Abstract: Objective  To investigate the comparative efficacy of different frequencies of pelvic floor electrical stimulation (PFES) on stress urinary incontinence (SUI) in rats.Methods  Twenty female Sprague-Dawley rats were randomly divided into 6, 15, 30 and 50 Hz group by random number table method. All rats underwent vaginal dilatation (VD) to simulate postpartum SUI. One week after VD, the sneeze test was conducted to determine whether the modeling was successful. If the sneeze test was positive, the modeling was successful. The miniature and wireless electric pelvic floor stimulator were implanted into the pelvic floor muscle of the modeled rats, and PFES were treated for 2 weeks in each group at the rates of 6, 15, 30 and 50 Hz, respectively. The Leak point pressure (LPP) of all rats before VD, 1 week after VD and 2 weeks after stimulation were measured by cystometrograms (CMGs) for comparison.Results  LPP was significantly reduced in all groups of rats after VD 1 week (P < 0.001). Compared with after VD 1 week, after two consecutive weeks of PFES at four different frequencies of 6, 15, 30 and 50 Hz, LPP was again significantly increased (P < 0.001) and reached the baseline level (P > 0.05) in all groups of rats. In the between-group comparison of the rats in each group, there was no significant difference in their LPP at baseline value, after VD 1 week and after stimulation 2 weeks (P > 0.05).Conclusion  The present study suggests that of the several stimulation frequencies explored so far, 6 Hz may be a more appropriate choice for PFES. Further studies are still needed to evaluate more frequencies and the long-term efficacy of PFES.

Key words: stress urinary incontinence, pelvic floor electrical stimulation, frequency, neuromuscular stimulation, implantable, Wireless