Is Our Limited Understanding of the Effects of Nerve Stimulation Resulting in Poor Outcomes and the Need for Better "Rescue Programming" in SNM and PTNS, and Lost Opportunities for New Sites of Stimulation? ICI-RS 2024.

Abstract

Aims: Sacral neuromodulation (SNM) and percutaneous tibial nerve stimulation (PTNS) are strongly recommended by international guidelines bodies for complex lower urinary tract dysfunctions. However, treatment failure and the need for rescue programming still represent a significant need for long-term follow-up. This review aimed to describe current strategies and future directions in patients undergoing such therapies.

Materials and methods: This is a consensus report of a Think Tank discussed at the Annual Meeting of the International Consultation on Incontinence - Research Society (ICI-RS), June 6-8, 2024 (Bristol, UK): "Is our limited understanding of the effects of nerve stimulation resulting in poor outcomes and the need for better 'rescue programming' in SNM and PTNS, and lost opportunities for new sites of stimulation?"

Results: Rescue programming is important from two different perspectives: to improve patient outcomes and to enhance device longevity (for implantable devices). Standard SNM parameters have remained unchanged since its inception for the treatment of OAB, nonobstructive urinary retention, and voiding dysfunction. SNM rescue programming includes intermittent stimulation (cycling on), increased frequency and changes in pulse width (PW). The effect of PW setting on SNM outcomes remains unclear. Monopolar configurations stimulate more motor nerve fibers at lower stimulation voltage; hence, this could be an option in patients who failed bipolar stimulation in the long term. Unfortunately, there is little evidence for rescue programming for PTNS. However, the development of implantable devices for intermittent stimulation of the tibial nerve may increase long-term adherence to therapy and increase interest in alternative programming. There has been recent promising neurostimulation targeting the pudendal nerve (PNS), especially in BPS/IC. More recently, preliminary data addressed the benefits of high-frequency bilateral pudendal nerve block for DESD and adaptive PNS on both urgency and stress UI in women.

Conclusion: The exploration of rescue programming and new stimulation sites remains underutilized, and there are opportunities that could potentially expand the therapeutic applications of nerve stimulation. By broadening the range of target sites, clinicians may be able to tailor treatments according to individual patient needs and underlying conditions, thereby improving overall outcomes. However, further studies are still needed to increase the level of evidence, potentially allowing for an individualized treatment both in patients who are candidates for electrostimulation and in those who have already received surgical implants but seek a better outcome.