The static urethral closure pressure profile in female incontinence. A comparison between sphincter and detrusor incontinence.

The objective of the study was to ascertain if the determination of urethral data in static conditions allows to discriminate between sphincter and detrusor incontinence. Using a standardized recording technique with three Millar microtransducer catheters (in bladder, urethra and rectum) urethral pressure profile measurements were done in two groups of female patients, with either sphincter incontinence (n = 38) or detrusor incontinence (n = 28). The urethral examination was performed in two conditions, with an empty bladder when the patient was in supine position and with a full bladder in standing position. A Millar catheter with a small balloon was drawn through the urethra at a speed of 25 mm per minute (static, i.e. without coughing). The parameters measured were the functional urethral length, the anatomical urethral length and the maximal urethral closure pressure. Results showed that there was no clear difference between both groups with respect to the urethral lengths or the maximal closure pressure. Comparing the data in the condition of empty bladder supine, with those in the condition of full bladder standing, we could not demonstrate clear specificity for either sphincter or detrusor incontinence. It was concluded that static urethral profile studies are of poor value to discriminate between sphincter incontinence and detrusor incontinence.