To free the spinal cord, neurosurgeons do a surgery called a laminectomy. They remove one or more parts of bones in the spine (vertebrae). This lets them reach the spinal cord, the spinal nerve roots and the thecal sac around the spinal cord.
The neurosurgeons then free the spinal cord by gently cutting, or teasing, it away from the scar tissue or fat. Neurosurgeons use a microscope to help them see the area during the surgery.
After the spinal cord is free, neurosurgeons sometimes apply a patch to the covering of the spinal cord (dura mater). This limits the chances cerebrospinal fluid (CSF) will leak.