Other names: esophageal achalasia, achalasia cardiae, cardiospasm, dyssynergia esophagus, and esophageal aperistalsis
Achalasia is a swallowing disorder that makes it difficult for food and liquid to pass into the stomach. It is an esophageal motility disorder where the smooth muscle layer of the esophagus loses normal peristalsis (the muscular action of moving food down the esophagus), and the lower esophageal sphincter (LES) does not respond properly to swallowing. There is an inability of the lower sphincter to relax and open to let food pass into the stomach. These abnormalities of the lower sphincter and esophagus can cause food to get stuck in the esophagus.
The condition is fairly rare, affecting about 1 in every 100,000 people. It affects men and women equally between the ages of 30-60. It can also occur in infancy and childhood..
The cause of achalasia is unknown. Patients with achalasia have two problems in the esophagus:
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).
The most common symptom of achalasia is difficulty swallowing (dysphagia). Patients typically describe food sticking in the chest after it is swallowed. Dysphagia occurs with both solid and liquid food, during virtually every meal.
Regurgitation of food that is trapped in the esophagus can occur, especially when the esophagus is dilated. If the regurgitation happens at night while the patient is sleeping, food can enter the throat and cause coughing and choking. If the food enters the trachea and lung, it can lead to pneumonia (aspiration pneumonia).
Other symptoms can include chest pain or a heavy sensation in the chest, coughing, heartburn, difficulty burping, a sensation of fullness or a lump in the throat, hiccups, and weight loss. The symptoms are slow to develop and gradually worsen over time.
The diagnosis of achalasia often is suspected on the basis of the symptoms, although tests are needed to confirm the diagnosis and to rule out other conditions with similar symptoms, such as gastroesophageal reflux disease, hiatus hernia, pseudoachalasia (a rare condition in which certain tumors can mimic the features of achalasia), an infection called Chagas' disease, (almost exclusively seen in Central and South America), and even psychosomatic disorders.
The dysphagia in achalasia also is different from the dysphagia of esophageal stricture (narrowing of the esophagus due to scarring) and esophageal cancer. In achalasia, dysphagia occurs with both solid and liquid food, whereas in esophageal stricture and cancer, the dysphagia typically occurs only with solid food.
The diagnosis of achalasia usually is made by an x-ray study called a video-esophagram in which video x-rays of the esophagus are taken after barium is swallowed. The barium fills the esophagus, and the emptying of the barium into the stomach can be observed. In achalasia, the video-esophagram shows that the esophagus is dilated with a characteristic tapered narrowing of the lower end. Also, the barium stays in the esophagus longer than normal before passing into the stomach.
The test involves swallowing a chalky-tasting, thick mixture of barium while x-rays are taken. The barium shows the outline of the esophagus and LES. Barium swallows are usually performed with fluoroscopy, a continuous low-grade x-ray, which is helpful for studying the motion in the esophagus. In achalasia, barium swallows usually reveals an absence of contractions in the esophagus after swallowing. Sometimes this test reveals spastic contractions of the esophagus in response to swallowing; this variation of achalasia is known as vigorous achalasia.
After the barium swallow, patients should drink extra fluid. Stools may be light in color for a few days after testing as a result of the barium.
Esophageal manometry can identify the abnormalities of muscle function that are characteristic of achalasia, that is, the failure of esophageal muscles to contract with swallowing and the failure of the lower esophageal sphincter to relax. For manometry, a thin tube that measures the pressure created by the contracting esophageal muscle is passed through the nose into the esophagus. In a patient with achalasia, no peristaltic waves are seen in the lower half of the esophagus after swallows, and the pressure within the contracted lower esophageal sphincter does not fall with the swallow.
Manometry is almost always used to confirm achalasia. The test typically reveals these three abnormalities: high pressure in the LES at rest, failure of the LES to relax after swallowing, and an absence of useful (peristaltic) contractions in the lower esophagus.
An advantage of manometry is that it can diagnose achalasia early in its course at a time at which the video-esophagram may be normal.
Endoscopy is a procedure in which a flexible fiberoptic tube with a light and camera on the end is swallowed allowing the physician to see the inside of the esophagus, LES, and stomach. Endoscopy is done while the person is sedated.
This test is usually recommended for people with suspected achalasia and is especially useful for detecting other conditions that can mimic achalasia. Two conditions can mimic achalasia, esophageal cancer and Chagas' disease of the esophagus. Both can give rise to video-esophageal and manometric abnormalities that are indistinguishable from achalasia.
Endoscopy often reveals distortion of the esophagus and the presence of residual food; it may also reveal inflammation or small ulcers caused by residual food or pills, and candida (yeast) infection. Endoscopy may reveal a dilated esophagus and a lack of peristaltic waves. Endoscopy also is important because it excludes the presence of esophageal cancer. Cancer in the upper part of the stomach can produce symptoms almost identical to those of achalasia, and is called pseudoachalasia (meaning "false" achalasia). Thus, biopsies (small samples of tissue) are often obtained in the lower portion of the esophagus. Having a biopsy while sedated is not painful and is very safe.
Because patients typically will learn to compensate for their dysphagia by taking smaller bites, chewing well, and eating slowly, the diagnosis of achalasia often is delayed by months or even years. The delay in diagnosis of achalasia is unfortunate because it is believed that early treatment--before marked dilation of the esophagus occurs-can prevent esophageal dilation and its complications..
Oral medications to relax the esophageal sphincter are taken before each meal. This allows more food to pass into the stomach. The drugs may be nitrates (e.g. isosorbide dinitrate or nitroglycerin) and/or calcium-channel blockers (e.g., nifedipine (Procardia) and verapamil (Calan)). Side effects such as headache, low blood pressure and pedal edema (swollen feet) are common. Oral medications are recommended only for patients who are in the very early stages of the disease, are not candidates for surgery, or who have not received relief with botulinum toxin injections.
Botox is injected directly into the esophageal sphincter during endoscopic surgery. The toxin weakens the sphincter muscle, which allows food to pass into the stomach. Botulinum toxin injections are effective for many people, but they must be repeated every few months. This treatment is usually reserved for elderly patients or patients who are at high surgical risk (Botox was developed from the toxin causing botulism, a form of food poisoning, but the very low doses used as treatment for achalasia present no risk).
In balloon (pneumatic) dilation (also called dilatation) the muscle fibers are stretched and slightly torn by inflating balloon-like device inserted into the esophagus to stretch the esophageal sphincter. A local anesthetic is used to numb the throat and medication is given intravenously to help the patient relax. This procedure is successful 50 to 80 percent of the time and does not require hospitalization. If balloon dilatation is successful, its benefits are usually permanent for patients over 40, however, a small number of people, usually younger patients may need further treatments.
There is a 4% - 5% risk of esophageal tearing during the procedure. If a tear occurs, emergency surgery is performed to repair the tear.
Surgery to cut the esophageal sphincter muscle (esophagomyotomy ) is called a Heller Myotomy. The myotomy is a lengthwise cut along the esophagus, starting above the LES and extending down onto the stomach a little way. A laparoscope (a telescope-like instrument) and operating instruments are inserted through several keyhole slits made in the abdomen. Through the laparoscope, the esophageal sphincter muscle is cut. The esophagus is made of several layers, and the myotomy only cuts through the outside muscle layers which are squeezing it shut, leaving the inner muscosal layer intact. A partial fundoplication or "wrap" is generally added in order to prevent excessive reflux, which can cause serious damage to the esophagus over time.
This procedure lasts about two hours and usually requires one to two days in the hospital. The Heller Myotomy has a success rate of 90% and when the surgery is successful, the benefits are usually permanent.
By Mortin - Copyright 2009
Last modification 30/12/2009