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

Background: While 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). Methods: Thirty-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 Results: Anal 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 & Inferences: Among 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.