What is the lumbar sympathetic chain and ganglion? The sympathetic nervous system is a primitive alternative nervous system that exists in our bodies and usually is outside our conscious control. It controls the amount of blood going through the arteries, the heart rate, breathing rate, etc. The lumbar sympathetic chain and ganglia are the lower end of this primitive nervous system that travels to the thighs, legs, and feet and can transmit some types of pain back to the spine. The sympathetic chain is located to the front and sides of the vertebrae of the spine and run from the upper rib level down to the end of the coccyx (tailbone), then on into the legs and feet on blood vessels and with other nerves. In some diseases, the nerve signals going through this nerve chain are overactive and can be interrupted by injection of a local anesthetic onto this chain.
For what conditions in the lumbar sympathetic block used? Foot and leg pain, reflex sympathetic dystrophy and other conditions transmitted by the sympathetic nervous system, peripheral vascular disease, some diabetic conditions, etc. The injections may be used as a diagnostic injection or in a series as therapeutic injections. However, if more than 3 injections are needed, it is prudent to consider other technologies such as spinal cord stimulation as a permanent alternative.
How is the injection performed? The injection is always performed under x-ray fluoroscopic guidance usually with minimal or no sedation. Failure to use fluoroscopy with iodinated contrast is inappropriate. After skin preparation and cleansing, a long but thin needle is inserted several inches to the side of the spine, angling towards the side and front of the spine. Once the appropriate location is reached, iodinated contrast is used to outline the sympathetic chain as shown on the right. Then local anesthetics (bupivicaine or lidocaine) are injected to interrupt the transmission of this nervous system. Onset of pain relief is nearly immediate if the sympathetic nervous system is carrying the painful signals through this ganglion. . The patient is awakened, and determines any relief over the next 6 hours.