Electrical stimulation of sacral roots for micturition after spinal cord injury.

In patients with suprasacral spinal cord injury, electrical stimulation of the sacral anterior nerve roots can produce micturition with low residual volumes of urine and reduced urinary tract infection. Voiding pressures can be maintained at acceptable levels by selective peripheral neurotomy and myotomy or, more commonly, by an intermittent pattern of stimulation. Occasionally, external sphincterotomy is required. The procedure is usually combined with division of the sacral posterior roots, which increases bladder capacity and continence; this also increases bladder compliance, which may be protective for the upper urinary tracts. A reduction in constipation usually is observed, and some patients are able to defecate with the aid of electrical stimulation. Penile erection is produced in a substantial proportion of male patients. The procedure has now been applied in about 700 patients with spinal cord injury, some of whom have been followed for nearly 15 years. The nerves do not appear to be damaged by long-term stimulation, and technical faults with the equipment are now uncommon.