Achalasia Cardia Diagnosis and Pseudo-achalasia Differential
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Direct answer
Achalasia cardia is a primary oesophageal motility disorder in which the lower sphincter fails to relax and peristalsis is lost, caused by degeneration of inhibitory myenteric neurons. High-resolution manometry is the diagnostic standard, showing incomplete sphincter relaxation and absent peristalsis, while barium swallow shows a bird-beak narrowing at the junction. Treatment lowers outflow resistance by pneumatic dilatation, Heller myotomy or peroral endoscopic myotomy, after malignant pseudo-achalasia is excluded.
What you must remember
- Pathology: loss of inhibitory neurons in the myenteric plexus, with a non-relaxing lower oesophageal sphincter and absent peristalsis in the body of the oesophagus.
- Manometry: high-resolution manometry shows raised sphincter pressure with incomplete relaxation; the Chicago classification subtypes achalasia into types I, II and III, with type II responding well to myotomy.
- Barium swallow: a dilated oesophagus with retained food and a tapered bird-beak narrowing at the junction, with an absent gastric air bubble.
- Malignant mimic: carcinoma at the gastro-oesophageal junction causes pseudo-achalasia, so endoscopy with biopsy precedes any treatment decision.
- Dilatation: pneumatic dilatation is effective, particularly in older patients, though perforation is a recognised complication.
- Surgery and POEM: laparoscopic Heller myotomy with fundoplication, or peroral endoscopic myotomy, relieves symptoms in fit patients.
- Long-term risk: aspiration pneumonia and squamous cell carcinoma of the oesophagus are recognised complications.
Diagnosing a young woman with progressive dysphagia
A 32-year-old woman has two years of dysphagia to both solids and liquids, regurgitation of undigested food at night and a four-kilogram weight loss. Barium swallow shows a dilated oesophagus with a tapered bird-beak narrowing at the junction.
- Exclude malignancy first: Because weight loss is a warning feature, endoscopy comes first and shows no mass, with biopsies negative for malignancy.
- Confirm with manometry: High-resolution manometry shows absent peristalsis and incomplete relaxation of the lower sphincter, which confirms primary achalasia cardia.
- Offer dilatation: Pneumatic dilatation can be offered with a perforation warning, depending on her fitness and preferences.
- Discuss durable options: Peroral endoscopic myotomy or laparoscopic Heller myotomy is discussed as a more durable option.
- Reserve botulinum toxin: Botulinum toxin injection is kept for patients who cannot undergo either.
- Plan follow-up: Follow-up addresses reflux and recurrent symptoms after the chosen procedure. Patients are warned that reflux can follow myotomy, so acid suppression is used, and that dysphagia returning months later may call for repeat dilatation.
Where the exam tries to catch you
Achalasia questions turn on a few contrasts and mimics.
- Trap: Reading any malignant narrowing as achalasia. Correct: The bird-beak sign of achalasia is contrasted with the apple-core lesion of carcinoma, and a malignant stricture is not an achalasia sign.
- Trap: Treating with calcium channel blockers or nitrates as definitive therapy. Correct: These offer only temporary symptom relief.
- Trap: Choosing manometry alone as the complete workup. Correct: Manometry is the diagnostic test, but endoscopy is always done first to exclude malignancy.
- Trap: Missing Chagas disease in a patient from an endemic area. Correct: Chagas is a classic secondary cause, though uncommon in India, and examiners set it up as a stem about a patient from an endemic area.
The lesson is to check for the mimic before accepting the primary diagnosis.
Frequently asked questions
What is the diagnostic standard investigation for achalasia cardia?
High-resolution manometry is the diagnostic standard for achalasia cardia, showing incomplete relaxation of the lower oesophageal sphincter and absent peristalsis. Endoscopy is done first to exclude a malignant mimic, while barium swallow demonstrates the classic bird-beak narrowing.
What does the bird-beak sign on barium swallow indicate?
The bird-beak sign describes tapering narrowing at the lower oesophagus on barium swallow, corresponding to the failed relaxing sphincter in achalasia cardia. Dilatation of the oesophagus above the narrowing with retained food is typical, whereas a carcinoma produces an apple-core lesion.
Which treatment option is preferred for achalasia cardia in fit patients?
Peroral endoscopic myotomy or laparoscopic Heller myotomy with fundoplication is widely used in fit patients with achalasia cardia, and pneumatic dilatation remains an effective alternative. Botulinum toxin injection is reserved for patients unsuitable for dilatation or surgery, because its effect often wears off.
Why is Chagas disease relevant to achalasia cardia?
Chagas disease, caused by Trypanosoma cruzi, produces a secondary form of achalasia by destroying myenteric neurons, and it can mimic primary achalasia cardia on barium studies. It is endemic in Latin America and uncommon in India, so serology should be sought when the epidemiology fits.