What diagnostic studies and treatment options are recommended for a patient suspected of having achalasia?

Diagnostic Studies to Confirm Achalasia

Esophageal manometry is the gold standard and must be performed to confirm the diagnosis of achalasia, with high-resolution manometry (HRM) providing superior diagnostic accuracy (98% sensitivity, 96% specificity) compared to standard manometry. 1

Essential Diagnostic Workup

Primary Confirmatory Test

• High-resolution manometry (HRM) is mandatory to establish the diagnosis definitively 1
• HRM demonstrates impaired lower esophageal sphincter (LES) relaxation and absent peristalsis with 98% sensitivity and 96% specificity using the 4-second integrated relaxation pressure (IRP) 1
• HRM also identifies achalasia subtypes (Types I, II, III), which predict treatment response and guide therapeutic decisions 1

Initial Screening Studies (Performed Before Manometry)

Upper endoscopy (esophagogastroduodenoscopy) should be performed first to exclude malignancy and pseudoachalasia 1

• Careful retroflexed examination of the gastroesophageal junction is mandatory to exclude irregularities suggesting pseudoachalasia 1
• Obtain biopsies at two levels in the esophagus to exclude eosinophilic esophagitis 1
• Look for characteristic findings: frothy retained secretions, food debris, puckered gastroesophageal junction 1, 2
• Important caveat: Endoscopic findings have poor sensitivity—resistance at the esophagogastric junction is present in only 30-50% of achalasia patients, and food debris in only 40-70% 3

Timed barium esophagram provides complementary anatomical information 1

• Documents barium retention confirming outflow obstruction 1
• Administration of a 13-mm barium tablet can reveal subtle narrowing at the esophagogastric junction 1
• Particularly useful when stricture prevents endoscope passage or for monitoring disease severity 1
• Characteristic findings (dilated esophagus, air-fluid level) are present in >80% of achalasia patients but <10% of non-achalasia patients 3

Adjunctive Studies When Diagnosis Remains Equivocal

Endoscopic functional luminal impedance planimetry (FLIP) can be useful when diagnosis is uncertain 1

• Impaired esophagogastric junction opening (low distensibility index) supports achalasia diagnosis when manometry is inconclusive 1

Computed tomography (CT) scanning and endoscopic ultrasound (EUS) should be performed when pseudoachalasia from occult malignancy is suspected 1

• These imaging modalities help exclude mechanical obstruction when other tests fail to confirm diagnosis 1
• CT findings (dilated esophagus, air-fluid level) have >80% sensitivity for achalasia 3

Critical Diagnostic Algorithm

1. Start with upper endoscopy with biopsies to exclude structural/mucosal disease and malignancy 1
2. Obtain timed barium esophagram for anatomical detail and confirmation of retention 1, 3
3. Perform high-resolution manometry to definitively confirm achalasia and determine subtype 1
4. Add FLIP testing if manometric findings are equivocal 1
5. Pursue CT/EUS imaging if pseudoachalasia is suspected based on age >60, rapid symptom onset (<1 year), or significant weight loss 1

Common Pitfalls to Avoid

• Do not rely on endoscopy alone—it misses approximately 50-70% of achalasia cases due to poor sensitivity of classic findings 3
• Do not skip manometry—clinical features and barium/endoscopic findings only suggest the diagnosis but cannot confirm it 1
• Do not overlook pseudoachalasia—always perform careful endoscopic assessment of the gastroesophageal junction and consider CT/EUS in patients with atypical presentations 1
• Patients with achalasia require prolonged fasting (>4-6 hours) or esophageal lavage before procedures due to esophageal stasis 1