Factores de riesgo de fracaso de la corrección quirúrgica de la incontinencia urinaria de esfuerzo mediante cinta suburetral transobturatriz

[Effects of delivery and oophorectomy on urethral collagen: an experimental study]

OBJECTIVE

Stereological evaluation of the concentration of type I and III collagen fibers in the urethral tissue of rats subjected to simulated labor and oophorectomy. To compare the concentrations of collagen between oophorectomized and non-oophorectomized rats.

MATERIAL AND METHOD

Sixty adult Wistar rats were divided into six groups. A group made up of virgin rats was used as control group and another group was made up of oophorectomized rats. Two groups underwent vaginal distention for 30 and 120 minutes, respectively. The two other groups were subjected to the same distension periods, followed by oophorectomy. Sixty days later, euthanasia and removal of urethral tissue was carried out for stereological analysis of type I and III collagen after staining with hematoxylin and eosin and picrosirius red.

RESULTS

A decrease in estrogen levels was observed in the oophorectomized rats. There was a reduction of type III collagen in the oophorectomized control group compared to the control group when analyzed independently. No significant differences were observed among the other groups. Type I collagen decreased in all groups compared to the control group. However, in the prolonged vaginal distension and oophorectomy group, these fibers increased.

CONCLUSION

In normal rats, simulation of labor does not alter the collagen III levels. In hypoestrogenic rats, the concentration of collagen type I and III decreased, except in those undergoing prolonged labor simulation in which collagen I increased.

[Urodynamic aspects of feminine urinary incontinence treated with slings]

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.