• Clinical science

Achalasia

Summary

Achalasia is a failure of the lower esophageal sphincter (LES) to relax that is caused by the degeneration of inhibitory neurons within the esophageal wall. It is classified as either primary (idiopathic) or secondary (in the context of another disease). In patients with achalasia, the chief complaint is dysphagia to both solids and liquids, although regurgitation, retrosternal pain, and weight loss may also occur. Upper endoscopy, esophageal barium swallow, and esophageal manometry play complementary roles in the diagnosis of achalasia. While upper endoscopy and/or esophageal barium swallow are often obtained initially, manometry usually confirms the diagnosis, and upper endoscopy is indicated to rule out a malignant underlying cause. In good surgical candidates, achalasia is usually treated with pneumatic dilation or myotomy. In most other cases, an injection of botulinum toxin is attempted. If these measures fail to provide relief, medical therapy (e.g., nifedipine) is indicated.

Definition

  • Esophageal mobility disorder characterized by inadequate relaxation of the lower esophageal sphincter (LES) and nonperistaltic contractions in the distal two-thirds of the esophagus due to the degeneration of inhibitory neurons
  • Etymology: A (absent) -chalasia (relaxation)

Epidemiology

  • Rare disorder (∼ 1.6/100,000 individuals)
  • Most commonly occurs in middle-aged individuals

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

CHAgas disease may lead to secondary aCHAlasia.

References:[1]

Pathophysiology

References:[1]

Clinical features

  • Dysphagia to solids and liquids; can be progressive or paradoxical
  • Regurgitation
  • Retrosternal pain and cramps
  • Weight loss

Achalasia typically manifests with progressive dysphagia to solids and liquids while esophageal obstruction manifests with dysphagia to solids only.

References:[1]

Diagnostics

References:[1][2]

Differential diagnoses

Differential diagnoses of achalasia

Differential diagnosis of esophageal motility disorders

Esophageal motility disorders range from hypomotile dysfunction (achalasia) to hypermotile dysfunction (diffuse esophageal spasm, nutcracker esophagus); of the esophagus. They have similar symptoms with dysphagia, chest pain, and regurgitation of food, but are differentiated based on findings in esophagograms and esophageal manometry.

Normal esophagus

Achalasia

Distal esophageal spasm

(Corkscrew esophagus/rosary bead esophagus)

Hypertensive peristalsis

(Supersqueeze esophagus/nutcracker esophagus)

Symptoms
  • None
  • Progressive dysphagia or paradoxical dysphagia
  • Regurgitation of undigested food/saliva
  • Weight loss

Lower esophageal sphincter (LES) pressure and relaxation

  • Normal
  • LES pressure: high (failure to relax)
  • LES relaxation: incomplete/absent
  • Normal
  • Normal

Contraction waves

  • Progressive (toward the LES)
  • Simultaneous, nonprogressive

  • Simultaneous, nonprogressive, repetitive
  • Nonperistaltic contractions
  • Long duration
  • High pressure waves

Esophageal barium swallow

  • Normal
  • Dilated esophagus that tapers distally (bird-beak sign/rat tail appearance)
  • LES spasm and delayed barium emptying
  • Normal progressive contractions, but high amplitude (supersqueeze, nutcracker)

Esophageal manometry

  • Normal (40–100 mm Hg)
  • High LES resting pressure
  • High esophageal body pressure
  • Low peristaltic contraction pressure
  • Simultaneous multi-peak contractions
  • High pressure contractions
  • Intermittent normal peristalsis
  • Hypertensive contractions (> 400 mm Hg)
Treatment
  • See “Treatment.”

The differential diagnoses listed here are not exhaustive.

Treatment

If a low surgical risk

The preferred treatment often depends on the surgeon and the patient's situation. However, attempting pneumatic dilation before myotomy is gaining popularity because it is less invasive and the time of recovery is faster. This approach is already more popular in Europe.

  • Pneumatic dilation
    • Endoscope-guided graded dilation of the LES that tears the surrounding muscle fibers with the help of a balloon
    • The success rate at one month is ∼ 85%; perforation risk is ∼ 2%.
  • LES myotomy (Heller myotomy)

If a high surgical risk

References:[2][3]

Complications

References:[1][3]

We list the most important complications. The selection is not exhaustive.