Dural and Pial Arteriovenous Fistulas Connected to the Same Drainer in the Middle Cranial Fossa: A Case Report.

BACKGROUND: Dural arteriovenous fistulas (AVFs) in the middle cranial fossa are rare. Pial AVFs are similarly rare but differ from dural AVFs in that they derive their arterial supply from pial or cortical arterial vessels and do not lie within the intradural region. We report an extremely rare case of dural and pial AVF connected to the same drainer in the middle cranial fossa. CASE DESCRIPTION: In a 58-year-old man with a subcortical hemorrhage in the right temporal lobe, digital subtraction angiography showed a dural AVF in the middle cranial fossa fed by the middle meningeal artery (MMA) and draining into the sphenopetrosal vein. A combination with a small pial AVF connected to the same sphenopetrosal vein was suspected. Open surgery was performed to directly observe the shunt points. Transarterial indocyanine green (ICG) angiography using the MMA via the superficial temporal artery on a skin flap was performed to repeatedly and distinctly evaluate the dural shunt points and to prevent cerebral thromboembolism. Although the dural supply was completely disconnected, the sphenopetrosal vein remained arterialized. ICG angiography revealed pial AVF, which was fed by the cortical arteries draining into the same drainer. The pial supply was completely disconnected, and disappearance of the dural and pial AVF was confirmed.
CONCLUSIONS: We report an extremely rare case of dural and pial AVF connected to the same drainer in the middle cranial fossa. To our knowledge, this is the first such case report described in the literature.