Intracranial dural arteriovenous fistulas (dAVF) supplied by the ethmoidal arteries
present a challenging surgical problem if not amenable to endovascular treatment.
These dAVFs historically require larger open approaches via pterional or bifrontal
craniotomies. We present a series of two cases via novel endonasal and transorbital
approaches sparing the need for craniotomy.
Patient 1: A 64-year-old male presented with an intraparenchymal hemorrhage of the right gyrus
rectus and diffuse subarachnoid hemorrhage. A cerebral angiogram demonstrated an ethmoidal
dAVF (Fig. 1) with frontal basal vein venous drainage (Fig. 2). The dAVF was unable
to be embolized due to difficulty penetrating the main draining vein.
Patient 2: A 60-year-old female presented with a diffuse subarachnoid hemorrhage secondary to
a basilar tip aneurysm which was treated endovascularly. An incidental ethmoidal dAVF
was found with drainage through a small frontal vein to the superior sagittal sinus.
Follow-up angiogram showed a basilar tip aneurysm neck remnant requiring pipeline
flow diversion and dual antiplatelet therapy (DAPT). Given the risk of hemorrhage
on DAPT, it was decided to treat the dAVF first. Small lateral feeders prevented embolization
of the dAVF. An endoscopic endonasal and transorbital approach was planned.
A right superior eye lid incision was carried deep to the orbital rim periosteum and
the periosteum was elevated (Fig. 3). Care was taken to avoid significant depression
of the orbit. The anterior ethmoidal artery was identified with a zero degree endoscope,
ligated with hemoclips, and subsequently cauterized. A pedicled nasoseptal flap was
harvested endonasally. The natural ostium of the sphenoid was opened and to gain access
to the anterior skull base the ethmoid and maxillary sinuses were opened widely. High
speed drill was used to perform a transcribiform craniotomy. The dura was opened and
reflected away revealing several dural-based, arterialized venous structures originating
from the ethmoid arteries. These venous structures were coagulated and cut. One large
draining vein along the falx and several smaller draining veins were also coagulated
(Fig. 4). Closure was performed with a dura repair inlay, dural flap, and the previously
harvested nasoseptal flap. A follow-up angiogram demonstrated complete obliteration
of the dAVF.
Conclusion: dAVFs with arterial supply from the ethmoidal arteries present a challenging problem
that can be successfully and safely treated through endonasal and transorbital approaches
sparing the need for pterional or bifrontal craniotomy.
