Microvascular decompression (MVD) is a surgical procedure that relieves abnormal compression of a cranial nerve. It is performed to treat trigeminal neuralgia, vagoglossopharyngeal neuralgia, and hemifacial spasm.
MVD is a surgical procedure to relieve the symptoms (pain, muscle twitching) caused by compression of a nerve by an artery or vein. MVD involves surgically opening the skull (craniotomy) and exposing the nerve at the base of the brainstem to insert a tiny sponge between the compressing vessel and the nerve.
This sponge isolates the nerve from the pulsating effect and pressure of the blood vessel. Trigeminal neuralgia is an irritation of the fifth cranial nerve causing severe pain that usually affects one side of the face, normally in the forehead, cheek, jaw, or teeth.
There are 5 steps of the procedure.The operation generally takes 2 to 3 hours.
Step 1: Prepare the patient
In the OR room, general anesthesia is administered while you lie on the operating table.Once asleep, your body is rolled over on its side and your head is placed in a 3-pin skull fixation device, which attaches to the table and holds your head in position during the procedure. Next, the area behind your ear is prepped with antiseptic. A hair-sparing technique may be used, where only a 1/4-inch wide area along the proposed skin incision is shaved.
Step 2: Perform a craniectomy A 3-inch curved skin incision is made behind the ear. The skin and muscles are lifted off the bone and folded back. Next,1-inch opening is made in the occipital bone with a drill.The bone is removed to expose the protective covering of the brain called the dura. The dura is opened with surgical scissors and folded back to expose the brain.
Step 3: Xpose the nerve Retractors placed on the brain gently open a corridor to the trigeminal nerve at its origin with the brainstem.The surgeon exposes the trigeminal nerve and identifies any offending vessel causing compression. The vessel and nerve are often restricted by thickened connective tissue that must be dissected free with scissors and knife.
Step 4: Insert a sponge The surgeon cuts an appropriate size of teflon sponge and inserts it between the nerve and the vessel.Sometimes a vein is adherent to the nerve and causing compression. In these cases, the vein is cauterized and moved away.
Step 5: Closure Once the sponge is in place, the retractor is removed and the brain returns to its natural position. The dura is closed with sutures and made watertight with tissue sealant. Since the bone opening is very small, it is not replaced. Instead, a titanium plate covers the skull opening and is secured with tiny screws.
Following symptoms are occured in Microvascular decompression (MVD):
- Trigeminal neuralgia that is not well controlled with medication and you desire minimal to no facial numbness that may be associated with other treatments such as percutaneous stereotactic radiofrequency rhizotomy (PSR)
- Glycerol injection facial pain isolated in the ophthalmic division or in all three trigeminal divisionsfacial pain recurrence after a previous percutaneous or radiosurgery procedure.
The procedure is done under general anesthesia in the supine position, with a wedge under the shoulder and with the head put aside so that the space behind the ear is freely accessible. The operation begins with a slightly curved incision just behind the ear, after which the muscle attachment is detached. Hair behind the ear is shaved and a small part of your skull is removed. The nerve is identified and pieces of Teflon are placed between the nerve and the offending blood vessel(s). The small area of bone removal is then covered with a thin metal mesh.
Recovery depends upon the type of surgery done and the medical condition of the patient. For procedure such as open surgery or Craniotomy, you would stay at the hospital for 8-10 days and recovery would take around 3-4 weeks, while with a non invasive procedure such as gamma knife or cyberknife, recovery is much faster.
General complications of any surgery include bleeding, infection, blood clots, and reactions to anesthesia. Specific complications related to a craniotomy may include stroke, seizures, venous sinus occlusion, swelling of the brain, and CSF leak. The most common complication related to MVD is nerve damage, which varies depending on the nerve being treated; these include hearing loss, double vision, facial numbness or paralysis, hoarseness, difficulty swallowing (dysphagia), and unsteady gait.
MVD is highly successful in treating trigeminal neuralgia(95% effective) with a relatively low risk of pain recurrence (20% within 10 years). The major benefit of MVD is that it causes little or no facial numbness compared to percutaneous stereotactic rhizotomy (PSR).
Following restrictions should be followed:
- Do not drive after surgery until discussed with your surgeon and avoid sitting for long periods of time.
- Do not lift anything heavier than 5 pounds (e.g., 2-liter bottle of soda), including children.
- Housework and yard-work are not permitted until the first follow-up office visit.
- Do not drink alcoholic beverages.