Upper Esophageal Sphincter Motility and Thoracic Pressure are Determinants of Pressurized Waves in Achalasia Subtypes According to the Chicago Classification.

BACKGROUND

Phenotypes of achalasia are based on esophageal body pressurization during swallow. The reasons that lead to pressurized waves are still unclear. This study aims to evaluate manometric parameters that may determine pressurized waves in patients with achalasia.

METHODS

A total of 100 achalasia high-resolution manometry tests were reviewed. We measured before each swallow: upper esophageal sphincter (UES) basal pressure, esophageal length, lower esophageal sphincter (LES) basal pressure, LES length, gastric and thoracic pressure, transdiaphragmatic pressure gradient and the LES retention pressure (LES basal pressure-TPG); during swallow: UES pressure, UES residual pressure, UES recovery time, LES relaxation pressure, gastric and thoracic pressure, transdiaphragmatic pressure gradient and after swallow: esophageal length, LES length, wave pressure, gastric and thoracic pressure and transdiaphragmatic gradient pressure.

RESULTS

Univariate analysis showed in pressurized waves before swallow: higher thoracic, UES and LES basal pressure, longer LES length and decrease in LES retention pressure; during swallow: higher thoracic, gastric and UES pressure, higher UES and LES relaxation pressure and after swallow: higher thoracic and gastric pressure. Multivariate analysis in pressurized waves showed as significant before swallow: thoracic and UES basal pressure; during swallow: thoracic, gastric and UES pressure, UES residual pressure and UES recovery time and after swallow: thoracic pressure.

CONCLUSIONS

Basal esophageal pressurization and the UES are independent variables that may be associated with pressurized waves.