Early versus late treatment of voiding dysfunction with pelvic neuromodulation

Introduction: Pelvic neuromodulation is an established method of treating voidingdysfunction. Little is known about the pathophysiology associated with voiding dysfunction. Reports have suggested that a delay in treating patients with sacral neuromodulation therapy can impact the success rate of this type oftreatment in voiding dysfunction. We examined patient response to pelvic neuromodulationwhen it was applied early versus late in the postdiagnosis of voidingdysfunction. Methods: We conducted a retrospective study of 42 patients (38 women and4 men) with voiding dysfunction who underwent surgery for implant with the Interstim (Medtronic, Minneapolis, Minn.). Prior to implantation, patients wererequired to pass a percutaneous nerve evaluation (PNE) over a 1-week period. Patients were observed for 20–48 months postimplantation. All patients recorded their voiding parameters at baseline, after screening and every 6 months thereafter. Twenty patients (in the early group) underwent implant surgery withthe neurostimulator 2–4 weeks post-PNE, and 22 patients (the late group)had the device implanted 6–24 months post-PNE owing to local logisticalcircumstances. Results: In the early group, 16 of 20 patients (80%) maintained a good response.In the late group, 13 of 22 (59%) patients showed a good response. Groupswere well matched in terms of age, duration of voiding dysfunction and incidenceof comorbidity. Conclusion: Patients who were delayed more than 6 months in receiving the neurostimulatorimplant showed a worse response than did patients who had thedevice implanted soon after PNE. This indicates the possibility of disease progression,which may limit the response to sacral neuromodulation.