Intravaginal electrical stimulation. Clinical experiments of urethral closure.

The effect on the urethra of intravaginal electrical stimulation (IVS) was registered by means of urethral pressure profiles (UPP). With the object of finding the most appropriate electrical parameters and optimal electrode positions within the vagina, 24 patients with stress incontinence, 22 with urgency and 4 continent women were studied. Electrical stimulation was given via an obturator with seven electrodes, which could be connected in different combinations of pairs. In all the women, stimulation with the electrodes in specific positions effected a more marked rise in the UPPs than with the electrodes in other positions. A change in position of more than 5 to 10 mm caused a decrease in the response. It was determined that a frequency of between 20 to 50 Hz with a pulse duration of 1 to 5 ms was most effective for urethral closure.