What Is in the Pipeline on Investigational Neuromodulation Techniques for Lower Urinary Tract Dysfunction: A Narrative Review

Objectives: Overactive bladder (OAB) affects millions of patients worldwide. Its treatment is challenging but improves the patient's quality of life. Besides standard techniques for neuromodulation (sacral and pudendal neuromodulation and posterior tibial nerve stimulation), several new techniques have been investigated to treat symptoms of refractory OAB. The purpose of the present review is to outline the state of the art of new neuromodulation techniques for lower urinary tract dysfunction (LUTD). Materials and Methods: In March 2023, a comprehensive MEDLINE, EMBASE, and Scopus search was carried out (keywords: LUTD, new technologies, neuromodulation, LUTS, OAB, painful bladder syndromes, etc). Articles were included according to inclusion (randomized controlled trials, prospective trials, large retrospective studies) and exclusion (case reports, outcomes not clearly expressed in full text, animal studies) criteria. The reference lists of the included studies also were scanned. Both adult and pediatric populations were included, in addition to both neurogenic and nonneurogenic OAB. A narrative review was then performed. Results: Peroneal neuromodulation, transcutaneous electrical nerve stimulation, magnetic nerve stimulation, and parasacral transcutaneous neuromodulation are the most studied investigative techniques and were shown to yield promising results in treating OAB symptoms. Most studies showed promising results even in the complex scenarios of patients with OAB refractory to standard treatments. Comparing investigational techniques with standard of care and their respective clinical outcomes and safety profiles, and confronting their pros and cons, we reasonably believe that once such treatment modalities are further developed, they could play a role in the OAB treatment algorithm. Conclusions: Although the described neuromodulation techniques are being intensely studied, the available results are not yet sufficient for any guidelines to recommend their use.