PMC8769438_01
Initial preoperative MRI and MRA. (a) MRA revealed the manifestation of the right TSS and SSS with signs of tiny feeding vessels assembling into the right sigmoid sinus. (b) MRI revealed the dilation of the bilateral SOVs with predominance on the right side. MRA: magnetic resonance angiography, MRI: magnetic resonance imaging, SOVs: superior ophthalmic veins, SSS: superior sagittal sinus, TSS: transverse-sigmoid sinus.
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Additionally, there were signs of tiny feeding vessels assembling into the right sigmoid sinus (Fig. 1a). Notably, bilateral SOV dilation was observed predominantly on the right side (Fig. 1b).
Preoperative cerebral angiogram revealing a Cognard type 2a right sigmoid sinus dAVF. (a-d) Right external carotid angiography demonstrated an extensive dAVF at the right sigmoid sinus. This dAVF exhibited venous reflux into the SSS and left TSS without cortical venous reflux. (e and f) Right internal carotid angiography revealed a severely hindered cerebral venous outflow that mainly flowed out into the CS and subsequently into the right SOV and pterygoid plexus due to the congestion of the SSS. The right SOV was significantly dilated (blue arrows). In addition, there was mild stenosis in the left TSS (red circle). (g) Left internal carotid angiography revealed dilation of the left SOV (blue arrow) due to obliteration of cerebral venous outflow. (h) Left internal carotid angiography revealed that the fistulous point at the right sigmoid sinus (orange circle) was supplied from the left ascending pharyngeal artery arising from the left internal carotid artery. CS: cavernous sinus, dAVF: dural arteriovenous fistula, SSS: superior sagittal sinus, SOV: superior ophthalmic vein, TSS: transverse- sigmoid sinus.
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Diagnostic cerebral angiography showed extensive right sigmoid sinus dAVF with retrograde venous reflux into the SSS and contralateral TSS without cortical venous reflux (Fig. 2a-2d). Thus, outflow had concentrated into the bilateral CSs and subsequently into the bilateral SOVs and pterygoid plexus (Fig. 2e-2g). Left internal carotid angiography revealed that the fistulous point at the right sigmoid sinus was also supplied from the left ascending pharyngeal artery arising from the left internal carotid artery (Fig. 2h).
Transarterial sinus occlusion using Onyx via the petrosquamous branch of the right MMA. (a) Right external carotid angiography demonstrated that this fistulous connection was mainly supplied by the branches from the right middle meningeal (petrosquamous branch) (green arrow), posterior auricular (purple arrow), and occipital (blue arrow) arteries. (b and c) A 4 x 11-mm Scepter XC balloon catheter (yellow arrow) and a Defrictor Nano Microcatheter (blue arrow) with a 4.2-French Fubuki guiding catheter (120 cm, red arrow) were, respectively, navigated up to the portion just proximal to the fistula. (d and e) Non-subtracted image of the skull demonstrated the Onyx cast of the sigmoid sinus and the petrosquamous branch of the MMA used for embolization. (f) Right common carotid angiography revealed the obliteration of the shunt immediately following treatment. MMA: middle meningeal artery.
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USA) was performed via the right petrosquamous branch of the middle meningeal artery (Fig. 3a). Under general anesthesia, a 7-French (Fr) Cook shuttle sheath (80 cm; Cook Medical, Bloomington, IN, USA) was advanced up to the external carotid artery via a femoral site. Osaka, Japan) with a 4.2-Fr Fubuki guiding catheter (120 cm; Asahi Intecc Co Ltd.) with a microguidewire (ASAHI CHIKAI X 010; Asahi Intecc Co Ltd.), respectively, were navigated up to the portion just proximal to the fistula (Fig. 3b and 3c). Onyx 18 was injected from the Defrictor microcatheter with the Scepter XC for flow control. Using TAE, near-complete packing of the entire right part of the sigmoid sinus was obtained (Fig. 3d-3e). Right carotid angiography performed immediately following TAE confirmed the obliteration of the fistula (Fig. 3f).
Angiography immediately after treatment and MRI 2 months after treatment. (a-c) Right common carotid angiography revealed that the SSS was restored to be a part of normal cerebral venous return. Retrograde drainage of the SOVs was still confirmed in the venous phase; however, the flow drastically decreased. (d and e) Left common carotid angiography demonstrated only a residual shunt at the extreme proximal segment of the right sigmoid sinus (orange circle) fed by the left ascending pharyngeal artery. However, the shunt flow drained only proximally (blue arrow) and not into the intracranial side. It also showed left cerebral venous drainage normalization, although retrograde drainage of the SOV was still observed in the venous phase. (f) MRI 2 months following treatment revealed significant contraction of both SOVs. MRI: magnetic resonance imaging, SOVs: superior ophthalmic veins, SSS: superior sagittal sinus.
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Retrograde drainage of the SOV was still observed in the venous phase; however, drastic flow reductions were observed (Fig. 4a-4c). However, further treatment was avoided because the distal segment of the right sigmoid sinus was completely obliterated by Onyx; consequently, the entire shunt drained only proximally and not into the intracranial side (Fig. 4d). Left carotid angiography also showed left cerebral venous drainage normalization, although retrograde drainage of the SOV was still observed in the venous phase (Fig. 4e). MRI at 2 months following treatment revealed significant contraction of both SOVs (Fig. 4f).