Selective detrusor activation by sacral ventral nerve-root stimulation: results of intraoperative testing in humans during implantation of a Finetech-Brindley system

Electrical sacral nerve-root stimulation can be used to induce bladder contraction. However, bladder emptying is hampered by simultaneous contraction of the external urethral sphincter. Voiding may improve when using a stimulation method that allows selective detrusor activation. Both theoretical and animal studies have demonstrated that it is possible to obtain selective detrusor activation by sacral root stimulation using an selective anodal block. The objective of this paper is to demonstrate the feasibility of this stimulation method in humans. For investigation of the stimulation method, intraurethral and intravesical pressure responses to sacral root stimulation were measured in acute experiments on 12 patients. The results show that selective detrusor activation is possible in patients. Future perspectives are discussed.