- Motor disorder of the oesophagus, due to damaged/degenerated cells in the myenteric plexus
- Results in complete loss of oesophageal peristalsis and failure of lower oesophageal sphincter (LOS) relaxation
- Leads to obstruction at the gastro-oesophageal junction (GOJ) and loss of effective propulsion
Etiology
- Decrease/absence of ganglions in myenteric plexus
- Most commonly it is idiopathic degeneration of Auerbach’s myenteric plexus
- Other causes
- Stress, vitamin B1 def
- Chagas disease – Trypanosoma cruzi (sleeping sickness)
- It is a precancerous condition – x7 chance of getting small cell cancer
- Mean age of onset is between 30-60 years
Pathology
- Thickening of circular muscle fibres in the distal oesophagus
- Myenteric inflammation, depletion of ganglion cells and neural fibrosis
- Levels of NO and VIP are reduced (mediators of LOS relaxation)
- There is absence of peristalsis, raised LOS pressure and failure of relaxation with functional obstruction of GOJ
- There is narrowing of the cardia with enormous dilation of the proximal oesophagus
- Contains foul-smelling fluid – patients are more prone to aspiration pneumonia
Clinical features
- Triad – dysphagia, regurgitation, weight loss
- Initially presents as solid food dysphagia – as food is unable to pass into the stomach and accumulates above LOS
- Eventually there is dysphagia to solids and liquids
- Chest pain occurs in early stage
- Regurgitation and recurrent pneumonia
- Heartburn
- Malnutrition and general ill health
- Lung abscess formation
Investigations
- Barium swallow XR
- Bird beak sign – narrowing of the lower oesophagus
- Dilation of proximal oesophagus
- Oesophageal manometry – gold standard
- Demonstrates unrelaxed LOS with high resting pressure
- Shows failure of LOS to relax during swallowing and absence of peristalsis
- Oesophagoscopy – confirms diagnosis and rules out carcinoma of the oesophagus
Treatment
- Drugs – botulinum toxin, nitroglycerine, nifedipine
- Modified Heller’s op – oesophagoardiomyotomy
- Thickened muscle fibres cut longitudinally
- Forcible dilation – stretches spasmodic segment
- Gradual repeat dilations
- Plummer’s pneumatic dilation – use balloons of 30-40mmHg
- Negus hydrostatic dilation – dilates GOJ (high risk of perforation)
- Gradual repeat dilations
- Laparoscopic/thoracoscopic cardiomyotomy
- Resection – done if there is failure of myotomy or when mega-oesophagus/metaplasia present