The needle is smaller in size than that used during a conventional epidural approach. The procedure is performed with the patient lying on their belly using fluoroscopic (real-time x-ray) guidance, which helps to prevent damage to the nerve root. A radiopaque dye is injected to enhance the fluoroscopic images and to confirm that the needle is properly placed (See Figure 2). This technique allows the glucocorticoid medicine to be placed closer to the irritated nerve root than using conventional interlaminar epidural approach. The exposure to radiation is minimal.
The anterior divisions communicate with the sympathetic trunk . Near the origin of the divisions, they are joined by gray rami communicantes from the lumbar ganglia of the sympathetic trunk. These rami consist of long, slender branches which accompany the lumbar arteries around the sides of the vertebral bodies, beneath the Psoas major . Their arrangement is somewhat irregular: one ganglion may give rami to two lumbar nerves, or one lumbar nerve may receive rami (branches) from two ganglia . The first and second, and sometimes the third and fourth lumbar nerves are each connected with the lumbar part of the sympathetic trunk by a white ramus communicans .