PMC9479601_01
Representative Case 1 (a) T2-weighted image shows flow void in the medial aspect of the left occipital lobe (white arrow). (b and c) The left common carotid angiograms (b: frontal view and c: lateral view) confirm a dural arteriovenous fistula (dAVF) fed by the mastoid branch of the left occipital artery (OA) (white arrowhead) and middle meningeal artery (MMA) (black arrowhead) on the left occipital convexity with cortical venous reflux (CVR, white arrow). The black arrow indicates the shunt site. (d and e) The right common carotid angiograms (d: frontal view and e: lateral view) reveal the dAVF (white arrow) supplied by the mastoid branch of the right OA (white arrowhead) and MMA (black arrowhead) with the drainage into the occipital cortical vein. The black arrows indicate the shunt site. (f) Schema of the angioarchitecture delineating the feeding arteries (red), CVR (blue), and sinus (light blue). (g) Postoperative magnified X-ray (frontal view) demonstrates that the CVR, the mastoid branch of the left OA, and the posterior branch of the MMA were filled with Onyx (black arrowhead). The white arrowhead indicates the injection point on the MMA (tip of the balloon catheter). (h) Schematic drawing of the Onyx embolization material (black), feedeing arteries (red), CVR (blue), and sinus (light blue). (i and j) Postoperative left (i) and right (j) common carotid injections (frontal view) identify complete disappearance of the dAVF.
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F1
A flow void in the left occipital lobe was detected incidentally [Figure 1a]. The bilateral occipital arteries and the bilateral middle meningeal arteries (MMAs) were the feeders [Figures 1b-f]. A balloon catheter (Scepter XC; Microvention, CA, USA) was navigated to the distal portion of the posterior branch of the left MMA [Figure 1g] and under flow control using balloon inflation, Onyx 34 was injected; it traveled into the OA through artery-to-artery anastomosis and reached the shunt site. After the injection of a small additional amount of Onyx 18, the cortical draining vein and the feeders were sufficiently filled with the embolization material [Figure 1h] and the shunt disappeared [Figures 1i and j].
PMC9479601_02
Representative Case 2: (a) T2-weighted image shows dilated cortical vessels (white arrows) in and around the left central sulcus. (b and c) Selective right external carotid angiograms (b: frontal view and c: lateral view) identified a dural arteriovenous fistula (dAVF) on the left parietal convexity. It was fed from the right anterior (black arrowhead) and posterior (white arrowhead) branch of the middle meningeal artery (MMA). Drainage was into a dilated Rolandic vein (white arrow). Black arrows indicates the shunt site. (d and e) Selective left external angiograms (D: frontal view and E: lateral view) also reveal the arteriovenous shunt arising from the left anterior (black arrowhead) and posterior (white arrowhead) branch of the MMA with cortical venous reflux (CVR) (white arrows). The black arrows indicate the shunt site. (f) Selective left internal carotid angiogram (frontal view) demonstrates pial arterial supply from the left middle cerebral artery (MCA). Black and white arrows indicate the shunt site and CVR, respectively. (g) Schema of the angioarchitecture delineating the feeding arteries from the external carotid arteries (red), the pial arterial supply from the left MCA (pink), CVR (dark blue), and the sinus (light blue). (h) X-ray (frontal view) demonstrates CVR and the bilateral MMAs filled with NBCA. (i) Schematic drawing of NBCA distribution (black). Black arrowheads indicate the 5 NBCA injection sites. Red, pink, dark blue and light blue also indicate feeding arteries, the pial arterial supply, CVR and the sinus respectively. (j and k) Selective right (j: lateral view) and left external (k: lateral view) carotid angiograms confirming complete obliteration of the dAVF immediately after the second TAE session. (l and m) Selective left internal carotid angiograms (lateral views) demonstrate a slight residual shunt flow (white arrows) from the left MCA just after the second session (l), and complete disappearance of the shunt 6 months after the procedures (m).
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F2
MRI identified flow voids and dilated cortical vessels in and around the left central sulcus [Figure 2a]. Angiography revealed a dAVF on the left parietal convexity arising from the anterior and posterior branches of the bilateral MMAs, pial arterial supply from the left middle cerebral artery (MCA) [Figures 2b-g], and cortical venous drainage into the SSS. Akita, Japan) was advanced to the distal part of the anterior branch of the right MMA [Figures 2h, i] using a TENROU S10 guidewire (Kaneka Medix, Osaka, Japan) supported by a TACTICS catheter (Technocrat Corp., Aichi, Japan), the distal access catheter that was placed in the foramen spinosum. Another DeFrictor microcatheter was retained at the shunt site [Figure 2i] through the anterior branch of the contralateral MMA as described above. Then, another DeFrictor microcatheter was advanced to near the shunt site [Figure 2i] through the posterior branch of the left MMA, and a 25% concentration of NBCA was injected. At a second TAE session, performed 1 month later, we injected NBCA (25% concentration) through the posterior branch of the right and the anterior branch of the left MMA [Figure 2i]. Shunt flow from the bilateral external carotid arteries disappeared [Figures 2j and k], but a slight residual shunt flow from the pial supply delivered by the left MCA remained [Figure 2l]. All shunt flow and CVR had completely and spontaneously disappeared 6 months after the second session [Figure 2m].