Dural arteriovenous fistulas

Diagnosis

If you have symptoms of a dural arteriovenous fistula (dAVF), you may need imaging tests.

• Digital subtraction angiography (DSA). DSA is the most reliable tool to diagnose dAVF. It takes very clear pictures of blood flow and is essential for defining:
  • How many fistulae exist and where.
  • Anatomy of the external carotid arteries and any branches between them and the dura. Carotid arteries deliver blood to the brain and head.
  • Fistula blood vessels' structure.
  • Whether cardiovascular disease also is present.
  • How much narrowing or blockage has occurred in the dural sinus.
  • Whether any affected veins are dilated and to what extent.
• Time-resolved CT angiography (CTA). CTA imaging can help your healthcare professional see if the arteries and veins are connected incorrectly or if there's any unusual blood flow.
• Magnetic resonance angiography (MRA). An MRA is a special type of MRI that is used to watch how blood flows through your brain. A dye may be used during an MRA to highlight blood vessels and create more-detailed images.
• Magnetic resonance imaging (MRI). MRI images can reveal the shape of a dAVF. An MRI also can detect very small bleeds. The test may determine the impact of any irregular blood vessel structures.
• Computerized tomography (CT) scans. These tests can show fluid buildup caused by increased blood pressure in the brain. They also can show bleeding that may be caused by a dAVF.

Treatment

Treatment for a dural arteriovenous fistula (dAVF) involves a procedure to block or disconnect the fistula.

Dural arteriovenous fistula surgery

Procedures that can treat dAVF include:

• Endovascular procedures. In an endovascular procedure, a long, thin tube called a catheter is inserted into a blood vessel in your leg or groin. It is threaded through blood vessels to the dural arteriovenous fistula using X-ray imaging. Coils or a glue-like substance is released to block the connection in the blood vessels.
• Stereotactic radiosurgery. In stereotactic radiosurgery, precisely focused radiation blocks the irregular connection in the blood vessels. This causes blood vessels in the fistula to close off, destroying the dAVF. Different types of technology may be used in stereotactic radiosurgery. They include the linear accelerator, Gamma Knife, CyberKnife and proton beam therapy.
• dAVF surgery. If an endovascular procedure or stereotactic radiosurgery aren't options for you, you may need dAVF surgery. Surgery may be performed to disconnect the dAVF or cut off the blood supply and remove the fistula.

Sometimes, a combination of surgeries is recommended. For example, endovascular embolization may be performed shortly after radiosurgery. This can help speed up symptom relief and provide long-term results.

Preparing for your appointment

What you can do

• Keep a detailed symptoms calendar. Each time a symptom occurs, write down the date and time, what you experienced and how long it lasted.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements that you're taking and the doses.
• Take a family member or friend along. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who comes with you may remember something that you missed or forgot.
• Bring along any recent brain scans in a CD to your appointment. Also, if you've experienced seizures, your healthcare professional may want to ask questions of someone who has witnessed them. It's common not to be aware of everything that happens during a seizure.

Write down questions to ask your doctor.

Preparing a list of questions will help you make the most of your time during your appointment. List your questions from most important to least important in case time runs out. Some examples of questions include:

• Where is the fistula located?
• Will I need follow-up tests?
• If so, how often will I follow up with you?
• How long would you estimate I'd be in surgery?
• How long does surgery recovery usually take?
• How long should I plan to be in the hospital?
• How many dAVFs have you seen and how many have you treated?
• Does your institution have a cerebrovascular specialty practice?

In addition to the questions you've prepared, don't hesitate to ask others during your appointment at any time that you don't understand something.

What to expect from your doctor

Your healthcare professional is likely to ask you a number of questions:

• When did you first begin experiencing symptoms? For example, have you experienced hearing or vison problems, seizures, speech issues, paralysis, or other symptoms?
• Do your symptoms come and go or are they persistent?
• Do your symptoms seem to be triggered by certain events or conditions?

What you can do in the meantime

Certain conditions and activities can trigger seizures, so it may be helpful if you:

• Don't drink excessive amounts of alcohol.
• Don't use nicotine.
• Get enough sleep.
• Reduce stress.