Evaluation of the esophagogastric junction using high resolution manometry and esophageal pressure topography

Background The assessment of the esophagogastric junction (EGJ) is the most challenging aspect of clinical esophageal manometry. Although conventional manometric systems can be optimized toward interrogating specific aspects of the EGJ, they are too limited in recording channels and/or fidelity for a comprehensive assessment. The technological advantages inherent in high resolution manometry (HRM) with esophageal pressure topography (EPT) analysis substantially change this equation providing a technology sufficiently robust to dynamically record the contractile activity within the EGJ with both good fidelity and good spatial resolution. Purpose This review is an update on our understanding of the application of HRM and EPT to the analysis of EGJ function. With respect to sphincter relaxation, the integrated relaxation pressure (IRP) has proven to be a robust metric in differentiating intact from impaired EGJ relaxation. In the process, it revealed that impaired EGJ relaxation could occur not only in the setting of achalasia but also with other causes of EGJ outflow obstruction including hiatus hernia. The morphological description of the EGJ by EPT has also revealed not only a spectrum of ab-normality ranging from an intact sphincter to overt herniation, but also the surprise finding of spontaneous conversion among sphincter configurations, emphasizing its dynamic nature. With respect to barrier function, preliminary data have refocused on the crural diaphragm as a key-differentiating feature between preserved and compromised function. Finally, although the accomplishments summarized above are substantial, much work remains to fully exploit the potential of EPT in the clinical characterization of the EGJ.