High-resolution esophageal manometry: interpretation in clinical practice

Abstract

Purpose of review: Esophageal high-resolution manometry (HRM) is the current state-of-the-art diagnostic tool to evaluate esophageal motility patterns and, as such, is widely adopted in clinical practice. This article will review the interpretation of esophageal HRM in clinical practice.

Recent findings: HRM uses a high-resolution catheter to transmit intraluminal pressure data that are subsequently converted into dynamic esophageal pressure topography (EPT) plots. Metric data from EPT plots are synthesized to yield an esophageal motility diagnosis according to the Chicago Classification, a formal analytic scheme for esophageal motility disorders, which is currently in version 3.0. The standard HRM protocol consists of a baseline phase and a series of 10 wet swallows in the supine or reclined position. In addition, data from swallows in the seated position and provocative HRM maneuvers provide useful information about motility properties. Combined high-resolution impedance technology is also clinically available and enables concurrent assessment of bolus transit and postprandial responses. Finally, there is ongoing interest to optimize the training and competency assessment for interpretation of HRM in clinical practice.

Summary: Esophageal HRM is a valuable and sophisticated clinical tool to evaluate esophageal motility patterns. Emerging clinical applications of esophageal HRM include combined impedance technology, provocative maneuvers, and postprandial evaluation.

Figure 1. Baseline Period

In high-resolution manometry with esophageal pressure topography, pressure is assessed in relation to time and distance. Pressure is displayed as a heat map with dark blue representing lower pressures and higher pressures colored red to purple. The horizontal axis represents time. In this window, time is displayed in 10 second intervals; zooming in or out will change the time interval. The vertical axis represents distance and each black circle corresponds to a pressure sensor. In this window distance is portrayed as cm from the nares; clicking on ‘Fr. Nares’ can change the display to represent cm from the lower esophageal sphincter (LES) or sensor number. In this window, the interpreter is clicked into the baseline period, as represented by the red frame. There are two high-pressure zones corresponding to the upper esophageal sphincter (UES) and lower esophageal sphincter (LES). As depicted by the yellow boxes, the corresponding markers are positioned to reflect UES and LES (proximal and distal border). In addition, the gastric marker is positioned at least 2cm below the distal border of the LES and in this particular case is positioned distal to the hiatus hernia. The pressure inversion point (PIP) is identified (purple box labeled PIP). The separation between the crural diaphragm (CD) and the LES is assessed; in this case, it is estimated at 5.7 cm consistent with a type III esophagogastric junction morphology. (Esophageal pressure topography plot reproduced with permission from the Esophageal Center at Northwestern Medicine Digestive Health Center.)

Figure 2. Swallow Phase

In this high-resolution manometry esophageal pressure topography plot, the interpreter is viewing swallow #1. The swallow begins with the relaxation of the upper esophageal sphincter (UES) and deglutitive relaxation of the lower esophageal sphincter (LES) with aboral contraction along the length of the esophagus and restoration of the baseline LES pressure. The yellow circle corresponds to the contractile deceleration point (CDP). The distal contractile integral (DCI) measures the contractile vigor along time and the distance spanning the transition zone and proximal border of the LES. The distal latency (DL) measures the time interval from UES relaxation to CDP, represented by the yellow dashed line. The integrated relaxation pressure (IRP) corresponds to the lowest mean 4 seconds of axial pressure from onset of UES relaxation. In this example the DCI is normal (between 450 to 8,000 mmHg·s·cm), the DL is normal (greater than 4.5s), and the IRP is normal (less than 15mmHg using the Sierra system).

Figure 3. Hierarchical interpretation scheme according to the Chicago Classification version 3.0

The colored boxes correspond to 10 esophageal motility patterns per the Chicago Classification v3.0. The red boxes denote the major motility disorders, with those outlined in yellow representing disorders with an esophagogastric junction outflow obstruction. The blue boxes correspond to the minor motility disorders. Integrated relaxation pressure (IRP); Esophagogastric junction (EGJ).