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The Canine Esophagram
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An Simple Physiologic Assessment
X-ray procedure for Achalasia known as the Esophagram or "barium swallow"
can confirm a diagnosis of megaesophagus and can often identify the location
of the defect causing it. An esophagram (e-SOFF-ah-gram) is an X-ray test
that takes pictures of the esophagus (ee-SOFF-ah-gus). The esophagus is
the tube in the neck that connects the mouth to the stomach through which
food passes as it is eaten. An esophagram shows the vet how well the
esophagus is working and gives detailed information about your dog's
esophagus that they cannot learn from a physical
examination.
In this procedure, a special, barium-containing dye outlines the dilated
esophagus. With vascular ring anomalies like PRAA (Persistent Right Aortic
Arch), a constriction is seen over the base of the heart, with the dilatated,
barium-filled portion of the esophagus seen only in front of that location.
With an esophageal stricture caused by scar tissue or from a congenital
lack of muscle fibers in a particular location, the dilatated area is seen
in front of the level of the specific defect. With a generalized, neuromuscular
defect in the esophagus, or with a constriction at the level of the gastroesophageal
(G-E) sphincter, the dilatation occurs over the entire length of the esophagus.
To narrow down the possible causes for a general dilatation, "fluoroscopy"
(Constant motion radiographic studies) may be required. With fluoroscopy, the X-ray procedure
is an active process which displays the actual movements of the esophagus
and its related structures in "real time." Using this procedure, a physical
constriction may be distinguished from a functional abnormality.
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The Canine and Feline Esophagram
(Barium Swallow) Performing an esophagram in the dog or cat is a simple, quick,
and inexpensive test that is use to evaluate the esophagus whenever a dilated
esophagus is identified on survey radiographs or if there is a clinical suspicion
of regurgitation or dysphagia. An esophagram is useful in the work up of
disorder such as:
• Megaesophagus
• Dysphagia
• Regurgitation
• Mediastinal or esophageal masses
• Gastroesophageal intussusceptions
• Esophageal Perforations
• Esophageal foreign bodies
• Vascular ring anomalies
Contrast Considerations: The contrast used in the examination must
be able to coat and temporarily adhere to the esophageal mucosa so it will
be visible on survey radiographs. Commercially prepared barium paste (not
liquid barium) is generally the contrast agent of choice used to perform an
esophagram. Again, barium paste should be your first choice when performing
an esophagram. However, there are certain situations where other agents are
indicated. These are:
• Iodinated contrast (such as gastrograffin): Iodine should be used
if there is a suspicion of an esophageal perforation because extravasated
barium is irritating to the mediastinum. However, iodine will not coat the
esophageal mucosa and small periesophageal accumulations may be difficult
to identify. Therefore, if there is a strong suspicion of an esophageal perforation
and a perforation is not identified with an iodine study, the esophagram should
be repeated with barium paste.
• Barium Burger: If the barium paste esophagram study is normal it
may be beneficial to repeat the study with a mixture of liquid barium suspension
(not the barium paste) with wet dog food. This mixture will evaluate the patient’s
ability to swallow solid material. An esophagram with a barium burger should
never precede a study performed with barium paste.
Technique:
• Always obtain survey radiographs immediately prior to performing an esophagram.
• No preparation or sedation is required
• Administer 5-15ml of barium paste orally by syringe into the mouth.
• Expose lateral and ventrodorsal radiographs immediately after the paste
is
swallowed.
• If the barium paste esophagram is normal, you may want to repeat the study
with a
barium burger.
Complications: The primary complication is aspiration of the contrast.
However, small volumes of aspirated barium (such as those used in this study)
are well tolerated. Conversely, aspirated iodinated contrast agents are very
irritating to the lung and can cause significant respiratory compromise. Be
cautious of using iodinated agents in patients at risk for aspiration.
The above information is simply informational. It's intent is
not to replace the advice of a veterinarian nor to assist you in making
a diagnosis of your pet. Please consult with your own veterinarian for
confirmation of any diagnosis. Your pets life may depend on it.