Extravasation of contrast medium into the subdural space during cavernous sinus venography: a rare complication

Typical subdural contrast effusion secondary to endovascular treatment of a pediatric pial arteriovenous fistula

Subdural contrast effusion secondary to endovascular treatment is exceptionally rare and might be mistaken as subdural hematoma because of similar hyperattenuation on computer tomography. The authors present the case of a 13-month-old girl with a history of increased head circumference and developmental retardation. Cerebral digital subtraction angiography showed a high-flow pial arteriovenous fistula fed by multiple arteries on the right cerebellar surface, with occlusion of the right sigmoid sinus and severe stenosis of the left sigmoid sinus. Staged endovascular treatments were performed to eliminate the fistula. Follow-up head computer tomography scans performed 3 h after both procedures demonstrated typical high-density subdural effusion with computer tomography attenuation value similar to hemorrhage. These effusions did not aggravate the condition and disappeared spontaneously 32 h after the first treatment and 29 h after the second, respectively.

Subdural contrast effusion during endovascular therapy: case report

Accumulation of contrast medium in the subdural space after diagnostic intraarterial contrast administration is a rare observation. The authors report the case of a subdural contrast effusion (SCE) presenting during endovascular treatment of an intracranial dural arteriovenous fistula (DAVF) mimicking an acute subdural hematoma. Differentiation between the two by computed tomography (CT) or intraprocedural Dyna CT and early neurological examination can be crucial for patient management. We believe that repeated large-volume contrast injections via large-bore intermediate catheters into the territory of an (even partly) occluded DAVF may induce leakage of contrast medium into the extravascular subdural space thereby causing a SCE.