Achalasia

Achalasia, also known as esophageal achalasia, achalasia cardiae, cardiospasm, dyssynergia esophagus, and esophageal aperistalsis, is an esophageal motility disorder: The smooth muscle layer of the esophagus loses normal peristalsis (muscular ability to move food down the esophagus), and the lower esophageal sphincter (LES) fails to relax properly in response to swallowing.

Achalasia is characterized by difficulty swallowing, regurgitation, and sometimes chest pain. Diagnosis is reached with esophageal manometry and barium swallow X-ray studies. Various treatments are available, although none cure the condition completely. Certain medications or Botox may be used in some cases, but more permanent relief is brought by esophageal dilatation and surgical cleaving of the muscle (Heller myotomy).

The most common form is primary achalasia, which has no known underlying cause. However, a small proportion occurs as a secondary result of other conditions, such as esophageal cancer or Chagas disease (an infectious disease common in South America). Achalasia affects about one person in 100,000 per year.

Signs and symptoms

The main symptoms of achalasia are dysphagia (difficulty in swallowing), regurgitation of undigested food and chest pain. The dysphagia tend to be progressively worse over time, and to involve fluids and solids simultaneously. Some also experience coughing, especially when lying in a horizontal position. Food and liquid, including saliva, are retained in the esophagus and may be inhaled into the lungs (aspiration), potentially leading to aspiration pneumonia. If the swallowing problems are severe, the inadequate intake of nutrients may lead to weight loss.

Diagnosis

Due to the similarity of symptoms, achalasia can be mistaken for more common disorders such as gastroesophageal reflux disease (GERD), hiatus hernia, and even psychosomatic disorders.

("Bird's beak" appearance, typical in achalasia.)

Specific tests for achalasia are barium swallow and esophageal manometry. In addition, a CT scan of the chest and endoscopy of the esophagus, stomach and duodenum (esophagogastroduodenoscopy or EGD), with or without endoscopic ultrasound, are typically performed to rule out the possibility of cancer. The internal tissue of the esophagus generally appears normal in endoscopy, although a "pop" may be observed as the scope is passed through the non-relaxing lower esophageal sphincter with some difficulty.

Barium swallow

(Schematic of manometry in achalasia showing aperistaltic contractions, increased intraesophageal pressure and failure of relaxation of the lower esophageal sphincter.)

The patient swallows a barium solution, with continuous fluoroscopy (X-ray recording) to observe the flow of the fluid through the esophagus. Normal peristaltic movement of the esophagus is not seen. There is acute tapering at the lower esophageal sphincter and narrowing at the gastro-esophageal junction, producing a "bird's beak" or "rat's tail" appearance. The esophagus above the narrowing is often dilated (enlarged) to varying degrees as the esophagus is gradually stretched, and it may contain food debris. An air-fluid margin is often seen over the barium column due to the lack of peristalsis. A five-minute timed barium swallow can provide a useful benchmark to measure the effectiveness of treatment.

Esophageal manometry

Because of its sensitivity, manometry (esophageal motility study) is considered the key test for establishing the diagnosis. A thin tube is inserted through the nose, and the patient is instructed to swallow several times. The probe measures muscle contractions in different parts of the esophagus during the act of swallowing.

Biopsy

Biopsy, the removal of a tissue sample during endoscopy, is not typically necessary in achalasia, but if performed shows hypertrophied musculature and absence of certain nerve cells of the myenteric plexus, a network of nerve fibers that controls esophageal peristalsis.

Treatment

Medication

Drugs that reduce LES pressure may be useful, especially as a way to buy time while waiting for surgical treatment. These include calcium channel blockers such as nifedipine, and nitrates such as isosorbide dinitrate and nitroglycerin. However, many patients experience unpleasant side effects such as headache and swollen feet, and these drugs often stop helping after several months.

Botulinum toxin (Botox) may be injected into the lower esophageal sphincter to paralyze the muscles holding it shut. As in the case of cosmetic Botox, the effect is only temporary, and symptoms return relatively quickly in most patients. Botox injections cause scarring in the sphincter which may increase the difficulty of later Heller myotomy. This therapy is only recommended for patients who cannot risk surgery, such as elderly persons in poor health.

Pneumatic dilatation

In balloon (pneumatic) dilation, also called dilatation, the muscle fibers are stretched and slightly torn by forceful inflation of a balloon placed inside the lower esophageal sphincter. Gastroenterologists who specialize in achalasia and have performed many of these forceful balloon dilations achieve better results and fewer perforations. There is always a small risk of a perforation which must be fixed by surgery right away. This treatment causes some scarring which may increase the difficulty of Heller myotomy if this surgery is needed later. Gastroesophageal reflux (GERD) occurs after pneumatic dilation in some patients. Pneumatic dilation is most effective on the long term in patients over the age of 40; the benefits tend to be shorter-lived in younger patients. It may need to be repeated with larger balloons for maximum effectiveness.

Surgery

Heller myotomy helps 90% of achalasia patients. It can usually be performed by a keyhole approach, or laparoscopically. The myotomy is a lengthwise cut along the esophagus, starting above the LES and extending down onto the stomach a little way. 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. After surgery, patients should keep to a soft diet for several weeks to a month, avoiding foods that can aggravate reflux.

Alternative medicine

Temporary improvement of achalasia symptoms in some cases has been reported with acupuncture, traditional Chinese herbal medicine, and relaxation techniques.

Lifestyle changes

Both before and after successful treatment, achalasia patients may need to eat slowly, chew very well, drink plenty of water with meals, and avoid eating near bedtime. Raising the head of the bed or sleeping with a wedge pillow promotes emptying of the esophagus by gravity. After surgery or pneumatic dilatation, proton pump inhibitors can help prevent reflux damage by inhibiting gastric acid secretion; and foods that can aggravate reflux, including ketchup, citrus, chocolate, mint, alcohol, and caffeine, may need to be avoided.

Follow-up

Follow-up monitoring: Even after successful treatment of achalasia, swallowing may still deteriorate over time. The esophagus should be checked every year or two with a timed barium swallow because some may need pneumatic dilations, a repeat myotomy, or even esophagectomy after many years. In addition, some physicians recommend pH testing and endoscopy to check for reflux damage, which may lead to a premalignant condition known as Barrett's esophagus or a stricture if untreated.