Sacral neuromodulation for the treatment of overactive bladder: systematic review and future prospects

Sacral Neuromodulation (SNM) is a minimally invasive treatment for OAB patients following failure of conventional interventions. Patient selection, lead placement, and testing technique are important pillars in optimizing success rates.A comprehensive literature search was conducted on 'sacral neuromodulation' and 'overactive bladder.' There was no date restriction, with the last search dated 31 May 2021. Patient selection, lead placement, test phases, safety, efficacy, and available devices are thoroughly discussedLastly, future perspectives will be presented with the anticipated trajectory of sacral neuromodulation over the next five years.SNM has proved to be a safe and effective therapy on the short-, medium- and long-term without precluding any other treatment options. In all studies reviewed, no life threatening or major irreversible complications were presented. However, surgical re-intervention rates were high with a median of 33.2% (range: 8-34%) in studies with at least 24 months follow-up. No true consensus could be made regarding prognostic factors. However, optimized lead placement, consequent ideal motor thresholds, and the use of a curved stylet theoretically facilitates reaching maximal success with SNM. Test phase success rates increased to such a level that from a cost-effective point of view, single-stage implants could be considered.Abbreviations: OAB: overactive bladder; SNM: sacral neuromodulation; BoNT-A: Botulinum toxin A; PFM EMG: pelvic floor muscle electromyography; IPG: implantable pulse generator; PNE: percutaneous nerve evaluation; FSTLP: first-stage tined lead procedure; NLUTD: neurogenic lower urinary tract dysfunction; ITT: intention to threat; PPMC: per protocol modified completers; PPC: per protocol completers; AE: adverse event; MRI: magnetic resonance imaging; RCT: randomized controlled trial.