Bilateral pudendal afferent stimulation improves bladder emptying in rats with urinary retention

Study Type – Therapy (individual cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Previous study demonstrated that unilateral electrical stimulation of the proximal transected sensory pudental nerve during distention‐evoked voiding contractions significantly improved voiding efficiency. The current study extends previous study from unilateral (UniES) to bilateral (BiES) stimulation of pudental afferent nerve fibres to determine whether this approach further enhances the improved voiding efficiency (VE) that we reported previously which unilateral stimulation. Our results show in most instances BiES consistently generated more efficient bladder emptying than did UniES but these differences were not significant. OBJECTIVE To determine whether bilateral electrical stimulation (BiES) of the transected pudendal sensory nerves could further enhance the voiding efficiency beyond that produced by unilateral electrical stimulation (UniES) of transected pudendal afferents in rats with urinary retention. MATERIALS AND METHODS The efficiency of bladder emptying with either UniES or BiES of pudendal nerve afferents was measured after acute bilateral transection of the sensory branch of the pudendal nerve. The effects of UniES and BiES on voiding in a partially denervated bladder and acute spinal transection, respectively, were determined. RESULTS The voiding efficiency (VE) was reduced from 69 to 22% after bilateral transection of the sensory branch of the pudendal nerve. UniES or BiES increased the VE to 49–62%. Although in most instances BiES consistently generated more efficient bladder emptying than did UniES, these differences were not significant. Both UniES and BiES increased VE after unilateral pelvic nerve transection, demonstrating efficacy in a partially denervated bladder. The enhancement of VE by either UniES or BiES was preserved after acute T 9 –T 10 , demonstrating the spinal origin of this augmenting reflex. CONCLUSIONS The results of the present study are consistent with an essential role for pudendal sensory feedback in efficient bladder emptying, and unilateral and bilateral electrical activation of pudendal nerve afferents are equally efficient in improving bladder emptying in an animal model of urinary retention. This could provide an approach to improve bladder emptying in patients with non‐obstructive urinary retention.