Non-aggressive, sinus-type greater sphenoid wing dural arteriovenous fistula with shunt point in the laterocavernous sinus mimicking a cavernous sinus dural arteriovenous fistula converted to aggressive, non-sinus-type

Abstract

Sphenoid wing dural arteriovenous fistulae (DAVFs) are rare. Although the imaging findings of greater sphenoid wing DAVFs may resemble those of cavernous sinus DAVFs (CSDAVFs), their respective presentations differ. Benign CSDAVFs rarely convert to the aggressive type. Conversely, as greater sphenoid wing DAVFs are often of the aggressive type, with intracranial cortical venous reflux and varices, treatment is recommended. Sphenoid wing DAVFs tend to be of the non-sinus type, and transarterial embolisation is often an effective endovascular treatment. We present a case of an asymptomatic greater sphenoid wing DAVF mimicking a CSDAVF that converted from a non-aggressive sinus-type to an aggressive non-sinus-type due to compartmentalisation and thrombotic occlusion. Transarterial embolisation with Onyx and a transarterial venous coil resulted in complete disappearance of the DAVF. Greater sphenoid wing DAVFs can be misdiagnosed as CSDAVFs and require accurate imaging evaluation and careful follow-up, even in asymptomatic or non-aggressive cases.

Keywords: Neuroimaging; Stroke.

Figure 1. Magnetic resonance angiography (MRA) 5 years before transarterial embolisation (TAE) (A–D) and just before TAE (E–H). The shunt points, as detected on MRA, are at the same location at both time points (white arrows) (A, E). High signal areas are seen around the left internal carotid artery (black asterisks), which suggests shunt flow draining to the left cavernous sinus (CS) (white arrowheads) (B). An MRA 5 years before the TAE shows no left uncal vein or intracranial veins (C, D). In the MRA just before the TAE, there is no outflow of the shunt in the left CS (F). The MRA just before the TAE shows the left uncal vein (red arrowhead) (G) and intracranial veins (white dashed circle) (H).

Figure 2. Preoperative digital subtraction angiography of the left external carotid artery. The anteroposterior (A) and lateral views (B) demonstrate a dural arteriovenous fistula with feeders from the left accessory meningeal artery (white arrowheads). The fistula drains into the left uncal vein (black arrowheads) and intracranial veins (black arrow: laterocavernous sinus). Backflowing intracranial veins are accompanied by varices (white asterisks). The left laterocavernous sinus does not communicate with the left cavernous sinus. Schematic illustration of the present case (C). ACV, anterior communicating vein; AMA, accessory meningeal artery; BrV, bridging vein; BVR, basal vein of Rosenthal; CS, cavernous sinus; IPS, inferior petrosal sinus; LCS, laterocavernous sinus; lt, left; rt, right; SMCV, superficial middle cerebral vein; SpbV, sphenobasal vein; SS, straight sinus; SSS, superior sagittal sinus; UV, uncal vein.

Figure 3. Right lateral view of the preoperative three-dimensional rotational angiogram of the left accessory meningeal artery (white arrowheads) confirms that the shunt point (black dashed circle) is located at the anterior left laterocavernous sinus.

Figure 4. Postoperative skull roentgenogram images (A, B) and digital subtraction angiography of the left external carotid artery (C, D). One coil is loosely placed inside the left laterocavernous sinus ((A) anteroposterior view, (B) lateral view). The Onyx cast has low visibility probably due to the small amount used (A, B). The anteroposterior (C) and lateral views (D) show complete disappearance of the dural arteriovenous fistula.