Direct electrical neurostimulation of the bladder wall, is a promising restorative therapy for detrusor underactivity, a condition that commonly necessitates intermittent catheterization. Magasi [1,2] conducted the most successful clinical studies using this approach and assessed both anterior and posterior electrode placements. They reported that placements close to the ureteral–bladder junction on the bladder wall were most important for effective bladder wall stimulation; however, comparative efficacy between the posterior and anterior sides of the ureteral-bladder junction was not directly evaluated. Preclinical studies [3] have similarly explored electrode placements across the bladder, but relative effectiveness between locations remains unclear. Therefore, this translational study evaluated the non-surgical safety and efficacy of a novel direct electrical neurostimulation device at locations anterior and posterior to the ureteral-bladder junction in a short-term chronic canine model.

Six healthy canines underwent surgical implantation of a novel direct electrical neurostimulation system comprising of an implantable pulse generator (IPG) and leads terminating into surface electrodes implanted on the bladder wall near the bladder neck. A sample size of six animals was selected to minimize animal use while accounting for potential attrition and variability in healing and biological response; formal power calculations were not performed. Animals were separated into two groups based on electrode placement locations (anterior vs posterior). After a 2-week surgical recovery, animals received small intervals of stimulation, summing up to 6 minutes daily up to 6 weeks. Safety assessments included behavioral and clinical observations, and macro- and microscopic tissue analysis to evaluate stimulation effects and biocompatibility. Functional outcomes were evaluated by measuring voided volume (VV - mL) once a week, and a daily bladder voiding rate of voiding attempts during stimulation.

All animals tolerated surgical implantation and stimulation without major complications and survived till the study endpoint. Behavioral observations indicated no signs of sustained pain, distress, or off-target stimulation. Adverse events including IPG rotation and seroma with short-term chronic infection, were each observed in 16.67% of animals and were all managed with standard veterinary care. The tissue healing response and biocompatibility of the direct electrical neurostimulation system were similar between the two groups and aligned with an expected foreign body response. There were no indications of thermal damage or necrosis related to stimulation at the bladder electrode interface. The electrodes remained adhered for the duration of the study. 

Bladder voiding was commonly observed during active stimulation with animals voiding 65.6±2.3% of stimulations, confirming the system can effectively induce voiding. Animals in the posterior group had greater bladder percentage response by voiding with stimulation than the anterior group, with values of 72.4±9.0% and 59.3±12.1%, respectively (Significant, p=0.02, Wilcoxon t-test). The average VV across animals was 35.4±2.2mL. The posterior group demonstrated higher VV than the anterior group, with values of 40.2±3.1mL and 31.2±2.7mL, respectively (Not significant, p=0.07, Wilcoxon t-test).

Direct electrical neurostimulation of the bladder wall was well tolerated with no adverse stimulation related findings. Further, stimulation reliably induced bladder voiding in anterior and posterior locations, with a significantly greater efficacy at the posterior side, likely due to higher nerve density in the trigone area. The small sample size (N=3 in both groups) should be taken into consideration while interpreting this result.

Overall, this study demonstrates the safety and efficacy of direct electrical neurostimulation of the bladder wall at both anterior and posterior implant locations, reinforcing its promise as a restorative therapy while allowing flexibility in electrode placement and potentially safer surgical approaches, as anterior placement is more accessible than posterior.

Magasi P, Ruszinkó B, Meluzsin J. Evacuation of paralysed human bladder by electric stimulation. Int Urol Nephrol. 1969;1(4):345–353. doi:10.1007/BF02424998
Magasi P, Simon Z. Electrical stimulation of the bladder and gravidity. Urol Int. 1986;41(3):190-193. doi:10.1159/000281251
Walter JS, Wheeler JS, Cogan SF, Plishka M, Riedy LW, Wurster RD. Evaluation of Direct Bladder Stimulation with Stainless Steel Woven Eye Electrodes. The Journal of Urology. 1993;150(6):1990-1996. doi: https://doi.org/10.1016/s0022-5347(17)35952-9

Continence 19S (2026) 102569
DOI: 10.1016/j.cont.2026.102569