Microvascular Decompression for Hemifacial Spasm

Download a pamphlet on Microvascular Decompression or view a list of pamphlets available at the Vancouver General Hospital.

Introduction

The MVD operation is designed to cure the problem. It is very similar to that described on the MVD for Trigeminal Neuralgia page only in this case, it is the VIIth cranial nerve (the facial nerve) that is decompressed. This operation is done under a general anesthetic and takes approximately three hours. Patients go home after several days in hospital. The scalp behind the ear (on the side of the spasm) is shaved and an incision made through the skin and muscles. A small hole is drilled through the skull. The surgeon operates around the outside of the brain until the facial nerve is seen through the microscope. The offending artery or vein is identified and moved away from the nerve. A small patch of padding is placed between the nerve and artery to prevent future compression. The hole in the skull is replaced with acrylic and the muscles and scalp sutured closed.

At the University of British Columbia, this operation is performed with intraoperative monitoring (IOM) of the facial and acoustic (hearing) nerves. The IOM team is led by Dr. Charles Dong and provides the surgeons with crucial information about when the facial nerve is adequately decompressed and if the hearing nerve is being compromised. We feel this IOM is essential to the safe performance of this operation.

Benefits

The cause of the HFS is fixed and the patient is left with normal sensation and movement in the face.

Risks

Patients are urged to speak directly with their surgeons about complication rates, which can vary among institutions. This is a complex operation and has potentially serious risks. With the general anesthetic and operating close to the brain stem there is the rare chance of death or disabling stroke. Injury to the surrounding nerves could cause deafness, facial droop, double vision, facial numbness or difficulty swallowing. There is a risk of infection or delayed CSF leak (salt water-like fluid escaping from around the brain and draining through the middle ear into the back of the throat). Patients can temporarily complain of discomfort around the incision or develop chemical meningitis. There is a small chance that the spasms will not be fixed or will recur.

 

Post-operative Instructions

Patients typically leave hospital after two nights.  There will be a small wound behind their ear covered with a bandage and a tensor bandages wrapped around the head.  Keep the wound dry (no swimming or shower but bath is OK if bandage stays dry) until the family doctor removes the stitches.  Stitches should be removed after 10 days and the tensor bandage can be thrown away at that time as well.  There should be no strenuous activity for 6 weeks.  “Strenuous activity’ means anything where you might grit your teeth in order to lift something.  Lifting a bag that does not change the way you breath is OK.  Walking is fine.  Avoid any activities where you might fall and hit your head (e.g. bicycling, roller-bladding, skiing ect.)  We expect that you will have some headache or wound discomfort for a few weeks.  This discomfort responds to Tylenol.

If there are any problems with the wound (your family doctor thinks it might be infected) please call us.  If you develop a severe headache a few days after discharge from the hospital, please call us. 

We expect to see you in our office 6 weeks after surgery for a follow-up examination.

If you continue to have hemifacial spasm after surgery do not panic.  The operation was designed to decompress the nerve to not heal it.  Your body will take time to heal the facial nerve (i.e. remyelinate it).  This can take upto a year.  Many patient, however, are spasm free immediately after surgery.