[Evaluation of urodynamic parameters following the placement of tension-free tape]

To analyse the urodynamic changes subsequent to the placement of TVT tension-free tape (retropubic tension-free vaginal tape) or TVT-O (obturator tension-free vaginal tape).

We carried out a retrospective cohort study that included women with urodynamic diagnosis of stress incontinence, in whom we placed type TVT or TVT-O tension-free tape, and on whom we performed a urodynamic study one year later. We calculated the size of the sample based on the area of continence and it consisted of 15 women per group. We included 40 women. 22 had TVT placed and 18 had TVT-O. We carried out the trial between February 1999 and March 2009. We analysed the means of the pre and postoperative urodynamic parameters using the Student's t-test for dependent variables.

We noted an average decrease in the maximum flow of 9 ml/s following the placement of the TVT-O (p=0.05). For the TVT group, we noted an increase in the flow and micturition times of 5.3 and 6 seconds, as well as in the detrusor pressure at the maximum flow of 6.2 cm H(2)O and of the maximum detrusor pressure when voiding, of 8 cm H(2)O (p=0.37, 0.47, 0.21 and 0.12, respectively).

In women with urodynamic stress incontinence, the maximum flow decreased a year after the TVT-O was placed.