Determining the role of clinical factors in pelvic organ prolapse
Pelvic organ prolapse (POP) is a pelvic floor disorder characterized by the descent of the female pelvic organs. 11% of women will require surgical intervention for POP at some point in their lifetime. While it is evident that POP results from a weakening of the tissues that support the pelvic organs, little has been done to identify associations between this loss of mechanical integrity and the risk factors for POP. The objective of this study was to determine correlations between POP risk factors and the structure-function relationships of the uterosacral ligament (USL), a supportive structure of the upper vagina and cervix that weakens in cases of POP. To achieve this, USL samples and pertinent clinical information were collected from consented female patients at Ochsner Medical Center receiving routine gynecological procedures under IRB approval. Clinical factors were compared between POP and non-POP groups. Post-menopausal USL tissue samples were analyzed through biaxial mechanical testing and histology, and the results were correlated to quantify USL structure-function relationships. Statistical associations were then determined between risk factors and changes in USL structure and mechanics. The post-menopausal POP group had a significantly higher proportion of Caucasian women, vaginal atrophy, instrumented delivery, and episiotomy compared to non-POP controls. Non-POP and POP stage I/II USLs were significantly less extensible than POP stage III/IV USLs, and higher collagen content was associated with decreased tissue extensibility. Smoking was the primary risk factor associated with both structural and mechanical changes in the USL; it was associated with both lower collagen content and higher tissue extensibility. The findings of this study are essential to understand POP etiology, and they have the potential to impact clinical care for POP by allowing for the development of predictive models to determine patient-specific treatment strategies.