Sacral Neuromodulation in Patients with Underactive Bladder: the Outcome of a Case Series

Abstract

This study aimed to report the outcome of sacral neuromodulation (SNM) in detrusor underactivity (DU). Methods: This multi-centric retrospective case series study was conducted between March 2017-June 2021. Forty-six cases were enrolled in this investigation. Initial phase stimulation was offered before permanent SNM implantation in order to assess the response to treatment. Patients with favorable response to initial stage (≥50% improvement in symptoms, CIC frequency and/or post voiding residual (PVR), voided volume, and BVE (bladder voiding efficacy) based on the bladder diary), underwent the implantable pulse generator (IPG) implantation as the stage II. Results: The mean age of patients was 37.46 ± 13.58 years. Thirty-two patients had non-neurogenic etiology, and the rest had neurogenic etiology. Among 46 cases, 32 (69.6 %) patients responded to initial stage. Seven patients with non-neurogenic etiology and seven patients with neurologic etiology didn’t response to stage I (initial stage), thus, didn’t undergo IPG. Seventy-five percent of patients had favorable response at stage II. The mean follow-up interval was 26.16 (13.55) months. Voided volume, PVR, and the median maximum flow rate (Qmax) improved significantly (p < 0.001).In terms of favorable response to permanent SNM implantation, there was no significant difference between acontractile detrusor group and others.