Ultrasonic evaluation of bladder neck position and mobility: the influence of urethral catheter, bladder volume, and body position.

The influence of urethral catheter, bladder volume, and body position on the ultrasonic assessment of bladder neck position and mobility was evaluated in 24 incontinent women. The bladder neck position was described by two independent parameters: BS-distance, from the bladder neck to the lower tip of the symphysis pubis, and the rotation angle between the BS-line and the symphyseal middline. Catheterisation resulted in apposition of the bladder neck towards the symphysis pubis, seen as a significant shortening of the BS-distance in postmenopausal women without estrogen replacement. The rotation angle was unaffected. Increasing the bladder volume to symptomatically full resulted in increased capacity to withhold, since the rotation angle decreased 6.6 degrees. Examination in the sitting position, compared to the supine resulted in bladder neck descent to a "lower level," and the rotation angle increased in average 16 degrees. Bladder neck mobility was unaffected by catheterisation and body position. Vaginal ultrasonic evaluation of bladder neck suspension is recommended to be performed without a catheter, with a comfortably full bladder in a convenient, but standardised examination position.