Endovascular treatment and computed imaging follow-up of 14 anterior condylar dural arteriovenous fistulas

Abstract

We report our experience in treating the anterior condylar dural arteriovenous fistula (DAVF) and confirm the location of the coils in the follow-up images after successful endovascular treatment. We retrospectively reviewed the 14 patients with anterior condylar DAVF treated successfully in our institute. Twelve of them had CT or MR follow-up images. All the patients had intravascular coiling of the fistula. Seven of our patients had retrograde drainage to different sinuses. Three had ocular symptoms as a clinical manifestation. We treated nine patients with coils alone (eight transvenous, one transarterial), four with adjuvant transarterial treatment with particles or liquid embolic for minimal residual after coiling packing. One patient had failed onyx treatment and successful treatment by following transvenous packing. All patients had total obliteration of the DAVF fistula on immediate post-procedure angiogram or on the follow-up images and no evidence of recurrence clinically. The mean follow-up period was 34.2 months (standard deviation=39.8). Twelve patients had computed images (CT alone in four, MR alone in five, both CT and MR in three). These findings were analyzed by four certified neuroradiologists. We found 100% of the coils at the anterior condylar veins inside the hypoglossal canal, 54.2% at the lateral lower clivus, and only 14.2% at the anterior condylar confluence which is ventrolateral to the anterior orifice of the hypoglossal canal. Intravascular coiling is the treatment of choice in patients with anterior condylar DAVF. All the coils were found at the anterior condylar veins inside the hypoglossal canal after successful treatment.

Keywords: anterior condylar vein; arteriovenous fistula; clivus; coiling; endovascular treatment; hypoglossal canal.

Figures

Figure 1

Frontal views of 3 patients of anterior condylar DAVF in the hypoglossal canal with retrograde flow. The fistula site is shown with large black arrows (A-D). On the left external (A) and right ascending pharyngeal (B) angiograms (patient 9), the antegrade flow refluxes into the left inferior petrous sinus then to jugular bulb (large white arrow). It shows retrograde flow to the transverse-sigmoid sinus (small white arrows) and antegrade flow to the internal jugular vein (small black arrows). C) (patient 10, occipital artery angiogram) Reflux into the cavernous sinus through the internal petrous sinus (white arrows). D) (patient 5, left external carotid) Fistula on the right side with antegrade flow to the internal jugular vein (small white arrows), internal paraspinal venous plexus (small black arrows), and retrograde flow into the cavernous sinus (large white arrow).

Figure 2

Case 11. A patient had pulsatile tinnitus for 2 years and right proptosis recently. Diagnostic angiographies of the external carotid on the right (A) and left (B) show a dural arteriovenous fistula (DAVF) (arrow) in the right anterior condylar veins. The inferior petrosal sinus was occluded in below. Retrograde flow to the cavernous sinus and superior ophthalmic vein are noted. Maximal intensity projection view (C) of CT angiogram shows a prominent artery (arrows) from the left side communicating to the venous sac which is confirmed on the superselective angiogram (D) at the clival branch of the left ascending pharyngeal artery (arrows). Embolization was performed with a microcatheter navigating into the venous sac (E) and coil packing (F, arrow). Immediate post-procedure angiogram (G) shows the complete obliteration of the fistula (arrow) and follow-up CT scan shows the coil mass in the hypoglossal canal and anterior condylar confluence (arrow).

Figure 3

Case 6. A patient suffered from vascular tinnitus for 1 year. Diagnostic angiographies of left vertebral (A), left common carotid (B), left external carotid (C) show a DAVF in the left hypoglossal canal. The drainage is mainly to the internal paraspinal venous plexus (D). On virtual reality images (E) of the CT angiogram, the fistula (arrow) and drainage are identified. The inferior petrosal sinus is not visualized in the above studies. The fistula is obliterated by paraspinal venous approach (small yellow arrows) with coil packing (large blue arrows). The follow-up CT study shows the coil mass inside the occipital condyle (G), hypoglossal canal (H), and lateral lower clivus (I).

Figure 4

Case 13. A patient had pulsatile tinnitus and left eye congestion for 1 year. Diagnostic angiography of left external (A), left common (B), and right common carotid arteries (C) show a DAVF in the left hypoglossal canal with obstruction of the lower inferior petrosal sinus. Retrograde flow shows reflux to the right cavernous sinus and right inferior petrosal sinus. The microcatheter was navigated from right inferior petrosal sinus to left inferior petrosal sinus and then the anterior condylar DAVF through the communication between both cavernous sinuses (D). Immediate post-procedure angiogram shows no residue on left common carotid (E) and left vertebral artery (F) injection.

Figure 5

Case 6. Pre-embolization time of flight MR angiography source image at the level of the hypoglossal canal showshigh flow inside the left hypoglossal canal (black arrow) and adjacent basiocciput (white arrow). It is also well depicted on the CT angiography source image (B). Post-embolization CT angiography shows a coil mass inside the basiocciput (C, white arrow) and hypoglossal canal (D, black arrow).

Figure 6

Case 7. Pre-embolization time of flight MR angiography source image at the level of hypoglossal canal shows high flow inside the right adjacent basiocciput (A, white arrow). The fistula (black arrow) is well depicted on CT angiography source (B) and coronal reconstruction images (C), on which the bone component is also shown (white arrow). Post-embolization CT angiography shows a coil mass inside the hypoglossal canal (D, F) and basiocciput (E, white arrow).