What Is Microvascular Decompression?

"Microvascular decompression" has become the standard method for treating trigeminal neuralgia. The advantage is that the local vascular compression can be relieved while the sensory conduction of the trigeminal nerve is kept intact, and no loss of facial sensation will occur. Microvascular decompression was first proposed by Professor Jannatta in 1967. Later, Haines et al. Conducted a more in-depth anatomical study of the relationship between trigeminal nerves and microvasculature, and found that 92.5% of trigeminal nerves were present in the cases of pontine microvascular compression on trigeminal root Symptoms of pain.

Microvascular decompression

Right!

"Microvascular decompression" has become a treatment

Trigeminal nerve microvascular decompression is the preferred surgical method for primary trigeminal neuralgia, and it is currently the only one that can cure

The blood vessels that compress the nerves and cause pain are called "responsible vessels". Common responsible vessels are:

Causes of ineffective microvascular decompression

Leakage of blood vessels

Causes omission of blood vessels, which may be difficult to identify due to changes in the patient's head position, cerebellar hemisphere traction, excessive discharge of cerebrospinal fluid, and extensive incision of the arachnoid due to displacement of the responsible vascular stroke; secondly, parallel or simple contact with nerves The blood vessels were mistaken for the responsible vessels and decompressed, and the main responsible vessels located deep in the vascular plexus were omitted.

Isolation and displacement of the isolation pad The isolation pad used in the first MVD was small or improperly placed. Although the compression point was separated from the responsible blood vessel at that time, the isolation pad was slipped away from the decompression as the cerebellum was reset and the cerebrospinal fluid flowed. position.

Too large or too many isolation pads may cause the nerve axis to bend, shift or form new compression points. If the responsible blood vessel is tortuous, sclerotic or short, it should be wrapped with cotton pads and then fixed on the rock and dura mater to achieve a sufficient decompression effect.

Arachnoid adhesions A wide range of arachnoid adhesions can be seen. Once again, vascular-nerve relaxation has a clear therapeutic effect, suggesting that adhesions and thickened arachnoids may be the cause of new compression.

Venous compression and other causes It was found that 3 cases of the first surgical isolation cotton pad were well placed and the symptoms disappeared after another MVD. The reason is not clear.

Trigeminal neuralgia experience with reoperation

Pay attention to the correct placement of the head position to avoid excessive pulling on the cerebellum, and to observe and find responsible blood vessels while maintaining the original appearance of blood vessels and nerves. During the operation, pay attention to keeping the optical axis of the microscope consistent with the approach to ensure that the trigeminal nerve REZ is well exposed. The acute separation covers the trigeminal nerve REZ and the arachnoid around the local blood vessels, but the local blood vessels should be observed before dissecting the arachnoid, so as not to affect the judgment of the responsible blood vessels. If the decompression cotton sheet is too large and the nerve axis is bent, replace the isolation cotton sheet again. Severe adhesions without typical responsible blood vessels were performed with lax adhesion. For older people who do not observe a clear responsibility for blood vessels during the operation, partial root resection is feasible. Although facial numbness remains after surgery, the pain symptoms can often disappear.

The efficacy of trigeminal neuralgia after surgery

In this group, 9 cases of symptoms disappeared immediately after surgery, the early cure rate reached 75%, 2 cases of symptoms disappeared in 1 to 3 months, and the follow-up effect was good. We think that for those who have failed or relapsed with MVD for the first time, ITN should be the best choice. Some studies have proposed delayed cure, which believes that long-term compression of the responsible blood vessels causes local demyelination changes and increased central excitability. Although vascular compression is relieved after MVD, the repair of nerve myelin sheaths and neural excitability tend to stabilize. It takes a certain period. Therefore, we recommend that patients who are ineffective after the first MVD do not have to rush to the second MVD, and can be followed up for about half a year with drug maintenance.