A catheter based method to activate urethral sensory nerve fibers.

Abstract

The ability to control bladder activity would provide a valuable tool to assist individuals with neurological disorders or spinal cord injury (SCI). Recent studies in animal models have shown that bladder contractions can be evoked by electrical stimulation of urethral afferent nerves. We developed and validated in cats a minimally invasive method to stimulate electrically the sensory nerve fibers that innervate the urethra. The urethra was stimulated electrically along its length via a catheter mounted circumferential electrode in 6 cats. The urethra was similarly stimulated in a male individual with complete SCI. Robust bladder contractions were generated via intraurethral electrical stimulation in all cat experiments. Peak responses were obtained in the proximal and prostatic urethra. In the individual with SCI bladder contractions were generated via intraurethral stimulation at a position 4 cm distal to the bladder. Responses in cats and the human depended on bladder volume. To our knowledge this study provides the first documentation of generating bladder contractions via intraurethral electrical stimulation in cats and humans. This method provides a research tool for future studies to investigate these pathways in humans. Preliminary human results suggest that urethral afferent mediated neural pathways demonstrated in animal models exist in humans and support the development of neural prostheses using electrical stimulation of these nerves to restore control of bladder function in individuals with neurological disorders or SCI.