What is Microvascular Decompression?

Microvascular decompression (MVD) is a procedure used as trigeminal neuralgia treatment. Trigeminal neuralgia is a neuropathic disease with symptoms of intense facial pain. One cause of this disorder is the compression of cranial nerve V, the trigeminal nerve, by an enlarged blood vessel such as the superior cerebellar artery. Microvascular decompression, also called Janetta procedure, works by isolating or increasing the distance between the blood vessel and the nerve. As a neurosurgical procedure, it involves craniotomy, opening the skull, to expose the fifth cranial nerve and adjacent blood vessel.

In neurosurgery, microvascular decompression is done to relieve the compression of the trigeminal nerve, thereby serving as trigeminal neuralgia treatment. The paroxysms of pain in trigeminal neuralgia are believed to be linked to the pulsations of the involved blood vessel, which compresses the nerve. Therefore, separation of the nerve and blood vessel is essential in alleviating the symptom of pain.

To do microvascular decompression, the patient is asked to lie on his or her back and is put to sleep with general anesthesia. The patient’s head is then turned so that the symptomatic side is accessible to the neurosurgeon. Monitoring of the patient’s brain activity, facial function, and hearing is done throughout the procedure.

An incision is then made behind the ear to expose the brain covering, called dura, and the part of the brain known as the cerebellum. With microscopic dissection, the trigeminal nerve is exposed and the offending blood vessel, which may be the superior cerebellar artery or a branch of the petrosal vein, is mobilized. A small spongelike material is then inserted between the vessel and the nerve to ease the compression.

Not all patients with trigeminal neuralgia can undergo microvascular decompression. The physician usually designates a patient as a candidate for this procedure if the patient has trigeminal neuralgia that cannot be controlled with medication and other treatments, facial pain that affects only the ophthalmic division of the trigeminal nerve or all three divisions, and recurrence of symptoms after undergoing procedures like percutaneous rhizotomy or radiosurgery. Patients who have underlying medical conditions, hearing loss, or multiple sclerosis may be excluded as candidates.

Success rates for microvascular decompression vary, but this procedure can provide relief to up to 95% of patients. Ten years postsurgery, about 68% maintain relief from symptoms, but about 32% have symptom recurrence. Microvascular decompression is nondestructive, and among the trigeminal neuralgia treatments available it has the best potential for long-term relief of pain. It carries a small risk of complications such as hearing loss, facial numbness, stroke, and infection.