What is Dural Arteriovenous Fistulae or DAVF?
A membrane enveloping the human spine and brain which is the outermost part is called as dura. The word arteriovenous stands for that which is connecting both veins and arteries of the body. Here dural arteriovenous fistulae (DAVF) means there is an abnormal connections/passageways between a draining vein, an artery and the dura part of the spine or brain.
Ruptures or aneurysms in veins are caused by an extraordinarily heavy blood flow. It is a sort of condition which is caused by infection, head trauma, blood clots or surgery to the human brain. It can also be caused by birth or congenital defect. Dural arteriovenous fistulae can also develop anywhere in the body.
Causes of Dural Arteriovenous Fistulae or DAVF
- You may be born with dural arteriovenous fistulae or DAVF. There are lots of people who are born with an arteriovenous fistula. It is here that the exact can be clear.
- Genetic conditions can cause dural arteriovenous fistulae or DAVF. In the lungs, the arteriovenous fistulae are the result of a genetic disease which results where the blood develop abnormally throughout your body, but especially in the lungs.
- Injuries that pierce the skin may be a cause. You will also be able to develop the arteriovenous fistula whenever a piercing injury results.
- Dural arteriovenous fistulae or DAVF is usually caused by a complication of a procedure called cardiac catheterization. A tube which is long and thin which is known as inserted in a vein or an artery in your neck, groin or arm. It is then threaded through your blood vessels to your heart during cardiac catheterization. If the needle which is made use of in the catheterization crosses a vein or an artery during your procedure this results in an arteriovenous fistula. This rarely happens.
- Certain surgeries can cause dural arteriovenous fistulae or DAVF. People having symptoms of late-stage kidney failure will also be able to get this disease which is surgically created thereby making it simpler to perform dialysis.
Symptoms of Dural Arteriovenous Fistulae or DAVF
Symptoms and signs of the dural arteriovenous fistulae or DAVF and differ extensively, basing on the site of the fistulae. There are lots of cases of dural arteriovenous fistulae or DAVF where there are no signs and symptoms at all. They are also not discovered until the patients have been appraised for other vascular or neurological illnesses.
Dural arteriovenous fistulae or DAVF are the results of infection or traumatic injuries. The patients are also able to develop them that bear no specific precipitating event. Patients who have dural arteriovenous fistulae or DAVF usually have a rumbling noise in one ear that follows the heartbeat, which we can call as a bruit. Other common symptoms of dural arteriovenous fistulae include:
- In dural arteriovenous fistulae or DAVF, headaches are a very common symptom.
- Ringing in the ears is also a symptom of dural arteriovenous fistulae or DAVF. A patient may develop an unusual humming or ringing in their ears especially if the dural arteriovenous fistulae is close to the ear. There are lots of patients who hears a highly pulsating sound/noise which is the result of flow of blood via fistula.
- Signs and symptoms which mimic stroke are also seen. If a dural arteriovenous fistulae or DAVF ruptures then it can lead to stroke-like seizures and symptoms. The critical side effect is the bleeding inside the human brain. It can result in death or long lasting disability.
- If the dural arteriovenous fistulae or DAVF are present closer to the human eye, at times the patients usually complain of sinus congestion, eye swelling /redness or impaired vision.
Tests to Diagnose Dural Arteriovenous Fistulae or DAVF
The diagnosis of dural arteriovenous fistulae or DAVF can be done in multiple ways basing on the location of the problem. Usually the sufferers of dural arteriovenous fistulae or DAVF know that something is not right with them such as headaches, ringing in the ears, vision difficulties etc... and will consult the doctor for the same. The doctor will use new MRI methods such as time resolved contrast Magnetic Resonance Angiogram (MRA), 4D or new dynamic CT angiographic techniques to successfully diagnose dural arteriovenous fistulae or DAVF. The use of normal MRI is not useful in detecting dural arteriovenous fistulae or DAVF. If the doctor suspects that the patient is suffering from brain dural arteriovenous fistulae or BDAVF, then he/she will prescribe catheter cerebral (brain) angiography as it is the best way to find the fistula in the brain.
Treatment for Dural Arteriovenous Fistulae or DAVF
In the process of treating dural arteriovenous fistulae or DAVF, it becomes necessary for the patient to have a clear entire picture of a dural arteriovenous fistulae or DAVF.
Cerebral angiography is the norm as well as the most accurate way to do so of the patient has fistulae in the brain.
A worrisome finding in this disease is known as cortical venous reflux. It is a sign that blood flow can come back to the brain and is compromised. It is also associated with high risk of brain hemorrhage irrespective of the symptoms. Nowadays there are many sorts of dural arteriovenous fistulae which can be treated by endovascular embolization.
If a patient is not able to bear the symptom such as pulsating noise then the treatment which is known endovascular embolization is considered.
The treatment also depends on the drainage pattern of the dural arteriovenous fistulae or DAVF and your symptoms.
There are many different kinds of dural arteriovenous fistulae or DAVF which can be treated with endovascular embolization which is a minimally invasive procedure where the catheter is placed through the common femoral artery in the groin. It is then passed through the arterial system until it reaches the dural arteriovenous fistulae. After this, the fistula is closed with a material such as a metal coil, glue or a balloon to correct the abnormal pattern of blood flow.
Your doctor may recommend microsurgery for some dural arteriovenous fistulae or DAVF instead of or in conjunction with endovascular embolization.
You can come across many different kinds of dural fistulas which are managed by endovascular means. However, others can be best treated with surgery.
In surgical method to treat dural arteriovenous fistulae or DAVF, the specialist will conduct a surgery to disconnect/ cut-off the dural arteriovenous fistulae.
Another way to treat dural arteriovenous fistulae or DAVF is by stereotactic radiosurgery where the specialist will use focused radiation in order to block the abnormal connections/passageways.
Prognosis/Outcome for Dural Arteriovenous Fistulae or DAVF
The prognosis or outcome of dural arteriovenous fistulae or DAVF is based on the symptoms as well as on the degree of the illness. Pulsatile tinnitus which is the result of fistula can be eradicated permanently when the fistula is closed. Even the problems related to the eye are usually completely cured or made much better. Seizures often stop or markedly improve.