DX: Brain Dural Arterio-Venous Fistulae (Borden Type I) with concomitant Aneurysms

Ok past post I didn't include CT scan so here it goes: (CT images provided by Tecniscan of Guatemala)

CT scan shows an acute hemorrhage over parieto-occipital lobe. Volumetric reconstruction shows a suspicious abnormal vessel in subcortical region below the hemmorrhage but it was not very conclusive so she underwent a brain angiography.

This study in AP projection showed abnormal saculations in posterior temporal artery and SUCA segments. Also, there's an assymetry on parieto-occipital branches with more widening on right side. Cappilary phase (see previous post) showed perivascular staining due to hemorrhage. Early venous phase shows an abnormal comunication to superior sagital sinus. This was confirmed in lateral projection.

Findings are consistent with Dural AV fistulae with concomitant aneurysms.

The association of aneurysms and cerebral arteriovenous malformations is well established in the literature. Aside from a small number of case reports and small patient series, this association has not been well explored with cerebral dural arteriovenous fistulas.

Brain arteriovenous fistulas are rare neurovascular lesions of the brain (accounting for only 1.6%–4.7% of all brain AV malformations) that have been considered a distinct pathologic entity from other brain AV malformations (BAVMs). BAVFs differ from BAVMs in that they lack a true nidus and differ from dural arteriovenous fistulas (AVFs) in that they derive their arterial supply from pial or cortical arterial vessels, and the lesion does not lie within the dural leaflets. 

They are composed of a single venous channel in communication with 1 or more arterial connections, with no intervening nidus of vessels. Because of their high-flow nature, they often are associated with a venous varix and have a poor natural history. The pathologic aspects of BAVFs arise from their high-flow dynamics. The complex hemodynamics of large AVFs makes them challenging lesions to treat. Endovascular management of high-flow AVFs has not always been successful in previous literature so these malformations have to be treated with surgery, with or without endovascular techniques. In this case, we decided not to perform endovacular embolization and neurosurgeon decided that it was as peripheral as needed to be treated surgically.

Grading scales based on the anatomy of venous outflow have been developed to predict the risk of brain hemorrhage. According to the Borden-Shucart grading system, type I dural arteriovenous fistulas exhibit antegrade drainage through a venous sinus; type II exhibit antegrade venous sinus and retrograde cortical venous drainage; and type III exhibit only retrograde cortical venous drainage. 

The University of California, San Francisco also developed a grading system.

For more info, 

http://www.medscape.com/viewarticle/763632_4

http://neuroangio.org/patient-information/patient-information-brain-dural-fistula/

http://www.ajnr.org/content/30/4/851.full.pdf+html

http://www.thebarrow.org/Neurological_Services/Aneurysms_and_Cerebrovascular_Disorders/203378

Thank you for your valuable participation in FB groups, to Dr. Roopa Seshadri and Dr. Pankaj Sharma.