Motility disorders and diverticula
Oesophageal motility disorders
Motility
disorders may affect the whole gut
Pain
in functional gastrointestinal disorders
Pain that is assumed to arise from dysfunction of the GI tract has three
components, namely, abnormal motility and ‘spasm’, visceral hypersensitivity
in which the gut is relatively intolerant of distension, and psychosocial
factors. All three components are still poorly understood and it is
therefore impossible to give dogmatic guidelines for treatment. Dealing with
these conditions involves more art than science, but scientific understanding is
slowly increasing.
Achalasia
Pathology
and aetiology
Selective
loss of inhibitory neurons in achalasia
Beware
pseudoachalasia
Look
for tumour
Pseudoachalasia
is an achalasia-like disorder which is usually produced by
adenocarcinoma of the cardia (Fig. 50.63) and sometimes also by cancers outside
the oesophagus such as bronchogenic cancer, especially oat cell cancer, and
pancreatic cancer.
Clinical
features
The disease is commonest in middle life, but can occur at any age. It
typically presents with dysphagia. In patients who have remained untreated for
many years regurgitation is frequent and there may be overspill into the
trachea, especially at night. In the early stages achalasia may present with
retrosternal discomfort and this may lead to a mistaken diagnosis of GORD.
Diagnosis
Achalasia may be suspected at endoscopy by finding a tight cardia and
food residue in the oesophagus. Barium radiology may show hold-up in the distal
oesophagus, peristaltic dysfunction and a tapering stricture in the distal
oesophagus often described as a bird’s beak (Fig.
50.62). The gastric gas
bubble is usually absent. However, these typical features of well-developed
achalasia are often absent, and endoscopy and radiology are often normal. The
barium meal may even be reported as showing gastro-oesophageal reflux. A firm
diagnosis can only be made by oesophageal manometry. Classically there is a
hypertensive lower oesophageal sphincter that does not relax completely on
swallowing, a-peristalsis of the oesophageal body and a raised resting pressure
in the oesophagus (Fig. 50.64). In practice the LOS pressure is often normal.
Treatment
Alone among motility disorders achalasia responds well to treatment. The
two main methods are forceful dilatation of the cardia and Heller’s myotomy.
Beware
perforation
Forceful
dilatation. This involves stretching the cardia with a balloon to disrupt the
muscle and render it less competent. The treatment was first described in
the Mayo Clinic by Plummer. Many varieties of balloon have been available in the
past, but nowadays plastic balloons with a precisely controlled external
diameter are used. If the pressure in the balloon is too high the balloon is
designed to split along its length rather than expanding further. Balloons of
30—40 mm diameter are available and are inserted over a guide wire (Fig.
50.65). Perforation is the major complication. With a 30-mm balloon the
incidence of perforation should be less than 0.5 per cent. The risk of
perforation increases with the bigger balloons and they should be used
cautiously for progressive dilatation over a period of weeks. Forceful
dilatation is curative in 75—85 per cent of cases. The results are best in
patients aged more than 45 years.
Beware
postoperative reflux
Heller’s
myotomy. This involves cutting the muscle of the lower oesophagus and cardia
(Fig. 50.66). The major complication is gastro-oesophageal reflux. Reflux may
be avoided by limiting the incision to the lower oesophagus and not more than 1
cm of the stomach. If the myotomy is carried further on to the stomach a
prophylactic antireflux operation should be done. It is customary to perform a
partial rather than a total fundoplication in this situation because of the risk
of causing dysphagia in the presence of an a-peristaltic oesophagus. However, a total fundoplication may be done provided that
great care is taken to produce a very short and floppy fundoplication that does
not cause obstruction. The proximal extent of the myotomy does not seem to
matter provided that the obstructing segment is divided.
Heller’s
myotomy is ideally suited to a minimal access approach by either thoracoscopy or
laparoscopy. It is successful in more than 90 per cent of cases and may be
used after failed myotomy.
Botulinum
toxin. This may be given by endoscopic injection into the LOS. This is a new
form of treatment whose place is not yet established. It acts by interfering
with cholinergic excitatory neural activity at the LOS.
Drugs.
Drugs, such as calcium channel antagonists, have been used but are ineffective
for long-term use. Sublingual nifedipine may, however, be useful for transient
relief of symptoms if definitive treatment has to be postponed.
Other
oesophageal motility disorders
Disorders
of the pharyngo-oesophageal junction
These are for the most part neurological disorders and surgery has
very little place in their management. Rarely, cricopharyngeal myotomy may be
performed to reduce dysphagia in a myopathy affecting the pharyngeal muscles.
For this to be successful there must be some preserved contraction of the
pharynx and a stable neurological condition.
Cricopharyngeal
‘achalasia’ is a condition in which the upper oesophageal sphincter does not
open adequately during swallowing. A cricopharyngeal ‘bar’ may be visible
on a barium swallow. The disorder is probably caused by degeneration of the
cricopharyngeal muscle with consequent loss of elasticity. The condition is
rare, but responds well to cricopharyngeal myotomy. A similar abnormality of
the
Diffuse oesophageal spasm is a condition in which there are incoordinate
contractions of the oesophagus causing dysphagia and chest pain. The condition
may be dramatic with spastic pressures on manometry of 400—500 mmHg, marked
hypertrophy of the circular muscle and a corkscrew oesophagus on barium swallow
(Fig. 50.67). If chest pain is the only symptom and the abnormality is
not particularly dramatic it may be difficult to be sure that the disorder is
the cause of the pain and not an epiphenomenon. Prolonged ambulatory oesophageal
manometry with a detailed record of the timing of episodes of chest pain may
help to make a diagnosis.
Dysphagia
due to diffuse spasm may respond to forceful dilatation of the cardia, but the
results are not as predictable as in achalasia. In very severe cases extended
oesophageal myotomy up to the aortic arch may be required. Surgical treatment of
diffuse spasm is more successful in improving dysphagia than chest pain and
caution should be exercised in patients in whom chest pain is the only symptom.
Nutcracker
oesophagus is a condition in which peristaltic pressures greater than 180 mmHg
are developed. It is said to cause chest pain, but there is still some debate as
to whether it is a real disorder.
Hypoperistalsis
of the oesophagus occurs in the CREST variant of systemic sclerosis (Fig.
50.68),
in severe GORD
When
GORD and dysmotility occur together it is best to treat the reflux and ignore
the dysmotility. It is commonly held that weak peristalsis is a contraindication
to total fundoplication, but the author has not found this to be the case
provided that care is taken with the construction of the fundoplication.
Eosinophilic
oesophagitis is a distinct pathological entity described in patients who have
intermittent dysphagia without GORD and without anatomical obstruction.
Episodes of dysphagia may be severe and painful with bolus obstruction. Between
episodes swallowing may be completely normal.
Hypertensive
lower oesophageal sphincter is defined as an LOS pressure greater than 45 mmHg
with normal relaxation during swallowing. It is said to be associated with chest
pain and dysphagia.
Oesophageal
diverticula
Most oesophageal diverticula are pulsion
diverticula that develop
at a site of weakness as a result of chronic pressure against an obstruction.
The symptoms are mostly caused by the underlying disorder unless the
diverticulum is particularly large. Traction diverticula (Fig.
50.69)
are much less common. They are mostly a consequence of chronic granulomatous
disease affecting the tracheobronchial lymph nodes due to tuberculosis, atypical
mycobacteria or histoplasmosis. Fibrotic healing of the lymph nodes exerts
traction on the oesophageal wall and produces a focal outpouching that is
usually small and has a conical shape. There may be associated
broncholithiasis and additional complications may occur such as
oesophagobronchial fistulation (Fig. 50.70) and bleeding.
Zenker’s
diverticulum (pharyngeal pouch) is not really an oesophageal diverticulum as it
protrudes posteriorly above the cricopharyngeal sphincter through the natural
weak point between the oblique and horizontal fibres of the inferior
pharyngeal constrictor (Figs 50.71 and 50.72). Nevertheless it
is the commonest diverticulum affecting the region of the oesophagus. The
underlying abnormality is the same as in cricopharyngeal achalasia. The
diverticulum may be large and extend into the posterior mediastinum. Treatment
is always necessary sooner or later. The optimum treatment is excision of the
diverticulum combined with cricopharyngeal myotomy to deal with the underlying
obstruction. In frail patients or those who decline formal operation an
endoscopic
linear cutting staple gun may be inserted through the mouth and fired to divide
the septum between the diverticulum and the upper oesophagus producing a
diverticulooesophagostomy.
Excision and myotomy for
Zenker’s diverticulum
Mid-oesophageal
diverticula are usually small pulsion diverticula of no particular consequence.
The underlying motility disorder does not usually require treatment. The
exception to this rule is in areas of the world in which granulomatous diseases
of the mediastinum are common, such as parts of the USA, where the possibility
of a traction diverticulum should be considered. Some pulsion diverticula may
fistulate into the trachea (Fig. 50.70), but this is much more common in
granulomatous disease.
Epiphrenic
diverticula are situated in the lower oesophagus above the diaphragm (Fig.
50.73).
They may be quite large, but cause surprisingly few symptoms. If surgical
The diverticulum may not be the
cause of the symptoms
Diffuse
intramural pseudodiverticulosis is a rare condition in which there are multiple
tiny outpouching from the lumen of the oesophagus. The pseudodiverticula are
dilated excretory ducts of oesophageal sebaceous glands. It is questionable
whether the condition produces any symptoms in its own right.