Achalasia

Disease/Disorder

Also known as: Esophageal achalasia, achalasia cardiae, cardiospasm, esophageal aperistalsis

Anatomy or system affected: Chest, gastrointestinal system

Definition: A swallowing disorder that prevents the movement of food from the esophagus to the stomach.

Key terms:

esophagus: the muscular tube that connects the pharynx with the stomach

GERD: gastroesophageal reflux disease or acid efflux disease; regurgitation of stomach acid into the esophagus

peristalsis: The successive waves of contraction and relaxation that pass along the muscular wall of the gastrointestinal tract

sphincter: a circular band of voluntary or involuntary muscle that encircles an orifice of the body or one of its hollow organs

Causes and Symptoms

The muscular tube called the esophagus has three parts: (1) the upper esophageal sphincter, a ring of muscle that separates the esophagus from the throat; (2) the middle esophagus (about 8 inches long); and (3) the lower esophageal sphincter, another specialized ring of muscle at the junction of the esophagus with the stomach. Both of these sphincters remain closed to prevent food from backing up either into the throat or from the stomach into the esophagus. Upon swallowing, the upper sphincter relaxes and opens to allow the passage of food and then contracts and propels the food into the esophagus. This wave of muscle contraction progresses down the esophagus (peristalsis), driving the food to the lower esophageal sphincter. When the wave of esophageal muscle contractions reaches the lower esophageal sphincter (LES), the LES relaxes and opens to allow passage of the food to the stomach.

In people with achalasia, the inhibitory nerves that innervate the esophagus (myenteric plexus) degenerate for unknown reasons. Consequently, the LES cannot effectively relax and open to allow food to pass into the stomach and the muscles that line the esophagus do not contract, preventing the movement of food through the esophagus to the stomach. As the disease progresses, the muscles of the esophagus begin to degenerate and, over time, the esophagus stretches and dilates. Achalasia affects approximately 1 in 100,000 people per year.

The most common symptoms of achalasia include difficulty swallowing (dysphagia) and the sensation that swallowed materials get stuck in the chest. Other symptoms include regurgitation of swallowed food and liquids, chest pain, heartburn, hiccups, a sensation of a lump or fullness in the throat, and weight loss.

The routine regurgitation of food may lead to the aspiration of food into the lungs, and aspiration pneumonia. Also the irritating effects of pooling food and liquids in the esophagus may cause chronic inflammation of the esophagus (esophagitis). Constant irritation of the esophagus increases the risk of esophageal cancer.

Because other conditions, such as hiatus hernia and gastroesophageal reflux disease (GERD), can produce similar symptoms, confirming an achalasia diagnosis requires other tests. A barium swallow test involves swallowing a thick, chalky-tasting barium solution while X-rays are taken. The barium outlines the esophagus on the X-ray and reveals an esophagus dilated above a constricted region. Esophageal manometry or esophageal motility studies examine the pressure in the esophagus. In this test a pressure sensor is inserted through the mouth or nose into the esophagus. To confirm a diagnosis of achalasia, the LES should show high pressure at rest, a failure to relax after swallowing, and the lower esophagus should show no peristaltic contractions. Endoscopy uses a thin, lighted, flexible tube (endoscope) that is inserted through the mouth to view the inside of the gastrointestinal tract. Patients with achalasia have a dilated esophagus that retains food with small erosions or ulcers on the inner surface.

Two different diseases, Chagas disease and esophageal cancer, can mimic achalasia. Endoscopy can detect esophageal cancer, but Chagas disease, caused by infection with the parasite Trypanosoma cruzi, can affect any portion of the gastrointestinal tract.

Treatment and Therapy

Two classes of drugs, organic nitrates and calcium channel blockers can relieve achalasia symptoms. Unfortunately, these agents have undesirable side effects and lose effectiveness over time.

Balloon dilation requires that the patient swallow a small, collapsed balloon. An X-ray machine is used to guide the balloon, and once positioned at the LES, the balloon is inflated to stretch the lower esophagus. Although patients may require more than one balloon dilation treatment, about 60 percent of patients show relief of symptoms one year after this procedure and 25 percent five years after.

Botox injections utilize a modified version of a toxin made by the bacterium Clostridium botulinum. Endoscopic injections of botulinum toxin (Botox) into the esophageal muscles relax it and relieve obstruction. Botox injections work well in older patients.

Surgery that cuts the muscles of the esophagus (myotomy) can also relieve symptoms long term. Surgeons also wrap part of the stomach around the esophagus (fundoplication) to prevent the reflux of stomach contents into the esophagus. A 2015 study showed that in the short term, patients who have myotomies show greater improvement (and lower failure rates) than those who have balloon dilations, although both treatments decline in efficacy after five years.

Patients who have Botox injections, myotomies or balloon dilations have an increased risk of GERD after the surgery and might need to take proton-pump inhibitors (e.g., omeprazole, lansoprazole, rabeprazole, and others) after surgery.

Procedures and Prospects

The first description of achalasia dates from Sir Thomas Willis in 1672. In 1913, Ernest Heller performed the first successful surgical myotomy to treat achalasia. For this reason, the myotomy procedure used to treat achalasia is called a Heller myotomy. In 1929, Hurt and Rake discovered that the inability of the LES to relax caused the symptoms of “cardiospasm,” as it was known then, and they renamed the condition “achalasia,” which means “failure to relax.”

New developments in achalasia treatment involve reducing the trauma of myotomy and improving its outcomes. Laparoscopic myotomies insert small instruments and a fiber optic camera into the abdomen through a small incision and greatly shorten the patient's recovery time and reduce complications. An even less invasive procedure called peroral endoscopic myotomy inserts all surgical instruments into the esophagus through the mouth by means of an endoscope. Since peroral endoscopic myotomy does not require an incision, it further shortens the recovery time and decreases the rate of complications.

Bibliography

Clayton, Steven B., and Donald O. Castell. "Multiple Good Options Are Available for Achalasia Management." Journal of Clinical Gastroenterology 29.3 (2015): 194–98. Print.

Longo, Dan L., and Anthony S. Fauci. Harrison's Gastroenterology and Hepatology. 2nd ed. New York: McGraw, 2013. Print.

Moonen, An J., and Guy E. Boekxstaens. “Management of Achalasia.” Gastroenterology of North America 42.1 (2013): 45–55. Print.

Persson, Jan, et al. "Treatment of Achalasia with Laparoscopic Myotomy or Pneumatic Dilatation: Long-Term Results of a Prospective, Randomized Study." World Journal of Surgery 39.3 (2015): 713–20. Print.

Sayadi, Roya, and Joel Herskowitz. Swallow Safely: How Swallowing Problems Threaten the Elderly and Others. Natick: Inside/Outside, 2010. Print.

Stavropoulos, Stavros N., Rani Modayil, and David Friedel. “Achalasia.” Gastrointestinal Endoscopy Clinics of North America 23.1 (2013): 53–75. Print.