What study can I order to diagnose esophageal achalasia?

Diagnostic Testing for Esophageal Achalasia

For suspected achalasia, order an upper endoscopy first to exclude structural/mucosal causes, followed by high-resolution manometry (HRM) for definitive diagnosis, with a biphasic barium esophagram serving as a valuable complementary study. 1

Initial Diagnostic Approach

Step 1: Upper Endoscopy with Biopsies

• Endoscopy should be performed first in patients with dysphagia to rule out structural and mucosal disorders before proceeding to manometry. 1
• Obtain biopsies at two levels in the esophagus to exclude eosinophilic esophagitis and pseudoachalasia (secondary causes like malignancy at the gastroesophageal junction). 1
• Endoscopy has poor sensitivity and specificity for diagnosing achalasia itself, but is critical for excluding mimics. 2

Step 2: High-Resolution Manometry (Gold Standard)

• HRM is the definitive diagnostic test for achalasia, with 98% sensitivity and 96% specificity using the 4-second integrated relaxation pressure (IRP). 1
• HRM is superior to standard manometry in terms of reproducibility, speed, and ease of interpretation. 1
• HRM provides critical achalasia subtype information (Type I, II, or III) that predicts treatment outcomes. 1
  • Type II responds best to all therapies (pneumatic dilation, botulinum toxin, myotomy)
  • Type III has the poorest response to treatment
  • Type I has intermediate outcomes 1

Step 3: Biphasic Barium Esophagram (Complementary Study)

• A biphasic barium esophagram is highly valuable as it can simultaneously detect both structural abnormalities and functional motility disorders. 3
• Videofluoroscopy has 80-89% sensitivity and 79-91% specificity for diagnosing esophageal motility disorders including achalasia compared to manometry. 1, 3
• The classic "bird's beak" appearance of distal esophageal narrowing with proximal dilation suggests achalasia. 1, 4
• Barium studies may occasionally reveal dysmotility not detected on manometry, as some achalasia patients show complete lower esophageal sphincter relaxation on manometry despite characteristic radiographic findings. 1

Advanced/Adjunctive Testing

Timed Barium Esophagram (TBE)

• TBE quantitatively assesses esophageal emptying and can differentiate achalasia from other causes of dysphagia. 5, 6
• A barium column height >2 cm at 5 minutes has 85% sensitivity and 86% specificity for untreated achalasia. 5
• Combining liquid barium with a barium tablet increases diagnostic yield from 79.5% to 100% in untreated achalasia patients. 5
• TBE is particularly useful for monitoring treatment response post-intervention. 5, 6

Clinical Pearls and Pitfalls

Common Pitfalls to Avoid:

• Do not rely on endoscopy alone—it will miss achalasia in most cases as the mucosa typically appears normal. 2
• Do not skip endoscopy before manometry, as pseudoachalasia from gastroesophageal junction malignancy can mimic primary achalasia on manometry. 1, 2
• Barium swallow should be considered when endoscopy is not possible or when structural disorders require further scrutiny. 1

Key Diagnostic Sequence:

1. Upper endoscopy with biopsies (exclude structural/mucosal disease and pseudoachalasia) 1
2. High-resolution manometry (definitive diagnosis and subtyping) 1
3. Biphasic barium esophagram (complementary structural and functional assessment) 1, 3
4. Consider timed barium esophagram for quantitative assessment and treatment monitoring 5, 6