Oesophageal Motility Disorders
There are 2 main primary oesophageal motility disorders to be aware of.
Achalasia
Definition
Achalasia is a primary oesophageal motility disorder characterised by:
- Impaired relaxation of the lower oesophageal sphincter + loss of normal peristalsis in the oesophageal body
- Causing functional obstruction
Pathophysiology
Loss of inhibitory neurons of the myenteric plexus in the distal oesophagus and lower oesophageal sphincter (deficiency in NO-mediated inhibitory neurotransmission). [Ref]
Aetiology
The exact initiating event remains unknown, it is best understood as a multifactorial disorder with autoimmune, infectious, and genetic components. [Ref]
Clinical Features
Key clinical features: [Ref]
- Non-progressive dysphagia (affecting liquid predominantly or affecting both solid and liquid from the onset)
- Regurgitation of undigested food
- Heart burn
- Weight loss
The pattern / trend of dysphagia is important:
- In oesophageal motility disorders, the dysphagia classically affects both solid and liquid from the onset, or it could be affecting liquid predominantly and the dysphagia fluctuates (comes and goes)
- In oesophageal cancer (or other mechanical causes of obstruction, e.g. stricture, ring), the dysphagia is persistent and progressively gets worse and there is dysphagia predominantly to solid (solid affected first, then liquid later)
Complications
Key complications: [Ref]
- Increases risk of oesophageal squamous cell carcinoma
- Pulmonary aspiration
- Progressive oesophageal dilation (sigmoid oesophagus / megaoesophagus)
- Poor oral intake may lead to weight loss and nutritional deficiencies
Investigation and Diagnosis
The following tests should be performed routinely [Ref]
| Test | Findings |
|---|---|
| Barium swallow |
|
| Upper GI endoscopy |
Upper GI endoscopy itself is non-diagnostic of achalasia; it is mainly performed to exclude mechanical obstruction or pseudo-achalasia |
| High-resolution oesophageal manometry (gold-standard test) |
Manometry is the gold standard diagnostic test for any type of oesophageal motility disorders |
Management
Technically, the management of achalasia is guided by the Chicago classification (classified based on manometry findings).
- However, this is not included as it is a specialist-level knowledge
- The key difference is that pneumatic dilation is less effective for type III, myotomy is usually necessary
1st line management (all are effective): [Ref]
- Serial pneumatic dilation
- Laparoscopic Heller myotomy (division of LOS muscle fibres) + fundoplication
- Peroral endoscopic myotomy
2nd line: endoscopic botulinum toxin injection [Ref]
- Botulinum toxin is a potent pre-synpatic acetylcholine release inhibitor
- Thereby, causing smooth muscle relaxation
3rd line: medical therapy (smooth muscle relaxants) [Ref]
- Sublingual calcium channel blocker / isosorbide dinitrate
- Medical therapy has limited efficacy in achalasia
Last resort: oesophagostomy
Diffuse Oesophageal Spasm
Definition
Diffuse oesophageal spasm is a primary oesophageal motility disorder characterised by uncoordinated, simultaneous premature contractions of the oesophagus, resulting in impaired normal peristalsis.
Pathophysiology
Impaired neural inhibition within the oesophageal smooth muscle (deficiency in NO-mediated inhibitory neurotransmission) [Ref]
Aetiology
Similar to achalasia, the exact cause remains unknown, it is considered multifactorial. [Ref]
Clinical Features
Key clinical features: [Ref]
- Intermittent non-progressive dysphagia (affecting liquid predominantly or affecting both solid and liquid from the onset)
- The dysphagia is often precipitated by rapid eating and stress
- Chest pain associated with dysphagia
- Weight loss
The pattern / trend of dysphagia is important:
- In oesophageal motility disorders, the dysphagia classically affects both solid and liquid from the onset, or it could be affecting liquid predominantly and the dysphagia fluctuates (comes and goes)
- In oesophageal cancer (or other mechanical causes of obstruction, e.g. stricture, ring), the dysphagia is persistent and progressively gets worse and there is dysphagia predominantly to solid (solid affected first, then liquid later)
Investigation and Diagnosis
Gold standard: high-resolution oesophageal manometry [Ref]
- Intermittent, premature (simultaneous) contraction with swallowing
- Alternating with normal peristalsis
- Preserved LOS relaxation
Other studies: [Ref]
- Upper GI endoscopy to exclude structural obstruction (typically normal appearance)
- Barium swallow (classic corkscrew appearance)
As diffuse oesophageal spasm presents with chest pain, it is important to exclude cardiac causes of chest pain.
Management
- 1st line: medical therapy (smooth muscle relaxants) [Ref]
- Nitrates (sublingual nitroglycerin or long-acting nitrates)
- Calcium channel blockers
- Anticholinergics
- 2nd line: endoscopic botulinum toxin injection [Ref]
- 3rd line: consider pneumatic dilation / myotomy [Ref]
Concurrent GORD should also be treated, as it may exacerbate symptoms.