[7] Oesophageal Motility Disorders Flashcards
What are oesophageal motility disorders?
A group of conditions characterised by abnormalities in oesophageal peristalsis
How does the prevalence of oesophageal motility disorders compare to other oesophageal disorders?
They are less common than mechanical and inflammatory diseases of the oesophagus
How do oesophageal motility disorders typically manifest?
With difficulty swallowing solids and liquids
What are the major causes of oesophageal dysmotility?
Achalasia
Diffuse oesophageal spasm
How long is the oesophagus?
25cm
What is the upper third of the oesophagus composed of?
Skeletal muscle
What is the middle third of the oesophagus composed of?
It is a transition zone comprised of both skeletal and smooth muscle
What is the lower third of the oesophagus composed of?
Smooth muscle
What is the upper oesophageal sphincter comprised of?
Skeletal muscle
What is the purpose of the upper oesophageal sphincter?
It prevents air from entering the GI tract
What is the lower oesophageal sphincter composed of?
Smooth muscle
What is the purpose of the lower oesophageal sphincter?
It prevents reflux from the stomach
What propels ingested food down the oesophagus?
Peristaltic waves
What controls the peristaltic waves in the oesophagus?
Oesophageal myenteric neurones
What is the primary peristaltic wave of the oesophagus under the control of?
Swallowing centre
What is the secondary peristaltic wave of the oesophagus controlled by?
It is activated in response to distention
What happens as food descends the oesophagus?
The lower oesophageal sphincter relaxes, and remains so until food has passed
What is achalasia?
A primary motility disorder of the oesophagus, characterised by failure of smooth muscle relaxation
How common is achalasia?
Relatively rare (1 per 100,000)
What is the mean age of diagnosis of achalasia?
About 50 years
What is the pathophysiology of achlasia?
Unknown
What is a common histological feature of achlasia?
Progressive destruction of the ganglion cells in the myenteric plexus.
What does the failure of smooth muscle to relax in achalasia cause?
An inability of the oesophagus to relax, and a high resting tone and failure of relaxation of the lower oesophageal sphincter
What is the result of failure of the oesophagus to relax in achalasia?
Causes difficulty in passing food boluses down the oesophagus
What is the result of the high resting tone and failure of relaxation of the lower oesophageal sphincter in achalasia?
Means that the food bolus may get stuck, and fail to pass into the stomach
What is the result of the failure of food to pass into the stomach in achalasia?
Produces the symptoms of vomiting, discomfort, and developing poor nutritional status
Why is achlasia a progressive disease?
The current theory in its pathophysiology suggests that as the ganglionitis progresses, there is destruction of more and more neurones and subsequent worsening of severity of the condition
How will achalasia classically present?
With progressive dysphagia when ingesting solids and liquids Regurgitation of food Coughing Chest pain Weight loss
How can achalasia cause coughing?
Due to overspill and aspiration, especially at night
What may be found on examination with achalasia?
There are rarely any obvious signs of note, except for visible weight loss in longstanding or severe cases
What are the main differential diagnoses for achalasia?
Other oesophageal motility disorders
GORD
Oesophageal malignancy
Angina
What needs to be excluded in any patient presenting with dysphagia?
Oesophageal cancer
What is the result of the need to exclude oesophageal cancer in patients with dysphagia?
Nearly all patients will require urgent endoscopy
What may be found on endoscopy in achalasia?
May be normal
Rarely, there is a tight lower oesophageal sphincter (which may suddenly give way)
What is the gold standard for diagnosis of achalasia?
Oesophageal manometry
What happens in oesophageal manometry?
A pressure sensitive probe is inserted into the oesophagus (tip placed 5cm above lower oesophageal sphincter). Then, the pressure of the sphincter and the surrounding muscle is measured
What are the key features of oesophageal manometry in achalasia?
Absence of oesophageal peristalsis
Failure of relaxation of the lower oesophageal sphincter
High resting lower oesophageal sphincter tone
What may barium swallows show in achalasia?
May show proximal dilation of the oesophagus, with a characteristic ‘birds beak’ appearance distally
What is involved in the conservative management of achalasia?
Sleep with many pillows
Eating slowly and chewing foods thoroughly
Taking plenty of fluids with meals
What medications can be used in the conservative management of achalasia?
Calcium channel blockers or nitrates
Botox injections
How useful are calcium channel blockers/nitrates in achalasia?
They can be partly effective for temporary relief, but their action is typically short live
How are botox injections given in achalasia?
They are injected into the lower oesophageal sphincter by endoscopy
How long are botox injections effective for in achalasia?
A few months at most
What are the surgical techniques that can be used in achalasia?
Endoscopic balloon dilation
Laparoscopic Heller myotomy
What happens in endoscopic balloon dilation for achalasia?
A balloon is inserted into the lower oesophageal sphincter, which is dilated to stretch the muscle fibres
What % of patients have a good response to endoscopic balloon dilation?
75%
What are the risks with endoscopic balloon dilation?
Perforation
Need for further intervention
What is the risk of perforation with endoscopic balloon dilation?
5%
What happens in a laparoscopic Heller myotomy?
There is division of the specific fibres of the lower oesophageal sphincter which fail to relax
What % of patients with achalasia have a long-term improvement in swallowing with a laparoscopic Heller myotomy?
85%
What is the advantage of a laparoscopic Heller myotomy over endoscopic balloon dilation?
It has a lower side effect profile
By how much does having long-standing achalasia increase the risk of oesophageal cancer?
8-16x, although the absolute risk remains small
What is diffuse oesophageal spasm (DOS)?
A disease characterised by multi-focal, high amplitude contractions of the oesophagus
What is diffuse oesophageal spasm thought to be caused by?
Dysfunction of the oesophageal inhibitory nerves
What can DOS progress too in some patients?
Achalasia
How will patients with DOS typically present?
Severe dysphagia to both solids and liquids
Central chest pain, usually exacerbated by food
What may the pain from DOS respond well to?
Nitrates
What is the problem with the pain from DOS responding well to nitrates?
it can make it difficult to distinguish from angina
What feature might differentiate NOS pain from angina?
NOS pain is rarely exertional
What is found on examination in NOS?
Examination is usually normal
How is DOS investigated?
In the same manner as other motility disorders, with the definitive diagnosis being made via manometry
What is found on endoscopy in DOS?
Usually normal
What does manometry characteristically show in DOS?
A pattern of repetitive, simultaneous, and ineffective contractions of the oesophagus
May also be dysfunction of the lower oesophageal sphincter
What may a barium swallow show in DOS?
‘Corkscrew’ appearance
What is the initial management of DOS?
Agents that act to relax the oesophageal smooth muscle, typically nitrates or calcium channel blockers as first line
How effective are nitrates or calcium channel blockers at managing DOS?
They limit the strongest contractions, so provide symptomatic improvement, although their long-term efficacy is unceratin
Which patients with DOS might benefit from pneumatic dilation?
Patients with DOS and documented hypertension of the lower oesophageal sphincter
When is myotomy used in DOS?
Reserved for the most severe cases
Why must myotomy be used with caution in DOS?
Due to its invasive nature
Describe the excision used in myotomy for DOS?
It is extensive, involving the entire spasmic segment and the lower oesophageal sphincter
What other conditions are associated with oesophageal dysmotility?
A number of autoimmune and connective tissue disorders
How is oesophageal dysmotility managed when it is secondary to another condition?
Treatment is directed at the underlying cause, with nutritional modification and PPIs as required
