How Microvascular Decompression Works

According to the Mayfield Clinic in Cincinnati, Ohio, microvascular decompression (MVD) is one of the most invasive surgeries to treat Trigeminal Neuralgia, vagoglossopharyngeal neuralgia, and hemifacial spasms, but it may actually preserve facial sensation. MVD is an applicable treatment for neuralgia when the nerve pain is caused by compression from a proximal blood vessel; the pulsing of the vessel and its pressure on the nerve causes the nerve to send "bad" messages, translating to pain. MVD is a specific treatment for cranial nerves that is performed by inserting a tiny sponge between the vessel and the nerve at the base of the brainstem. Specifically, for TN, the sponge is placed between the trigeminal nerve and the superior cerebellar artery or a branch of the petrosal vein. The sponge separates the nerve from the pulsing vessel without creating more pressure.

The Mayfield Clinic indicates that the most viable patients for the procedure are those who desire minimal facial numbness (this can result from treatments like glycerol injections), or who experience recurrent pain after other radiosurgeries.

Generally, the procedure is as follows: the surgeon will make a small incision behind the ear (on the side of the face where pain is located), and then a circular opening (about a inch) in the back of the skull, to expose the trigeminal nerve. The surgeon will separate the nerve from the vessel and place a sponge between the two. If the vein is stuck to the nerve, it is cauterized (burnt with electric current to stop blood flow and remove the vessel). If no vessel is visible near the nerve, the surgeon may just sever the nerve. This does not usually happen, however. Typically, the nerve remains undamaged, which is why few patients have facial numbness. Because the bone opening is small enough, it is usually covered by a titanium plate and the skin is stitched back together. Statistics from the Mayfield Clinic say that this procedure is effective for 95% of patients. The major benefit of MVD is that it causes little or no facial numbness. After MVD, 20% of patients have pain recur within 10 years.

The risks that accompany MVD are those typical for any surgery (bleeding, infection, blood clots, and reactions to anesthesia), but risk is also greater because the surgery involves nerves in the brain. There are small chances of decreased hearing, facial weakness, facial numbness, double vision, paralysis, or even death. Often, surgery is a last resort for patients suffering TN or other nerve pain or facial spasms. Although there are many different surgical options, and the invasiveness of MVD makes it a more extreme choice, it has high effectiveness rates and few side effects. Of course, the few side effects that distinguish MVD from other neuralgia operations are dramatic. Most other surgeries dealing with nerve pain result in decreased sensation, and for those who are interested in not only halting their pain, but also preserving sensation, MVD is an option to consider.