Urethral pressure and power generation during coughing and voluntary contraction of the pelvic floor in females with genuine stress incontinence.

A probe which permits continuous measurement of the related values of pressure and cross-sectional area in the female urethra was used for a quantitative description of the adjunctive closure forces in terms of pressure and power generation during coughing and squeezing in 30 females with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, midurethrally and distally in the urethra. A statistically significant decrease in power generation was found at the bladder neck and midurethrally during squeezing compared with the values in healthy females. During coughing the power generation was significantly decreased midurethrally and measurement of pressure generation revealed similar results. These findings indicate that the active closure mechanisms at the bladder neck and midurethra are significantly weakened in females with GSI. The results do not support the concept that impaired passive pressure transmission to the urethra is an important pathophysiological factor in GSI.