Abstract
Abstract Objective: We aimed to study the kinematic indices of the pelvic floor, anorectal angle and the descent of perinea, and the differing movement, in dyssynergic defecation patients in comparison with healthy controls, based on MR defecography. Methods: Twenty-two individuals involved with dyssynergic defecation constipation and fourteen healthy asymptomatic subjects fell into this study. In four dynamic pelvic floor MRI indices, namely paradox (unusual change of anorectal angle), perineal descent during straining, perineal ascent, and narrowing of anorectal angle at squeeze, were measured in patients and healthy subjects. Results: Paradox Index had the highest sensitivity (95.45%) and specificity (92.86%) for detection of dyssynergic defecation, with an R2 value of near 1 (0.902). The sensitivity and specificity of other indices were not high; therefore, no significant improvement could be achieved using other indices along with Paradox Index. Negative Predictive Value (92.85%) and Positive Predictive Value (95.45%) were only high in Paradox Index. Conclusion: Paradox Index was indicated to be the best finding of MR defecography for identifying dyssynergic defecation patients from healthy controls. Hence, MR defecography could be exploited as an authentic tool to manifest the patients the paradoxical function and the relevant muscles of pelvic floor, which could enhance their imagination of the correct defecation pattern during their treatment.
Highlights
Disordered defecation can result as a consequence of many structural and functional causes in the pelvic floor region
According to the outcome of a study by Chu et al on dynamic MRI in pediatric subjects with Dyssynergic Defecation" (DD), which suggested significant difference of abnormal angle ofanorectal (ARA) changes "Paradox Index" during straining, comparing the patients and the healthy subjects [16].We found that our primary outcome measure, i.e., "Paradox Index", is the best indicator for identifying patients from healthy controls, which resulted in high values of specificity (92.86), sensitivity (95.45), PPV (95.45) and NPV (92.85)
No abnormal ARA changes, which could be helpful for identifying patients with DD, was observed when ARA was interpreted as an independent parameter
Summary
Disordered defecation can result as a consequence of many structural and functional causes in the pelvic floor region. "Dyssynergic Defecation" (DD) or contraction syndrome of paradoxical puborectalis, as the most common disorders of defecation, recognized as a fundamental cause of functional "chronic constipation". Muscle of puborectalis is a section of the sphincter of anal, originates from the trunk of pubic bone and shapes a ring just round the rectum [2].With contraction of puborectalis the joining point of the rectum is pulled and the canal of anal comes forward. It forms the angle of anorectum "ARA". While straining the "ARA" gets more widen (15-20o), in accordance with the relaxation of the puborectalis muscle [2]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
