Once your child is asleep under general anesthesia, the neurosurgeon makes a small cut in the upper lumbar region of the spine and removes a small section of bone to expose the nerve roots as they leave the spinal cord. Looking through a microscope, the surgeon then separates the nerve roots into groups, finding those that bring sensation back from the legs and leaving the motor nerves aside.
The surgeon tests each sensory nerve root in turn by stimulating it electrically, while a specialist called an electrophysiologist monitors the response in your child's leg muscles. If the nerve responses are abnormal, these nerve roots may be selectively cut. After about half of the abnormal nerve roots have been cut, the surgical team leaves a temporary epidural catheter for optimal pain control and then carefully closes the wound.