Novel ultra-miniaturized sacral neuromodulation system shows promise for UUI

A novel, ultra-miniaturized sacral nerve modulation (SNM) system was shown to be both efficacious and safe in treating patients with urge urinary incontinence (UUI), according to findings from the feasibility phase of the SANS-UUI study shared during the 2021 AUA Annual Meeting.1

Over 90% of the patients in this study experienced a 50% improvement in their UUI symptoms after undergoing 2 hours of daily stimulation using the new implantable pulse generator (IPG), and 36% of those patients were 100% dry at 6 months. The device is manufactured by Neuspera Medical.

“The goals of [this phase of the] trial were to confirm system performance, to evaluate patient compliance, and to determine daily stimulation duration,” said co-author and presenter Steven W. Siegel, MD, director of the Minnesota Urology Centers for Female Urology and Continence Care.

SNM has been the standard of care for UUI treatment for many years. This new ultra-miniaturized-IPG/lead (0.12cc), however, is unique in that it is implanted in a single procedure, is wirelessly powered using an external device for shorter daily durations and has the potential to reduce the risk of infection or other complications that would normally be associated with the standard SNM system.

In this study, 39 patients participated from 11 different centers worldwide (3 in Europe, 8 in America). Enrolled participants had to have a diagnosis of UUI at least 6 months prior to the trial, at least 4 UUI episodes on a 72-hour diary, and at least 1 UUI episode per 24-hour period. Additionally, the participants must have had a washout from OAB medications, a BMI greater than or equal to 18 kg/m2, as well as at least 1 failed or inadequate antimuscarinic or beta 3 adrenoceptor agonist medication.

Patients were excluded from participating in this study if they had percutaneous tibial nerve stimulation (PTNS) in the past 3 months, treatment using BoNT in the past 12 months, or failed sacral nerve stimulations (SNS) therapy in their lifetime. They also couldn’t be unresponsive during the intraoperative testing of the implant procedure, have A1c greater than 8%, have diabetes mellitus or glucosuria, have urinary retention prior to the baseline visit, or have active implantable devices, such as neurostimulators, drug pumps, pacemakers, or defibrillators.

“The baseline demographics show that the average age was 62, the average BMI as about 30, and 95% of the patients were female,” said Siegel.

Of the 39 patients who were screened, 34 were implanted. These subjects completed a 21-day trial period of 2 hours of stimulation per day. Non-responders to this initial treatment (1 patient) continued SNM for 14 more days at a higher stimulation rate of 4 hours. Then, non-responders to the 4-hour treatment (none) continued SNM for another 14 days at an even higher stimulation rate of 8 hours. Post-trial follow-up data was gathered at 1, 3, and 6 months.

“The degree of reduction in the urinary urge incontinence episodes started out at a baseline of slightly over 4, and then less than 1 episode at each of the points in time through follow up of 6 months—all significant…74 and 78% of the patients, respectively, at 3 and 6 months, had a 75% or greater reduction in the number of urge incontinence episodes...The number of voids per day were also decreased in those patients who had equal to or greater than 8 voids per day and that was significant at all the time periods. There were also significant improvements in quality of life on all 4 measures using the ICIQ OAB Quality of Life Index,” said Siegel.

Similarly, the feasibility subject user experience questionnaire produced favorable outcomes at 3 months. Many subjects agreed that the therapy gave them flexibility with UUI management, was easy to use and that they were very satisfied with their experience and would recommend SNM to other patients with UUI.

Regarding safety, 28.2% (11/39) of the patients reported 25 adverse events (AEs) related to the device and/or the procedure; however, were no serious AEs and zero infections. The safety data were consistent with current commercial therapies and the manufacturer made direct changes to address the 2 device dislodgements and 2 device fractures that occurred during the trial.

In his conclusion, Siegel reiterated that the feasibility phase of the SANS-UUI study produced statistically significant results, demonstrating that the ultra-miniaturized SNM system is efficacious and safe in treating patients with UUI.


1. Padron O, Hanson C, McCrery R, et al. Treatment of urinary urgency incontinence (UUI) with an ultra-miniaturized sacral nerve modulation (SNM) system: Preliminary outcomes of the SNAS-UUI study. Paper presented at: 2021 American Urological Association Annual Meeting; September 10-13, 2021; virtual. Abstract PD66-01.