Results of sacral nerve modulation for treatment of overactive bladder

Currently, sacral nerve modulation (SNM) is an effective treatment for overactive bladder symptoms which are refractory to anticholinergic or muscarinergic treatment. However, SNM requires the implantation of stimulation electrodes at the sacral nerves and a subcutaneous impulse generator. The SNM procedure can be divided into three phases: the acute phase comprising the implantation of the test stimulation electrodes, the subchronic stimulation phase over a period of 714 days during which neurostimulation takes place by means of an external impulse generator, and finally chronic SNM after implantation of the final impulse generator. In 1981 the SNM technique for treatment of bladder dysfunctions was first developed by Tanagho and Schmidt and has since been refined, while the range of indications has been extended continuously. It has been shown that patients with neurogenic bladder dysfunctions are able to gain the greatest benefit from SNM. The long-term results of SNM are very encouraging so far. In addition, a highly innovative and promising technique is the implantation of a miniaturized impulse generator with integrated stimulation electrode at the n. pudendus. However, the outcome of these trials has not fully been capable of living up to the expectations so far.