Pudendal neuromodulation improves voiding efficiency in diabetic rats

Aims: Diabetic cystopathy is typically manifested as bladder voiding dysfunction, and numerous patients are refractory to standard therapy. In this study, we determined whether electrical stimulation (ES) of the sensory branch of the pudendal nerve could engage an augmenting reflex and thereby improve bladder emptying in a diabetic animal model with cystopathy. Methods: The efficiency of bladder emptying with ES of the sensory branch of the pudendal nerve at different stimulation intensities was measured in rats at 8 or 18 weeks after the induction of diabetes with streptozotocin. Results: The voiding efficiency (VE) was reduced from 74 ± 4% to 30 ± 8% in rats with diabetes for 8 weeks and from 73 ± 6% to 20 ± 6% in rats with diabetes for 18 weeks. ES at lower intensities (0.025-0.05 mA) applied to the pudendal sensory nerve did not affect the VE in rats with diabetes for 18 weeks but increased the VE in rats with diabetes for 8 weeks. Subsequently, when the stimulation intensity was elevated to 0.1-0.3 mA, the VEs in rats with diabetes for both 8 and 18 weeks increased to 40-50%. Conclusions: The results of the present study are consistent with the essential role for pudendal sensory feedback in efficient bladder emptying, and electrical activation of the sensory branch of the pudendal nerve was efficient restoring the voiding function in diabetic animals with cystopathy. This could provide an approach to improve bladder emptying in diabetic patients with voiding dysfunction.