[Experimental and clinical evaluation of functional electrical stimulation of the anal sphincter]

To determine the most effective parameter of functional electrical stimulation of the anal sphincter (FES), the present study was carried out in female mongrel dogs anesthetized with alpha-chloralose urethane. When spontaneous and rhythmic micturition contractions of the bladder were present, they were more effectively inhibited by the stimulation with low frequency (5 to 10 Hz). Based on the results of this experiment 18 patients with urge incontinence were treated by maximal electrical stimulation with the following parameters. The duration for each stimulus was 0.2 msec, frequency 5 Hz, amplitude 30 to 150 volts. Every patient received ten treatments for two weeks, each lasting for 30 minutes. A clinical cure for urge incontinence was noted in 12 patients. As for urodynamic studies, FES increased significantly the volumes of the first desire to void (FDV) and maximum desire to void (MDV); however, it did not increase significantly the maximum urethral closure pressure or residual urine volume. Eighteen patients were divided into two groups; an unstable bladder group and a neurogenic bladder group. In the latter, the increases in volumes of FDV and MDV were significant. Second, 18 patients were divided into two groups according to the administration of lack of anticholinergic agents. For subjective symptoms, the rate of improvement of urge incontinence was significantly higher in the group administered the agents. These findings suggested that FES was very useful for the treatment of urge incontinence, with its efficacy augmented by the administration of anticholinergic agents.