A potential therapeutic strategy using a miniature, implantable, wireless nerve stimulation device for treating stress urinary incontinence in rats.

Purpose: The present study examined the effects of a miniature, implantable, wireless stimulation device for treating stress urinary incontinence (SUI) in rats.

Methods: Twenty-four female Sprague-Dawley rats were randomly assigned to three groups: Group 1 (Control), Group 2 (Sham), and Group 3 (Stimulation). All animals underwent vaginal distension (VD) to mimic postpartum SUI. Groups 2 and 3 were implanted with a stimulator in the pelvic floor muscle, but only Group 3 received continuous stimulation for two weeks. Multiple cystometrograms (CMGs) were performed to determine the leak point pressure (LPP) and maximal bladder capacity (MBC).

Results: In the rat model, LPP in Group 1 after VD and after two weeks decreased significantly from baseline (21.1 ± 2.5 and 30.8 ± 5.2 vs. 52.5 ± 6.3 cmH₂O, P < 0.001). LPP improved after two weeks compared to after VD (P < 0.01), but did not return to baseline. In Group 2, LPP at baseline, after VD, and after two weeks were 50.8 ± 4.9, 23.1 ± 6.3, and 31.5 ± 6.9 cmH₂O, respectively, showing similar changes to Group 1. In Group 3, LPP values were 48.4 ± 4.8, 17.8 ± 3.9, and 48.4 ± 8.5 cmH₂O, with significant improvement after two weeks compared to after VD (P < 0.001), returning to baseline. MBC showed no significant differences across conditions.

Conclusions: The current study demonstrated the effectiveness of the implantable stimulation device for treating SUI in a rat model. Further studies are needed to determine its long-term safety and action mechanism.