Sacral neuromodulation in the treatment of urgency-frequency symptoms: A multicenter study on efficacy and safety

Purpose: Neuromodulation of sacral nerves has shown promising results in co rrecting voiding dysfunction. We report the results of a multicenter trial designed to assess the efficacy of sacral nerve neuromodulation in patients presenting with refractory urinary urgency-frequency. Materials and Methods: A total of 51 patients from 12 centers underwent bas eline assessment, including a detailed voiding diary, urodynamic evaluation and percutaneous test stimulation of the sacral nerves at S3 and/or S4. Al l patients enrolled in the study had undergone prior conventional treatment , such as pharmacotherapy, hydrodistention and surgical intervention, which failed. All patients demonstrated a satisfactory response to trial stimula tion and were randomly divided into a stimulation group (25 patients) and a control group (26), A sacral nerve stimulation device was implanted after 6 months in the control group. Patients were followed at 1, 3 and 6 months, and at 6-month intervals for up to 2 years after implantation of a neuropr osthetic InterStim* system.dagger The study variables included the number o f voids daily, volume voided per void and degree of urgency before void. Results: Compared to the control group, 6-month voiding diary results demon strated statistically significant improvements (p <0.0001) in the stimulati on group with respect to the number voids daily (16.9 +/- 9.7 to 9.3 +/- 5. 1), volume per void (118 +/- 74 to 226 +/- 124 ml.) and degree of urgency ( rank 2.2 +/- 0.6 to 1.6 +/- 0.9). Patients in the control group showed no s ignificant changes in voiding parameters at 6 months. Significant improveme nts in favor of the stimulation group were noted in various parameters with respect to water cystometry and quality of life (SF-36). At 6 months after implant, neurostimulators were turned off in the stimulation group and uri nary symptoms returned to baseline values. After reactivation of stimulatio n sustained efficacy was documented at 12 and 24 months. Conclusions: Neuromodulation of the sacral nerves is an effective, safe the rapy that successfully treats significant symptoms of refractory urgency-fr equency.