Achalasia
Achalasia is a rare swallowing disorder that affects only 1 in every 100,000 people. Most people are diagnosed between the ages of 25 and 60 years.
CAUSE
The specific cause of achalasia is unknown. However, patients with achalasia have two problems in the esophagus
The first is that the lower two-thirds of the esophagus does not propel food toward the stomach properly.
The second problem is in the lower esophageal sphincter (LES). The LES normally helps prevent food from flowing backwards, from the stomach into the esophagus. The LES should relax in response to swallowing to allow food to enter the stomach. In patients with achalasia, the LES fails to relax, creating a barrier that prevents food and liquids from passing into the stomach.
Damage to the LES and esophagus causes large volumes of food and saliva to accumulate in the esophagus. Patients can initially compensate for this but eventually the barrier progresses to the point where food and saliva cannot reliably enter the stomach, and, as a result, build up in the esophagus.
SYMPTOMS
The major symptom is difficulty swallowing (liquids or solids). Other symptoms include chest pain, regurgitation of swallowed food and liquid, heartburn, difficulty burping, a sensation of fullness or a lump in the throat, hiccups, and weight loss.
DIAGNOSIS
Achalasia is usually suspected based upon the presence of the symptoms described above, but tests are needed to confirm the diagnosis.
■Chest x-rays :
A simple chest x-ray may reveal distortion of the esophagus and absence of air in the stomach, two abnormalities that suggest achalasia.
■Barium swallow test :
The barium swallow test is the primary screening test for achalasia. The barium shows the outline of the esophgus and LES. In achalasia, barium swallows usually reveals an absence of contractions in the esophagus after swallowing.
■Manometry :
Manometry refers to the measurement of pressure within the esophagus and the LES. The test is done after patients have had nothing to eat or drink for eight hours, while patients are awake. Patients will be asked to swallow while the tube is in place.
Manometry is always used to confirm achalasia. The test typically reveals three abnormalities in people with achalasia: 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. The last two features are the most important and are required to make the diagnosis.
■Endoscopy :
Endoscopy allows for direct visualization of the inside of the esophagus, LES, and stomach. This test is usually recommended for people with suspected achalasia and is especially useful for detecting other conditions that mimic achalasia.
TREATMENT
several options are available for the treatment of achalasia. Unfortunately, none can halt or reverse the underlying problem. However, all of the treatments are effective for improving symptoms.
Two of these treatments (drug therapy and botulinum toxin injection) work by reducing the LES pressure while two other treatments (balloon dilatation and surgery) work by mechanically weakening the muscle fibers of the LES.
Drug therapy :
Two classes of drugs, nitrates and calcium channel blockers have muscle-relaxing effects on LES. They are usually taken by placing a pill under the tongue 10 to 30 minutes before meals.
Balloon dilatation (pneumatic dilatation) :
Balloon dilatation mechanically stretches the contracted LES. This procedure is effective for relieving symptoms of achalasia in two-thirds of patients. Up to half of patients may require more than one treatment for adequate relief.
Success rate :
A single balloon dilatation session continues to relieve symptoms of achalasia in about 60% of people one year after the procedure and in about 25 % of people five years after the procedure.
Surgery (myotomy) :
Myotomy can be used to directly cut the muscle fibers of the LES. In the past, surgery was performed through an open incision in the chest or abdomen, but it can now be performed through a tiny incision using a laparoscope.
Success rate :
Surgery relieves symptoms in 70 to 90 % of people. Symptom relief is sustained in about 85 % of people 10 years after surgery and in about 65 % of people 20 years after the surgery. Thus, surgery is a more permanent solution for achalasia than others. However, surgery can also be associated with complications, is more invasive than balloon dilatation (and more costly).
Botulinum toxin injection :
Botulinum toxin injection is the newest treatment for achalasia. The botulinum toxin temporarily paralyzes the nerve cells that signal the LES to contract thereby helping to relieve the obstruction. Botulinum toxin injection is more likely to be effective in people over the age of 50 years . Botulinum toxin injection may also be used as a diagnostic test in people with suspected achalasia who have inconclusive test results.
Success rate :
A single botulinum toxin injection session relieves symptoms in 65 to 90 % of people in the short term (three months to approximately one year). Additional injections can relieve symptoms in patients whose symptoms return.
RISK OF ESOPHAGEAL CANCER
People with achalasia have an increased risk of esophageal cancer, particularly if obstruction is not adequately relieved. As a result, doctors recommend regular endoscopic screening for early detection of this cancer.
