Achalasia

Question 1

Define achalasia

Answer 1

An oesophageal motility disorder, characterised by loss of peristalsis and failure of relaxation of the lower oesophageal sphincter (LOS)

Question 2

What is the pathophysiology of achalasia?

Answer 2

Degeneration of inhibitory neurons within myenteric plexuses in the oeseophagus →
→ failure to relax + higher resting pressure of the LOS + dysfunctional peristalsis
→ oesophageal dilation proximal to LOS

Question 3

What is the aetiology of achalasia?

Answer 3

Primary achalasia (most common):
- cause is unknown

Secondary achalasia (pseudoachalasia): 
- mechanical obstruction that mimics achalasia - e.g. oesophageal/stomach cancer,

Achalasia secondary to Chagas’ disease

Autoimmunity:
- patients with previous autoimmunity are more likely to have achalasia

Genetic factors:
- familial achalasia very rare but more likely among children of consanguineous couples

Question 4

What are the risk factors for achalasia?

Answer 4

• Patients with history of autoimmune conditions
• History of Chagas’ disease infection
• Consanguineous parents

EXTRA:
- Allgrove syndrome (characteristic features are achalasia, alacrima and adrenal insufficiency)

Question 5

What is the epidemiology of achalasia?

Answer 5

Rare (1 in 100,000)

Usual presentation age: 25–60 years

Question 6

What are the presenting symptoms of achalasia?

Answer 6

• Intermittent dysphagia involving solids AND liquids (dysphagia is progressive)
• Difficulty belching
• Regurgitation (particularly at night)
• Heartburn
• Chest pain (atypical/cramping, retrosternal)
• Weight loss (because they are eating less)

Question 7

How could you possibly differentiate between achalasia and pseudoachalasia?

Answer 7

Achalasia - gradual and mild weight loss

Pseudoachalasia (malignancy) - rapid and severe weight loss

Question 8

What investigations would you do if you were suspecting achalasia and what would you expect to see?

Answer 8

Oesophageal manometry - confirmatory test of choice, will show:

• elevated resting LOS pressure (>45 mmHg)
• incomplete LOS relaxation;
• absence of peristalsis in the distal 2/3rds (smooth muscle portion) of the oesophagus

Upper GI endoscopy:

• rules out mechanical obstruction/malignancy (i.e. pseudoachalasia)
• results are usually normal in true achalasia

Barium swallow:
- ‘bird-beak appearance’ → dilated of the proximal oesophagus which tapers down to the sphincter

Chest x-ray:

• widened mediastinum
• air-fluid level in the upper chest
• possible absence of gastric air bubble

Serology for antibodies against T. cruzi if Chagas’ disease is suggested by epidemiology and symptoms

Question 9

What is the management of achalasia?

Answer 9

LOW SURGICAL RISK:

Pneumatic balloon dilation of LOS (essentially opens up the sphincter)

Surgical myotomy of the LOS (weakening LOS by cutting muscle fibres)
BUT
GORD is a frequent post operative complication of this so patients might need a fundoplication surgery as well to prevent reflux

HIGH SURGICAL RISK

Botulinum toxin injected into LOS (inhibits ACh release from the excitatory neurones that increase smooth muscle tone)

Nitrates and CCBs (relax smooth muscle of LOS)

Question 10

What are the complications of achalasia?

Answer 10

• Aspiration pneumonia
• Malnutrition and weight loss
• Increased risk of oesophageal cancer

Question 11

What is the prognosis for achalasia?

Answer 11

Good if treated

If untreated, oesophageal dilation may worsen causing pressure on mediastinal structures

Question 12

What is Chagas disease?

Answer 12

Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi (T. cruzi)

It is seen in Central and South America

It causes damage to the myenteric plexus → inability to relax LOS → achalasia