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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 part 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 is the Lumbar Sympathetic Block Used?

Foot and leg pain, complex regional pain syndrome 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 to relieve pain. However, if more than 3-5 injections are needed to completely relieve your pain or if the pain is relieved for a week or so but keeps returning, it is often then considered to employ 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 sedation. After skin preparation and cleaning, 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, odinated contrast dye is used to outline the sympathetic chain. Then local anesthetics (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.

Do the Injections Hurt?

Typically where the skin is numbed just stings for a few seconds, the plexus injection may hurt briefly a small amount, but your doctor will usually give sedation for this procedure, which means you should be comfortable.

If the Injection Works, can it be Repeated?

Yes, it is possible to repeat the injection two or three times if there is significant relief of pain or other desired symptom relief from the first injection. A series of these blocks is a reasonable choice to desensitize the nervous system and the goal is to obtain longer and longer periods of relief, but if more than 3 blocks are used in a 1 month time period, or the time between injection and return of pain does not progressively lengthen with each injection, then other alternatives need to be considered. Your doctor will discuss this with you.

Risks of this Procedure?

Generic risks include infection and bleeding. We do not perform this injection unless you are off any blood thinners like Plavix and coumadin, aspirin is acceptable. There is a specific risk of bleeding from the kidney or aorta if the needle goes a little astray, although if there is no bleeding tendency or anticoagulant therapy, these bleeds tend to stay small and self contained, and do not pose a severe problem. Infection is not usually a problem as the entire procedure is performed in a sterile manner. Other risks include allergic reaction to the dye or lidocaine (rare), low blood pressure or seizures if the local anesthetic goes intravascularly, but we employ several safety measures to ensure this does not occur, and it is extremely rare as well.

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