A high-resolution view of achalasia.

Background: High-resolution manometry (HRM) makes it possible to better evaluate spatial and temporal characteristics of esophageal motor function. This technology is revealing new observations regarding disordered motor function in esophageal diseases.
Goal: The aim of this study was to define the essential features of achalasia using HRM.
Study: We performed HRM on 27 patients with achalasia, 10 patients with gastroesophageal reflux disease, and 10 controls. Ten 5 mL water swallows were recorded with a solid-state manometric assembly incorporating 36 circumferential sensors spaced at 1-cm intervals.
Results: The resting lower esophageal sphincter pressure was greater in achalasia than in controls or gastroesophageal reflux disease. There was an absence of peristalsis in the smooth muscle esophagus and failure of lower esophageal sphincter relaxation. The resting upper esophageal sphincter pressure was not different among the 3 groups. In addition to the typical manometric findings of achalasia, new observations are included. Esophageal shortening, pressurization of the esophagus, and rhythmic contractions of the upper esophageal sphincter and striated muscle esophagus were frequently observed.
Conclusions: HRM demonstrates alterations of esophageal motor function in achalasia that are not easily observed with other manometric techniques.