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 ‐ ARM 1); on the same day, after randomization, 21 had a second ( HD ‐ ARM 2). Sixteen women had a third ( HD ‐ ARM 3) 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 ‐ ARM 1 vs HD ‐ ARM 2, CCC  = 0.73 (95% confidence interval [ CI ]: 0.53–0.94), and for HD ‐ ARM 1 vs HD ‐ ARM 3, CCC  = 0.60 (95% CI : 0.28–0.93). For maximum squeeze pressures of HD ‐ ARM 1 vs HD ‐ ARM 2, CCC  = 0.86 (95% CI : 0.75–0.97), and for HD ‐ ARM 1 vs HD ‐ ARM 3, CCC  = 0.56 (95% CI : 0.21–0.91). The rectoanal gradient during evacuation was significantly concordant between HD ‐ ARM 1 and HD ‐ ARM 2 but not HD ‐ ARM 1 and HD ‐ ARM 3. 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 ‐ ARM 1 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.