Sacral anterior root stimulation and posterior rhizotomy in spastic neuropathic bladder

Abstract

The combination of sacral anterior root stimulation (SARS) and posterior rhizotomy is a successful procedure for the restoration of bladder function after supraconal spinal cord injury. Today, complete posterior rhizotomy has become part of the standard therapy. Conventional SARS leads to simultaneous activation of both the detrusor muscle and the external urethral sphincter. We evaluated the possibilities of different neurostimulation techniques to overcome stimulation-induced detrusor-sphincter-dyssynergia and to achieve physiological voiding. Selective detrusor activation improves current sacral neurostimulation of the bladder, including the poststimulus voiding principle. Selec-tive neurostimulation is possible in the following techniques: anodal block, high-frequency block, depolarizing prepulses, sinusoidal pulses and cryoblock. The anodal block technique and cryotechnique are excellent methods for selective bladder activation to avoid detrusor-sphinc-ter-dyssynergia and thus improve stimulation-induced voiding. Our experience has shown that future modern selective bladder neurostimulation systems will be based on either the anodal block technique or the cryotechnique.