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Achalasia

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Overview

Achalasia describes the failure of the smooth muscle fibres of the lower oesophageal to relax, leading to the closure of the lower oesophageal sphincter (LOS).

Aetiology

Primary achalasia occurs due to inflammation and destruction of the Auerbach plexus which consists of inhibitory neurones that ordinarily promote LOS relaxation.

  • This is similar to Hirschsprung’s disease as they both describe aganglionic segments in the gut, however, primary achalasia differs as it is acquired, not congenital.

Achalasia can also occur secondary to other conditions such as:

Epidemiology

  • The mean age of diagnosis is around 50 years
  • The annual incidence is estimated to be 1.5/100,000

Presentation

Dysphagia is a red-flag symptom that always raises suspicion of malignancy. Achalasia cannot be diagnosed based on clinical features alone.

  • Dysphagia – the main presenting complaint:
    • This often tends to be to both food and drink from the start
  • Regurgitation
  • Heartburn
  • Strategies to cope with dysphagia:
    • Some patients may sit or stand up straight or have other coping mechanisms

Differential Diagnoses

Oesophageal cancer

  • Dysphagia tends to affect solids more than liquids, however, as the disease progresses, dysphagia may affect both
  • Weight loss may be more severe

Investigations

Referral

Dysphagia must always be promptly investigated. See Dysphagia for more regarding referral.

Overview

  • Upper gastrointestinal endoscopy:
    • The first-line investigation to rule out malignancy
  • Barium swallow:
    • Shows a dilated oesophagus that narrows down into a bird-beak-like narrowing
  • Oesophageal manometry:
    • The gold-standard test to diagnose achalasia
    • Shows incomplete LOS relaxation and increased resting pressure

Management

For patients that are suitable for surgery:

  • 1st-line: pneumatic dilation
    • Can be done on an outpatient basis with conscious sedation
    • An inflated balloon stretches the LOS and tears its muscle fibres
  • If recurrent/persisting symptoms: laparoscopic Heller cardiomyotomy

For patients that are unsuitable for surgery:

  • Pharmacological therapy:
    • Isosorbide dinitrate
    • Nifedipine or verapamil
  • Botulinum toxin A injections

Complications

  • Aspiration pneumonia
  • Oesophageal squamous cell carcinoma
  • GORD may develop following treatment
    • This is because treatment is aimed at relaxing the LOS, allowing acid reflux 

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