Case Of the Week (COW) 15 May 2016
Dural AV Fistula with venous hypertension
Findings:
Chronic thrombosis of right transverse and sigmoid sinus noted with abnormally enlarged and tortuous cortical veins in the subarachnoid space. Arterial feeders from enlarged transosseous vessels and branches of external carotid artery to noted . No identifiable nidus was found.Deep white matter edema with foci of cortical diffusion restriction noted - suggestive of venous ischemia due to retrograde leptomeningeal venous drainage.
Discussion:
A dural AV fistula is a network of tiny, crack-like vessels that shunt blood between meningeal arteries and small venules within the wall of a dural venous sinus.They most commonly occur as a result of neovascularisation induced by a previously thrombosed dural venous sinus.The most common site is the transverse/sigmoid sinus junction.Complications include haemorrhage, intracranial hypertension ,venous congestion and oedema. DSA remains the gold standard in both diagnosis and accurate classification of DAVF, allowing systematic evaluation of feeding vessels and demonstrating the presence and extent of retrograde venous drainage. The two most commonly used classification systems are Cognard classification & Borden classification .Both classifications revolve around the knowledge that venous drainage pattern correlates with increasingly aggressive neurological clinical course.
Dural AV Fistula with venous hypertension
Findings:
Chronic thrombosis of right transverse and sigmoid sinus noted with abnormally enlarged and tortuous cortical veins in the subarachnoid space. Arterial feeders from enlarged transosseous vessels and branches of external carotid artery to noted . No identifiable nidus was found.Deep white matter edema with foci of cortical diffusion restriction noted - suggestive of venous ischemia due to retrograde leptomeningeal venous drainage.
Discussion:
A dural AV fistula is a network of tiny, crack-like vessels that shunt blood between meningeal arteries and small venules within the wall of a dural venous sinus.They most commonly occur as a result of neovascularisation induced by a previously thrombosed dural venous sinus.The most common site is the transverse/sigmoid sinus junction.Complications include haemorrhage, intracranial hypertension ,venous congestion and oedema. DSA remains the gold standard in both diagnosis and accurate classification of DAVF, allowing systematic evaluation of feeding vessels and demonstrating the presence and extent of retrograde venous drainage. The two most commonly used classification systems are Cognard classification & Borden classification .Both classifications revolve around the knowledge that venous drainage pattern correlates with increasingly aggressive neurological clinical course.