Sacral neuromodulation for neurogenic lower urinary tract, bowel and sexual dysfunction: A single-center randomized two-arm parallel-group, non-blinded pilot trial for patients with MS suffering from refractory NLUTD

Introduction/background:
We are presenting outcomes of a pilot trial performed to test the feasibility of a multicenter double-blinded randomized controlled trial (RCT), which will evaluate clinical efficacy of sacral neuromodulation (SNM) in patients with multiple sclerosis (MS) suffering from neurogenic lower urinary tract dysfunction (NLUTD).
Methods/Materials: This parallel two-arm pilot trial took place between September 2021 and June 2023. MS patients with NLUTD refractory to conservative treatment were recruited from the urological outpatient clinic at a tertiary health care unit. Potential participants underwent standard investigations for NLUTD and continued to SNM test phase. Those showing more than 50% improvement of key bladder variables, were implanted with pulse generators (IPG) and subsequently randomized to the intervention group (IPG ON) or to the sham group (IPG OFF) for one month. For another month, all patients had the IPG ON until the end of the trial. The primary outcomes were to assess recruitment potential, eligibility, retention rate and treatment adherence. Secondary outcomes included changes in key bladder variables and patient reported outcomes required to design a definitive randomized clinical trial. Finally, the need of re-programming and adverse events were monitored.
Results: Thirty-two patients were screened; seventeen (53%) were assessed for eligibility and 13 (76%) were included in the SNM test phase. Eleven patients, 10 females and one male (85%) were implanted with IPG. Subsequently, five patients were randomized to the intervention group and six patients to the sham group. All randomized patients adhered to the protocol with 100% retention rate. No adverse events or need of re-programming were reported. At the end of trial six patients (54.5%) were completely satisfied, three patients (27.3%) were mostly satisfied with the treatment and 18.2% were indifferent to treatment. Both objective and subjective improvements were seen in the intervention group, while the sham group remained mainly unchanged.
Conclusions: This pilot trial showed that a reasonable proportion of screened MS patients could be recruited and that retention and adherence rates were high. The treatment, including the period with no treatment, was well tolerated. A multicenter double-blinded RCT is being planned based on these experiences.

Funding: This trial was funded by the Multiple Sclerosis Association, Denmark, the Department of Urology, Odense University Hospital, Faculty scholarship, the University of Southern Denmark