Microvascular decompression (MVD) is a surgical procedure that relieves pain or involuntary muscle spasms caused by a blood vessel pressing against a nerve where it exits the brain. The surgeon physically moves the offending blood vessel away from the nerve and places a small cushion between them so the compression doesn’t return. It is the only surgical treatment that addresses the root cause of certain cranial nerve disorders rather than simply dampening the nerve signal, and it has strong long-term success rates, particularly for trigeminal neuralgia and hemifacial spasm.
Why Blood Vessels Pressing on Nerves Cause Problems
Nerves exiting the brainstem pass through tight spaces alongside arteries and veins. Over time, a blood vessel can shift position or enlarge enough to make direct contact with a nerve. Each pulse of blood flow then delivers a tiny mechanical jolt to the nerve, gradually wearing down its protective insulation. The exposed nerve begins firing on its own, producing intense facial pain (in the case of the trigeminal nerve) or involuntary twitching of the facial muscles (when the facial nerve is affected). This mechanism is called neurovascular compression, and it tends to worsen with age as blood vessels become more rigid and tortuous.
Conditions Treated With MVD
The two most common reasons for microvascular decompression are trigeminal neuralgia and hemifacial spasm. Trigeminal neuralgia causes sudden, severe, shock-like facial pain, often triggered by chewing, talking, or even a light breeze on the face. Hemifacial spasm produces involuntary twitching or contracting of muscles on one side of the face, typically starting around the eye and spreading to the cheek and mouth.
MVD is also used for glossopharyngeal neuralgia, a rarer condition that causes stabbing pain deep in the throat, ear, or tongue. In a study of 30 patients treated with MVD for glossopharyngeal neuralgia, about 87% were completely pain-free immediately after surgery, and 97% were either pain-free or had only occasional mild pain within two years.
How Surgeons Diagnose Nerve Compression
Before surgery, specialized MRI sequences are used to visualize the exact relationship between the nerve and the blood vessel compressing it. Standard brain MRIs often lack the resolution to show this clearly, so high-resolution sequences (commonly called CISS or FIESTA imaging) are combined with MR angiography. These techniques produce detailed images that let the surgical team identify which vessel is the culprit, where it contacts the nerve, and how to plan the approach.
What Happens During the Surgery
MVD is performed under general anesthesia. You are positioned on your side with the affected side facing up, and the surgeon makes a small incision (roughly 3 to 5 centimeters) behind your ear. A piece of skull bone about the size of a nickel is removed to create a window into the space around the brainstem. The surgeon then opens the dura, the thin membrane that covers the brain, and uses a surgical microscope or endoscope to navigate to the affected nerve.
Once the compressed nerve is identified, the surgeon gently lifts the offending blood vessel away from it. To keep the vessel in its new position, a small cushion is placed between the vessel and the nerve. The most common material is a tiny piece of shredded Teflon felt. In some cases, surgeons use a Teflon tape fashioned into a sling, secured with fine sutures and biological glue to anchor the vessel against nearby bone. Titanium clips or biologic adhesives alone are also options depending on the anatomy. The goal is simply to eliminate contact between the vessel and the nerve permanently. Afterward, the dura, bone, and skin are closed.
Long-Term Success Rates
For trigeminal neuralgia, MVD has the highest long-term success rate of any available treatment. In a study following 156 patients for a median of nearly 10 years, 73% remained pain-free after the first year, and that number held steady over the long term. Among patients with a classic pattern of trigeminal neuralgia symptoms, 82% had good long-term outcomes. After 8 to 10 years, pain relief rates across multiple large studies range from 58% to 68%, reflecting that some patients do experience recurrence over time.
MVD Compared to Gamma Knife Radiosurgery
Gamma Knife radiosurgery is a noninvasive alternative that delivers a focused beam of radiation to the trigeminal nerve. It requires no incision and carries fewer surgical risks, which makes it appealing for older patients or those with other health conditions. However, the pain relief it provides is generally less durable. In a comparative study, 68% of MVD patients had complete pain relief at both 12 and 18 months. Among Gamma Knife patients, 58% had complete relief at 12 months, but that dropped to just 24% by 18 months. When including patients who achieved at least 90% pain reduction, MVD maintained a 78% success rate at 18 months compared to 48% for Gamma Knife. MVD also provides immediate relief in many cases, while Gamma Knife can take weeks or months to reach full effect.
Risks and Complications
MVD is brain surgery, and while it is considered relatively low-risk for a neurosurgical procedure, complications can occur. The most significant concern is hearing loss on the side of surgery, which happens permanently in roughly 4% of patients. This occurs because the nerve responsible for hearing runs close to the surgical field and can be affected by retraction or manipulation during the operation. Permanent facial weakness is much rarer, reported at about 0.5% of cases.
Other possible complications include cerebrospinal fluid leaks from the surgical site, infection, and the general risks associated with any surgery performed under general anesthesia. Temporary numbness or tingling in the face can occur but usually resolves. Serious complications like stroke or brainstem injury are very uncommon in experienced surgical centers.
Recovery After Surgery
Most patients spend two to three days in the hospital after MVD. The incision behind the ear is small, and the bone opening is typically either replaced or covered with a small plate during closure. Headache and neck stiffness around the surgical site are common in the first week or two. Many people return to light daily activities within two to three weeks, with a full return to work and exercise typically happening within four to six weeks depending on the physical demands of the job.
Pain relief from trigeminal neuralgia is often immediate upon waking from surgery. For hemifacial spasm, the twitching may take days or even weeks to fully stop as the nerve recovers from years of compression. Your surgical team will usually want to see you for follow-up imaging and a clinical check within a few weeks of the procedure, then periodically over the following year to monitor for any recurrence.