Sacral nerve stimulation for fecal disorders: evolution, current status, and future directions

Sacral nerve stimulation (SNS) aims to recruit residual function of the anorectal continence organ by electrostimulation of its peripheral nerve supply. Since its first application for the treatment of fecal incontinence in 1994, its acceptance has been broadened and it is today considered a valuable addition to the therapeutic armentarium. Initially, its use was based on conceptual considerations, but changed to a pragmatic trial and error approach. Thus, the patients selection evolved: patients suffering from fecal incontinence due to a wide variety of causes are today selected for permanent SNS after a phase of temporary test stimulation. This test is highly predictive. If it is of clinical benefit, a neurostimulation device is implanted for chronic stimulation. Permanent stimulation not only improves or restores continence, but also has a substantial impact on quality of life. This has been uniformaly proven in multiple single and multicentre trials in a wide variety of aetiologies causing fecal incontinence. Despite the growing experience with the clinical use of SNS and its therapeutic effectiveness, the knowledge of its mechanism of action remains limited. Current research aims to improve our understanding of its action, to expand the spectrum of clinical applications and to implement recent technical developments.