Vesical pacing: pacing parameters required for normalization of vesical electric activity in patients with overactive bladder

Abstract

There are several modalities for the treatment of the overactive bladder (OAB), but the results may not be satisfactory. A recent study has demonstrated that the OAB has a dysrhythmic electric activity that seems to result from a disordered vesical pacemaker. We hypothesized that vesical pacing may correct the irregularities of the vesical electric waves and consequently normalize the vesical contractility. In this communication, we primarily defined the adequate pacing parameters required for correction of the vesical dysrhythmia. 36 patients with OAB were divided into a study group (22; 13 women; mean age 40.2 years) and a control group (14; 8 women; mean age 41.8 years). Ten healthy volunteers (6 women; mean age 39.8 years) were included in the study. Three 28-gauge cardiac pacing electrodes were hooked to the vesical mucosa: one (pacing) to the vault, and two (recording) to the lateral wall. Electric activity at rest and during stimulation of the pacing electrode was recorded in the study group and the healthy volunteers. In the control group, recording was done without pacing. Reproducible regular triphasic SWs were recorded from the 2 electrodes of the healthy volunteers with a similar pattern from the 2 electrodes of each individual subject. The optimal pacing parameters we determined were: an amplitude of 5 mA, a pulse width of 200 ms and a frequency of 20% higher than the frequency of the basal vesical waves. Vesical pacing effected a significant increase of waves' variables. The OAB patients exhibited a "dysrhythmic" wave pattern which was normalized during vesical pacing using the aforementioned pacing parameters. The optimal parameters required for vesical pacing of the dysrhythmic waves of the OAB were determined and succeeded in normalization of the vesical electric activity. Vesical pacing is suggested to be used as a therapeutic tool for the treatment of the OAB.