What is achalasia?

Achalasia: A Primary Esophageal Motility Disorder

Achalasia is a primary esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation and absent peristalsis in the esophageal body, resulting in progressive dysphagia, regurgitation, chest pain, and weight loss. 1

Pathophysiology and Etiology

Achalasia has a strong autoimmune component, with potential triggers including viral infections in genetically susceptible individuals. The classical pathology involves inflammation of the myenteric plexus leading to aganglionosis. 2, 1

Clinical Presentation

Patients typically present with:

• Dysphagia to both solids and liquids (primary symptom)
• Regurgitation of undigested food
• Chest pain
• Weight loss
• Aspiration and respiratory complications (cough, pneumonia)

A key diagnostic challenge is that achalasia is often initially misdiagnosed as gastroesophageal reflux disease, delaying proper treatment by several years. 3

Diagnostic Approach

High-Resolution Manometry (Gold Standard)

• Demonstrates absent peristalsis and impaired LES relaxation
• Elevated integrated relaxation pressure (IRP) with 98% sensitivity and 96% specificity
• Early in disease, provocative maneuvers (multiple rapid swallows, rapid drink challenge) may help unmask impaired inhibition 1

Classification

Achalasia is categorized into three subtypes based on manometric findings:

1. Type I (Classic): Negligible pressurization within the esophagus
2. Type II: Panesophageal pressurization with uniform simultaneous pressurization bands
3. Type III (Spastic): Premature (spastic) contractions

Type II is the most common presenting subtype and generally has the best response to therapy, while Type III has the poorest response to all treatments. 2, 1

Additional Diagnostic Tests

• Barium esophagram: Shows "bird's beak" appearance and esophageal dilation
• Endoscopy: Rules out mechanical obstruction or malignancy
• Functional luminal imaging probe (FLIP): Helps establish diagnosis in challenging cases 1

Treatment Options

Since there is no curative treatment for achalasia, management focuses on disrupting the LES to improve bolus passage. 4

First-Line Treatments

1. Pneumatic Dilation

   • Highly efficacious for Type I and II achalasia
   • Graded approach using Rigiflex balloons (3.0,3.5, and 4.0 cm)
   • Symptom improvement in up to 90% of patients 1, 5

2. Laparoscopic Heller Myotomy (LHM)

   • Efficacy comparable to pneumatic dilation for Type I and II achalasia
   • Reduced morbidity and hospitalization time compared to open surgical approach 1, 5

3. Per-Oral Endoscopic Myotomy (POEM)

   • Preferred for Type III achalasia as it allows for a longer myotomy
   • Comparable efficacy to LHM for Types I and II
   • Important caveat: Post-POEM patients have high risk of developing reflux esophagitis and should be advised about potential indefinite PPI therapy and/or surveillance endoscopy 2, 1

Second-Line Treatments

• Medical therapy (calcium channel blockers and nitrates)

  • Reserved for patients who are not candidates for more definitive procedures
  • Limited efficacy compared to invasive options 1, 5

• Botulinum toxin injection

  • Reserved for patients who cannot undergo balloon dilation and are not surgical candidates
  • Temporary effect, often requiring repeated treatments 5, 6

Post-Treatment Considerations

Monitoring

• Evaluate for immediate complications (perforation, chest pain, fever)
• Monitor for symptom recurrence (50-60% may need repeat procedures)
• Surveillance for reflux symptoms, especially after POEM
• Watch for late complications including megaesophagus and increased risk of esophageal carcinoma 1

Red Flags Requiring Urgent Evaluation

• Significant weight loss
• Sudden worsening of dysphagia
• Recurrent chest infections due to aspiration
• Hematemesis or melena
• Progressive regurgitation with aspiration symptoms 1

Achalasia remains an incurable condition, but with proper diagnosis and appropriate treatment selection based on achalasia subtype, most patients can achieve significant symptom relief and improved quality of life.