I had been thinking about blogging about a new approach to repairing severed nerves when I saw this blog entry on NPR's health site about the same topic -- but covering a different procedure. Who knew there was so much going on in the world of nerve-damage repair?
Peripheral nerves transmit signals between the brain and spinal column and the rest of the body.
A severed nerve can sometimes repair itself, with the broken ends growing toward one another and eventually reconnecting, This can take a long time, though, if it ends up happening at all. So people who suffer a severed nerve typically either have had to just live without the use of that nerve (and the resulting loss of sensation or muscle control) or have it repaired surgically.
Except in cases where the two ends of the damaged nerve sheath are close enough to be directly reconnected, that surgery has long involved removing a healthy nerve from another part of the body and inserting it at the damaged site to provide a “scaffold” to support the nerve endings as they grow to reconnect. That procedure -- called an “autograft” -- meant two scars and diminished nerve capacity in two areas.
As an alternative, in a procedure called an “allograft,” nerve tissue from someone else’s body, usually a cadaver, has been used to repair a damaged nerve. But the receiving body would often reject the transplanted tissue.
Nerve injury is a fairly common occurrence, though its incidence is hard to pin down, as nerve damage can result from everything from a gunshot wound to a cut from a broken wine glass. In 1995 about 50,000 surgeries to repair severed peripheral nerves were performed.
Given the problems with repairing nerve damage, researchers have naturally sought better solutions.
One of those is the Avance Nerve Graft, made by a Florida company called AxoGen. It’s human nerve that’s been sterilized to remove any cells that could provoke a receiving body to reject it; the inner structure of tiny pathways remains intact, so nerves are protected as they grow and eventually reconnect. One of the big advantages to this kind of allograft is that it can bridge long spans of missing nerve, so it’s good for repairing both large and small nerve injuries. Research published in January shows it works for people of varying ages and for repairing sensory nerves, motor nerves and nerves that perform both functions.
The procedure described in the NPR report uses chemicals, not surgery, to speed the healing process; it’s still in animal-study phase, according to the report, but it’s apparently been shown to work wonders in rats.
Have you suffered nerve damage? Have you had it repaired, or are you just living with the consequences. And, please, don’t feel compelled to share too many details about your injury; today's Scientific American story about mere paper cuts was enough to give me the willies.