The effect of transcutaneous neurostimulation on filling cystometry

Introduction: Modulation of third sacral nerve (S3) activity is an effective treatment for irritative voiding dysfunction. Present techniques are invasive, requiring the implantation of a neurostimulator. We examined the effect of non-invasive transcutaneous S3 neurostimulation on bladder activity during filling. Patients and methods: Thirty-two patients (21 women and 11 men. mean age 48 years) with irritative voiding dysfunction (22 sensory urgency and 10 detrusor instability) underwent standard filling cystometry at 50 mL/min. In the 16 patients in the study group, the electrode pads of a BioTens transcutaneous neurostimulator were taped bilaterally to the S3 dermatomes. Current (10 mA) was applied at 10 Hz, and a 200 ins pulse-width in continuous mode at the maximum tolerable level. Neurostimulation was performed throughout a second filling cystometry. The control group of 16 patients underwent second-fill cystometry without neurostimulation. Results: Bladder volume and detrusor pressure values for second-fill cystometry for the two groups were as shown in the table. Mean (SEM) Neuro- P (Mann-Cystometry Control stimulation Whitney U) First desire to void (mL) 136 (2.9) 176.9(2.6) 0.05 Pressure at first desire 10.1 (0.4) 5.1(0.2) 0.04 to void (cmH ₂O) Maximum capacity (mL) 307.5 (5.9) 461.6 (5.4) 0.03 End-fill pressure (cmH ₂O) 40.1(2.0) 24.2(0.6) 0.03 Conclusion: Transcutaueous stimulation of the third sacral nerve produces significant improvements in urodynamic bladder volumes and pressures in patients with irritative voiding dysfunction. This non-invasive, ambulatory technique may be a useful treatment option for such patients.