An endoscope (which contains a surgical light and small camera) is placed through the tube, allowing the surgeon to view the annulus, disc, and epidural space on a video monitor.

First, a local anesthetic is used to numb the skin above the injection site. Using X-rays, the needle is guided into the epidural space.

Objective:To investigate the anatomical features of lumbosacral nerve roots in epidural space to provide the anatomical basis for selective posterior rhizotomy (SPR).