Achalasia is characterised by failure of the lower oesophageal sphincter to relax and absent peristalsis. The Chicago Classification v4.0 of oesophageal motility disorders identifies three subtypes of achalasia based on high-resolution manometry (HRM). In Type II achalasia, the Chicago criteria require:

• A Absence of peristalsis with premature contractions in >20% of swallows
• B Elevated IRP with normal peristalsis in some swallows
• C Elevated IRP with distal latency <4.5 seconds in >20% of swallows
• D Elevated integrated relaxation pressure (IRP) with panesophageal pressurisation in ≥20% of swallows ✓

Explanation

Chicago Classification v4.0 achalasia subtypes: Type I = elevated IRP, 100% failed peristalsis (no pressurisation); Type II = elevated IRP with panesophageal pressurisation in ≥20% of swallows (best prognosis, responds best to treatment); Type III = elevated IRP with spastic contractions (DL <4.5 s) in ≥20% of swallows. Type II has the best treatment response to Heller myotomy or POEM.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.