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Structural Disorders of Esophagus

Posted Jun 02 2009 4:39pm

DYSPHAGIA

Dysphagia, a common symptom in those with
esophageal disorders,may arise from a multitude of
causes. Dysphagia ordifficulty swallowing refers a sensation
of impairment of the normalprogression of the bolus from the
mouth into the stomach. Dysphagiashould be distinguished
from odynophagia or pain upon swallowing.Recognizing
dysphagia and gauging its clinical significance appears simple.
are, however, several important points that may be brought up
by the following questions:

* Is the patient complaining truly of dysphagia? In most cases,
* patients can express clearly symptoms of difficulty in
* swallowing.Alternative terms such as "food sticking" or
* "food moving downslowly into the chest" may assist in
* identifying those with dysphagia.Is the dysphagia for solids,
* liquids, or both? Mucosal lesions,benign or malignant,
* that produce a narrowing of the esophageallumen will not
* usually interfere with the passage of liquid substances
* and dysphagia is limited to solid foods. On the other hand,
* disordersimpairing esophageal peristalsis will cause difficulty
* with both solids and liquids.
* Is the dysphagia intermittent or progressive? Structural lesions
* of thelower esophagus such as rings and strictures, produce
* intermittent obstruction related to the size of the bolus with often
* prolonged periods of symptoms. In motor disorders, on the other
* hand, dysphagia is insidious and becomes progressively worse.

Proper clinical evaluation of dysphagia requires a detailed history.
Multiple diagnostic techniques are available and their use depends
upon the presenting clinical features. The initial test however is often
a barium swallow or an endoscopic examination. The choice between
these two techniques, as the most useful and least costly for the
evaluation of dysphagia, is the subject of debate. In a patient who
presents with intermittent solid dysphagia, suggesting a benign
obstructing lesion such as peptic stricture or ring,starting with
endoscopy is reasonable as it allows making the diagnosis and
simultaneously treating the lesion by dilation. In cases of dysphagia
to both solids and liquids and suspicion of a motor disorder,
a barium swallow provides more useful information by evaluating
esophageal peristalsis.The guidelines of the American
Association (AGA) support the choice of barium swallow in these
cases, a recommendation
that most clinicians would agree with.

Various known causes of esophageal disorders may be
classified into four different groups:

* Disorders caused by mucosal injury
* Neoplastic disorders
* Anomalies of esophageal lumen
* Motor disorders

DISORDERS CAUSED BY MUCOSAL INJURY
DEFINITION

Mucosal injury is defined as mucosal damage resulting from an
intrinsic or extrinsic agent capable of disrupting the integrity of the
mucosa, leading to acute inflammation and potentially chronic
inflammation with possible permanent scarring. The most common
syndromes of mucosal injuries are:

* Acid reflux disease (GERD)
* Infectious esophagitis
* Radiation esophagitis
* Esophagitis due to caustic ingestion
* Pill esophagitis

PREVALENCE

While GERD is very prevalent, causing symptoms in 20% of the
population at least once a week, other causes of mucosal injury are
less frequent. Infectious esophagitis is rare in normal persons.
In an immunocompromised individual, infection occurs today at
a lesser rate than in the past because of diagnostic and
therapeutic techniques. Candida is the most frequent
organism responsible for causing esophagitis. Radiation
esophagitis is reported by some patients during treatment but
long term lesions are not frequent. Caustic ingestions has been
reduced dramatically since protection laws have been instituted.
It is estimated that 5,000 cases occur each year in the U.S.
The prevalence of pill induced esophagitis is not known.
There are increasing number of cases reported but they
constitute a small number compared to the innumerable
pills ingested by the public.

PATHOPHYSIOLOGY

Virtually all mucosal injuries are accompanied by inflammation
with various degrees of severity including from erythema,
frank ulcers with potential scarring and bleeding and strictures.
Infectious esophagitis occurs almost always in
immunocompromisedpatients such as post-transplant patients
or patients with cancer or AIDS. Predisposing factors include
diabetes, alcoholism, malnutrition and old age as well as
treatment with corticosteroids. Diseases leading to stasis
such as achalasia may also predispose to some infections.
Radiation esophagitis occurs with radiation therapy to the
chest and mediastinum. It is dependent upon the total dose
administered as well as the time over which treatment is applied.
Injury by caustic ingestion is most commonly caused by alkali
agents producing burns or acid agents producing necrosis.

Pill esophagitis was first reported with tetracycline. Doxycline
and other tetracyclines account for the majority of cases but
injuries have been reported with other antibiotics, antiviral
agents, nonsteroidal anti-inflammatory drugs,
potassium preparations and many other medications.There
is some evidence that sustained release medications are
more commonly associated with injury. The lesion occurs
most often between the junction of the proximal and
mid-esophagus at the point of impression by the aortic arch
or above the esophagogastric junction.

SIGNS AND SYMPTOMS

Mucosal injury may be asymptomatic or may manifest by
odynophagia or chest pain. Patients whose nutrition may
already be affected by their immunocompromised status
and anorexia are jeopardized by their inability to eat.
Candida esophagitis is often asymptomatic and is
discovered at endoscopy. Pill injury is accompanied
by sudden onset of severe pain over one to three days.
Pain is aggravated
by eating.

DIAGNOSIS

The diagnosis of mucosal injury is suspected based on
patient's background and is established by a barium
swallow but more precisely by endoscopy.Candida
esophagitis shows typical white plaques scattered
throughout the esophagus . Viral infections caused
either by herpes simplex or CMV will reveal focal or
disseminated ulcers and the diagnosis is established by
biopsy and special stains. About 40% of ulcers seen in patients
with AIDS are not due to a specific infection and are termed
idiopathic ulcers. They are typically large and deep.
Radiation esophagitis is characterized by erythema and
friability during the acute stages and by strictures in the late stages.
Caustic ingestion is rare in the adult population and is almost always
due to suicidal attempts. Endoscopy is relatively contraindicated
in the acute stages. Pill induced esophagitis causes a typical
discreet ulcer surrounded by a normal surrounding mucosa .

TREATMENT AND OUTCOMES

The treatment of infectious esophagitis depends upon the
isolation of the causative agent. In immunocompromised
patients, multiple infections may co-exist. Treatment of candida
esophagitis is best carried out with ketaconazole 200-400 mg/day
or fluconazole 100 mg/day for 7 -14 days. Nystatin in oral solution
may be effective in mild cases and in the absence of immunodeficiency.
Viral infections respond in part to antiviral agents. Idiopathic ulcers
of AIDS are treated with prednisone 40 mg/day with tapering over
4 weeks by 10 mg/week or thalidomide 200-300 mg/day over
4 weeks. The potential risk of birth defects limits the use of
thalidomide.

In pill injury the offending medication should be withdrawn
and antireflux therapy prescribed to prevent exacerbation
of the injury. When odynophagia is pronounced, the use
of topical anesthetic agents administered orally may help
relieve the pain. In most cases, symptoms disappear
within a few days and bleeding and perforation
are rare. More importantly, pill injury should be prevented by
encouraging patients to drink large amounts of fluid with their
pills, to remain upright for 30 minutes after taking the pills
and to avoid pills known to cause frequent injury particularly
in patients with esophageal strictures or who are bedridden.
These preventive measures are very important in elderly
patients who tend to take multiple medications particularly
at bedtime.

Chronic lesions caused by mucosal injury often lead
to strictures. Strictures are managed by periodic dilations
and antireflux treatment. In GERD, the use of potent acid
suppressing agents has reduced the frequency with which
dilation needs to be performed.

NEOPLASTIC DISORDERSBENIGN TUMORS

Benign esophageal tumors are non-malignant neoplasms
arising from the mucosal or muscular layers of the
esophagus. Benign tumors of the esophagus are rare.
Leiomyoma, the most common, has been described in
5% of autopsy specimens. Benign tumors are classified
as mucosal or intramural. Mucosal tumors tend to produce
a filling defect in the lumen; they include fibrovascular polyps,
granular cell tumors, papillomas and lipomas. Intramural lesions
are more common than mucosal tumors. They produce an
extrinsic mass projecting from the wall into the lumen.
Such tumors include leiomyomas and cysts.

SIGNS AND SYMPTOMS

Most benign tumors of the esophagus are asymptomatic and
discovered by chance during an examination obtained for
other reasons. When symptomatic, benign tumors cause mostly
dysphagia and, in some cases, chest pain and regurgitation.
The most important issue is to differentiate them from
malignant tumors.

DIAGNOSIS

A barium swallow will often determine if the lesion is
intramural or mucosal. Endoscopy is often helpful in
determining the tumor's nature . Some polyps appear
on a long stalk and may be seen flopping into the lumen.
Endoscopic examination will reveal intramural tumors as
smooth protrusions covered by normal mucosa.
Cysts appear as round and smooth. Mucosal lesions may
sometimes ulcerate. Endoscopic ultrasound is helpful in
distinguishing a leiomyoma from leiomyosarcoma. Unfortunately,
when the tumor is large the differentiation is more difficult.

THERAPY AND OUTCOMES

Small asymptomatic lesions require no treatment. Surgical
enucleation is the treatment of choice for symptomatic
intramural lesions or when intervention is necessary because
malignancy cannot be ruled out with certainty.
Polyps are treated by local resection.

MALIGNANT TUMORS DEFINITION AND
CLASSIFICATION


Malignant tumors of the esophagus constitute the majority of
esophageal tumors. Different types of tumors have been
described and include:

* Squamous cell carcinoma
* Adenocarcinoma
* Sarcoma
* Lymphoma
* Primary melanoma
* Metastatic tumors (breast, lung, melanoma)

Squamous cell carcinoma and adenocarcinoma represent,
by far, the largest number of esophageal malignancies. About
13,000 cases of esophageal cancer are diagnosed each year
in the United States. Squamous cell carcinoma used to
account for the majority of malignancies but adenocarcinoma
has been rising steadily and now accounts for about 50% of
all tumors. Squamous cell carcinoma arises from the squamous
epithelium and is encountered most commonly in the mid-esophagus.
A smaller number of tumors arise in the distal and upper
esophagus. Environmental factors seem to play an important
role in the genesis of squamous cell carcinoma with wide
geographic variations. Other predisposing factors include alcohol,
tobacco, long history of achalasia, previous ingestion of caustic
agents, and genetic factors. In the United States, squamous cell
carcinoma is more common in African-Americans.
Adenocarcinoma of the esophagus is increasing in frequency and
is more commonly seen in white men. Most tumors arise in the
distal third of the esophagus. Barrett's esophagus is the
major predisposing factor for adenocarcinoma
of the esophagus. Tylosis or hyperkeratosis of palms and
soles is an autosomal dominant disorder strongly associated
with gastrointestinal malignancy particularly squamous cell
carcinoma of the esophagus.

While there are differences between squamous cell carcinoma
and adenocarcinoma in epidemiology, location and patterns
of spread, both diseases tend to spread early outside the
esophagus and both share a rather poor prognosis unless
discovered early. For this reason, efforts are undertaken
to detect early signs of cancer or precancer. A guideline
of the American Society of Gastrointestinal Endoscopy
the conditions for which screening is recommended for
early detection:

Screening recommended (every 1-3 years):

* Barrett's esophagus
* Caustic ingestion: start 15-20 years after injury
* Tylosis: Start at age 30

Screening not recommended:

* Achalasia

SIGNS AND SYMPTOMS

The most common clinical manifestation of esophageal tumors is
dysphagia which occurs to solid foods first then progresses to
soft foodsand, eventually, liquids. Odynophagia is reported in
some cases. Chest pain, when present, may represent an
ominous sign as it indicates invasion to the mediastinum.
Weight loss is frequent as a result of difficulty swallowing and,
in late stages, because of anorexia. Bleeding is rare.
Physical examination will reveal signs of weight
loss. In some cases, supraclavicular nodes may be detected.

DIAGNOSIS

Carcinoma of the esophagus should be suspected in any individual
with recent onset dysphagia particularly after the age of 50. A long history
of reflux diseases raises the possibility of carcinoma arising in Barrett's
esophagus especially in white men. The following diagnostic modalities
are used in the evaluation of malignant neoplasms:

* Barium swallow
* Endoscopy
* Computerized tomography (CT)
* Endoscopic ultrasound (EUS)
* Bronchoscopy

Barium swallow gives an indication of tumor location and size .
Endoscopy determines the size of the esophageal lumen .
Biopsy and cytologic brushings establish the tumor's histologic
type. The central issue, at that point, is the appropriateness of
surgical intervention. The decision to operate is based on
tumor staging. Both squamous cell carcinoma and
adenocarcinoma are staged according to the TNM system
(Tumor invasion, lymph nodes and metastasis).

EUS is more sensitive than CT but a combination of both improves
staging's accuracy.

TREATMENT AND OUTCOMES

Curative Treatment:

When full evaluation reveals a favorable stage and the patient's
general condition is not a contraindication to surgery, tumor
resection represents the most promising treatment.
Surgical resection is indicated when the lesion is considered curable.
Combined chemo and radiotherapy followed by surgery is offered
to patients with local extension. Even in adenocarcinoma which
is less sensitive chemo and radiotherapy, combined treatment
improves prognosis. The best chance of significant survival
in esophageal cancer resides in a multidisciplinary approach
in institutions possessing good experience in gastroenterology,
thoracic surgery, chemotherapy and radiation oncology.

The ASGE guideline outlines the advantages of and the treatment
approach for esophageal cancer with an algorithm .

Palliative Treatment:

When surgery is ruled out because of tumor extension or
complications and in cases of tumor recurrence, several
palliative methods are available. Esophageal cancer is
often diagnosed at an advanced incurable stage and when
patients present with dysphagia, 50% of the lumen may already
be occluded.

Palliation methods include radiotherapy and the following
endoscopic modalities:

* Periodic dilation
* Esophageal stenting
* Photodynamic ablation
* Laser ablation
* Endoscopic mucosal resection

Endoscopic techniques have various rates of success and they
all carry a risk of complications including perforation, infection and
bleeding as well as worsening of the initial symptoms. In late
stages and in patients whose dysphagia is insurmountable,
insertion of a gastrostomy feeding tube is often necessary.

ANOMALIES OF ESOPHAGEAL LUMENRINGS AND WEBS

The definition of webs and rings is confusing because the terms have
been used interchangeably. A web is a thin membrane occupying part
of the esophageal lumen and is most commonly seen on the anterior
aspect of the area just below the cricopharynx.

Rings are concentric narrowings of the lumen usually seen in the
lower esophagus. The B-ring or muscular ring occurs at the junction
of the tubular portion of the esophagus and the most distal part called
the vestibule. The ring is often described by radiologists but is
rarely symptomatic. The A or mucosal ring occurs most distally at the
esophagogastric junction and usually in association with a hiatal hernia.
Also known as Schatzki's ring, it deserves particular attention because
it is often symptomatic

PREVALENCE

Both webs and rings are frequently seen during radiologic or
endoscopic examination. It is estimated that webs are present in
0.5 to 1% of asymptomatic people. Lower esophageal rings are
found in 10 to 15% of barium swallow studies. It is now not known how
many are symptomatic.

PATHOPHYSIOLOGY

The exact nature of webs is unknown. It is thought that webs result
an anomaly of development in the epithelium of the upper esophagus.

A Schatzki's ring consists of esophageal mucosa and submucosa.
This ring is almost always associated with the presence of a
hiatal hernia. While it is histologically and probably pathogenetically
different from esophageal peptic strictures, the association of a
lower esophageal ring with gastroesophageal reflux is frequent.
In addition, distinguishing one from the other endoscopically is
sometimes difficult. Therefore, many clinicians manage
esophageal rings as they do strictures. The PlummerVinson
and the Paterson Kelly syndromes refer to the association of webs
iron deficiency anemia and other oropharyngeal abnormalities.
These associations are rarely described
today and the terms have largely been abandoned.

SIGNS AND SYMPTOMS

When either a cricopharyngal web or a ring causes difficulty,
the patient presents with dysphagia. In the case of a web,
the dysphagia is oropharyngeal, associated with solid foods and
is rarely severe. The dysphagia associated with a lower
esophageal ring is intermittent, occurring with solid foods
particularly meat with occasional impaction and is referred,
in the old literature, as the "steakhouse syndrome."

DIAGNOSIS

Barium x-ray is the most sensitive method to detect webs and rings.
Webs should not be confused with the normal impression of the
cricopharynx . On x-ray, a web is seen as an indentation on the
anterior aspect of the pharynx . The diagnostic yield for a ring is higher
when a solid bolus is given during the test. Endoscopic examination
is less sensitive in detecting subtle rings particularly with the use of
the new thin endoscopes which may pass through the ring without
the endoscopist seeing the luminal narrowing.

TREATMENT AND OUTCOMES

Most webs do not require treatment. When they are symptomatic,
however, endoscopic dilation is useful but has to be performed with
caution by an experienced operator. Lower esophageal rings are
treated easily with dilation by bougies or over a guidewire. The
response to treatment is generally good in most patients. There
is a small risk of perforation. An acid suppressing agent is
usually prescribed.

DIVERTICULA DEFINITION

An esophageal diverticulum is a sac protruding from the
esophageal wall and containing all layers of the esophagus.
Esophageal diverticula may be congenital or acquired.
The simplest way to classify them is according to anatomy:

* Zenker's diverticula
* Mid-esophageal diverticula
* Epiphrenic diverticula
* Intramural pseudodiverticulosis

PREVALENCE

Esophageal diverticula have been described in all age groups but
they are most commonly seen in adults. They are rare, occurring
in less than 1% of upper gastrointestinal X-rays and accounting
for less than 5% of dysphagia cases.

PATHOPHYSIOLOGY

Zenker's diverticulum or pharyngoesophageal diverticulum
occurs in a location proximal to the esophagus above the upper
esophageal sphincter. The diverticulum bulges posteriorly and its
size increases over time. The most widely accepted mechanism
for a Zenker's diverticulum is a functional disturbanc
e of the . The most popular explanation is an incoordination
between the pharynx and the cricopharyngeus muscle
called "cricopharyngeal achalasia." Most recent evidence however
suggests that the diverticulum occurs because of reduced
compliance of the upper sphincter rather than because of
incoordination. Mid-esophageal diverticula have been divided
into traction and pulsion diverticula. This distinction has no
practical value. The exact cause of a mid-esophageal diverticulum
is not known but the condition has been associated with scarring
and various esophageal motor abnormalities. Epiphrenic
diverticula are almost always the result of an esophageal
motor abnormality, namely an incoordination between the
distal esophagus and the lower esophageal sphincter.

Esophageal intramural pseudodiverticulosis is characterized by
numerous, minute, flask-like outpouchings along the esophageal
wall. They can be segmental or generalized. They are associated
with strictures, carcinoma, candidiasis and motor abnormalities .

SIGNS AND SYMPTOMS

Many esophageal diverticula are discovered by chance during
radiologic evaluation. In early stages of Zenker's diverticulum,
the patient may complain of vague throat irritation and, when the
becomes large, more severe symptoms develop particularly
dysphagia, regurgitation of food ingested several hours
earlier and gurgling sounds upon swallowing. Complications
of Zenker's diverticulum such as bleeding, obstruction,
or fistulization are rare. Mid-esophageal diverticula are often
asymptomaticunless they become so large that food gets trapped
in the pouch.For epiphrenic diverticula the severity of symptoms
depends upon the associated motor abnormality. The most frequent
conditions associated with such diverticula are achalasia and
diffuse spasm.

DIAGNOSIS

A barium esophagram with special attention to the oropharyngeal
phase of swallowing is the best diagnostic test for Zenker's
diverticulum. The diverticulum is seen to protrude posteriorly and
the barium tends to fall into the pouch before progressing into the
esophagus . Endoscopy adds very little to the evaluation of Zenker's
diverticulum. Manometric testing of upper esophageal function is not
clinically useful. Both mid-esophageal and epiphrenic diverticula
are best diagnosed by barium swallow and an associated motor
disorder is usually suspected if present.

TREATMENT AND OUTCOMES

Symptomatic Zenker's diverticula can be treated by surgical excision.
Newer treatments are applied endoscopically. A transection is made
to create a communication between the diverticulum and the esophagus
allowing the diverticulum to drain into the esophagus. This technique
can be carried out with or without the assistance of laser.Most surgeons
agree that whatever the surgical technique, a myotomy of the
cricopharyngeus muscle is necessary to prevent recurrence of the
diverticulum. Mid-esophageal diverticula are treated by surgical
excision. For anepiphrenic diverticulum the goal of therapy should be
to treat the underlying motor disorder with the hope of avoiding further
enlargement of the diverticulum. In the absence of achalasia, a long
esophagomyotomy is recommended but published results involve a
small number of patients. Intramural pseudodiverticulosis requires
treatment of the underlying infection or obstruction with dilatation
inthe case of a distinct obstructing area.



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