Normal values for esophageal high-resolution manometry

Background: Esophageal high-resolution manometry (HRM) is a novel method to assess esophageal motility. Several software and hardware systems are currently available. A set of normal values for HRM parameters was established in the US, using proprietary tactile-sensing catheter technology (Given Imaging). We wished to determine normal values for HRM performed with another type of catheter (Unisensor).

Methods: Fifty-two healthy volunteers underwent supine HRM. Each subject swallowed 10 liquid water boluses. Esophageal contraction parameters were evaluated and normal values were calculated (defined as 5th and 95th percentile of values).

Key results: The normal range for the following parameters was calculated; distal contractile integral (mean 1319.44, with a 5-95th percentile range [185.65-3407.60]), contractile front velocity (mean 3.98, 5-95th percentile range [2.40-6.50]), Intrabolus pressure (mean 9.68, range [1.00-19.00]), contraction amplitude measured 5 cm above the esophagogastric junction (EGJ; mean 78.76, range [23.00-146.00]), contraction amplitude 15 cm above the EGJ (mean 43.66, range [3.60-96.00]), transition zone (TZ) length (mean 1.34, range [0.00-5.63]), upper esophageal sphincter (UES) pressure (mean 81.63, range [19.50-165.10]), EGJ length (mean 2.97, range [2.17-4.00]), EGJ resting pressure (mean 29.35, range [8.95-51.40]), EGJ relaxation pressure (mean 16.79, range [1.00-39.35]), IRPs4 (mean 13.42, range [2.59-28.28]), and gastric pressure (mean 5.06, range [0.00-9.46]).

Conclusions & inferences: Overall, the normal values of esophageal HRM parameters obtained with the Unisensor catheter resemble those of the previously published series. Marked differences in upper limits of normal were found for parameters related to the esophageal sphincters and TZ length. Users of HRM should be aware of these differences and define pathology based on comparison to appropriate normal values.