Peripheral nerve surgery for chronic pain
Peripheral nerve surgery can relieve chronic pain in some patients. Broadly speaking, there are three instances where peripheral nerve surgery may be of benefit.
1. Nerve Compression
Firstly, when the chronic pain is caused by nerve compression. This includes the relatively common conditions of carpal tunnel syndrome and cubital tunnel syndrome. Nerve compression can develop for no particular reason but it can also be the result of trauma or surgery. Relief of this type of pain can be achieved by surgical decompression. For individuals who have nerve compression as a result of trauma or surgery, a good result from surgical decompression is most likely if the pain can be completely temporarily relieved by injection of local anaesthetic at the area of suspected compression.
Secondly, surgery may be of benefit when the chronic pain is caused by a neuroma. A neuroma can grow at the site of an injured nerve, and comprises regrowing nerve ends that form a little ball because they have nowhere to grow. A neuroma is often exquisitely tender to pressure. Removing the neuroma and placing the cut nerve end where it will be less likely to be subjected to pressure can be of great benefit to individuals who have chronic pain from a neuroma.
3. Denervation Surgery
Thirdly, surgery may be of benefit when the chronic pain affects a region of the body that can be denervated - where the nerves to the body region (often a joint) are severed. This treatment is only suitable in select cases. The treatment cannot be guaranteed and may not be permanent in all patients, as it is possible that a) not all the involved nerves will be able to be identified, and b) in some instances the nerves may regrow. Often numbness of the skin is a tradeoff of the surgery - while the cut nerve no longer transmits pain signals, it also does not transmit sensation signals.
Nerve conduction studies can diagnose nerve compression and are recommended prior to decompression if there is any doubt or question about the diagnosis. If a neuroma is suspected your surgeon may conduct a diagnostic "test" where local anaesthetic is injected at the site of the suspected neuroma to see if this temporarily relieves your symptoms. This type of "test" may also be tried prior to denervation surgery.
References & further reading
Souza, Jason M. M.D.; Nystrom, Ake N. M.D., Ph.D.; Dumanian, Gregory A. M.D. Patient-Guided Peripheral Nerve Exploration for the Management of Chronic Localized Pain. Plast Reconstr Surg. 2012 Jan; 129(1):221-225Elliot D, Sierakowski A.The surgical management of painful nerves of the upper limb: a unit perspective. J Hand Surg Eur Vol. 2011 Nov;36(9):760-70.