Electrical stimulation for the treatment of urinary incontinence

To describe the rationale for the use of electrical stimulation (ES) for the treatment of urinary incontinence, and to summarize the results of clinical studies assessing these techniques.

The effect of ES on the lower urinary tract (LUT) is explained, and the literature on clinical application of this technique is reviewed.

The use of ES is aimed at altering LUT function by stimulation of the sacral autonomic or somatic nerves. Two types of ES have been used: chronic stimulation and acute maximal functional electrostimulation. The frequency used depends on the clinical diagnosis. In patients with stress incontinence, uncontrolled studies suggest that high frequency and high amperage are required to obtain a 50% success rate, although success does not necessarily equate with cure. The only placebo-controlled trial in this population found that 62% of patients experienced significant improvement on provocative pad test determinations, but only 20% were dry. Researchers agree that low frequency and moderate amperage are required in patients with detrusor instability. The reported effectiveness of ES in this population has ranged widely, from 45% to 91%, but all studies agree that approximately one-third of patients will obtain a good long-term results. A review of multiple studies found that 20% of patients were reported as dry and 37% were significantly improved with functional ES.

Although nearly all studies of ES have been uncontrolled, a substantial body of "soft" data attests to the efficacy and safety of this technique.