
        • Sub-platysmal flaps
        • Dissect along medial edge of SCM
        • Divide posterior belly of omohyoid, or just retract it anteromedially
        • Thyroid medial, carotid sheath lateral - ligate middle thyroid vein if needed
        • Finger dissection to get onto spine - identify pre-vertebral fascia, which needs to be mobilised to access posterior oesophagus
        • Once oesophagus has been nicely dissected, identify diverticulum
      • Dissect diverticulum free to base
        • Grasp sac with babcock, use peanut to bluntly dissect onto base of diverticulum
      • Identify cricopharyngeus
        • Divide over right angle with some sort of bipolar, to see mucosa underneath
        • Textbook is posterior midline
        • The mucosa will then bulge without restriction. This muscle division usually decreases the upper sphincter resting tone by about 50%.
      • Stapled diverticulectomy
        • TA white 40 or EndoGIA purple if articulation is required for access
      • If get stuck at any point, and at the end for a leak test, use the gastroscope
    • Myotomy of proximal and distal thyropharyngeus and cricopharyngeus alone (generally sufficient in diverticula <2cm)
    • Myotomy + diverticulopexy
      • Suture the diverticulum to the posterior pharynx as opposed to the prevertebral fascia to allow free vertical movement during deglutition
  • Endoscopic
    • Harder with smaller/rounder diverticula
    • Favoured in more frail patients
    • Shorter post-op course
    • Favoured for diverticula between 2 and 5cm
    • Endoscopic exclusion (Dohlman procedure)
    • Endoscopic division of the common wall between oesophagus and diverticulum (stapler, laser, or electrocautery)

Mid-oesophageal diverticula

• Anatomy
  • Typically seen on the right due to an overabundance of structures in the mid-thoracic region on the left
• Pathophysiology
  • Traction diverticula
  • Historically mostly TB
  • Now more commonly caused by histoplasmosis and resultant fibrosing mediastinitis
  • Some may also be caused by a primary motility disorder
• Presentation
  • Mostly asymptomatic
  • Often incidentally found
  • Can get dysphagia, chest pain and regurgitation
  • Can present with chronic cough or haemoptysis from a bronchoesophageal fistula
• Diagnosis
  • Barium swallow
  • CT scan essential
  • Gastroscopy as part of workup to rule out mucosal abnormalities
  • Manometric studies highly recommended by Sabiston's to exclude a primary motility disorder - aetiology will determine treatment
• Management
  • Diverticula <2cm can be observed
  • Asymptomatic patients with inflamed mediastinal lymph nodes - treat underlying cause
  • Symptomatic or >2cm diverticula - surgery
    • Diverticulopexy to thoracic vertebral fascia if it has a wide mouth and rests close to the spine
    • Diverticulectomy if anatomically favourable - take care not to narrow oesophageal lumen
  • Severe chest pain or dysphagia and a documented motor abnormality - long oesophagomyotomy

Epiphrenic diverticula

• Anatomy
  • Distal third of oesophagus (within 10cm of GOJ), adjacent to the diaphragm
  • Mostly on the right side and mostly wide-mouthed
• Pathophysiology
  • Pulsion diverticula
  • Related to thickened distal oesophageal musculature or increased intraluminal pressure
  • Associated with diffuse oesophageal spasm, achalasia or hypertensive LOS disorders
  • Can be seen in EDS or trauma too
• Presentation
  • Mostly asymptomatic
  • Can have dysphagia or chest pain, especially with an underlying motility disorder
• Diagnosis
  • Barium swallow - identify size, position and proximity to diaphragm
  • Manometric studies for the underlying disorder
  • Gastroscopy to look for mucosal lesions including Barrett's, oesophagitis and cancer
• Treatment
  • Similar to midoesophageal diverticula
  • Generally, a myotomy is necessary to treat the underlying pathology
  • <2cm diverticula can be suspended from vertebral fascia without being excised, and perform a myotomy
  • Diverticulectomy - use a bougie to prevent narrowing the oesophagus, close muscle over excision site, and perform a myotomy on the opposite oesophageal wall from the level of the diverticulum to the LOS
  • If a large hiatal hernia is present, excise the diverticulum, perform a myotomy, and repair the hernia (otherwise high incidence of reflux)