Pudendal nerve stimulation therapy of the overactive bladder -- an alternative to sacral neuromodulation?

Sacral neuromodulation is known to be an alternative therapeutic option for patients with anticholinergic resistant overactive bladder (OAB). For the same indication, a microstimulation system called BION is available since last year. The BION-stimulator, which only measures 2.8 x 0.3 cm, is designed for pudendal nerve stimulation. Its implantation technique as well as the first clinical results are presented and discussed. During an outpatient percutaneous screening test (PST), a pudendal nerve stimulation is performed with a needle electrode in local anesthesia. A 50 % increase in the urodynamic parameters (bladder capacity, first desire to void, compliance, etc.) is an indication for a chronic implantation of the BION stimulator, which also can be placed in local anesthesia. Two patients have been treated with a BION-stimulator in our clinic so far. Patient I suffered from an OAB with frequent urinary incontinence and patient II had a sensory OAB with high voiding frequency. After the BION(R)-implantation, patient I showed a reduction in incontinence episodes by 31.5 % a day and patient II had lowered voiding frequencies from 12.6 to 7 a day. The postoperative urodynamic investigations confirmed these clinical results. The BION-system and chronic pudendal nerve stimulation seem to be alternatives to sacral neuromodulation, however, patient selection is difficult as subchronic stimulation for a longer period of time is not possible so far.