Perineal bladder neck ultrasound: appearances before and after continence surgery.

An objective method of quantifying suture tension during bladder neck elevation for genuine stress incontinence has long been sought. Perineal ultrasonography has been used to measure bladder neck position and excursion in continent and incontinent women. This study used perineal ultrasound findings to determine surgical positioning of the bladder neck and predict outcome. Eighteen asymptomatic controls and 72 women with genuine stress incontinence were studied before and after continence surgery. Perineal ultrasonography was used to plot bladder neck position at rest and on maximum Valsalva maneuver on an x, y co-ordinate system to allow comparison between groups. Logistic regression analysis was then performed to derive an equation for the likelihood of continence. In both pre-and postoperative analysis, the best correlation with continence was achieved with the use of the patient's age and the distance of the bladder neck resting position measured along the x-axis. An equation was derived to give the probability of continence. The equation is easily calculated using a pocket calculator. The distance of the bladder neck along the x-axis is under the direct control of the surgeon, so the patient's age can be put into the equation and the distance along the x-axis most likely to make the patient continent can be calculated. This can be done during surgery to provide an objective method for evaluating suture tension.