Normal values and pressure morphology for three-dimensional high-resolution anorectal manometry of asymptomatic adults: a study in 110 subjects

Abstract

This study establishes normal values for anorectal pressure by 3D-HRM in asymptomatic volunteers. There are significant gender differences concerning squeeze patterns. Increasing age is associated with lower maximum resting pressure, mean resting pressure, and maximum squeeze pressure. Normal characteristic pressure morphology of anorectum can be obtained at rest, during squeeze, and bear down as in defecation by 3D-HRM.

How to Perform and Interpret a High-resolution Anorectal Manometry Test

“…24,27 Increasing age is associated with a lower anal resting pressure. 22,23,27 Interestingly, anal resting pressure in healthy women was lower in a study from Korea 24 than in different studies from the United States and Europe. 7,22,26 These differences are more likely explained by differences in techniques rather than ethnic differences because anal pressures in healthy Asian volunteers 23,25 were similar to those from a group that included participants from Western countries.…”

“…22,23,27 Interestingly, anal resting pressure in healthy women was lower in a study from Korea 24 than in different studies from the United States and Europe. 7,22,26 These differences are more likely explained by differences in techniques rather than ethnic differences because anal pressures in healthy Asian volunteers 23,25 were similar to those from a group that included participants from Western countries. 7,22,26 The HR-ARM system (Sandhill Scientific) used in the Korean study 24 averages anal pressures across radial sensors at any level of the catheter.…”

“…7,[22][23][24][25][26][27] However, because the sample size in these studies was relatively small, additional studies are necessary to more precisely define the normal range for anorectal pressures. The interpretation of findings will rely on studies conducted with HRM where available and supplemented by data from studies conducted with non-HRM only when necessary.…”

“…Squeeze pressures are lower in women than men and in older than younger people. [22][23][24]27 Hence, normal values are stratified by age and sex. The absolute squeeze pressure and the change from the resting pressure should be considered when interpreting the test.…”

“…Two-dimensional maps show a high-pressure band in the middle of the image. 23,25 During normal anal contraction (squeeze), the 3-D map depicts an "hourglass" appearance while the 2-D map has a "λ" shape (Fig. 4B).…”