[Urodynamic aspects of feminine urinary incontinence treated with slings]

Abstract

Objectives: Treatment of feminine stress urinary incontinence (SUI) with slings aims to supplement the function of the damaged ligaments, favoring the correct transmission of the tensions. Our objective is to determine which preoperative variables could predict the outcome of surgical treatment of SUI and to study the urodynamic changes produced by the surgery.

Material and methods: 139 women (age X =61.7; σ=10.88) operated on due to SUI were studied retrospectively. In 118 cases (84.8%), sling techniques (TVT, TOT, TVT-Safyre, REEMEX) were used. Clinical evaluation and complete preoperative video -urodynamics were made pre-operatively and at 3 months of surgery. A statistical study (Fisher's test, Wilcoxon, Friedman, Student's T and Pearson's χ(2)) and analysis of multivariant logistic regression analysis by step elimination method were performed.

Results: Post-operatively, the SUI (p=0.000) and bladder hyperactivity syndrome decreased. The success percentages (urodynamic absence of SUI) for each technique were: TVT-Safyre (75%), TOT (73%), TVT (60%) and REEMEX (57%), without significant differences. Age (ROC cut-off: 61 years) was a prognostic factor of success (p=0.024). Preoperative maximum flow (Qmax) (16 ml/s) constituted the only urodynamic parameter with a predictive value for success (p=0.026). An open bladder neck was a risk factor for persistence of postoperative SUI (RR=2.78). A significant decrease of the postsurgical Qmax (p=0.017) was verified, without increase of the post micturation residue or of the Wmax. An increase of the postsurgical urethral resistance (UR) was also observed (p=0.004).

Conclusions: The pre-operative Qmax is the most important urodynamic prognostic parameter in feminine SUI surgery, its normality being associated to a greater probability of cure of the incontinence. In the cases of decreased preoperative flow, use of slings that increase urethral resistance more (REEMEX) is not recommended. Hyperactivity of the preoperative detrusor does not significantly modify the results of surgery of the SUI.