Oesophageal Diverticulum

Section: UGI Sub-section: Oesophagus Curriculum: Curriculum, page 94

Definition

• Outpouching of the oesophageal wall
• True diverticulum
  • Involves all layers of oesophageal wall
    • Mucosa, submucosa, muscularis
  • Results from external inflammatory LN’s adhering to oesophagus, contracting as they heal and pulling oesophagus
  • Tend to be mid-oesophagus (around carina LNs)
• False diverticulum
  • Involves only mucosa and submucosa
  • Includes pulsion diverticulum
    • Zenker’s Diverticulum
    • Epiphrenic Diverticulum
  • Most due to oesophageal motility disorders, or abnormality of UOS or LOS
    • Tend to be just above the sphincters

Classification and Aetiology

• Classification based on anatomic location
  • Zenker’s/pharyngoesophageal diverticulum
  • Mid-oesophageal Diverticulum
    • Can be traction or pulsion
  • Epiphrenic diverticulum
    • Usually pulsion type
• Aetiology
  • Congenital
  • Secondary to motility disorder or abnormality of UOS or LOS
  • Secondary to chest inflammation – traction diverticulum

Pharyngeal pouch

Definition and Incidence

• Pulsion defect of the posterior mucosa between the two parts of inferior constrictor
  • Killian’s triangle
    • Oblique fibres of thyropharyngeus above
    • Horizontal fibres of cricopharyngeus below
• With enlargement, mucosal and
  • submucosal layers dissect
  • down left side of oesophagus
  • into the superior mediastinum
  • Posteriorly along prevertebral space
• Incidence
  • Most common type of oesophageal diverticulum
  • M > F 3:1
  • Most pts > 60yo; Rare < 30

Aetiology

• Loss of coordination during second stage of swallowing
  • Simultaneous uncoordinated contraction of pharyngeal contractions and (pathologically) the cricopharyngeus sphincter
  • “Herniation” through the unsupported triangular region devoid of muscle in the posterior wall
• With aging the sphincter muscle becomes non-compliant and fibrotic
• Histological changes
  • Fibrosis, necrosis, atrophy, hypertrophy & inflammation
• 1/3 of pts will have associated Oesophageal motility disorders
  • Hiatus hernia, achalasia, diffuse oesophageal spasm
• Can also occur as part of a hereditary syndrome:
  • Oculopharyngeal muscular dystrophy → Ptosis & Dysphagia

Clinical

• Dysphagia/ “Sticking in throat”
• Gurgling noises in the neck during swallowing
• Fetor oris / halitosis
• Regurgitation of undigested food; esp. when lying flat
• Respiratory complications – e.g. lung abscess, aspiration pneumonia
• Hoarse voice, pressure of the pouch on the RLN
• 30% of pts have associated GORD
• +/- may cause a swelling in the post triangle
• Below level of the thyroid cartilage
• Can be compressed / ‘emptied’

Investigations

• Barium Swallow
  • Diverticulum seen posteriorly at level of cricothyroid cartilage
    • Lateral views critical in diagnosis
• Oesophageal Manometry (not required)
  • Shows lack of coordination between pharynx and UOS
  • +/- Hypertensive UOS
• Consider endoscopy if obstruction/malignancy suspected
  • NB: Higher risk of perforation from scope in these patients
• CXR +/- Lung function tests
• Recurrent aspirations

Management

• Requires Rx, regardless of size
• Correct GORD first (before dividing the UOS) in order to avoid aspiration

Endoscopic approach

• Dohlman’s procedure
  • Oropharyngeally placed linear stapler/cutter to ablate the septum between the diverticulum & the cervical oesophagus

Surgery

• Cricopharyngeal Myotomy + Diverticulectomy or Diverticulopexy
  • NB: Myotomy alone may be enough if < 2cm
    • Get proximal and distal thyropharyngeus and cricopharyngeus
  • Diverticulopexy = Suspend diverticulum upside down to posterior pharynx to prevent refilling
    • Don’t suspend to prevertebral fascia as this will prevent movement with swallowing

Cricopharyngeal myotomy and diverticulectomy

Endoscopic

• One stage cricopharyngeal myotomy and diverticulectomy has been the preferred approach in patients who are good surgical candidates
• Can be performed with a rigid endoscope or with an open cervical approach.
• Rigid endoscopes with specialised staplers can be used to divide the muscular bar and tissue between the Zenker’s and the oesophagus.
  • NB: Need good neck extension (which some elderly don’t have!) Open
• In the open approach, the patient is positioned with the head and neck facing away from the affected side (most commonly left) and an incision is over the anterior border of SCM.
• The EJV may be ligated, the plane anterior to SCM developed with lateral retraction of the carotid sheath.
• The space between the carotid sheath laterally and the tracheo-oesophageal column medially is crossed by 3 structures;
  • Omohyoid (transect or retract),
  • Middle thyroid vein (ligate)
  • Inferior thyroid artery (lower than the space needed)
• The diverticulum is then dissected free of surrounding tissue, opened, a finger inserted into the oesophagus, and the horizontal fibres of cricopharyngeus divided under vision.
• The diverticulum is then stapled off.
• The wound is closed in layers over a closed-suction drain.

Approach

 - Open or transoral approach (rigid endoscope or a flexible endoscope) is made by clinicians on the basis of  - The ability to visualize the ZD and septum endoscopically  - Patient’s body habitus  - Support of the ZD pouch against the posterior wall  - Local expertise  - Short necks, decreased hyomental distance, and/or a high body mass index are most often associated with difficult exposures and require an open approach  - Diverticula less than 2 cm long are traditionally treated with open methods however knew techniques may allow endoscopic treatment of small diverticula

• Pros of endoscopic
  • Less invasive
  • shorter operation times
  • Shorter hospital stays
  • More rapid resumption of oral intake
  • Lower rate of complications (7% vs 11%)
  • Easy access in case of recurrence
  • BUT… high rate of recurrance (18% vs 4%)

Prognosis/ Natural Hx

• As diverticulum enlarges, tends to deviate from midline
  • 90% to the left
    • Likely due to the slight convexity of cervical oesophagus to left
    • Also more laterally positioned carotid A on the left, creating a potential space for the sac
• Potential complications if untreated:
  • Respiratory complications
  • Ulceration
  • Bleeding
  • Formation of tracheo-oesophageal fistula
  • Cancers occasionally occur in the pouch (SCC) ≈ 1%
• Results post-surgery (Mayo clinic data):

  • 90% of pts asymptomatic

• Complications
  • RLN palsy, cutaneous fistula, leak 5%
  • Mortality 1.2%

Management of Post-op Leak

• Investigations
  • Gastrograffin (or Barium, if subtle) swallow
  • CT neck and mediastinum
    • With on table PO contrast
• Management
  • IV ABs, IVF, NBM
  • Drain collections (including in the mediastinum)
  • Perc or open
  • Place a feeding tube (fluoroscopically)
    • Start feeding if stable
  • Then wait for leak to seal (usually 3-4wks)

Mid-oesophageal Diverticulum

Definition

• Diverticulum of mid-oesophageal body

Aetiology

• Usually traction diverticulum (True diverticulum)
• Historical cause was inflamed mediastinal LNs with TB
• Now more commonly histoplasmosis infection with fibrosing mediastinitis
• Some can be pulsion diverticulum from primary motility disorders

Clinical

• Most patients asymptomatic, often found incidentally
• Can also get dysphagia, regurgitation, chest pain
• Chronic cough can represent broncho-oesophageal fistula

Investigations

• Barium swallow for diagnosis
  • Typically R) sided as lots of structures on the left
• CT chest
  • Identify mediastinal lymphadenopathy
  • Lateralise side of sac
• Manometry in all
  • Identify if underlying motility disorder
  • Guides treatment decisions
• OGD
  • R/O malignancy and mucosal abnormalities
  • May identify fistula

Management

• Based on cause of diverticulum
• Manage conservatively if asymptomatic
• Treat underlying cause of lymphadenopathy
• Tend to remain asymptomatic
• If < 2cm
  • Observe
• If symptomatic or > 2cm, surgery
  • Do diverticulopexy to thoracic spine
  • Consider long oesophagomyotomy to manage an underlying motility disorder

Epiphrenic Diverticulum

Definition

• False pulsion diverticulum of the distal 1/3 of oesophagus, within 10cm of GOJ

Aetiology

• Most often related to thickened GOJ musculature and increased intraluminal pressure
  • DES, Achalasia or IEM
• Congenital (Ehlers-Danlos)
• Traumatic
• More common on the right side
• Tend to be wide mouthed

Clinical Presentation

• Most asymptomatic
• May have dysphagia or chest pain to indicate motility disturbance
• Symptoms of advanced disease
  • Regurgitation
  • Epigastric pain
  • Anorexia
  • Weight loss
  • Chronic cough
  • Halitosis

Investigations

• Barium swallow
  • For diagnosis
• Manometry
  • Diagnose underlying motility disorder
• Endoscopy
  • R/O mucosal lesions, Barrett’s, oesophagitis, cancer

Management

• If < 2cm
  • Diverticulopexy and myotomy
  • Myotomy from neck of diverticulum, extended onto LOS
• If symptomatic or > 2cm
  • Consider diverticulectomy
  • Vertical stapler across neck and diverticulum excised
  • Must have bougie to avoid narrowing oesophageal lumen
  • Close muscle over excision site
  • Perform myotomy on opposite side