Age-stratified diagnostic value of high-resolution anorectal manometry in women with severe rectocele: interactions between anal relaxation rate and maximum anal resting pressure.

PURPOSE

This study aimed to assess the diagnostic accuracy of combining anal relaxation rate (ARR) and maximum anal resting pressure (MARP), measured by three-dimensional (3D) high-resolution anorectal manometry (HR-ARM), in identifying high-risk phenotypes of severe rectocele in women (SRW) aged ≥ 50 years compared with healthy female volunteers (HFVs).

METHODS

This retrospective comparative study was conducted at the Tianjin Union Medical Center (2018-2024) and included 50 SRW scheduled for surgery and 40 age-matched HFVs aged ≥ 50 years. Log-linear regression was used to assess interaction effects, and the Hosmer-Rothman additive model evaluated qualitative and quantitative interactions. Diagnostic accuracy was assessed using receiver operating characteristic curve analysis.

RESULTS

The concurrent elevation of ARR and MARP (R phenotype) was an independent risk factor (P < 0.01), surpassing the diagnostic value of individual parameters. Interaction analysis showed improved diagnostic accuracy, achieving a sensitivity of 82.0%, specificity of 100.0%, area under the curve of 0.82, Youden index of 0.82, odds ratio of 6.14, and 95% confidence interval of 2.19-17.17. Defecography-based classification with SRW-concomitant diseases may be identified using 3D HR-ARM phenotypes, whereas the reverse diagnostic pathway is not feasible. The integration of these modalities holds promise for guiding evidence-based personalized treatment strategies.

CONCLUSIONS

Age-stratified 3D HR-ARM analysis of ARR and MARP interactions may help identify high-risk R phenotypes in SRW, providing enhanced diagnostic specificity. The R phenotype identified in the preoperative X-ray defecography classification for SRW holds the potential for informing tailored therapeutic strategies.