Investigation into the acute effects of various waveforms on tibial nerve stimulation for treating overactive bladder...

This study aimed to investigate the efficacy of different electrical waveforms in suppressing bladder overactivity during acute tibial nerve stimulation (TNS) in cats. Cystometric measurements were performed during intravesical infusion of either acetic acid (AA) or normal saline (NS) control solution. Bipolar hook electrodes were implanted on the left tibial nerve for stimulation. TNS with monophasic square waves, biphasic square waves, sine waves, and triangular waves were applied consecutively. Cystometrograms were utilized to evaluate the impacts of these different waveforms on the micturition reflex. Under physiological conditions, all four TNS waveforms significantly increased bladder capacity compared with NS control levels (10.96 ± 3.33 mL; P < 0.001). The relative increases were as follows: 151.10% ± 4.66%, 132.20% ± 3.47%, 131.30% ± 4.85%, and 128.60% ± 3.55% of control values. Under pathological conditions, the monophasic square wave demonstrated inhibitory effects compared with the other three waveforms (P < 0.001). In contrast, no significant differences in inhibitory efficacy were observed between waveforms under pathological conditions (P > 0.05). Quantitative analysis revealed significantly lower T values for both monophasic and biphasic square waves compared with sinusoidal and triangular waveforms (P < 0.001). Furthermore, the triangular wave exhibited significantly higher T values than the sine wave (P = 0.02). The efficacy of TNS waveforms showed condition-dependent variation, with no consistent performance pattern between physiological and pathological states. When considering practical clinical application factors, including stimulator longevity and minimization of tissue damage, the biphasic square wave may be more beneficial.NEW & NOTEWORTHY In this study, we determined the effects of tibial nerve stimulation (TNS) at different stimulation waveforms on bladder reflex in cats. Innovations are as follows: 1) as far as we know, the effects of TNS with different waveforms on overactive bladder has been not explored forever. 2) Our results may provide a basis for altering parameters to improve the therapeutic efficacy of TNS for overactive bladder.