Clinical relevance of transperineal ultrasound compared with anorectal manometry for the evaluation of female patients with obstructive defecation syndrome

Abstract

Abstract Background and aims The utility of transperineal ultrasound (TPUS) in combination with anorectal manometry (ARM) in the evaluation of women with obstructive defecation syndrome (ODS) remains unclear. We investigated the combined performance of TPUS and ARM in the evaluation of female patients with ODS, and determined the clinical utility of both modalities in the evaluation of female patients with ODS. Methods Female patients with ODS were evaluated by TPUS and ARM, and binary logistic regression models were exploited to evaluate the clinical association of abnormal TPUS variables with abnormal ARM variables. Results Two hundred ninety-six female patients with ODS underwent TPUS, of whom 209 patients underwent both TPUS and ARM. A binary logistic regression model was adopted to evaluate the utility of ARM in predicting abnormalities in TPUS. We found that an abnormal rectoanal gradient in ARM was independently associated with an abnormal ARA during strain maneuvers in TPUS, while reduced rectal defecation pressure was independently associated with rectocele, internal rectal intussusception, and internal rectal prolapse. Reduced anal squeeze pressure was independently associated with various pelvic floor anatomical abnormalities, while reduced anal resting pressure was independently associated with moderate-to-severe rectocele. Additionally, abnormal rectal sensory function was also independently associated with rectocele. Conclusions In patients with ODS, circumscribed yet specific anatomic-functional correlations exist between select ARM and TPUS parameters. Specifically, reduced anorectal pressure gradient emerged as the strongest ARM predictor of abnormal ARA during defecation. Furthermore, diminished rectal defecation pressure provides independent diagnostic support for pelvic floor laxity conditions, including rectocele, moderate-to-severe rectocele, internal rectal prolapse, and internal rectal intussusception in ODS. We assert that combined imaging and functional testing is essential for comprehensive assessment of pelvic floor structural and functional characteristics in refractory ODS.

Keywords

• Obstructed defecation syndrome
• Transperineal ultrasound
• Anorectal manometry
• Pelvic floor dysfunction