Dural arteriovenous fistula (dAVF) is a relatively rare condition which usually arises after clotting in one of the large veins (dural sinuses) around the brain. When the body’s healing mechanisms attempt to dissolve the clot and recanalise the veins, abnormal connections develop between the arteries supplying the dura (the tough, fibrous lining surrounding the brain which houses the dural sinuses) and the dural sinuses themselves. Occasionally, a dAVF develops in the large vein behind the eyes, the cavernous sinus. In such cases, the lesion is referred to as a caroticocavernous fistula (CCF).
Dural arteriovenous fistulae account for around 10 – 15% of all intracranial vascular malformations. The majority of the patients are asymptomatic while some patients may experience pulsatile tinnitus (a “whooshing” noise heard in the ears in time with the pulse), headaches and visual disturbances. Brain haemorrhage, seizures, weakness and dementia may also result. In the case of CCF, the most common symptoms are protrusion of one or both eyes, eye redness, deterioration of vision, and occasionally pulsatile tinnitus.
Diagnosis of dAVF and CCF can be difficult. Occasionally, under the keen eye of an expert neuroradiologist they can be detected on CT or MRI. However, most cases require cerebral angiography (DSA) for definitive diagnosis. In the event that your physician is planning these tests for you, it is strongly advised to have CT and MRI performed by a specialist neuroradiologist, and a DSA performed by an experienced interventional neuroradiologist.
The mainstay of treatment for dAVF and CCF in the 21st century is interventional neuroradiology with embolisation (targeted blocking of abnormal vessels under X-ray guidance).These procedures are performed under general anaesthesia. In the case of dAVF, the treatment is usually performed through a small (3-4mm) incision in the right groin. In the case of CCF, treatment can be conducted through the groin, or occasionally, by inserting a small needle under the eye to puncture the abnormal veins.
Dr Wenderoth has a special interest in dural arteriovenous fistula, and has pioneered and published on several techniques which have revolutionised the way dAVF is treated and led to much more robust and successful cure rates.