Electrical stimulation for stress incontinence

Electrical stimulation has been reported to be effective for stress incontinence, cure and improvement rates being reported to range from 30% to 50%, and from 6% to 90%, respectively. However, clinical application of this treatment is not common because there is little physiological and technical information. Electrodes for electrical stimulation are divided into two types: external (non-implantable) and internal (implantable), and there are two methods of stimulation: chronic (long-term, continuous) and short-term. Frequencies of 20-50 Hz, with a pulse duration of 1-5 ms, have been reported to be effective for urethral closure. The effectiveness of the treatment should be verified with placebo-controlled double-blinded trials, and four such studies using an active and a sham device have been reported. Two of these verified the superiority of the active device over the sham device, but the others did not demonstrate any significant difference between the two with regard to efficacy. Electrical stimulation has been reported to result in a long-term continuation of therapeutic effect. The effect has been explained as a re-education or a reactivation of lost functions of the pelvic floor muscles. As to adverse effects, there may be some complications in relation to anesthesia or surgical procedures, such as infection, pain and bleeding with implantable electrodes. The incidence of adverse effects in short-term electrical stimulation is less than 14%. In conclusion, short-term electrical stimulation using non-implantable anal or vaginal electrodes is the most recommendable because of safety and ease of use.