Contents
Introduction
Dysphagia means difficulty in swallowing. A separate term, odynophagia, exists to denote painful swallowing, but dysphagia is often also employed in this context. Longterm dysphagia may be associated with weight loss simply due to the difficult in swallowing adequate quantities of food.
There are numerous causes of dysphagia.
- Oesophageal tumour
- Hiatus hernia
- Benign stricture
- Plummer-Vinson syndrome
- Schatzki ring
- Eosinophilic oesophagitis
- Oesophagitis (other forms)
- Pharyngeal pouch
- Oesophageal atresia
- Bronchial carcinoma (left side)
- Multinodular goitre
- Thyroid tumour
- Aortic arch aneurysm
- Left atrial enlargement
- Mediastinal tumour
- Cerebrovascular accident
- Multiple sclerosis
- Motor neurone disease
- Myasthenia gravis
- Parkinson's disease
- Achalasia
- Chagas' disease
- Diffuse oesophageal spasm
- Rabies
The list may be considered in terms of four categories of causes that apply to obstruction of a hollow organ. The blockage may be due to something that is located in the lumen, something that occupies the wall of the organ, something that is located outside the organ but compresses the organ and dysfunction of the neuromuscular aspects of peristalsis (or related process).
Swallowing is a complex motor act and various diseases that damage the brain, motor nerves or skeletal muscle can impair swallowing. Neuromuscular disorders tend to produce dysphagia for solids and liquids whereas the other causes of dysphagia tend to be worse with solid food.
Oesophageal Webs, Rings and Benign Strictures
Strictures of the oesophagus can be caused by a malignant tumour, but many are benign. Most of these benign strictures are secondary to
gastro-oesophageal reflux disease but they can also be caused by radiation and ingestion of severe irritants (strong acids and alkalis).
Plummer-Vinson syndrome is a rare condition in which there is iron deficiency associated with glossitis and a web across the upper oesophagus.
The Schatzki ring is a web-like mucosal stricture located in the lower oesophagus close to the gastro-oesophageal junction.
Eosinophilic Eosophagitis
Eosinophilic oesophagitis is a relatively recently described condition that can cause dysphagia, especially in the form of the sensation of a bolus of food becoming stuck. It tends to present in younger people and is more common in males. Eosinophilic oesophagitis is associated with asthma and allergies.
The upper GI endoscopy may be normal in eosinophilic oesophagitis or there may be multiple rings in the oesophagus.
Oesophageal biopsy may show infiltration of the stratified squamous epithelium by eosinophils. The density of eosinophils should be at least 15 per high power field; eosinophilic microabscesses may be encountered. However, eosinophilic infiltration of the oesophageal epithelium is also seen, albeit to a lesser degree, in
gastro-oesophageal reflux disease.
Corticosteroids may be useful in controlling the disease.
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The endoscopic appearance of eosinophilic oesophagitis
Image courtesy of Wikipedia
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Oesophagitis
In addition to
gastro-oesophageal reflux disease and eosinophilic oesophagitis, the oesophagus may become inflamed secondary to infections such as candida and herpes simplex. A few bullous skin diseases, for example bullous pemphigoid, can occasionally involve the oesophagus. The problems in swallowing that are associated with these forms of oesophagitis may strictly speaking be more in the territory of odynophagia rather than dysphagia.
Pharyngeal Pouch
A pharyngeal pouch is a protrusion of the mucosa of the laryngopharynx just above the cricopharyngeus muscle (which forms the lower part of the inferior constrictor of the pharynx). Pharyngeal pouches occur in older people and are believed to be the result of failure of the cricopharyngeus muscle to relax properly during swallowing.
The pouch can cause dysphagia, often because it compresses the upper oesophagus from the outside. There can be a gurgling sound on swallowing. The patient may complain of a lump in their throat. Accumulation of stagnant food in the pouch can produce halitosis. Regurgitation of the contents of the pouch may occur and this can rarely take the form of aspiration pneumonia.
The pouch can be removed by surgery.
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The muscles of the pharynx.
The arrow indicates the inferior constrictor of the pharynx.
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Fluoroscopic X-ray of a pharyngeal pouch
Images courtesy of Wikipedia
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Oesophageal atresia
Oesophageal atresia is a congenital malformation in which the oesophagus does not develop properly and terminates in a blind ending before it reaches the stomach. It is often associated with a tracheo-oesophageal fistula (the lungs develop as an outpouch of the primitive foregut during embryology).
The condition presents very soon after birth. The baby will not be able to feed properly and will regurgitate milk. This may be complicated by aspiration of the milk into the lungs, especially if a tracheo-oesophageal fistula is present.
Achalasia
Achalasia is a rare disease in which there is degeneration of the myenteric plexus of the oesophagus. The incidence is 1 per 100,000 per year. The age of onset is usually between 30 and 60 years and the male : female ratio is equal.
Achalasia can be mimicked by tumours that infiltrate the lower oesophagus (such as gastric carcinoma or lymphoma), amyloidosis and irradiation. Chagas' disease is an infectious disease caused by the protozoa trypanasoma cruzi which can also mimic achalasia.
The damage to the myenteric plexus of the oesophagus means that the oesophagus cannot generate the normal peristaltic waves. In addition, the lower oesophageal sphincter fails to relax and has an abnormally elevated pressure. The oesophagus becomes dilated.
As well as dysphagia patients may also complain of odynophagia. The difficulty in swalloing may be improved by raising the intrathoracic pressure using the Valsalva manoeuvre (forced expiration against a closed epiglottis, as used when straining to lift a heavy object).
The large volumes of food that accumulate in the oesophagus can be regurgitated back into the mouth and in some cases may be aspirated into the lungs. Weight loss can occur.
Achalasia is associated with an increased risk of
oesophageal carcinoma.
The diagnosis is confirmed by a barium swallow (often with fluoroscopy to show the actual act of swallowing) and measurements of the pressure of the lower oesophageal sphincter (oesophageal manometry).
The initial treatment is with a calcium channel blocker to attempt to relax the smooth muscle of the lower oesophageal sphincter. Endoscopic dilatation of the lower oesophageal sphincter can also be tried. If these options fail, surgical division of the muscle of the sphincter can be performed.
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A barium swallow of achalasia.
The oesophagus is dilated and comes to a very narrow taper, which is sometimes referred to as a rat's tail.
Image courtesy of Wikipedia
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Diffuse Oesophageal Spasm
Diffuse oesophageal spasm is a rare disease in which there are spontaneous, powerful contractions of the oesophageal smooth muscle that are non-peristaltic.
The main symptom is retrosternal chest pain which tends to occur at rest and can be precipitated by swallowing or emotional distress. The pain can radiate to the jaw, neck and arms and thus can resemble angina or a myocardial infarction.
Dysphagia may also occur.
The pain can usually be controlled with calcium channel blockers or nitrates. Surgery is only rarely required.
General Investigations
The traditional advice as to the main investigation of dysphagia was to perform a barium swallow before an upper GI endoscopy. This advice was given because there were concerns that an unsuspected pharyngeal pouch could be ruptured by an endoscopy and lead to severe complications. This policy now seems to be have been relaxed and an upper GI endoscopy may be undertaken first.
A plain chest X-ray can disclose a dilated oesophagus or mass lesion that is compressing the oesophagus.
A CT or MRI may sometimes be necessary.