Achalasia

How achalasia works

Swallowing normally triggers a coordinated wave of contraction (peristalsis) down the esophagus, while the lower esophageal sphincter (LES) relaxes to let food into the stomach. In achalasia, the nerve cells in the esophageal wall (the myenteric plexus) are gradually lost, likely from an autoimmune process, sometimes after a viral infection. Two problems follow:

1. The LES fails to relax properly on swallowing.
2. The body of the esophagus loses its peristalsis.

Food and fluid pool above the tight valve, and over years the esophagus can widen and become twisted (a "sigmoid" esophagus).

Symptoms

• Difficulty swallowing (dysphagia) for both solids and liquids from the start. This is a key difference from a narrowing or cancer, where solids are usually affected first.
• Regurgitation of undigested food or frothy saliva, often hours after eating or at night, sometimes onto the pillow.
• Chest pain or pressure, especially in early disease.
• Heartburn that does not respond well to acid medicines, caused by fermenting food rather than acid reflux.
• Weight loss.
• Night-time coughing or choking from material entering the airway.
• Slow eating, and maneuvers to help food go down, such as drinking water, standing, arching the back or raising the arms.

Because symptoms build slowly, people often have them for years and are first treated for GERD before achalasia is diagnosed.

Causes and risk factors

Primary (idiopathic) achalasia has no single known cause. Proposed mechanisms include autoimmune damage to nerves, a viral trigger and genetic susceptibility. It affects men and women equally.

Secondary achalasia (pseudoachalasia) has the same pattern but a different cause:

• Chagas disease: a parasitic infection common in parts of Latin America that destroys esophageal nerves.
• Cancer at the junction of the esophagus and stomach, which can mimic achalasia. It is suspected with older age, short history and rapid weight loss.
• Prior surgery at the gastroesophageal junction, such as fundoplication or gastric banding.

Types of achalasia

High-resolution manometry divides achalasia into three types (the Chicago Classification), which helps choose treatment:

Diagnosis

• Upper endoscopy: a camera examines the esophagus and stomach. It is essential to rule out cancer and other causes. It may show retained food and a tight valve that "pops" open with gentle pressure.
• High-resolution esophageal manometry: a thin tube measures pressures while you swallow sips of water. This is the gold-standard test for achalasia and determines the type.
• Barium swallow (esophagram): X-rays as you swallow contrast show a widened esophagus narrowing smoothly to a point, called a "bird's beak". A timed barium swallow measures how well the esophagus empties, before and after treatment.
• CT scan or endoscopic ultrasound if pseudoachalasia from a tumor is suspected.

Treatment

No treatment restores the lost nerves. All treatments aim to open the LES so gravity can empty the esophagus.

Pneumatic dilation

A balloon is inflated in the LES during endoscopy to stretch and tear the muscle fibers. It often needs to be repeated over the years. The main risk is a tear (perforation) of the esophagus, which occurs in a small percentage of cases.

Laparoscopic Heller myotomy

Keyhole surgery cuts the muscle of the LES. It is usually combined with a partial fundoplication (wrapping part of the stomach around the esophagus) to reduce reflux afterward. Success rates are high and durable.

Peroral endoscopic myotomy (POEM)

The muscle is cut from inside the esophagus with an endoscope, without external incisions. It is effective for all types and especially useful for type III. Reflux after POEM is common, so long-term acid suppression and monitoring are often needed.

Botulinum toxin injection

Injected into the LES during endoscopy, Botox relaxes it temporarily. Effects typically last months and fade. It is used mainly for older or frail people who cannot have other treatments.

Medicines

Calcium channel blockers and nitrates taken before meals can relax the LES slightly but are rarely effective long-term and cause side effects such as headache and low blood pressure.

End-stage disease

If the esophagus becomes massively widened and does not respond, removal of the esophagus (esophagectomy) may be needed. This is rare.

Complications

• Aspiration pneumonia from regurgitated food entering the lungs
• Malnutrition and weight loss
• Esophagitis from stagnant food or, after treatment, from acid reflux
• Esophageal cancer: long-standing achalasia raises the risk of squamous cell esophageal cancer. Some experts recommend periodic endoscopy after many years of disease.

Living with achalasia

After treatment, most people eat a near-normal diet. Helpful habits include eating slowly, chewing well, drinking water with meals, sitting upright for 2 to 3 hours after eating, and raising the head of the bed. Long-term follow-up checks for recurring symptoms and reflux.

Frequently asked questions

What is achalasia?

Achalasia is a rare condition in which the nerves of the esophagus are damaged. The valve at the bottom does not relax and the esophagus does not push food down, so food and liquid get stuck, causing swallowing difficulty, regurgitation, chest pain and weight loss.

What are the first symptoms of achalasia?

Early symptoms are difficulty swallowing both solids and liquids, a feeling of food sticking in the chest, regurgitation of undigested food and chest pain. Many people are first thought to have acid reflux.

Can achalasia be cured?

The nerve damage cannot be reversed, but treatments such as balloon dilation, Heller myotomy and POEM relieve symptoms in most people for many years. Some people need repeat treatment over time.

Is achalasia serious?

It is not usually life-threatening, but untreated it can cause malnutrition, aspiration pneumonia and a widened esophagus. Long-standing achalasia slightly increases the risk of esophageal cancer, so ongoing follow-up is important.