Clinical Efficacy of Sacral and Tibial Nerve Neuromodulation

Neuromodulation has become a cornerstone therapy for patients with bladder dysfunction, particularly those with overactive bladder (OAB) and neurogenic bladder (NB) who have not responded to conservative or pharmacologic treatments. Both sacral nerve modulation (SNM) and tibial nerve modulation (TNM)—delivered via percutaneous, transcutaneous, or implantable systems—target the same sacral plexus network (S2–S4) that governs bladder storage and voiding reflexes. By restoring inhibitory control and modulating abnormal afferent signaling, both approaches yield durable symptom improvement and meaningful gains in quality of life.

Efficacy in Overactive Bladder (OAB)

Across decades of clinical use, sacral neuromodulation has demonstrated consistent efficacy in refractory OAB. Large trials report that 70–80% of patients achieve ≥50% reduction in urgency urinary incontinence (UUI) episodes, frequency, or urgency after SNM implantation, with sustained benefit at long-term follow-up (often 3–5 years). The 2024 meta-analysis of 20 studies encompassing 1,766 patients confirmed that SNM and implantable tibial neuromodulation (iTNM) produce comparable efficacy: weighted averages for OAB responder rates were 73.9% for SNM and 79.4% for iTNM, and UUI responder rates were 71.8% and 71.3%, respectively (Amundsen et al. 2025). Both therapies significantly reduced daily UUI episodes (≈3–3.5 fewer per day) and improved quality-of-life (OAB-q) scores by ~35 points (Amundsen et al. 2025). Importantly, these results were achieved with similar or lower adverse event rates in iTNM compared with SNM—despite iTNM being less invasive and not requiring an initial trial phase.

These findings align with earlier pivotal studies such as SUmiT and OrBIT, where PTNS (percutaneous tibial nerve stimulation) demonstrated equivalent or superior symptom reduction compared to pharmacologic therapy (tolterodine), with >50% of participants reporting marked improvement (Peters et al. 2009, 2010). Long-term maintenance sessions sustain benefit for >90% of responders at one year. The latest AUA/SUFU guidelines (2024) now recognize PTNS, iTNM, and SNM as minimally invasive, high-efficacy, third-line options that can be considered earlier in the treatment pathway, reflecting the growing preference for device-based over pharmacologic approaches (Cameron et al. 2024).

Efficacy in Neurogenic Bladder (NB)

In patients with neurological injury, such as spinal cord injury or multiple sclerosis, neuromodulation can restore elements of bladder control otherwise lost to neural disruption. Early studies in neurogenic populations show significant reductions in detrusor overactivity and incontinence episodes, alongside increased bladder capacity and compliance (Bapir et al. 2022). A 24-month PTNS study in MS patients with neurogenic OAB reported reductions of ~6–7 daytime voids and ~4 incontinence episodes per day, with no serious adverse events (Sevim et al. 2023). 

Historically the focus of clinical studies of neuromodulation treatment in neurogenic bladder has been in restoration of voiding, e.g, with the use of the brindley system (Brindley 1974, 1994). However, by improving bladder storage pressures, tibial and sacral stimulation may also reduce the need for intermittent catheterization and lower urinary tract infections—an outcome with major implications for long-term renal health in the SCI population. Although sacral neuromodulation is only FDA-approved for refractory idiopathic overactive bladder, its use has steadily expanded through off-label application in neurogenic bladder (Vogel and Nakib 2025). 

Safety and Practical Considerations

Both SNM and iTNM show favorable safety profiles. Meta-analysis data report serious device-related adverse events in only 0.3% of iTNM and 3.3% of SNM recipients. Revision and explant rates were markedly lower for iTNM (0–1.7%) compared to SNM (5.6–26.8%), reflecting the lower procedural complexity and absence of implanted leads or batteries in the sacral region. SNM remains the gold standard for patients requiring continuous stimulation or concomitant bowel modulation, while iTNM and PTNS provide less invasive options suitable for earlier intervention or for those seeking to avoid spinal surgery.

Together, these data confirm that neuromodulation of the sacral plexus—whether approached directly via the sacral roots or peripherally via the tibial nerve—offers comparable efficacy, excellent safety, and durable symptom relief. As implantable tibial systems continue to mature, they promise to expand access to effective, reversible, and low-burden therapy for the millions affected by OAB and neurogenic bladder dysfunction.