What Is Achalasia?
Since gastroesophageal reflux occurs when the lower esophageal
sphincter (LES) relaxes and opens when it shouldn't, you might say
achalasia is the complete opposite of GER. The term achalasia means
failure to relax, esophageal achalasia occurs when the LES does not relax
and allow food to pass through to the stomach. This can cause difficulty
or even the inability to swallow.
In addition the muscle of the lower half of the esophagus does not
contract normally, meaning the normal peristaltic waves that move food and
saliva down the esophagus do not occur. These dysfunctions of the lower
sphincter and esophageal body are responsible for food sticking in the
esophagus.
What Causes Achalasia?
It is not known what causes achalasia. There are theories that
suggest heredity, or an abnormality of the immune system such as
autoimmune disease.
The esophagus contains both muscle and nerves. The nerves coordinate the
relaxation and opening of the sphincters as well as the peristaltic waves
in the body of the esophagus. Achalasia has effects on both the muscles
and nerves of the esophagus; however, the effects on the nerves are
believed to be the most important. Early in achalasia, inflammation can be
seen under the microscope in the muscle of the lower esophagus, especially
around the nerves. As the disease progresses, the nerves begin to
degenerate and ultimately disappear, particularly the nerves that cause
the lower esophageal sphincter to relax. Still later in the progression of
the disease, muscle cells begin to degenerate, possibly because of the
damage to the nerves. The result of these changes is a lower sphincter
that cannot relax and muscle in the lower esophageal body that cannot
support peristaltic waves. With time, the body of the esophagus stretches
and becomes very enlarged (dilated).
What are the Symptoms of Achalasia?
The most common symptom of achalasia is dysphagia or difficulty
swallowing. Many of the other symptoms of achalasia are somewhat the
same as the symptoms of gastric reflux. These include regurgitation of
food, cough, heartburn, and weight loss.
How is Achalasia Treated?
Treatments for achalasia include oral medications such as long acting
nitrates or calcium channel blockers. Aside from medications there are
surgical procedures used such as dilation or stretching of the lower
esophageal sphincter (dilation), surgery to cut the sphincter (esophagomyotomy),
or the injection of botulinum toxin (Botox) into the sphincter. All four
treatments reduce the pressure within the lower esophageal sphincter to
allow easier passage of food from the esophagus into the stomach. |
