High-resolution manometry in diagnosis and treatment of achalasia: help or hype.

High-resolution manometry (HRM) with 36 pressure transducers spanning the esophagus has revolutionized the diagnosis and treatment of esophageal motility disorders, especially with respect to achalasia. The three major contributions of HRM are as follows: (a) Integrated relaxation pressure (IRP) at the esophagus gastric junction (EGJ) >15 mmHg has a sensitivity of 97 % for the diagnosis of achalasia; (b) there are three distinct subtypes of achalasia - type 1 (no distal pressurization), type II (panesophageal pressurization), and type III (spastic contractions); and (c) subtypes predict the success of treatment with type II patients doing the best and type III being the most difficult to treat. Recent studies also suggest that HRM is superior to conventional manometry for diagnosis of achalasia. Other useful observation from HRM is the recognition of EGJ outflow obstruction (type IV achalasia) with normal peristalsis which may be due to mechanical or functional impairment at the EGJ. Finally, after successful treatment of achalasia, the IRP falls to less than 15 mmHg and the achalasia pressurization pattern resolves sometimes with the return of weak peristalsis. This complements well with the information obtained by the timed barium esophagram.