Objective: The aim of our study was to asses changes in the mobility of the whole urethra after successful TVT procedure. Design: Prospective pilot study. Setting: Obstet. Gynecol Department, General Teaching Hospital, Ist Medical Faculty, Charles University, Prague; EuroMISE Centre of the Charles University and Academy of Sciences, Prague, Czech Republic. Methods: 101 women with proven stressed urinary incontinence were included in the study. After the TVT procedure 90 women were evaluated. As a part of the complex urogynecological investigation before surgery the transperineal ultrasound scan was performed in supine position, urinary bladder was filled to 300 ml. In the orthogonal system of coordinates the position and mobility of the whole urethra before surgery were assessed. Control examination was done 3–6 months after the surgery. The changes induced by the surgery were assessed. For the statistical evaluation t-test, Wilcox test, F test, Kruskal- Wallis test and ANOVA were used. Results: Surgery significantly decreased the mobility of the whole parts of the urethra during maximal Valsalva, but the position at rest is not influenced. The women with high urethral mobility have high mobility after the surgery. The operation was more effect in patients with high mobility. Never the less the change of relative mobility is the same in all women. Conclusions: The information about the type of urethral mobility is important and may increase the success rate of TVT. Therefore the tension of the tape should be different for patients with different urethral mobility.

        Key words: transperineal ultrasound, stress urinary incontinence, TVT