Dural Fistula Disconnection
Why is this surgery done?
A dural fistula is an abnormal connection between an artery and a vein in the body. Normally, arteries carry blood away from the heart to different parts of the body, and you can feel a pulse in an artery because they have high pressure in them. These arteries branch into smaller and smaller vessels until they get down to tiny little branches called capillaries, and that is where the oxygen and nutrients are exchanged with the tissues in your body. The blood is then returned from the tissues by the veins. The veins have very low pressure, and you cannot feel a pulse in a vein. In a dural fistula, there is an abnormal connection between an artery and a vein without going through the normal smaller branches first. When this happens, you get high pressure in the veins that can back up the system and lead to bleeding or other problems because the veins cannot handle this high pressure. When this occurs in the brain, it can potentially be a life-threatening problem.
Dural fistulas can occur after trauma, but many times they happen spontaneously for no known reason. Some people have no symptoms at all. The most common symptom is a pulsating, “whooshing” sound in the head. Other symptoms may include headaches, confusion or weakness, all depending on the location and size of the fistula.
Sometimes, a fistula will be seen on an MRI or a CT scan, but the gold standard to find a fistula is an angiogram. This involves placing a catheter inside the arteries, injecting dye through the artery and taking of picture while the dye travels through the arteries to show exactly where the abnormal connection between the artery and the vein lies.
If you have a fistula, there are four different ways it can be treated:
(1) Observation, which is recommended when there does not appear to be high pressure in the veins and the patients have minor or no symptoms.
(2) Radiation treatment, but this is generally not recommended unless the other options are not effective, because radiation does not lead to an immediate cure of the fistula and it may take many years for it to go away after the treatment.
(3) Embolization. This is where a catheter is placed in the arteries or veins and then snaked to where the fistula is located. A special glue is then injected to shut down the fistula from the inside. The advantage of this is you do not have to have surgery on your head, but there are some fistulas that embolization cannot cure.
(4) Surgery (see below)
How is the surgery done?
Surgery is done using anesthesia with the patient completely asleep. The hair is parted and not shaved and an incision is made, depending on the location of the fistula. A window is made in the bone and the same bone is put back at the end of the procedure.
The fistula is located using a microscope. Fistulas are usually on the surface of the brain, and it is rarely required to enter any brain tissue. Once the fistula is located, metal clips are placed on it to shut it down. If all of the abnormal connections are shut down, the fistula is cured. Usually, an angiogram is done during the surgery to make sure that the fistula is completely gone. At that point, the surgical wound is closed.
After surgery, patients will spend at least one night in intensive care. Next, they will move to the regular floor and usually go home within a few days. Sometimes, a final angiogram is done before patients are sent home, because an angiogram done in the radiology department is more clear than the angiogram performed during surgery. If the patient had weakness or confusion before surgery or developed weakness or confusion after surgery, they may need some rehabilitation before going home.
What are my risks? What are common complications?
Obviously, there are risks to surgery. Anesthesia, infection and bleeding are risks of any operation. It is unlikely that the patient will need a blood transfusion from this operation. Depending on the location of the fistula, there may be risk of weakness or numbness in an arm or leg. Weakness or numbness in the face, hearing loss, difficulty swallowing, double vision, vision loss, loss of balance and decreased sense of smell are all possible, depending on the location of the fistula. Any time we are dealing with the brain, we have to include the risk of catastrophic things such as stroke, coma and death. The chance of of any of these happening with this operation is extremely small, but it is never zero. Overall, the risks of this operation are generally quite low for most fistulas. Your surgeon will discuss all of these risks with you before surgery.
What do I need to know before surgery?
There is no special preparation required for this surgery. However, all patients are encouraged to quit smoking. You will be instructed not to eat or drink anything after midnight on the day before surgery.
General discharge instructions
Specific discharge instructions will be provided in writing to each patient. In general, patients are encouraged to take several short walks throughout the day. Patients should not spend the day lying in bed. Medicine can be taken if there are headaches. Patients are permitted to shower and wash their hair two days after surgery. Patients will be given a follow-up appointment to have their staples removed, usually within two weeks of surgery and will have a follow-up appointment with their surgeon approximately one month after surgery. At that time, there will be discussions about the patient’s potential to resume driving and returning to work.
What should I expect while recovering?
Headaches are common after brain surgery, but they generally improve over a few days or weeks. Most patients do not have their full energy level back for several weeks. Some patients benefit from participating in therapy (physical, occupational and/or speech) after surgery, depending on what problems they may be having.