Tibial nerve stimulation in the treatment of refractory overactive bladder syndrome

Abstract

Overactive bladder syndrome (OAB) is a common dysfunction of the lower urinary tract and has a large impact on the patient's quality of life. Percutaneous tibial nerve stimulation (PTNS) has been introduced as an alternative neuromodulative treatment. This thesis discusses the basic science and applications of tibial nerve stimulation in the treatment of refractory OAB. Though much research has been performed the mechanism of action of neuromodulation is still unclear. It is most likely a combination of the different suggested modes of action, involving the neuroaxis at different levels. The female cat model is suitable to investigate the effect of PTNS. In this thesis it demonstrates that PTNS modulates the micturition reflex reversibly. Moreover, the sacral plexus seems to be involved in the modulation process. Still, randomized studies in patients are needed to obtain irrefutable proof that neuromodulation is effective. It is generally assumed that the improved quality of life in PTNS treated patients is due to improved voiding parameters. The present thesis confirms this and shows that patients must have a reduction of at least 2 used pads before their quality of life improves. Maintenance treatment is performed after successful PTNS treatment, usually every 2-3 weeks. The thesis demonstrates that maintenance therapy is necessary in successfully treated patients. Furthermore, it shows that successful therapy can be reproduced. Maintenance therapy is demanding for both patient and hospital facilities, since each patient put on a maintenance schedule will visit the outpatients' department at least 20 to 30 times per annum. A subcutaneous implant has been developed to enable self-treatment at home. The thesis demonstrates that implant driven tibial nerve stimulation is possible and safe during 1-year follow up.