Clinical experience with urethral retro-resistance pressure measurement: a prospective pre- and postoperative evaluation in women with stress urinary incontinence

AIMS: To identify possible correlations of urethral retro-resistance pressure (URP) with clinically and urodynamically proven stress urinary incontinence (SUI) and the outcome of anti-incontinence surgery. MATERIALS AND METHODS: URP was measured using the Monitorr system in women with clinically and urodynamically proven SUI without prolapse before and after anti-incontinence surgery (colposuspension n = 8, tension-free vaginal tape n = 6, tension-free transobturator tape n = 34). RESULTS: Forty-eight women (mean age 61.8 +/- 8.9 years) were evaluated preoperatively and on average 10 weeks postoperatively. Mean URP was 75.6 +/- 20.8 cm H(2)O preoperatively versus 75.4 +/- 17.9 cm H(2)O postoperatively (P = 0.898). The type of anti-incontinence surgery performed had no significant effect on postoperative URP. While no association was found between age and URP (P = 0.35), there was a positive correlation between URP and body mass index (BMI; r = 0.49, P = 0.0004). There was no correlation of URP with the preoperative pad test (P = 0.17) and urethral closure pressure at rest (P = 0.51). Finally, URP did not correlate significantly with the preserved length of the continence zone (0-1/3-2/3-3/3) as determined by the urethral stress profile (P = 0.37-0.72) or with the objective cure rate (negative pad test). CONCLUSIONS: Preoperative URP does not correlate with SUI in all women, has no predictive value, and does not correlate with the outcome of anti-incontinence surgery. However, there seems to be an association with biomechanical factors such as obesity, which may open up a new area of application for URP measurement in urogynecologic diagnosis.