Clinical results of sacral neuromodulation for chronic voiding dysfunction using unilateral sacral foramen electrodes

The aim of this study was to determine the long-term clinical efficacy and complications of neuromodulation with a unilateral sacral foramen electrode in 36 patients with chronic voiding dysfunction. Following a positive effect of a percutaneous nerve evaluation test, patients underwent open surgery. A permanent electrode was implanted in 24 patients with urge incontinence, in 6 with urgency-frequency syndrome, and in 6 with nonobstructive urinary retention. After an average follow-up period of 37.8 months, 19 patients (52.8%) continue to benefit from the neuromodulation with a significant improvement of symptoms and urodynamic parameters. The median duration of the therapeutic effect for the total study population was longer than 60 months. No significant difference in the median duration of therapeutic effect with regard to sex, the type of voiding disorder, or the implant pulse generator was found. However, in patients with previous psychological disorders the median duration of therapeutic effect was only 12 months (P = 0.008). Complications were mild. In the group of patients in whom the therapeutic effect remains, 37 reoperations have had to be performed. We conclude that although reoperations were needed to overcome technical problems, patients can achieve lasting symptomatic improvement. Since technical changes in the equipment have reduced the number of complications, even better results can be expected in terms of the reoperation rate.