Reproducibility of high-definition (3D) manometry and its agreement with high-resolution (2D) manometry in women with fecal incontinence

BackgroundWhile widely used in clinical practice, the reproducibility of high-definition anorectal manometry (HD-ARM) remains unclear. We evaluated the intra-individual reproducibility of HD-ARM and compared pressures measured with HD-ARM and high-resolution anorectal manometry (HR-ARM). MethodsThirty-six women with fecal incontinence had an initial HD-ARM (HD-ARM1); on the same day, after randomization, 21 had a second (HD-ARM2). Sixteen women had a third (HD-ARM3) 4 weeks later. Twenty-five had also been evaluated by HR-ARM previously. Rectoanal pressures were assessed at rest, during squeeze and simulated evacuation. Concordance among pressures was assessed with Lin's concordance correlation coefficient (CCC). Key ResultsAnal resting and squeeze pressures measured with HD-ARM were reproducible on the same and different days; for average resting pressures of HD-ARM1 vs HD-ARM2, CCC=0.73 (95% confidence interval [CI]: 0.53-0.94), and for HD-ARM1 vs HD-ARM3, CCC=0.60 (95% CI: 0.28-0.93). For maximum squeeze pressures of HD-ARM1 vs HD-ARM2, CCC=0.86 (95% CI: 0.75-0.97), and for HD-ARM1 vs HD-ARM3, CCC=0.56 (95% CI: 0.21-0.91). The rectoanal gradient during evacuation was significantly concordant between HD-ARM1 and HD-ARM2 but not HD-ARM1 and HD-ARM3. Resting (CCC=0.38 [95% CI: 0.14-0.62]) and squeeze pressures (CCC=0.73 [95% CI: 0.57-0.89]) measured with HD-ARM1 and HR-ARM were also concordant. Conclusions & InferencesAmong women with fecal incontinence, measurements with HD-ARM were reproducible on the same (anal resting and squeeze pressures and rectoanal gradient during evacuation) and different days (anal resting and squeeze pressures) and correlated with HR-ARM measurements. These findings support use of HD-ARM and HR-ARM for longitudinal assessments of anal resting and squeeze pressures.