Initial experience using the Axonics sacral neuromodulation system in patients with multiple sclerosis

Sacral neuromodulation (SNM) is third-line therapy approved for urge urinary incontinence (UUI) and urgency, and nonobstructive urinary retention. Multiple sclerosis (MS) patients often suffer from neurogenic lower urinary tract dysfunction (NLUTD). The utility of SNM in the MS population is limited by magnetic resonance imaging (MRI) incompatibility as routine MRIs to evaluate for disease progression are required. The Axonics System is the first Food and Drug Administration-approved SNM device that is 1.5/3 T full-body MRI-conditionally safe. This study seeks to investigate the symptomatic improvement in MS patients after implantation of the Axonics System.

All MS patients who elected for Axonics SNM from December 2019 to January 2021 were included. Demographics and scores were queried for urogenital distress inventory (UDI-6), incontinence impact questionnaire (IIQ-7), and global response assessment (GRA).

Fifteen MS patients with UUI were included. The time to follow-up averaged 121 days. On UDI-6, 12 patients reported improvement, 1 worsening, and 2 no change. Average UDI-6 scores before and after implantation were 56.6 and 25.2 (p < 0.0001). Improvements were significant for all questions under stress urinary incontinence, UUI, and voiding difficulty subcategories. On IIQ-7, 14 patients reported improvement and 1 reported worsening. Average IIQ-7 scores before and after implantation were 59.0 and 22.2 (p < 0.001). Improvements were significant for travel, social, and emotional subcategories, but not for physical activity. The average GRA score was 6 ("moderately improved").

The majority of MS patients reported significant initial improvement in UUI and associated quality of life measures on validated questionnaires after implantation of the Axonics System. Future studies are needed to determine the long-term outcomes and durability of this MRI full-body conditionally-safe system.