ACHALASIA

RMacLean
January 2007

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.