Efficacy and safety of the implantable, magnetic resonance imaging-compatible StimRouter neuromodulation system in the treatment of refractory lower urinary tract symptoms in multiple sclerosis patients

Background and purpose: Lower urinary tract symptoms (LUTS) significantly affect quality of life (QoL) of multiple sclerosis (MS) patients, and pharmacotherapy has limited efficacy. We investigated efficacy and safety of the implantable StimRouter neuromodulation system for treating refractory LUTS in MS.Methods: This prospective, single-center, clinical trial was conducted at the Multiple Sclerosis Center of Lugano, Switzerland, involving MS patients treated with self-administered percutaneous tibial nerve stimulation delivered by StimRouter over 24 weeks. Changes in video-urodynamic parameters as well as LUTS severity were measured by Overactive Bladder Questionnaire (OAB-q), QoL using the Multiple Sclerosis Quality of Life (MSQoL-54), and treatment satisfaction using a 1-10 visual analogue scale. Adverse events were also recorded.Results: Of 23 MS patients recruited, six had neurogenic detrusor overactivity (NDO), five had detrusor sphincter dyssynergia (DSD), and 12 had both NDO and DSD. Of patients with NDO, median bladder volume at first uninhibited contraction significantly increased from baseline to week 24 (median = 136 mL, interquartile range [IQR] = 101-244 mL vs. 343 mL, IQR = 237-391 mL; beta = 138.2, p = 0.001). No significant changes of urodynamic parameters were found in patients with DSD. OAB-q symptom scores progressively decreased, and OAB-q quality of life scores increased (beta = -0.50, p < 0.001 and beta = 0.47, p < 0.001, respectively), whereas MSQoL-54 scores did not significantly change (beta = 0.24, p = 0.084) in the overall population. Treatment satisfaction was overall high (median = 8, IQR = 6-9). No serious adverse events were recorded.Conclusions: StimRouter represents a minimally invasive, magnetic resonance imaging-compatible, self-administered neuromodulation device leading to objective and subjective improvements of OAB symptoms and related QoL in MS patients with refractory LUTS.