Functional and tonometrical investigation of bladder and urethra in patients with stress incontinence.

During 1974, 80 women with symptoms of relative stress incontinence underwent cystotonometric, sphincterometric and urethrometric examinations. The average basal bladder pressure, sphincter resistance, urethral length with the patient in the lying position and functional urethral length (difference between urethral length in the lying and the upright positions) were measured. We tried to separate objectively stress from urge incontinence (about one-fourth of the patients). After statistical analyses of the data we concluded that there is neither correlation between sphincter resistance and urethral length, nor between sphincter resistance and functional length of the urethra but there is a correlation between sphincter resistance and basal bladder pressure. The functional length is the best method to separate patients with stress incontinence from thoses with urge incontinence, while sphincter resistance is of less importance. The functional length is also the best indicator of the seriousness of incontinence. The objective sign of a successful operation is the extension of the urethral length and the fixation of the functional length to 0 mm. In such cases sphincter resistance is slightly increased and inversely related to the size of the correction of functional urethral length.