Dural arteriovenous fistulas (DAVFs) are abnormal, rare connections between veins and arteries in the dura matter (lining of the brain or spinal cord). Here you will find information about this condition including how it is diagnosed and treated.

What are the symptoms of dural arteriovenous fistula?

Most people diagnosed with DAVF may not have any symptoms. In some cases, symptoms of DAVF can be categorised either as benign or aggressive:

Benign symptoms

The patient may experience hearing issues and vision problems. Vision problems can include eye bulge, visual deterioration, swelling in the eye lining, cavernous sinus syndrome, and eye-related palsies. There may be some cases of progressive dementia due to venous hypertension also.

Aggressive symptoms

Such aggressive symptoms can occur either due to intracerebral haemorrhage (bleeding in the brain) or due to some neurological effects of non-haemorrhaging neurological deficits (NHNDs).

Bleeding in the brain further leads to sudden headaches along with varying levels of neurological disability depending upon the location and size of the haemorrhage.

Some of the following are the neurological symptoms associated with DAVF of the brain:

  • Bruit (sound heard due to unusual blood flow)
  • Pulsatile tinnitus (ringing in the ears)
  • Visual difficulty
  • Headache
  • Seizures

What causes dural arteriovenous fistulas?

DAVFs usually have a sudden onset with an unclear origin, but they may occur due to some of the following factors:

  • Infection (present or past)
  • Head trauma
  • Tumours
  • Surgery
  • A blood clot in the brain’s venous sinus


Dural arteriovenous fistulas are classified as follows based on their risk:


These types of DAVF involve drainage into the veins of the brain but keeps the drainage in the venous sinuses (within the dura).


This type of DAVF increases pressure on the cortical veins (veins of the brain). This can lead to a haemorrhage where the patient will experience stroke-like symptoms.

Complications that can arise with Dural Arteriovenous Fistulas

Complications that may arise include some of the following:

  • Trigeminocardiac reflex
  • Hemifacial hypesthesia
  • Subdural hematomas
  • Hemifacial palsy
  • Intracerebral haemorrhage
  • Jaw pain
  • Seizures
  • Posterior fossa infarction
  • Microcatheter gluing 
  • Subarachnoid haemorrhage
  • Increased intracranial pressure

How is a Dural AV fistula diagnosed?

The diagnosis of DAVF is usually done using imaging techniques such as CT angiography (CTA), CT scan, MRI, or angiography. DAVFs appear in both women and men after the age of 50 to 60 years along with haemorrhage. But still, Dural AV fistulas are observed more commonly in men. 

What are the types of Dural AV fistulas?

According to the Cognard classification, Dural AV fistulas are categorised into the following seven categories. How they are classified depends upon the direction of flow, location, presence of venous ectasia, and presence of cortical venous drainage:

  • Type I: confined to sinus, antegrade flow, and no cortical drainage. They have a benign clinical course. 
  • Type IIa: confined to the sinus, retrograde flow into the sinus, no cortical drainage. These have a 20% risk of intracranial hypertension. 
  • Type IIb: drainage into a venous sinus, anterograde flow, reflux into cortical veins. These have a 10% risk of haemorrhage induced by venous reflux.
  • Type IIa+b: drainage into a venous sinus, retrograde flow, reflux into cortical veins. These have a 66% risk of haemorrhage with or without intracranial hypertension. 
  • Type III: direct drainage into a cortical vein without venous ectasia. These have a 40% risk of haemorrhage. 
  • Type IV: direct drainage into a cortical vein with venous ectasia. These have a 65% risk of haemorrhage. 
  • Type V: direct drainage into spinal peri medullary veins. They present with progressive myelopathy in 50% of cases.

What is the treatment for Dural Arteriovenous Fistulas?

The following are the popular 2 methods to treat DAVFs. Depending on the type of DAVF involved, a combination of the two methods can also be used:

Minimally invasive endovascular embolisation 

This technique is usually enough to treat various types of DAVFs. During this procedure, a catheter is passed through the groin up into the arteries that further lead to the brain. Similarly, if the spinal cord is involved, then it is known as spinal dural AV fistula. Then liquid embolic agents such as glue or Onyx are injected into the affected arteries. This injection helps to block this artery and therefore, the flow of blood is reduced through the DAVF.

Microsurgical resection 

This technique is usually recommended for patients whose DAVFs cannot be closed with other techniques like endovascular embolisation. During the microsurgical resection procedure, a craniotomy is performed on the patient. Then the DAVF is isolated from the issues around the spinal cord or the brand using the microscope.

What is the recovery and rehabilitation from treatment?

Many patients recover within the first 3 months after the fistula interruption either by endovascular embolization or microsurgery resection treatment. Most patients are also advised to go for rehabilitation after their treatment. This includes occupational therapy, physiotherapy, and rehabilitation nursing. During this, all the patients receive social worker and psychological support. Some patients were also recommended the robotic body weight-supported treadmill training which helps in the patient’s fast recovery.

Frequently asked questions

Can Dural Arteriovenous Fistula be cured?

The endovascular embolism treatment approach is usually considered as the first line of treatment option for DAVF. Both transvenous and transarterial methods are used to cure the patient from DAVF.

What are the risks of endovascular treatment of DAVF?

Some of the risks of endovascular treatment of DAVF include an increased risk of hypertension, haemorrhage and leptomeningeal venous varix.

What are the risks of surgical treatment of DAVF?

DAVF with cortical venous drainage can have relatively high risk of recurrent neurological events or haemorrhage.

Can DAVFs recur after treatment?

DAVF recurrence may happen despite initial cure. There may be a delay in recurrence if there is incomplete penetration of the embolic material into the proximal portion of the venous outlet.